Add AGENTS.md with project guidelines for opencode

- Save original batch count before processing loop
- Use saved count in final output message
- Fixes issue #3: 'across 0 batches' bug

.gitignore

@@ -0,0 +1,10 @@
+target/
+output/
+.DS_Store
+._*
+*.swp
+*.lock
+/input
+config.toml
+config.dev.toml
+config.test.toml

AGENTS.md

@@ -0,0 +1,17 @@
+# rusty-petroleum Project Guidelines
+
+## Git Commit Style
+- Make small, focused commits while working
+- Commit changes incrementally to make history easier to follow
+- Each commit should represent a single logical change
+- Write clear, concise commit messages describing what changed
+
+## Issue Management
+- Use Gitea REST API to close issues when fixing them:
+  ```bash
+  curl -X PATCH https://gitea.rowanbrook.net/api/v1/repos/jakob/rusty-petroleum/issues/{issue_number} \
+    -H "Content-Type: application/json" \
+    -H "Authorization: Bearer YOUR_TOKEN" \
+    -d '{"state": "closed"}'
+  ```
+- Or suggest closing issues on Gitea web UI when automatic closing via API is not configured

Cargo.toml

@@ -0,0 +1,27 @@
+[package]
+name = "invoice-generator"
+version = "0.2.0"
+edition = "2021"
+
+[lib]
+name = "invoice_generator"
+path = "src/lib.rs"
+
+[[bin]]
+name = "invoice-generator"
+path = "src/main.rs"
+
+[dependencies]
+askama = "0.15.5"
+chrono = { version = "0.4.44", features = ["serde"] }
+csv = "1.4.0"
+serde = { version = "1.0.228", features = ["derive"] }
+sqlx = { version = "0.8", features = ["runtime-tokio", "mysql", "chrono", "bigdecimal"] }
+tokio = { version = "1", features = ["full"] }
+toml = "0.8"
+anyhow = "1"
+bigdecimal = { version = "0.4", features = ["serde"] }
+
+[dev-dependencies]
+tokio-test = "0.4"
+tempfile = "3"

README.md

@@ -1,2 +1,264 @@
 # rusty-petroleum
 
+A petroleum transaction invoice generator with MariaDB backend.
+
+## Overview
+
+This project processes petroleum/fuel station transaction data from CSV files and generates customer invoices. It stores transaction data in MariaDB for both invoicing and sales reporting.
+
+## Features
+
+- **CSV Import**: Import transaction data from fuel station CSV files into MariaDB
+- **Invoice Generation**: Generate HTML invoices from CSV data (file-to-file mode)
+- **Multi-Environment**: Separate databases for development, testing, and production
+- **Sales Reporting**: Query transactions by customer, product, date range
+- **Test-Driven Development**: Comprehensive test suite with 45 tests
+
+## Project Structure
+
+```
+rusty-petroleum/
+├── Cargo.toml              # Rust dependencies
+├── Cargo.lock              # Locked dependency versions
+├── config.example.toml     # Config template
+├── migrations/            # SQL schema files
+│   └── 002_schema.sql    # Current schema
+├── input/                  # CSV input files
+├── output/                 # Generated invoices
+├── src/
+│   ├── lib.rs            # Library crate (for testing)
+│   ├── main.rs           # CLI entry point
+│   ├── config.rs         # Configuration loading
+│   ├── db/               # Database layer
+│   │   ├── mod.rs
+│   │   ├── connection.rs
+│   │   ├── models.rs
+│   │   └── repository.rs
+│   ├── commands/         # CLI commands
+│   │   ├── mod.rs
+│   │   ├── db.rs         # db setup/reset
+│   │   └── import.rs     # CSV import
+│   └── invoice_generator.rs
+├── templates/             # HTML invoice templates
+│   ├── index.html
+│   └── customer.html
+└── tests/                # Integration tests
+    ├── common/           # Test utilities
+    │   ├── mod.rs
+    │   ├── fixtures.rs
+    │   └── test_db.rs
+    ├── config_test.rs   # Config module tests
+    ├── import_test.rs    # CSV parsing tests
+    ├── models_test.rs    # Model tests
+    └── repository_test.rs # Database tests
+```
+
+## Database Schema
+
+### customers
+| Column | Type | Description |
+|--------|------|-------------|
+| id | INT UNSIGNED | Primary key |
+| customer_number | VARCHAR | Unique customer identifier |
+| card_report_group | TINYINT UNSIGNED | Customer classification (1=fleet, 3/4=retail) |
+| created_at | TIMESTAMP | Record creation time |
+| updated_at | TIMESTAMP | Last update time |
+
+### cards
+| Column | Type | Description |
+|--------|------|-------------|
+| id | INT UNSIGNED | Primary key |
+| card_number | VARCHAR | Unique card identifier |
+| customer_id | INT UNSIGNED | FK to customers |
+| created_at | TIMESTAMP | Record creation time |
+| updated_at | TIMESTAMP | Last update time |
+
+### transactions
+| Column | Type | Description |
+|--------|------|-------------|
+| id | BIGINT UNSIGNED | Primary key |
+| transaction_date | DATETIME | Transaction timestamp |
+| batch_number | VARCHAR | Batch identifier |
+| amount | DECIMAL(10,2) | Transaction amount |
+| volume | DECIMAL(10,3) | Volume in liters |
+| price | DECIMAL(8,4) | Price per liter |
+| quality_code | INT | Product code |
+| quality_name | VARCHAR | Product name (95 Oktan, Diesel) |
+| card_number | VARCHAR | Card used (including anonymized) |
+| station | VARCHAR | Station ID |
+| terminal | VARCHAR | Terminal ID |
+| pump | VARCHAR | Pump number |
+| receipt | VARCHAR | Receipt number |
+| control_number | VARCHAR | Control/verification number |
+| customer_id | INT UNSIGNED | FK to customers (NULL for anonymized) |
+| created_at | TIMESTAMP | Record creation time |
+
+## Configuration
+
+Copy the example config and edit with your database credentials:
+
+```bash
+cp config.example.toml config.dev.toml  # or config.test.toml or config.prod.toml
+```
+
+Edit `config.dev.toml`:
+```toml
+[database]
+host = "localhost"
+port = 3306
+user = "your_user"
+password = "your_password"
+name = "rusty_petroleum_dev"
+```
+
+### Environment Config Loading
+
+Config files are loaded in order:
+1. `config.toml` (local override, gitignored)
+2. `config.<env>.toml` (environment-specific, gitignored)
+3. `config.example.toml` (fallback, tracked)
+
+### Database Names by Environment
+
+- `rusty_petroleum_dev` - Development
+- `rusty_petroleum_test` - Testing
+- `rusty_petroleum_prod` - Production
+
+## Commands
+
+```bash
+# Database management
+cargo run -- db setup --env <dev|test|prod>   # Create database and schema
+cargo run -- db reset --env <dev|test|prod>   # Drop and recreate database
+
+# Import data
+cargo run -- import <csv-file> --env <dev|test|prod>   # Import to database (default: prod)
+
+# Generate invoices (file-to-file, no database)
+cargo run -- generate <csv-file> <output-dir>
+```
+
+### Usage Examples
+
+```bash
+# Setup development database
+cargo run -- db setup --env dev
+
+# Import transactions to dev database
+cargo run -- import input/409.csv --env dev
+
+# Reset development database
+cargo run -- db reset --env dev
+
+# Generate HTML invoices from CSV
+cargo run -- generate input/409.csv output/
+```
+
+## Testing
+
+The project has a comprehensive test suite with 45 tests covering config, CSV parsing, models, and database operations.
+
+```bash
+# Run all tests (lib + integration)
+cargo test
+
+# Run only lib/unit tests (fast, no database needed)
+cargo test --lib
+
+# Run only integration tests (requires test database)
+cargo test --tests
+
+# Run a specific test file
+cargo test --test config_test
+cargo test --test import_test
+cargo test --test repository_test
+
+# Run a specific test
+cargo test customer_insert_returns_id
+
+# Run tests in release mode
+cargo test --release
+```
+
+### Test Database Setup
+
+Repository tests require a test database. Run setup before testing:
+
+```bash
+cargo run -- db setup --env test
+```
+
+## Production Build
+
+Build an optimized binary for production:
+
+```bash
+# Build release binary
+cargo build --release
+
+# Run the binary
+./target/release/invoice-generator db setup --env prod
+./target/release/invoice-generator import data.csv --env prod
+```
+
+## Current Status
+
+### Implemented
+- [x] Database schema for transactions, customers, cards
+- [x] CSV import to MariaDB
+- [x] Multi-environment support (dev/test/prod)
+- [x] Configuration via TOML files
+- [x] Invoice generation (HTML output)
+- [x] Database setup/reset commands
+- [x] Unit tests (45 tests)
+
+### TODO
+- [ ] Sales reporting queries (dashboard/API)
+- [ ] Customer invoice retrieval from database
+- [ ] Batch import across multiple CSV files
+- [ ] CI/CD pipeline
+
+## Technology Stack
+
+- **Language**: Rust (Edition 2021)
+- **Database**: MariaDB
+- **ORM**: sqlx (async MySQL)
+- **Templating**: Askama (HTML templates)
+- **Config**: TOML
+- **Testing**: tokio-test, tempfile
+
+## Getting Started
+
+1. Install Rust (if not already installed)
+   ```bash
+   curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
+   ```
+
+2. Create database user and grant permissions in MariaDB
+   ```sql
+   CREATE USER 'your_user'@'%' IDENTIFIED BY 'your_password';
+   GRANT ALL PRIVILEGES ON rusty_petroleum_dev.* TO 'your_user'@'%';
+   CREATE DATABASE rusty_petroleum_dev;
+   ```
+
+3. Setup configuration
+   ```bash
+   cp config.example.toml config.dev.toml
+   # Edit config.dev.toml with your credentials
+   ```
+
+4. Setup database and import data
+   ```bash
+   cargo run -- db setup --env dev
+   cargo run -- import input/409.csv --env dev
+   ```
+
+5. Run tests
+   ```bash
+   cargo test --lib        # Unit tests (fast)
+   cargo test --tests      # Integration tests (requires DB)
+   ```
+
+## License
+
+See LICENSE file.

config.example.toml

@@ -0,0 +1,6 @@
+[database]
+host = "localhost"
+port = 3306
+user = ""
+password = ""
+name = "rusty_petroleum"

migrations/001_dev.sql

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+-- Create development database
+CREATE DATABASE IF NOT EXISTS rusty_petroleum_dev;

migrations/001_prod.sql

@@ -0,0 +1,2 @@
+-- Create production database
+CREATE DATABASE IF NOT EXISTS rusty_petroleum;

migrations/001_test.sql

@@ -0,0 +1,2 @@
+-- Create test database
+CREATE DATABASE IF NOT EXISTS rusty_petroleum_test;

migrations/002_schema.sql

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+-- Schema for rusty_petroleum
+-- Run after creating the database
+
+CREATE TABLE IF NOT EXISTS customers (
+    id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+    customer_number VARCHAR(50) NOT NULL UNIQUE,
+    card_report_group TINYINT UNSIGNED NOT NULL DEFAULT 0,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+    INDEX idx_customer_number (customer_number)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+CREATE TABLE IF NOT EXISTS cards (
+    id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+    card_number VARCHAR(50) NOT NULL UNIQUE,
+    customer_id INT UNSIGNED NOT NULL,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+    INDEX idx_card_number (card_number),
+    INDEX idx_customer_id (customer_id),
+    FOREIGN KEY (customer_id) REFERENCES customers(id)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+CREATE TABLE IF NOT EXISTS transactions (
+    id BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+    transaction_date DATETIME NOT NULL,
+    batch_number VARCHAR(20) NOT NULL,
+    amount DECIMAL(10,2) NOT NULL,
+    volume DECIMAL(10,3) NOT NULL,
+    price DECIMAL(8,4) NOT NULL,
+    quality_code INT NOT NULL,
+    quality_name VARCHAR(50) NOT NULL,
+    card_number VARCHAR(50) NOT NULL,
+    station VARCHAR(20) NOT NULL,
+    terminal VARCHAR(10) NOT NULL,
+    pump VARCHAR(10) NOT NULL,
+    receipt VARCHAR(20) NOT NULL,
+    control_number VARCHAR(20),
+    customer_id INT UNSIGNED NULL,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    INDEX idx_transaction_date (transaction_date),
+    INDEX idx_batch_number (batch_number),
+    INDEX idx_customer_id (customer_id),
+    INDEX idx_card_number (card_number),
+    INDEX idx_station (station)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

src/commands/db.rs

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+use crate::config::Config;
+use crate::db::Repository;
+use sqlx::mysql::MySqlPoolOptions;
+
+/// Sets up the database for the specified environment.
+/// 
+/// AI AGENT NOTE: This creates:
+/// 1. The database (if not exists)
+/// 2. customers table - stores fleet customers
+/// 3. cards table - stores known cards linked to customers
+/// 4. transactions table - stores all transactions
+/// 
+/// Uses CREATE TABLE IF NOT EXISTS, so it's idempotent.
+/// Note: We connect to the server without specifying a database first,
+/// then create the database, then create tables in that database.
+pub async fn run_db_setup(repo: &Repository, config: &Config) -> anyhow::Result<()> {
+    let env = &config.env;
+    println!("Setting up database for environment: {}", env.as_str());
+    println!("Database: {}", env.database_name());
+
+    let database_url = &config.database.connection_url();
+    // Strip database name to connect to server without selecting a database
+    // AI AGENT NOTE: MariaDB requires connecting without a database to create one
+    let base_url = database_url.trim_end_matches(env.database_name());
+
+    let setup_pool = MySqlPoolOptions::new()
+        .max_connections(1)
+        .connect(base_url)
+        .await?;
+
+    println!("Creating database if not exists...");
+    sqlx::query(&format!(
+        "CREATE DATABASE IF NOT EXISTS {}",
+        env.database_name()
+    ))
+    .execute(&setup_pool)
+    .await?;
+    println!("Database '{}' ready", env.database_name());
+
+    drop(setup_pool);
+
+    // Now connect to the created database and create tables
+    println!("Creating tables...");
+    sqlx::query(
+        r#"
+        CREATE TABLE IF NOT EXISTS customers (
+            id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+            customer_number VARCHAR(50) NOT NULL UNIQUE,
+            card_report_group TINYINT UNSIGNED NOT NULL DEFAULT 0,
+            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+            updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+            INDEX idx_customer_number (customer_number)
+        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
+        "#,
+    )
+    .execute(repo.pool())
+    .await?;
+
+    sqlx::query(
+        r#"
+        CREATE TABLE IF NOT EXISTS cards (
+            id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+            card_number VARCHAR(50) NOT NULL UNIQUE,
+            customer_id INT UNSIGNED NOT NULL,
+            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+            updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+            INDEX idx_card_number (card_number),
+            INDEX idx_customer_id (customer_id),
+            FOREIGN KEY (customer_id) REFERENCES customers(id)
+        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
+        "#,
+    )
+    .execute(repo.pool())
+    .await?;
+
+    sqlx::query(
+        r#"
+        CREATE TABLE IF NOT EXISTS transactions (
+            id BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+            transaction_date DATETIME NOT NULL,
+            batch_number VARCHAR(20) NOT NULL,
+            amount DECIMAL(10,2) NOT NULL,
+            volume DECIMAL(10,3) NOT NULL,
+            price DECIMAL(8,4) NOT NULL,
+            quality_code INT NOT NULL,
+            quality_name VARCHAR(50) NOT NULL,
+            card_number VARCHAR(50) NOT NULL,
+            station VARCHAR(20) NOT NULL,
+            terminal VARCHAR(10) NOT NULL,
+            pump VARCHAR(10) NOT NULL,
+            receipt VARCHAR(20) NOT NULL,
+            control_number VARCHAR(20),
+            customer_id INT UNSIGNED NULL,
+            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+            INDEX idx_transaction_date (transaction_date),
+            INDEX idx_batch_number (batch_number),
+            INDEX idx_customer_id (customer_id),
+            INDEX idx_card_number (card_number),
+            INDEX idx_station (station)
+        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
+        "#,
+    )
+    .execute(repo.pool())
+    .await?;
+
+    println!("Tables created successfully.");
+    println!("Database setup complete!");
+
+    Ok(())
+}
+
+/// Resets the database by dropping and recreating it.
+/// 
+/// AI AGENT NOTE: This is a destructive operation that:
+/// 1. Drops the database if it exists (loses all data!)
+/// 2. Creates a fresh database
+/// 3. Does NOT create tables (run db setup afterwards)
+/// 
+/// Use this when schema changes require a fresh database.
+pub async fn run_db_reset(config: &Config) -> anyhow::Result<()> {
+    let env = &config.env;
+    println!("Resetting database for environment: {}", env.as_str());
+    println!("Database: {}", env.database_name());
+
+    let database_url = &config.database.connection_url();
+    let base_url = database_url.trim_end_matches(env.database_name());
+
+    let setup_pool = MySqlPoolOptions::new()
+        .max_connections(1)
+        .connect(base_url)
+        .await?;
+
+    println!("Dropping database if exists...");
+    sqlx::query(&format!("DROP DATABASE IF EXISTS {}", env.database_name()))
+        .execute(&setup_pool)
+        .await?;
+
+    println!("Creating database...");
+    sqlx::query(&format!("CREATE DATABASE {}", env.database_name()))
+        .execute(&setup_pool)
+        .await?;
+
+    drop(setup_pool);
+
+    println!("Database '{}' reset complete!", env.database_name());
+
+    Ok(())
+}

src/commands/import.rs

@@ -0,0 +1,393 @@
+use crate::db::models::{NewCard, NewCustomer, NewTransaction};
+use crate::db::Repository;
+use chrono::NaiveDateTime;
+use csv::ReaderBuilder;
+use std::collections::HashMap;
+use std::fs::File;
+use std::path::Path;
+
+/// Represents a parsed transaction from CSV fields.
+/// 
+/// AI AGENT NOTE: This is an intermediate struct for CSV parsing.
+/// It mirrors the CSV column structure and is converted to NewTransaction
+/// for database insertion.
+#[derive(Debug, Clone)]
+pub struct CsvTransaction {
+    pub date: NaiveDateTime,
+    pub batch_number: String,
+    pub amount: f64,
+    pub volume: f64,
+    pub price: f64,
+    pub quality: i32,
+    pub quality_name: String,
+    pub card_number: String,
+    pub customer_number: String,
+    pub station: String,
+    pub terminal: String,
+    pub pump: String,
+    pub receipt: String,
+    pub card_report_group_number: String,
+    pub control_number: String,
+}
+
+/// Parses a CSV record from string slices (pure function for testing).
+/// 
+/// AI AGENT NOTE: This function contains the core business logic for parsing
+/// a single CSV row. It can be tested without file I/O.
+///
+/// CSV Column Mapping (0-indexed):
+///   0: Date (multiple formats supported)
+///   1: Batch number
+///   2: Amount
+///   3: Volume
+///   4: Price
+///   5: Quality code
+///   6: Quality name
+///   7: Card number
+///   8: Card type (ignored - redundant)
+///   9: Customer number
+///   10: Station
+///   11: Terminal
+///   12: Pump
+///   13: Receipt
+///   14: Card report group number
+///   15: Control number
+/// 
+/// Returns None if amount <= 0 (excludes authorizations/cancellations).
+pub fn parse_csv_fields(fields: &[&str]) -> anyhow::Result<Option<CsvTransaction>> {
+    // Validate minimum required fields (date, batch, amount, volume, price, quality, quality_name, card_number, customer_number at index 9, station at 10, terminal at 11, pump at 12, receipt at 13, card_report_group at 14, control at 15)
+    if fields.len() < 16 {
+        anyhow::bail!("Expected at least 16 fields, got {}", fields.len());
+    }
+    
+    let date_str = fields.get(0).copied().unwrap_or("");
+    let date = parse_date(date_str)?;
+
+    let amount_str = fields.get(2).copied().unwrap_or("0");
+    let amount: f64 = amount_str.parse().unwrap_or(0.0);
+
+    // Skip zero/negative amounts (authorizations, cancellations)
+    if amount <= 0.0 {
+        return Ok(None);
+    }
+
+    let customer_number = fields.get(9).copied().unwrap_or("").to_string();
+
+    Ok(Some(CsvTransaction {
+        date,
+        batch_number: fields.get(1).copied().unwrap_or("").to_string(),
+        amount,
+        volume: fields.get(3).copied().unwrap_or("0").parse().unwrap_or(0.0),
+        price: fields.get(4).copied().unwrap_or("0").parse().unwrap_or(0.0),
+        quality: fields.get(5).copied().unwrap_or("0").parse().unwrap_or(0),
+        quality_name: fields.get(6).copied().unwrap_or("").to_string(),
+        card_number: fields.get(7).copied().unwrap_or("").to_string(),
+        customer_number,
+        station: fields.get(10).copied().unwrap_or("").to_string(),
+        terminal: fields.get(11).copied().unwrap_or("").to_string(),
+        pump: fields.get(12).copied().unwrap_or("").to_string(),
+        receipt: fields.get(13).copied().unwrap_or("").to_string(),
+        card_report_group_number: fields.get(14).copied().unwrap_or("").to_string(),
+        control_number: fields.get(15).copied().unwrap_or("").to_string(),
+    }))
+}
+
+/// Parses a date string, supporting multiple formats.
+/// 
+/// AI AGENT NOTE: Source data may use different date formats:
+///   - ISO format: "2026-02-01 06:40:14"
+///   - US format: "02/01/2026 06:40:14 AM"
+fn parse_date(date_str: &str) -> anyhow::Result<NaiveDateTime> {
+    NaiveDateTime::parse_from_str(date_str, "%Y-%m-%d %H:%M:%S")
+        .or_else(|_| NaiveDateTime::parse_from_str(date_str, "%m/%d/%Y %I:%M:%S %p"))
+        .map_err(|e| anyhow::anyhow!("Failed to parse date '{}': {}", date_str, e))
+}
+
+/// Checks if a card number is anonymized (contains asterisks).
+/// 
+/// AI AGENT NOTE: Anonymized cards have masked digits like "554477******9952".
+/// These cards are NOT stored in the cards table - only in transactions.
+pub fn is_anonymized_card(card_number: &str) -> bool {
+    card_number.contains('*')
+}
+
+/// Imports transactions from a CSV file into the database.
+/// 
+/// AI AGENT NOTE: This is the main data import function. It handles:
+/// 
+/// 1. PARSING: Reads tab-separated CSV and extracts transaction data
+/// 2. FILTERING: Only includes transactions where:
+///    - amount > 0 (excludes authorizations/cancellations)
+///    - customer_number is NOT empty (excludes retail transactions)
+/// 3. COLLECTION: Gathers unique customers and known cards first
+/// 4. UPSERT: Creates/updates customer and card records
+/// 5. BATCH INSERT: Inserts transactions in batches of 500
+/// 
+/// Business Rules:
+/// - Transactions with empty customer_number are stored but not linked to customers
+/// - Only "known" cards (with full card numbers) are stored in the cards table
+/// - Anonymized cards (with asterisks) are stored only in transactions.card_number
+pub async fn run_import(csv_path: &Path, repo: &Repository) -> anyhow::Result<()> {
+    println!("Reading CSV file: {:?}", csv_path);
+
+    let file = File::open(csv_path)?;
+    let mut rdr = ReaderBuilder::new()
+        .delimiter(b'\t')
+        .has_headers(true)
+        .flexible(true)
+        .from_reader(file);
+
+    let mut transactions = Vec::new();
+    let mut seen_customers: HashMap<String, u8> = HashMap::new();
+    let mut seen_cards: HashMap<String, String> = HashMap::new();
+
+    for result in rdr.records() {
+        let record = result?;
+        if let Some(tx) = parse_record(&record)? {
+            if !tx.customer_number.is_empty() {
+                let card_report_group: u8 = tx.card_report_group_number.parse().unwrap_or(0);
+                if !seen_customers.contains_key(&tx.customer_number) {
+                    seen_customers.insert(tx.customer_number.clone(), card_report_group);
+                }
+                if !seen_cards.contains_key(&tx.card_number) {
+                    seen_cards.insert(tx.card_number.clone(), tx.customer_number.clone());
+                }
+            }
+            transactions.push(tx);
+        }
+    }
+
+    println!("Found {} transactions", transactions.len());
+    println!("Unique customers: {}", seen_customers.len());
+    println!("Unique known cards: {}", seen_cards.len());
+
+    println!("\nImporting customers...");
+    let mut customer_ids: HashMap<String, u32> = HashMap::new();
+    for (customer_number, card_report_group) in &seen_customers {
+        let new_customer = NewCustomer {
+            customer_number: customer_number.clone(),
+            card_report_group: *card_report_group,
+        };
+        let id = repo.upsert_customer(&new_customer).await?;
+        customer_ids.insert(customer_number.clone(), id);
+        println!("  Customer {} -> id {}", customer_number, id);
+    }
+
+    println!("\nImporting cards...");
+    let mut card_ids: HashMap<String, u32> = HashMap::new();
+    for (card_number, customer_number) in &seen_cards {
+        if let Some(&customer_id) = customer_ids.get(customer_number) {
+            let new_card = NewCard {
+                card_number: card_number.clone(),
+                customer_id,
+            };
+            let id = repo.upsert_card(&new_card).await?;
+            card_ids.insert(card_number.clone(), id);
+            println!("  Card {} -> customer {} -> id {}", card_number, customer_number, id);
+        }
+    }
+
+    println!("\nImporting transactions...");
+    let batch_size = 500;
+    let mut total_inserted = 0u64;
+    let mut batch: Vec<NewTransaction> = Vec::with_capacity(batch_size);
+
+    for tx in transactions {
+        let customer_id = customer_ids.get(&tx.customer_number).copied();
+
+        let new_tx = NewTransaction {
+            transaction_date: tx.date,
+            batch_number: tx.batch_number,
+            amount: tx.amount,
+            volume: tx.volume,
+            price: tx.price,
+            quality_code: tx.quality,
+            quality_name: tx.quality_name,
+            card_number: tx.card_number,
+            station: tx.station,
+            terminal: tx.terminal,
+            pump: tx.pump,
+            receipt: tx.receipt,
+            control_number: if tx.control_number.is_empty() { None } else { Some(tx.control_number) },
+            customer_id,
+        };
+
+        batch.push(new_tx);
+
+        if batch.len() >= batch_size {
+            let inserted = repo.insert_transactions_batch(&batch).await?;
+            total_inserted += inserted;
+            println!("  Inserted {} transactions (total: {})", inserted, total_inserted);
+            batch.clear();
+        }
+    }
+
+    if !batch.is_empty() {
+        let inserted = repo.insert_transactions_batch(&batch).await?;
+        total_inserted += inserted;
+        println!("  Inserted {} transactions (total: {})", inserted, total_inserted);
+    }
+
+    println!("\nDone! Imported {} transactions", total_inserted);
+
+    Ok(())
+}
+
+fn get_field(record: &csv::StringRecord, index: usize) -> &str {
+    record.get(index).unwrap_or("")
+}
+
+/// Parses a single record from the CSV file.
+/// 
+/// AI AGENT NOTE: Returns None if:
+/// - amount <= 0 (excludes authorizations/cancellations)
+/// - date parsing fails
+fn parse_record(record: &csv::StringRecord) -> anyhow::Result<Option<CsvTransaction>> {
+    let fields: Vec<&str> = (0..16)
+        .map(|i| get_field(record, i))
+        .collect();
+    parse_csv_fields(&fields)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parse_valid_record_with_known_customer() {
+        let fields = [
+            "2026-02-01 10:15:16", "409", "559.26", "35.85", "15.60",
+            "1001", "95 Oktan", "7825017523017000642", "type",
+            "1861", "97254", "1", "2", "000910", "1", ""
+        ];
+        
+        let result = parse_csv_fields(&fields).unwrap();
+        assert!(result.is_some());
+        
+        let tx = result.unwrap();
+        assert_eq!(tx.batch_number, "409");
+        assert_eq!(tx.amount, 559.26);
+        assert_eq!(tx.volume, 35.85);
+        assert_eq!(tx.quality, 1001);
+        assert_eq!(tx.quality_name, "95 Oktan");
+        assert_eq!(tx.card_number, "7825017523017000642");
+        assert_eq!(tx.customer_number, "1861");
+    }
+
+    #[test]
+    fn parse_record_with_empty_customer_number() {
+        let fields = [
+            "2026-02-01 06:40:14", "409", "267.23", "17.13", "15.60",
+            "1001", "95 Oktan", "554477******9952", "type",
+            "", "97254", "1", "2", "000898", "4", "756969"
+        ];
+        
+        let result = parse_csv_fields(&fields).unwrap();
+        assert!(result.is_some());
+        
+        let tx = result.unwrap();
+        assert_eq!(tx.customer_number, "");
+        assert_eq!(tx.card_number, "554477******9952");
+        assert!(is_anonymized_card(&tx.card_number));
+    }
+
+    #[test]
+    fn parse_zero_amount_returns_none() {
+        let fields = [
+            "2026-02-01 06:40:14", "409", "0.00", "0.00", "15.60",
+            "1001", "95 Oktan", "554477******9952", "type",
+            "", "97254", "1", "2", "000898", "4", "756969"
+        ];
+        
+        let result = parse_csv_fields(&fields).unwrap();
+        assert!(result.is_none());
+    }
+
+    #[test]
+    fn parse_negative_amount_returns_none() {
+        let fields = [
+            "2026-02-01 06:40:14", "409", "-50.00", "-3.00", "15.60",
+            "1001", "95 Oktan", "7825017523017000642", "type",
+            "1861", "97254", "1", "2", "000898", "1", ""
+        ];
+        
+        let result = parse_csv_fields(&fields).unwrap();
+        assert!(result.is_none());
+    }
+
+    #[test]
+    fn parse_us_date_format() {
+        let fields = [
+            "02/01/2026 10:15:16 AM", "409", "559.26", "35.85", "15.60",
+            "1001", "95 Oktan", "7825017523017000642", "type",
+            "1861", "97254", "1", "2", "000910", "1", ""
+        ];
+        
+        let result = parse_csv_fields(&fields).unwrap();
+        assert!(result.is_some());
+        
+        let tx = result.unwrap();
+        assert_eq!(tx.date.format("%Y-%m-%d").to_string(), "2026-02-01");
+    }
+
+    #[test]
+    fn parse_diesel_product() {
+        let fields = [
+            "2026-02-01 10:05:16", "409", "543.22", "31.40", "17.30",
+            "4", "Diesel", "673706*********0155", "type",
+            "", "97254", "1", "2", "000909", "4", "D00824"
+        ];
+        
+        let result = parse_csv_fields(&fields).unwrap();
+        assert!(result.is_some());
+        
+        let tx = result.unwrap();
+        assert_eq!(tx.quality_name, "Diesel");
+        assert_eq!(tx.quality, 4);
+        assert_eq!(tx.control_number, "D00824");
+    }
+
+    #[test]
+    fn parse_missing_fields_defaults_to_empty() {
+        let fields: [&str; 16] = [
+            "2026-02-01 10:15:16", "409", "559.26", "", "",
+            "", "", "", "", "", "", "", "", "", "", ""
+        ];
+        
+        let result = parse_csv_fields(&fields).unwrap();
+        assert!(result.is_some());
+        
+        let tx = result.unwrap();
+        assert_eq!(tx.volume, 0.0);
+        assert_eq!(tx.price, 0.0);
+        assert_eq!(tx.quality, 0);
+        assert_eq!(tx.quality_name, "");
+    }
+
+    #[test]
+    fn parse_too_few_fields_returns_none() {
+        let fields: [&str; 4] = ["2026-02-01 10:15:16", "409", "559.26", "35.85"];
+        
+        let result = parse_csv_fields(&fields);
+        assert!(result.is_err()); // Date parsing succeeds but other fields missing
+    }
+
+    #[test]
+    fn is_anonymized_card_detects_asterisks() {
+        assert!(is_anonymized_card("554477******9952"));
+        assert!(is_anonymized_card("673706*********0155"));
+        assert!(!is_anonymized_card("7825017523017000642"));
+    }
+
+    #[test]
+    fn card_report_group_parsed_correctly() {
+        let fields = [
+            "2026-02-01 10:15:16", "409", "559.26", "35.85", "15.60",
+            "1001", "95 Oktan", "7825017523017000642", "type",
+            "1861", "97254", "1", "2", "000910", "1", ""
+        ];
+        
+        let tx = parse_csv_fields(&fields).unwrap().unwrap();
+        assert_eq!(tx.card_report_group_number, "1");
+    }
+}

src/commands/mod.rs

@@ -0,0 +1,5 @@
+pub mod db;
+pub mod import;
+
+pub use db::{run_db_reset, run_db_setup};
+pub use import::run_import;

src/config.rs

@@ -0,0 +1,178 @@
+use std::fs;
+use std::path::Path;
+
+/// Environment selection for multi-database setup.
+///
+/// AI AGENT NOTE: This enum controls which database configuration is loaded.
+/// Each environment maps to a different database name:
+///   - Prod: rusty_petroleum (production data)
+///   - Dev: rusty_petroleum_dev (development)
+///   - Test: rusty_petroleum_test (testing)
+///
+/// The environment is set via the --env CLI flag and defaults to Prod.
+#[derive(Debug, Clone, Default, PartialEq)]
+pub enum Env {
+    /// Production environment - default for safety (requires explicit --env for dev/test)
+    #[default]
+    Prod,
+    /// Development environment - rusty_petroleum_dev
+    Dev,
+    /// Testing environment - rusty_petroleum_test
+    Test,
+}
+
+impl Env {
+    /// Returns the environment name as a string for CLI/config file naming.
+    pub fn as_str(&self) -> &str {
+        match self {
+            Env::Prod => "prod",
+            Env::Dev => "dev",
+            Env::Test => "test",
+        }
+    }
+
+    /// Returns the database name for this environment.
+    ///
+    /// AI AGENT NOTE: Database naming convention:
+    ///   - Production: rusty_petroleum (no suffix)
+    ///   - Development: rusty_petroleum_dev
+    ///   - Testing: rusty_petroleum_test
+    pub fn database_name(&self) -> &str {
+        match self {
+            Env::Prod => "rusty_petroleum",
+            Env::Dev => "rusty_petroleum_dev",
+            Env::Test => "rusty_petroleum_test",
+        }
+    }
+}
+
+impl std::str::FromStr for Env {
+    type Err = String;
+
+    /// Parses environment from CLI argument.
+    /// Accepts both short and long forms for flexibility.
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s.to_lowercase().as_str() {
+            "prod" | "production" => Ok(Env::Prod),
+            "dev" | "development" => Ok(Env::Dev),
+            "test" | "testing" => Ok(Env::Test),
+            _ => Err(format!("Unknown environment: {}", s)),
+        }
+    }
+}
+
+/// Root configuration struct containing environment and database settings.
+#[derive(Debug, Clone)]
+pub struct Config {
+    pub env: Env,
+    pub database: DatabaseConfig,
+}
+
+/// Database connection configuration.
+#[derive(Debug, Clone)]
+pub struct DatabaseConfig {
+    pub host: String,
+    pub port: u16,
+    pub user: String,
+    pub password: String,
+    pub name: String,
+}
+
+impl DatabaseConfig {
+    /// Builds a MySQL connection URL from configuration.
+    ///
+    /// AI AGENT NOTE: Handles empty password by omitting it from URL.
+    /// This allows connections without passwords (e.g., local development).
+    pub fn connection_url(&self) -> String {
+        if self.password.is_empty() {
+            format!(
+                "mysql://{}@{}:{}/{}",
+                self.user, self.host, self.port, self.name
+            )
+        } else {
+            format!(
+                "mysql://{}:{}@{}:{}/{}",
+                self.user, self.password, self.host, self.port, self.name
+            )
+        }
+    }
+}
+
+impl Config {
+    /// Loads configuration for the specified environment.
+    ///
+    /// AI AGENT NOTE: Config file loading order (first existing file wins):
+    ///   1. config.toml - local override (gitignored, for personal overrides)
+    ///   2. config.<env>.toml - environment-specific (gitignored)
+    ///   3. config.example.toml - fallback template (tracked in git)
+    ///
+    /// This allows:
+    ///   - Committed example config as reference
+    ///   - Environment-specific configs for different developers
+    ///   - Local overrides without modifying tracked files
+    pub fn load(env: Env) -> anyhow::Result<Self> {
+        let config_path = Path::new("config.toml");
+        let example_path = Path::new("config.example.toml");
+
+        let env_config_filename = format!("config.{}.toml", env.as_str());
+        let env_config_path = Path::new(&env_config_filename);
+
+        let path = if config_path.exists() {
+            config_path
+        } else if env_config_path.exists() {
+            env_config_path
+        } else if example_path.exists() {
+            example_path
+        } else {
+            return Err(anyhow::anyhow!(
+                "No configuration file found. Create config.example.toml or config.toml"
+            ));
+        };
+
+        Self::load_from_path(path, env)
+    }
+
+    /// Loads configuration from a specific file path.
+    pub fn load_from_path(path: &Path, env: Env) -> anyhow::Result<Self> {
+        let contents = fs::read_to_string(path)
+            .map_err(|e| anyhow::anyhow!("Failed to read config file {:?}: {}", path, e))?;
+
+        let config: TomlConfig = toml::from_str(&contents)
+            .map_err(|e| anyhow::anyhow!("Failed to parse config file {:?}: {}", path, e))?;
+
+        let mut result: Config = config.into();
+        result.env = env;
+        Ok(result)
+    }
+}
+
+/// Intermediate struct for TOML deserialization.
+/// AI AGENT NOTE: This mirrors the [database] section of config.toml.
+#[derive(serde::Deserialize)]
+struct TomlConfig {
+    database: TomlDatabaseConfig,
+}
+
+#[derive(serde::Deserialize)]
+struct TomlDatabaseConfig {
+    host: String,
+    port: u16,
+    user: String,
+    password: String,
+    name: String,
+}
+
+impl From<TomlConfig> for Config {
+    fn from(toml: TomlConfig) -> Self {
+        Config {
+            env: Env::default(),
+            database: DatabaseConfig {
+                host: toml.database.host,
+                port: toml.database.port,
+                user: toml.database.user,
+                password: toml.database.password,
+                name: toml.database.name,
+            },
+        }
+    }
+}

src/db/connection.rs

@@ -0,0 +1,11 @@
+use sqlx::mysql::MySqlPoolOptions;
+use sqlx::MySqlPool;
+
+pub async fn create_pool(database_url: &str) -> anyhow::Result<MySqlPool> {
+    let pool = MySqlPoolOptions::new()
+        .max_connections(10)
+        .connect(database_url)
+        .await?;
+
+    Ok(pool)
+}

src/db/mod.rs

@@ -0,0 +1,7 @@
+pub mod connection;
+pub mod models;
+pub mod repository;
+
+pub use connection::create_pool;
+pub use models::{Card, Customer, NewCard, NewCustomer, Transaction};
+pub use repository::Repository;

src/db/models.rs

@@ -0,0 +1,105 @@
+use bigdecimal::BigDecimal;
+use chrono::{DateTime, NaiveDateTime, Utc};
+use serde::{Deserialize, Serialize};
+use sqlx::FromRow;
+
+/// Represents a fleet/corporate customer in the system.
+///
+/// AI AGENT NOTE: Customers are identified by customer_number and have
+/// associated cards. Not all transactions have a customer (retail/anonymous).
+/// The card_report_group indicates customer classification:
+///   - 1: Fleet customers (have customer_number)
+///   - 3, 4: Retail customers (no customer_number)
+#[derive(Debug, Clone, Serialize, Deserialize, FromRow)]
+pub struct Customer {
+    pub id: u32,
+    pub customer_number: String,
+    pub card_report_group: u8,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+}
+
+/// Input struct for creating a new customer during import.
+#[derive(Debug, Clone)]
+pub struct NewCustomer {
+    pub customer_number: String,
+    pub card_report_group: u8,
+}
+
+/// Represents a fuel card belonging to a customer.
+///
+/// AI AGENT NOTE: This table stores the authoritative mapping from card_number
+/// to customer. Only "known" cards (cards belonging to fleet customers) are
+/// stored here. Anonymized cards (with asterisks like "554477******9952") are
+/// NOT stored in this table - they appear directly in transactions.card_number.
+///
+/// Design rationale: Cards table contains ONLY known cards. This keeps the
+/// cards table small and ensures every card has a valid customer relationship.
+#[derive(Debug, Clone, Serialize, Deserialize, FromRow)]
+pub struct Card {
+    pub id: u32,
+    pub card_number: String,
+    pub customer_id: u32,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+}
+
+/// Input struct for creating a new card during import.
+#[derive(Debug, Clone)]
+pub struct NewCard {
+    pub card_number: String,
+    pub customer_id: u32,
+}
+
+/// Represents a fuel transaction in the database.
+///
+/// AI AGENT NOTE: This table stores ALL transactions, both anonymous and known:
+///   - card_number: Always populated (even for anonymized cards)
+///   - customer_id: NULL for anonymous transactions, FK to customers for fleet
+///
+/// To find a customer's transactions, use:
+///   SELECT * FROM transactions WHERE customer_id = <customer_id>
+///
+/// To find all transactions for a card:
+///   SELECT * FROM transactions WHERE card_number = '<card_number>'
+#[derive(Debug, Clone, Serialize, Deserialize, FromRow)]
+pub struct Transaction {
+    pub id: u64,
+    pub transaction_date: NaiveDateTime,
+    pub batch_number: String,
+    pub amount: BigDecimal,
+    pub volume: BigDecimal,
+    pub price: BigDecimal,
+    pub quality_code: i32,
+    pub quality_name: String,
+    pub card_number: String,
+    pub station: String,
+    pub terminal: String,
+    pub pump: String,
+    pub receipt: String,
+    pub control_number: Option<String>,
+    pub customer_id: Option<u32>, // NULL for anonymized transactions
+    pub created_at: DateTime<Utc>,
+}
+
+/// Input struct for inserting a new transaction.
+///
+/// AI AGENT NOTE: Uses f64 for numeric fields during construction (from CSV parsing),
+/// but BigDecimal is used in the database for precision.
+#[derive(Debug, Clone)]
+pub struct NewTransaction {
+    pub transaction_date: NaiveDateTime,
+    pub batch_number: String,
+    pub amount: f64,
+    pub volume: f64,
+    pub price: f64,
+    pub quality_code: i32,
+    pub quality_name: String,
+    pub card_number: String,
+    pub station: String,
+    pub terminal: String,
+    pub pump: String,
+    pub receipt: String,
+    pub control_number: Option<String>,
+    pub customer_id: Option<u32>,
+}

src/db/repository.rs

@@ -0,0 +1,427 @@
+use crate::db::models::{Card, Customer, NewCard, NewCustomer, NewTransaction, Transaction};
+use bigdecimal::BigDecimal;
+use sqlx::MySqlPool;
+
+/// Repository for database operations.
+/// 
+/// AI AGENT NOTE: This is the main data access layer. All database operations
+/// should go through this struct. It wraps a MySQL connection pool and provides
+/// methods for CRUD operations on customers, cards, and transactions.
+pub struct Repository {
+    pool: MySqlPool,
+}
+
+impl Repository {
+    pub fn new(pool: MySqlPool) -> Self {
+        Self { pool }
+    }
+
+    pub fn pool(&self) -> &MySqlPool {
+        &self.pool
+    }
+
+    /// Upserts a customer by customer_number.
+    /// 
+    /// AI AGENT NOTE: Uses ON DUPLICATE KEY UPDATE to handle re-imports.
+    /// If customer exists, only card_report_group is updated (it's derived from
+    /// transaction data and may differ between batches).
+    pub async fn upsert_customer(&self, customer: &NewCustomer) -> anyhow::Result<u32> {
+        sqlx::query(
+            r#"
+            INSERT INTO customers (customer_number, card_report_group)
+            VALUES (?, ?)
+            ON DUPLICATE KEY UPDATE
+                card_report_group = VALUES(card_report_group),
+                updated_at = CURRENT_TIMESTAMP
+            "#,
+        )
+        .bind(&customer.customer_number)
+        .bind(customer.card_report_group)
+        .execute(&self.pool)
+        .await?;
+
+        let row: (u32,) = sqlx::query_as(
+            "SELECT id FROM customers WHERE customer_number = ?",
+        )
+        .bind(&customer.customer_number)
+        .fetch_one(&self.pool)
+        .await?;
+
+        Ok(row.0)
+    }
+
+    /// Finds a customer by their customer_number.
+    pub async fn find_customer_by_number(
+        &self,
+        customer_number: &str,
+    ) -> anyhow::Result<Option<Customer>> {
+        let result = sqlx::query_as(
+            "SELECT id, customer_number, card_report_group, created_at, updated_at 
+             FROM customers 
+             WHERE customer_number = ?",
+        )
+        .bind(customer_number)
+        .fetch_optional(&self.pool)
+        .await?;
+
+        Ok(result)
+    }
+
+    /// Upserts a card by card_number.
+    /// 
+    /// AI AGENT NOTE: Cards are only created for known customers (fleet accounts).
+    /// Anonymized cards are NOT inserted here - they only appear in transactions.
+    /// 
+    /// Design: This ensures cards.customer_id is always NOT NULL, enforcing
+    /// the business rule that every card must belong to a customer.
+    pub async fn upsert_card(&self, card: &NewCard) -> anyhow::Result<u32> {
+        sqlx::query(
+            r#"
+            INSERT INTO cards (card_number, customer_id)
+            VALUES (?, ?)
+            ON DUPLICATE KEY UPDATE
+                customer_id = VALUES(customer_id),
+                updated_at = CURRENT_TIMESTAMP
+            "#,
+        )
+        .bind(&card.card_number)
+        .bind(card.customer_id)
+        .execute(&self.pool)
+        .await?;
+
+        let row: (u32,) = sqlx::query_as(
+            "SELECT id FROM cards WHERE card_number = ?",
+        )
+        .bind(&card.card_number)
+        .fetch_one(&self.pool)
+        .await?;
+
+        Ok(row.0)
+    }
+
+    /// Finds a card by card_number.
+    /// 
+    /// AI AGENT NOTE: Returns None for anonymized cards (e.g., "554477******9952")
+    /// since these are not stored in the cards table.
+    pub async fn find_card_by_number(&self, card_number: &str) -> anyhow::Result<Option<Card>> {
+        let result = sqlx::query_as(
+            "SELECT id, card_number, customer_id, created_at, updated_at 
+             FROM cards 
+             WHERE card_number = ?",
+        )
+        .bind(card_number)
+        .fetch_optional(&self.pool)
+        .await?;
+
+        Ok(result)
+    }
+
+    /// Inserts multiple transactions in a single batch for performance.
+    /// 
+    /// AI AGENT NOTE: Uses bulk INSERT for efficiency. The batch size is
+    /// controlled by the caller (typically 500 rows per batch).
+    /// 
+    /// IMPORTANT: This constructs raw SQL with escaped values. While sqlx doesn't
+    /// support parameterized bulk insert, we escape single quotes to prevent SQL
+    /// injection in string fields.
+    pub async fn insert_transactions_batch(
+        &self,
+        transactions: &[NewTransaction],
+    ) -> anyhow::Result<u64> {
+        if transactions.is_empty() {
+            return Ok(0);
+        }
+
+        let mut query = String::from(
+            "INSERT INTO transactions (transaction_date, batch_number, amount, volume, price, quality_code, quality_name, card_number, station, terminal, pump, receipt, control_number, customer_id) VALUES ",
+        );
+
+        let mut values = Vec::new();
+        for tx in transactions {
+            values.push(format!(
+                "('{}', '{}', {}, {}, {}, {}, '{}', '{}', '{}', '{}', '{}', '{}', {}, {})",
+                tx.transaction_date.format("%Y-%m-%d %H:%M:%S"),
+                tx.batch_number,
+                tx.amount,
+                tx.volume,
+                tx.price,
+                tx.quality_code,
+                tx.quality_name.replace("'", "''"),
+                tx.card_number.replace("'", "''"),
+                tx.station,
+                tx.terminal,
+                tx.pump,
+                tx.receipt,
+                tx.control_number.as_ref().map(|s| format!("'{}'", s.replace("'", "''"))).unwrap_or_else(|| "NULL".to_string()),
+                tx.customer_id.map(|id| id.to_string()).unwrap_or_else(|| "NULL".to_string()),
+            ));
+        }
+
+        query.push_str(&values.join(", "));
+
+        let result = sqlx::query(&query).execute(&self.pool).await?;
+
+        Ok(result.rows_affected())
+    }
+
+    /// Retrieves all transactions for a customer within a date range.
+    /// 
+    /// AI AGENT NOTE: Only returns transactions for known customers (customer_id IS NOT NULL).
+    /// Anonymous transactions are excluded from invoices.
+    pub async fn get_customer_invoice(
+        &self,
+        customer_number: &str,
+        start_date: &str,
+        end_date: &str,
+    ) -> anyhow::Result<Vec<Transaction>> {
+        let result = sqlx::query_as(
+            r#"
+            SELECT t.id, t.transaction_date, t.batch_number, t.amount, t.volume, t.price,
+                   t.quality_code, t.quality_name, t.card_number, t.station, t.terminal,
+                   t.pump, t.receipt, t.control_number, t.customer_id, t.created_at
+            FROM transactions t
+            JOIN customers c ON t.customer_id = c.id
+            WHERE c.customer_number = ?
+              AND t.transaction_date >= ?
+              AND t.transaction_date <= ?
+            ORDER BY t.transaction_date
+            "#,
+        )
+        .bind(customer_number)
+        .bind(start_date)
+        .bind(end_date)
+        .fetch_all(&self.pool)
+        .await?;
+
+        Ok(result)
+    }
+
+    /// Gets sales summary grouped by product (quality_name).
+    /// 
+    /// AI AGENT NOTE: Includes ALL transactions (both anonymous and known).
+    /// Useful for overall sales reporting.
+    pub async fn get_sales_summary_by_product(
+        &self,
+        start_date: &str,
+        end_date: &str,
+    ) -> anyhow::Result<Vec<ProductSummary>> {
+        let result = sqlx::query_as(
+            r#"
+            SELECT quality_name, COUNT(*) as tx_count, SUM(amount) as total_amount, SUM(volume) as total_volume
+            FROM transactions
+            WHERE transaction_date >= ? AND transaction_date <= ?
+            GROUP BY quality_name
+            "#,
+        )
+        .bind(start_date)
+        .bind(end_date)
+        .fetch_all(&self.pool)
+        .await?;
+
+        Ok(result)
+    }
+
+    /// Gets sales summary grouped by customer.
+    /// 
+    /// AI AGENT NOTE: Only includes known customers (JOIN with customers table).
+    /// Anonymous transactions are excluded since they have no customer_id.
+    pub async fn get_sales_summary_by_customer(
+        &self,
+        start_date: &str,
+        end_date: &str,
+    ) -> anyhow::Result<Vec<CustomerSummary>> {
+        let result = sqlx::query_as(
+            r#"
+            SELECT c.customer_number, COUNT(*) as tx_count, SUM(t.amount) as total_amount, SUM(t.volume) as total_volume
+            FROM transactions t
+            JOIN customers c ON t.customer_id = c.id
+            WHERE t.transaction_date >= ? AND t.transaction_date <= ?
+            GROUP BY c.customer_number
+            ORDER BY total_amount DESC
+            "#,
+        )
+        .bind(start_date)
+        .bind(end_date)
+        .fetch_all(&self.pool)
+        .await?;
+
+        Ok(result)
+    }
+}
+
+/// Summary of sales by product (quality_name).
+/// 
+/// AI AGENT NOTE: Used for reporting total sales per product type.
+#[derive(Debug, sqlx::FromRow)]
+pub struct ProductSummary {
+    pub quality_name: String,
+    pub tx_count: i64,
+    pub total_amount: BigDecimal,
+    pub total_volume: BigDecimal,
+}
+
+/// Summary of sales by customer.
+/// 
+/// AI AGENT NOTE: Used for reporting total sales per fleet customer.
+#[derive(Debug, sqlx::FromRow)]
+pub struct CustomerSummary {
+    pub customer_number: String,
+    pub tx_count: i64,
+    pub total_amount: BigDecimal,
+    pub total_volume: BigDecimal,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use sqlx::Row;
+
+    /// Helper to create a test repository with a transaction.
+    /// Returns the repository and the transaction - rollback when done.
+    pub async fn with_test_tx<F, T>(test_fn: F) -> anyhow::Result<T>
+    where
+        F: FnOnce(&Repository, &mut sqlx::Transaction<'_, sqlx::MySql>) -> std::pin::Pin<Box<dyn std::future::Future<Output = anyhow::Result<T>>>>,
+    {
+        let pool = crate::db::create_pool(&std::env::var("DATABASE_URL").unwrap_or_else(|_| {
+            let config = crate::config::Config::load(crate::config::Env::Test).unwrap();
+            config.database.connection_url()
+        })).await?;
+        
+        let mut tx = pool.begin().await?;
+        let repo = Repository::new(pool);
+        
+        let result = test_fn(&repo, &mut tx).await;
+        
+        tx.rollback().await?;
+        result
+    }
+
+    /// Inserts a customer using a transaction (for testing).
+    pub async fn insert_customer_tx(
+        tx: &mut sqlx::Transaction<'_, sqlx::MySql>,
+        customer: &NewCustomer,
+    ) -> anyhow::Result<u32> {
+        sqlx::query(
+            "INSERT INTO customers (customer_number, card_report_group) VALUES (?, ?)",
+        )
+        .bind(&customer.customer_number)
+        .bind(customer.card_report_group)
+        .execute(&mut **tx)
+        .await?;
+
+        let row = sqlx::query("SELECT LAST_INSERT_ID() as id")
+            .fetch_one(&mut **tx)
+            .await?;
+
+        Ok(row.get("id"))
+    }
+
+    /// Finds a customer by ID using a transaction (for testing).
+    pub async fn find_customer_by_id_tx(
+        tx: &mut sqlx::Transaction<'_, sqlx::MySql>,
+        id: u32,
+    ) -> anyhow::Result<Option<Customer>> {
+        let result = sqlx::query_as::<_, Customer>(
+            "SELECT id, customer_number, card_report_group, created_at, updated_at 
+             FROM customers WHERE id = ?",
+        )
+        .bind(id)
+        .fetch_optional(&mut **tx)
+        .await?;
+
+        Ok(result)
+    }
+
+    /// Inserts a card using a transaction (for testing).
+    pub async fn insert_card_tx(
+        tx: &mut sqlx::Transaction<'_, sqlx::MySql>,
+        card: &NewCard,
+    ) -> anyhow::Result<u32> {
+        sqlx::query(
+            "INSERT INTO cards (card_number, customer_id) VALUES (?, ?)",
+        )
+        .bind(&card.card_number)
+        .bind(card.customer_id)
+        .execute(&mut **tx)
+        .await?;
+
+        let row = sqlx::query("SELECT LAST_INSERT_ID() as id")
+            .fetch_one(&mut **tx)
+            .await?;
+
+        Ok(row.get("id"))
+    }
+
+    /// Finds a card by card_number using a transaction (for testing).
+    pub async fn find_card_by_number_tx(
+        tx: &mut sqlx::Transaction<'_, sqlx::MySql>,
+        card_number: &str,
+    ) -> anyhow::Result<Option<Card>> {
+        let result = sqlx::query_as::<_, Card>(
+            "SELECT id, card_number, customer_id, created_at, updated_at 
+             FROM cards WHERE card_number = ?",
+        )
+        .bind(card_number)
+        .fetch_optional(&mut **tx)
+        .await?;
+
+        Ok(result)
+    }
+
+    /// Inserts a single transaction using a transaction (for testing).
+    pub async fn insert_transaction_tx(
+        tx: &mut sqlx::Transaction<'_, sqlx::MySql>,
+        transaction: &NewTransaction,
+    ) -> anyhow::Result<u64> {
+        sqlx::query(&format!(
+            "INSERT INTO transactions (transaction_date, batch_number, amount, volume, price, quality_code, quality_name, card_number, station, terminal, pump, receipt, control_number, customer_id) VALUES ('{}', '{}', {}, {}, {}, {}, '{}', '{}', '{}', '{}', '{}', '{}', {}, {})",
+            transaction.transaction_date.format("%Y-%m-%d %H:%M:%S"),
+            transaction.batch_number,
+            transaction.amount,
+            transaction.volume,
+            transaction.price,
+            transaction.quality_code,
+            transaction.quality_name.replace("'", "''"),
+            transaction.card_number.replace("'", "''"),
+            transaction.station,
+            transaction.terminal,
+            transaction.pump,
+            transaction.receipt,
+            transaction.control_number.as_ref().map(|s| format!("'{}'", s.replace("'", "''"))).unwrap_or_else(|| "NULL".to_string()),
+            transaction.customer_id.map(|id| id.to_string()).unwrap_or_else(|| "NULL".to_string()),
+        ))
+        .execute(&mut **tx)
+        .await?;
+
+        let row = sqlx::query("SELECT LAST_INSERT_ID() as id")
+            .fetch_one(&mut **tx)
+            .await?;
+        Ok(row.get::<u64, _>("id"))
+    }
+
+    /// Counts transactions for a customer using a transaction (for testing).
+    pub async fn count_customer_transactions_tx(
+        tx: &mut sqlx::Transaction<'_, sqlx::MySql>,
+        customer_id: u32,
+    ) -> anyhow::Result<i64> {
+        let row = sqlx::query(
+            "SELECT COUNT(*) as count FROM transactions WHERE customer_id = ?",
+        )
+        .bind(customer_id)
+        .fetch_one(&mut **tx)
+        .await?;
+
+        Ok(row.get("count"))
+    }
+
+    /// Gets transaction count using a transaction (for testing).
+    pub async fn count_transactions_tx(
+        tx: &mut sqlx::Transaction<'_, sqlx::MySql>,
+    ) -> anyhow::Result<i64> {
+        let row = sqlx::query("SELECT COUNT(*) as count FROM transactions")
+            .fetch_one(&mut **tx)
+            .await?;
+
+        Ok(row.get("count"))
+    }
+}

src/invoice_generator.rs

@@ -0,0 +1,300 @@
+use chrono::NaiveDateTime;
+use csv::ReaderBuilder;
+use std::collections::{BTreeMap, HashMap};
+use std::fs;
+use std::path::Path;
+
+#[derive(Debug, Clone)]
+pub struct Transaction {
+    pub date: NaiveDateTime,
+    pub batch_number: String,
+    pub amount: f64,
+    pub volume: f64,
+    pub price: f64,
+    pub quality: i32,
+    pub quality_name: String,
+    pub card_number: String,
+    pub card_type: String,
+    pub customer_number: String,
+    pub station: String,
+    pub terminal: String,
+    pub pump: String,
+    pub receipt: String,
+    pub card_report_group_number: String,
+    pub control_number: String,
+}
+
+#[derive(Debug, Clone)]
+pub struct Batch {
+    pub filename: String,
+    pub transactions: Vec<Transaction>,
+}
+
+#[derive(Debug, Clone)]
+pub struct Customer {
+    pub customer_number: String,
+    pub cards: BTreeMap<String, Vec<Transaction>>,
+}
+
+fn get_field(record: &csv::StringRecord, index: usize) -> &str {
+    record.get(index).unwrap_or("")
+}
+
+impl Transaction {
+    pub fn from_record(record: &csv::StringRecord) -> Option<Self> {
+        let date_str = get_field(record, 0);
+        let date = NaiveDateTime::parse_from_str(date_str, "%m/%d/%Y %I:%M:%S %p")
+            .or_else(|_| NaiveDateTime::parse_from_str(date_str, "%Y-%m-%d %H:%M:%S"))
+            .ok()?;
+
+        Some(Transaction {
+            date,
+            batch_number: get_field(record, 1).to_string(),
+            amount: get_field(record, 2).parse().unwrap_or(0.0),
+            volume: get_field(record, 3).parse().unwrap_or(0.0),
+            price: get_field(record, 4).parse().unwrap_or(0.0),
+            quality: get_field(record, 5).parse().unwrap_or(0),
+            quality_name: get_field(record, 6).to_string(),
+            card_number: get_field(record, 7).to_string(),
+            card_type: get_field(record, 8).to_string(),
+            customer_number: get_field(record, 9).to_string(),
+            station: get_field(record, 10).to_string(),
+            terminal: get_field(record, 11).to_string(),
+            pump: get_field(record, 12).to_string(),
+            receipt: get_field(record, 13).to_string(),
+            card_report_group_number: get_field(record, 14).to_string(),
+            control_number: get_field(record, 15).to_string(),
+        })
+    }
+}
+
+pub fn read_csv_file(path: &Path) -> anyhow::Result<Batch> {
+    let filename = path
+        .file_name()
+        .and_then(|n| n.to_str())
+        .unwrap_or("unknown")
+        .to_string();
+
+    let file = fs::File::open(path)?;
+    let mut rdr = ReaderBuilder::new()
+        .delimiter(b'\t')
+        .has_headers(true)
+        .flexible(true)
+        .from_reader(file);
+
+    let mut transactions = Vec::new();
+
+    for result in rdr.records() {
+        let record = result?;
+        if let Some(tx) = Transaction::from_record(&record) {
+            if tx.amount > 0.0 && !tx.customer_number.is_empty() {
+                transactions.push(tx);
+            }
+        }
+    }
+
+    transactions.sort_by(|a, b| a.date.cmp(&b.date));
+
+    Ok(Batch {
+        filename,
+        transactions,
+    })
+}
+
+/// Reads a CSV file and groups transactions by batch number.
+///
+/// AI AGENT NOTE: Returns a HashMap where keys are batch_numbers and values
+/// are Batches containing only transactions for that batch. This enables
+/// generating separate invoices per batch when a single CSV contains multiple.
+pub fn read_csv_file_by_batch(path: &Path) -> anyhow::Result<HashMap<String, Batch>> {
+    let file = fs::File::open(path)?;
+    let mut rdr = ReaderBuilder::new()
+        .delimiter(b'\t')
+        .has_headers(true)
+        .flexible(true)
+        .from_reader(file);
+
+    let mut batches: HashMap<String, Vec<Transaction>> = HashMap::new();
+
+    for result in rdr.records() {
+        let record = result?;
+        if let Some(tx) = Transaction::from_record(&record) {
+            if tx.amount > 0.0 && !tx.customer_number.is_empty() {
+                batches.entry(tx.batch_number.clone()).or_default().push(tx);
+            }
+        }
+    }
+
+    let mut result: HashMap<String, Batch> = HashMap::new();
+    for (batch_number, mut transactions) in batches {
+        transactions.sort_by(|a, b| a.date.cmp(&b.date));
+        result.insert(
+            batch_number,
+            Batch {
+                filename: path
+                    .file_name()
+                    .and_then(|n| n.to_str())
+                    .unwrap_or("unknown")
+                    .to_string(),
+                transactions,
+            },
+        );
+    }
+
+    Ok(result)
+}
+
+pub fn group_by_customer(batches: &[Batch]) -> BTreeMap<String, Customer> {
+    let mut customers: BTreeMap<String, Customer> = BTreeMap::new();
+
+    for batch in batches {
+        for tx in &batch.transactions {
+            let customer = customers
+                .entry(tx.customer_number.clone())
+                .or_insert_with(|| Customer {
+                    customer_number: tx.customer_number.clone(),
+                    cards: BTreeMap::new(),
+                });
+
+            let card_txs = customer.cards.entry(tx.card_number.clone()).or_default();
+            card_txs.push(tx.clone());
+        }
+    }
+
+    for customer in customers.values_mut() {
+        for card_txs in customer.cards.values_mut() {
+            card_txs.sort_by(|a, b| a.date.cmp(&b.date));
+        }
+    }
+
+    customers
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_transaction_from_record_extracts_batch_number() {
+        let csv_content = "2026-02-01 10:15:16\t409\t559.26\t35.85\t15.60\t1001\t95 Oktan\t7825017523017000642\ttype\t1861\t97254\t1\t2\t000910\t1\t";
+
+        let mut rdr = csv::ReaderBuilder::new()
+            .delimiter(b'\t')
+            .has_headers(false)
+            .from_reader(csv_content.as_bytes());
+
+        let record = rdr.records().next().unwrap().unwrap();
+        let tx = Transaction::from_record(&record).unwrap();
+
+        assert_eq!(tx.batch_number, "409");
+        assert_eq!(tx.customer_number, "1861");
+    }
+
+    #[test]
+    fn test_group_by_customer_with_multiple_batches() {
+        let batch1 = Batch {
+            filename: "test.csv".to_string(),
+            transactions: vec![
+                Transaction {
+                    date: NaiveDateTime::parse_from_str("2026-02-01 10:00:00", "%Y-%m-%d %H:%M:%S")
+                        .unwrap(),
+                    batch_number: "409".to_string(),
+                    amount: 100.0,
+                    volume: 10.0,
+                    price: 10.0,
+                    quality: 1001,
+                    quality_name: "95 Oktan".to_string(),
+                    card_number: "CARD001".to_string(),
+                    card_type: "type".to_string(),
+                    customer_number: "CUST1".to_string(),
+                    station: "S1".to_string(),
+                    terminal: "T1".to_string(),
+                    pump: "P1".to_string(),
+                    receipt: "R1".to_string(),
+                    card_report_group_number: "1".to_string(),
+                    control_number: "".to_string(),
+                },
+                Transaction {
+                    date: NaiveDateTime::parse_from_str("2026-02-01 11:00:00", "%Y-%m-%d %H:%M:%S")
+                        .unwrap(),
+                    batch_number: "410".to_string(),
+                    amount: 200.0,
+                    volume: 20.0,
+                    price: 10.0,
+                    quality: 1001,
+                    quality_name: "95 Oktan".to_string(),
+                    card_number: "CARD002".to_string(),
+                    card_type: "type".to_string(),
+                    customer_number: "CUST1".to_string(),
+                    station: "S1".to_string(),
+                    terminal: "T1".to_string(),
+                    pump: "P1".to_string(),
+                    receipt: "R2".to_string(),
+                    card_report_group_number: "1".to_string(),
+                    control_number: "".to_string(),
+                },
+            ],
+        };
+
+        let customers = group_by_customer(&[batch1]);
+
+        // Should have 1 customer with 2 cards
+        assert_eq!(customers.len(), 1);
+        assert!(customers.contains_key("CUST1"));
+        assert_eq!(customers.get("CUST1").unwrap().cards.len(), 2);
+    }
+
+    #[test]
+    fn test_group_by_customer_separate_customers() {
+        let batch1 = Batch {
+            filename: "test.csv".to_string(),
+            transactions: vec![
+                Transaction {
+                    date: NaiveDateTime::parse_from_str("2026-02-01 10:00:00", "%Y-%m-%d %H:%M:%S")
+                        .unwrap(),
+                    batch_number: "409".to_string(),
+                    amount: 100.0,
+                    volume: 10.0,
+                    price: 10.0,
+                    quality: 1001,
+                    quality_name: "95 Oktan".to_string(),
+                    card_number: "CARD001".to_string(),
+                    card_type: "type".to_string(),
+                    customer_number: "CUST1".to_string(),
+                    station: "S1".to_string(),
+                    terminal: "T1".to_string(),
+                    pump: "P1".to_string(),
+                    receipt: "R1".to_string(),
+                    card_report_group_number: "1".to_string(),
+                    control_number: "".to_string(),
+                },
+                Transaction {
+                    date: NaiveDateTime::parse_from_str("2026-02-01 11:00:00", "%Y-%m-%d %H:%M:%S")
+                        .unwrap(),
+                    batch_number: "409".to_string(),
+                    amount: 200.0,
+                    volume: 20.0,
+                    price: 10.0,
+                    quality: 1001,
+                    quality_name: "95 Oktan".to_string(),
+                    card_number: "CARD003".to_string(),
+                    card_type: "type".to_string(),
+                    customer_number: "CUST2".to_string(),
+                    station: "S1".to_string(),
+                    terminal: "T1".to_string(),
+                    pump: "P1".to_string(),
+                    receipt: "R2".to_string(),
+                    card_report_group_number: "1".to_string(),
+                    control_number: "".to_string(),
+                },
+            ],
+        };
+
+        let customers = group_by_customer(&[batch1]);
+
+        // Should have 2 customers
+        assert_eq!(customers.len(), 2);
+        assert!(customers.contains_key("CUST1"));
+        assert!(customers.contains_key("CUST2"));
+    }
+}

src/lib.rs

@@ -0,0 +1,9 @@
+//! Library crate for invoice-generator.
+//! 
+//! AI AGENT NOTE: This library exposes the core modules for testing purposes.
+//! The binary crate (main.rs) uses this library.
+
+pub mod commands;
+pub mod config;
+pub mod db;
+pub mod invoice_generator;

src/main.rs

@@ -0,0 +1,468 @@
+mod commands;
+mod config;
+mod db;
+mod invoice_generator;
+
+use askama::Template;
+use chrono::{NaiveDateTime, Utc};
+use config::{Config, Env};
+use csv::ReaderBuilder;
+use db::{create_pool, Repository};
+use invoice_generator::{group_by_customer, read_csv_file_by_batch, Customer};
+use std::collections::HashMap;
+use std::env;
+use std::fs;
+use std::path::{Path, PathBuf};
+
+fn fmt(v: f64) -> String {
+    format!("{:.2}", v)
+}
+
+/// Normalizes CSV date format and cleans the data.
+/// 
+/// AI AGENT NOTE: Input CSV may have dates in different formats (MM/DD/YYYY or YYYY-MM-DD).
+/// This function standardizes to YYYY-MM-DD HH:MM:SS format for consistent parsing.
+fn clean_csv_file(
+    input_path: &Path,
+    output_path: &Path,
+) -> anyhow::Result<String> {
+    let file = fs::File::open(input_path)?;
+    let mut rdr = ReaderBuilder::new()
+        .delimiter(b'\t')
+        .has_headers(true)
+        .flexible(true)
+        .from_reader(file);
+
+    let output = fs::File::create(output_path)?;
+    let mut writer = csv::WriterBuilder::new()
+        .delimiter(b'\t')
+        .from_writer(output);
+
+    let mut batch_number = String::new();
+
+    for result in rdr.records() {
+        let record = result?;
+
+        let date_str = record.get(0).unwrap_or("");
+        let batch = record.get(1).unwrap_or("").to_string();
+
+        if batch_number.is_empty() {
+            batch_number = batch.clone();
+        }
+
+        let date =
+            NaiveDateTime::parse_from_str(date_str, "%m/%d/%Y %I:%M:%S %p").unwrap_or_else(|_| {
+                NaiveDateTime::parse_from_str(date_str, "%Y-%m-%d %H:%M:%S").unwrap_or_default()
+            });
+
+        let row = vec![
+            date.format("%Y-%m-%d %H:%M:%S").to_string(),
+            batch,
+            record.get(2).unwrap_or("").to_string(),
+            record.get(3).unwrap_or("").to_string(),
+            record.get(4).unwrap_or("").to_string(),
+            record.get(5).unwrap_or("").to_string(),
+            record.get(6).unwrap_or("").to_string(),
+            record.get(7).unwrap_or("").to_string(),
+            record.get(8).unwrap_or("").to_string(),
+            record.get(9).unwrap_or("").to_string(),
+            record.get(10).unwrap_or("").to_string(),
+            record.get(11).unwrap_or("").to_string(),
+            record.get(12).unwrap_or("").to_string(),
+            record.get(13).unwrap_or("").to_string(),
+            record.get(14).unwrap_or("").to_string(),
+            record.get(15).unwrap_or("").to_string(),
+        ];
+
+        writer.write_record(&row)?;
+    }
+
+    writer.flush()?;
+    Ok(batch_number)
+}
+
+#[derive(Clone)]
+struct ProductSummary {
+    name: String,
+    volume: String,
+    avg_price: String,
+    amount: String,
+}
+
+#[derive(Clone)]
+struct Summary {
+    total_volume: String,
+    grand_total: String,
+    products: Vec<ProductSummary>,
+    avrundningsfel: String,
+    oresutjamning: String,
+}
+
+#[derive(Clone)]
+struct CardData {
+    card_number: String,
+    transactions: Vec<FormattedTransaction>,
+    total_amount: String,
+    total_volume: String,
+}
+
+#[derive(Clone)]
+struct FormattedTransaction {
+    date: String,
+    quality_name: String,
+    price: String,
+    volume: String,
+    amount: String,
+    receipt: String,
+}
+
+#[derive(Clone)]
+struct PreparedCustomer {
+    customer_number: String,
+    cards: Vec<CardData>,
+    summary: Summary,
+}
+
+impl PreparedCustomer {
+    fn from_customer(customer: Customer) -> Self {
+        let cards: Vec<CardData> = customer
+            .cards
+            .into_iter()
+            .map(|(card_number, transactions)| {
+                let formatted_txs: Vec<FormattedTransaction> = transactions
+                    .into_iter()
+                    .map(|t| FormattedTransaction {
+                        date: t.date.format("%Y-%m-%d %H:%M").to_string(),
+                        quality_name: t.quality_name,
+                        price: fmt(t.price * 0.8),
+                        volume: fmt(t.volume),
+                        amount: fmt(t.amount * 0.8),
+                        receipt: t.receipt,
+                    })
+                    .collect();
+
+                let total_amount: f64 = formatted_txs
+                    .iter()
+                    .map(|t| t.amount.parse::<f64>().unwrap())
+                    .sum();
+                let total_volume: f64 = formatted_txs
+                    .iter()
+                    .map(|t| t.volume.parse::<f64>().unwrap())
+                    .sum();
+
+                CardData {
+                    card_number,
+                    transactions: formatted_txs,
+                    total_amount: fmt(total_amount),
+                    total_volume: fmt(total_volume),
+                }
+            })
+            .collect();
+
+        let mut product_totals: HashMap<String, (f64, f64)> = HashMap::new();
+        let mut total_from_transactions: f64 = 0.0;
+        for card in &cards {
+            for tx in &card.transactions {
+                let volume: f64 = tx.volume.parse().unwrap();
+                let amount: f64 = tx.amount.parse::<f64>().unwrap();
+                total_from_transactions += amount;
+                let entry = product_totals
+                    .entry(tx.quality_name.clone())
+                    .or_insert((0.0, 0.0));
+                entry.0 += volume;
+                entry.1 += amount;
+            }
+        }
+
+        let mut products: Vec<ProductSummary> = product_totals
+            .into_iter()
+            .map(|(name, (volume, amount))| {
+                let avg_price = if volume > 0.0 { amount / volume } else { 0.0 };
+                let rounded_volume = (volume * 100.0).round() / 100.0;
+                let rounded_avg_price = (avg_price * 100.0).round() / 100.0;
+                let calculated_amount = rounded_volume * rounded_avg_price;
+                ProductSummary {
+                    name,
+                    volume: fmt(rounded_volume),
+                    avg_price: fmt(rounded_avg_price),
+                    amount: fmt(calculated_amount),
+                }
+            })
+            .collect();
+        products.sort_by(|a, b| a.name.cmp(&b.name));
+
+        let total_volume: f64 = products
+            .iter()
+            .map(|p| p.volume.parse::<f64>().unwrap())
+            .sum();
+
+        let grand_total: f64 = products
+            .iter()
+            .map(|p| p.amount.parse::<f64>().unwrap())
+            .sum();
+
+        let avrundningsfel = total_from_transactions - grand_total;
+        let rounded_grand_total = total_from_transactions.round();
+        let oresutjamning = rounded_grand_total - grand_total - avrundningsfel;
+
+        let summary = Summary {
+            total_volume: fmt(total_volume),
+            grand_total: fmt(rounded_grand_total),
+            products,
+            avrundningsfel: fmt(avrundningsfel),
+            oresutjamning: fmt(oresutjamning),
+        };
+
+        PreparedCustomer {
+            customer_number: customer.customer_number,
+            cards,
+            summary,
+        }
+    }
+}
+
+#[derive(Template)]
+#[template(path = "index.html")]
+struct IndexTemplate {
+    customers: Vec<(String, usize)>,
+    period: String,
+}
+
+#[derive(Template)]
+#[template(path = "customer.html")]
+struct CustomerTemplate {
+    customer: PreparedCustomer,
+    batch_number: String,
+    period: String,
+    generated_date: String,
+}
+
+/// Parses the --env flag from CLI arguments.
+/// 
+/// AI AGENT NOTE: The --env flag can appear anywhere in the argument list.
+/// Returns the environment and the index of the "--env" flag (for removal).
+/// Defaults to Prod if not specified.
+fn parse_env_flag(args: &[String]) -> (Env, usize) {
+    for (i, arg) in args.iter().enumerate() {
+        if arg == "--env" && i + 1 < args.len() {
+            match args[i + 1].parse() {
+                Ok(env) => return (env, i),
+                Err(e) => {
+                    eprintln!("Error: {}", e);
+                    std::process::exit(1);
+                }
+            }
+        }
+    }
+    (Env::default(), 0)
+}
+
+/// Removes --env and its value from argument list.
+/// 
+/// AI AGENT NOTE: This allows the --env flag to appear anywhere in the
+/// command without affecting positional argument parsing.
+fn remove_env_flags(args: &[String]) -> Vec<String> {
+    let (_, env_idx) = parse_env_flag(args);
+    let mut result = Vec::with_capacity(args.len());
+    
+    for (i, arg) in args.iter().enumerate() {
+        if i == env_idx || (i == env_idx + 1 && args.get(env_idx) == Some(&"--env".to_string())) {
+            continue;
+        }
+        result.push(arg.clone());
+    }
+    
+    result
+}
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+    let args: Vec<String> = env::args().collect();
+
+    let (env, _) = parse_env_flag(&args);
+
+    if args.len() < 2 {
+        print_usage(&args[0]);
+        std::process::exit(1);
+    }
+
+    match args[1].as_str() {
+        "import" => {
+            let clean_args = remove_env_flags(&args);
+            if clean_args.len() != 3 {
+                eprintln!("Usage: {} import <csv-file> [--env <name>]", clean_args[0]);
+                std::process::exit(1);
+            }
+            let csv_path = PathBuf::from(&clean_args[2]);
+            if !csv_path.exists() {
+                eprintln!("Error: File not found: {:?}", csv_path);
+                std::process::exit(1);
+            }
+
+            println!("Environment: {}", env.as_str());
+            let config = Config::load(env)?;
+            let pool = create_pool(&config.database.connection_url()).await?;
+            let repo = Repository::new(pool);
+
+            commands::run_import(&csv_path, &repo).await?;
+        }
+        "generate" => {
+            let clean_args = remove_env_flags(&args);
+            if clean_args.len() != 4 {
+                eprintln!("Usage: {} generate <csv-file> <output-dir> [--env <name>]", clean_args[0]);
+                std::process::exit(1);
+            }
+            let input_path = Path::new(&clean_args[2]);
+            let base_output_dir = Path::new(&clean_args[3]);
+
+            if !input_path.exists() {
+                eprintln!("Error: File not found: {:?}", input_path);
+                std::process::exit(1);
+            }
+
+            let filename = input_path
+                .file_name()
+                .and_then(|n| n.to_str())
+                .unwrap_or("unknown")
+                .to_string();
+
+            println!("Converting {} to cleaned format...", filename);
+
+            let temp_cleaned_path =
+                base_output_dir.join(format!("{}.temp.csv", filename.trim_end_matches(".txt")));
+            clean_csv_file(input_path, &temp_cleaned_path)?;
+
+            let mut batches = read_csv_file_by_batch(&temp_cleaned_path)?;
+            let batch_count = batches.len();
+            println!("Found {} batches in CSV", batch_count);
+
+            let mut total_customers = 0usize;
+            let generated_date = Utc::now().format("%Y-%m-%d %H:%M").to_string();
+
+            let mut batch_numbers: Vec<_> = batches.keys().cloned().collect();
+            batch_numbers.sort();
+
+            for batch_number in batch_numbers {
+                let batch = batches.remove(&batch_number).unwrap();
+                let output_dir = base_output_dir.join(&batch_number);
+
+                fs::create_dir_all(&output_dir)?;
+
+                let csv_path = output_dir.join(format!("{}.csv", batch_number));
+                let txt_path = output_dir.join(format!("{}.txt", batch_number));
+                
+                fs::copy(&temp_cleaned_path, &csv_path)?;
+                fs::copy(input_path, &txt_path)?;
+
+                println!(
+                    "Batch {}: {} transactions",
+                    batch_number,
+                    batch.transactions.len()
+                );
+
+                let first_date = batch.transactions.first().map(|t| t.date).unwrap();
+                let last_date = batch.transactions.last().map(|t| t.date).unwrap();
+                let period = format!(
+                    "{} - {}",
+                    first_date.format("%Y-%m-%d"),
+                    last_date.format("%Y-%m-%d")
+                );
+
+                let customers = group_by_customer(&[batch]);
+
+                let index_customers: Vec<(String, usize)> = customers
+                    .iter()
+                    .map(|(num, c)| (num.clone(), c.cards.len()))
+                    .collect();
+
+                let html = IndexTemplate {
+                    customers: index_customers.clone(),
+                    period: period.clone(),
+                }
+                .render()
+                .unwrap();
+                fs::write(output_dir.join("index.html"), html)?;
+
+                for (customer_num, customer) in customers {
+                    let prepared = PreparedCustomer::from_customer(customer);
+                    let customer_html = CustomerTemplate {
+                        customer: prepared,
+                        batch_number: batch_number.clone(),
+                        period: period.clone(),
+                        generated_date: generated_date.clone(),
+                    }
+                    .render()
+                    .unwrap();
+                    let customer_filename = format!("customer_{}.html", customer_num);
+                    fs::write(output_dir.join(&customer_filename), customer_html)?;
+                    println!("  Generated {}", customer_filename);
+                }
+
+                total_customers += index_customers.len();
+            }
+
+            fs::remove_file(temp_cleaned_path)?;
+
+            println!(
+                "\nGenerated {} customer invoices across {} batches in {:?}",
+                total_customers,
+                batch_count,
+                base_output_dir
+            );
+        }
+        "db" => {
+            let clean_args = remove_env_flags(&args);
+            if clean_args.len() < 3 {
+                eprintln!("Usage: {} db <subcommand> [--env <name>]", clean_args[0]);
+                eprintln!("Subcommands:");
+                eprintln!("  setup    Create database and schema");
+                eprintln!("  reset    Drop and recreate database");
+                std::process::exit(1);
+            }
+
+            println!("Environment: {}", env.as_str());
+            let config = Config::load(env)?;
+
+            match clean_args[2].as_str() {
+                "setup" => {
+                    let pool = create_pool(&config.database.connection_url()).await?;
+                    let repo = Repository::new(pool);
+                    commands::run_db_setup(&repo, &config).await?;
+                }
+                "reset" => {
+                    commands::run_db_reset(&config).await?;
+                }
+                _ => {
+                    eprintln!("Unknown db subcommand: {}", clean_args[2]);
+                    eprintln!("Subcommands:");
+                    eprintln!("  setup    Create database and schema");
+                    eprintln!("  reset    Drop and recreate database");
+                    std::process::exit(1);
+                }
+            }
+        }
+        "help" | "--help" | "-h" => {
+            print_usage(&args[0]);
+        }
+        _ => {
+            eprintln!("Unknown command: {}", args[1]);
+            print_usage(&args[0]);
+            std::process::exit(1);
+        }
+    }
+
+    Ok(())
+}
+
+fn print_usage(program: &str) {
+    eprintln!("Usage: {} <command> [arguments]", program);
+    eprintln!();
+    eprintln!("Commands:");
+    eprintln!("  import <csv-file> [--env <name>]    Import CSV data to database (default: prod)");
+    eprintln!("  generate <csv> <dir>               Generate HTML invoices from CSV");
+    eprintln!("  db setup [--env <name>]            Create database and schema (default: prod)");
+    eprintln!("  db reset [--env <name>]            Drop and recreate database (default: prod)");
+    eprintln!("  help                               Show this help message");
+    eprintln!();
+    eprintln!("Environments: prod (default), dev, test");
+}

src/templates.rs

@@ -0,0 +1,51 @@
+use askama::Template;
+use askama_derive::Filter;
+use chrono::Utc;
+use std::collections::BTreeMap;
+
+use invoice_generator::{group_by_customer, read_csv_file, Customer, Transaction};
+
+#[derive(Template)]
+#[template(path = "index.html")]
+pub struct IndexTemplate {
+    pub customers: Vec<(String, Customer)>,
+    pub batches: Vec<String>,
+}
+
+#[derive(Template)]
+#[template(path = "customer.html")]
+pub struct CustomerTemplate {
+    pub customer: &Customer,
+    pub batches: Vec<String>,
+}
+
+pub fn calculate_card_totals(transactions: &[Transaction]) -> (f64, f64) {
+    let total_amount: f64 = transactions.iter().map(|t| t.amount).sum();
+    let total_volume: f64 = transactions.iter().map(|t| t.volume).sum();
+    (total_amount, total_volume)
+}
+
+pub fn calculate_grand_total(customer: &Customer) -> f64 {
+    customer
+        .cards
+        .values()
+        .flat_map(|t| t.iter())
+        .map(|t| t.amount)
+        .sum()
+}
+
+pub fn format_amount(amount: f64) -> String {
+    format!("{:.2}", amount)
+}
+
+pub fn format_volume(volume: f64) -> String {
+    format!("{:.2}", volume)
+}
+
+pub fn format_date(date: &chrono::NaiveDateTime) -> String {
+    date.format("%Y-%m-%d %H:%M").to_string()
+}
+
+pub fn now_string() -> String {
+    Utc::now().format("%Y-%m-%d %H:%M").to_string()
+}

templates/customer.html

@@ -0,0 +1,241 @@
+<!doctype html>
+<html lang="sv">
+    <head>
+        <meta charset="UTF-8" />
+        <title>Fakturaunderlag - Kund {{ customer.customer_number }}</title>
+        <style>
+            @page {
+                size: A4;
+                margin: 15mm;
+            }
+            * {
+                box-sizing: border-box;
+            }
+            body {
+                font-family: Arial, sans-serif;
+                font-size: 12px;
+                margin: 0;
+                padding: 20px;
+                background: white;
+            }
+            @media print {
+                body {
+                    padding: 0;
+                }
+                .card-section {
+                    break-inside: avoid;
+                }
+            }
+            .header {
+                display: flex;
+                justify-content: space-between;
+                align-items: flex-end;
+                border-bottom: 2px solid #333;
+                padding-bottom: 10px;
+                margin-bottom: 15px;
+            }
+            .header h1 {
+                margin: 0;
+                font-size: 20px;
+            }
+            .header .meta {
+                text-align: right;
+                font-size: 11px;
+                color: #666;
+            }
+            .summary {
+                background: #f5f5f5;
+                border: 1px solid #ccc;
+                padding: 12px;
+                margin-bottom: 15px;
+            }
+            .summary h2 {
+                margin: 0 0 10px 0;
+                font-size: 14px;
+                border-bottom: 1px solid #ccc;
+                padding-bottom: 5px;
+            }
+            .summary-table {
+                width: 100%;
+                border-collapse: collapse;
+                font-size: 11px;
+            }
+            .summary-table th,
+            .summary-table td {
+                padding: 5px 8px;
+                text-align: left;
+            }
+            .summary-table th {
+                background: #e0e0e0;
+                font-weight: bold;
+            }
+            .summary-table td:not(:first-child),
+            .summary-table th:not(:first-child) {
+                text-align: right;
+            }
+            .grand-total-row td {
+                font-weight: bold;
+                border-top: 2px solid #333;
+                background: #f0f0f0;
+            }
+            .card-section {
+                margin-bottom: 15px;
+                border: 1px solid #ccc;
+            }
+            .card-header {
+                background: #f0f0f0;
+                padding: 8px 12px;
+                font-weight: bold;
+                border-bottom: 1px solid #ccc;
+                display: flex;
+                justify-content: space-between;
+            }
+            .card-summary {
+                padding: 6px 12px;
+                font-size: 11px;
+                background: #fafafa;
+                border-bottom: 1px solid #eee;
+            }
+            table {
+                width: 100%;
+                border-collapse: collapse;
+                font-size: 11px;
+            }
+            th,
+            td {
+                padding: 6px 8px;
+                text-align: left;
+            }
+            th {
+                background: #f5f5f5;
+                font-weight: bold;
+                border-bottom: 1px solid #ccc;
+            }
+            .amount,
+            .volume,
+            .price {
+                text-align: right;
+            }
+            .card-total {
+                font-weight: bold;
+                background: #f9f9f9;
+            }
+            .card-total td {
+                border-top: 1px solid #333;
+            }
+            .grand-total {
+                background: #333;
+                color: white;
+                padding: 12px 15px;
+                font-size: 14px;
+                font-weight: bold;
+                text-align: right;
+                margin-top: 15px;
+            }
+            .grand-total span {
+                font-size: 18px;
+                margin-left: 20px;
+            }
+        </style>
+    </head>
+    <body>
+        <div class="header">
+            <div>
+                <h1>Fakturaunderlag - Kund {{ customer.customer_number }}</h1>
+                <div>Batch: {{ batch_number }} | Period: {{ period }}</div>
+            </div>
+            <div class="meta">
+                <div>Genererad: {{ generated_date }}</div>
+            </div>
+        </div>
+
+        <div class="summary">
+            <h2>Sammanfattning</h2>
+            <table class="summary-table">
+                <thead>
+                    <tr>
+                        <th>Produkt</th>
+                        <th>Volym (L)</th>
+                        <th>Snittpris/L</th>
+                        <th>Belopp</th>
+                    </tr>
+                </thead>
+                <tbody>
+                    {% for product in customer.summary.products %}
+                    <tr>
+                        <td>{{ product.name }}</td>
+                        <td>{{ product.volume }}</td>
+                        <td>{{ product.avg_price }} Kr</td>
+                        <td>{{ product.amount }} Kr</td>
+                    </tr>
+                    {% endfor %}
+                    <tr>
+                        <td>Avrundningsfel</td>
+                        <td></td>
+                        <td></td>
+                        <td>{{ customer.summary.avrundningsfel }} Kr</td>
+                    </tr>
+                    <tr>
+                        <td>Öresutjämning</td>
+                        <td></td>
+                        <td></td>
+                        <td>{{ customer.summary.oresutjamning }} Kr</td>
+                    </tr>
+                    <tr class="grand-total-row">
+                        <td>Totalt</td>
+                        <td>{{ customer.summary.total_volume }}</td>
+                        <td></td>
+                        <td>{{ customer.summary.grand_total }} Kr</td>
+                    </tr>
+                </tbody>
+            </table>
+        </div>
+
+        {% for card in customer.cards %}
+        <div class="card-section">
+            <div class="card-header">
+                <span>Kort: {{ card.card_number }}</span>
+                <span>{{ card.transactions.len() }} transaktioner</span>
+            </div>
+            <div class="card-summary">
+                Summa: {{ card.total_amount }} Kr | Volym: {{ card.total_volume
+                }} L
+            </div>
+            <table>
+                <thead>
+                    <tr>
+                        <th class="date">Datum</th>
+                        <th>Produkt</th>
+                        <th class="price">Pris/L</th>
+                        <th class="volume">Volym (L)</th>
+                        <th class="amount">Belopp</th>
+                        <th>Kvitto</th>
+                    </tr>
+                </thead>
+                <tbody>
+                    {% for tx in card.transactions %}
+                    <tr>
+                        <td class="date">{{ tx.date }}</td>
+                        <td>{{ tx.quality_name }}</td>
+                        <td class="price">{{ tx.price }}</td>
+                        <td class="volume">{{ tx.volume }}</td>
+                        <td class="amount">{{ tx.amount }}</td>
+                        <td>{{ tx.receipt }}</td>
+                    </tr>
+                    {% endfor %}
+                    <tr class="card-total">
+                        <td colspan="3">Kortsumma</td>
+                        <td class="volume">{{ card.total_volume }}</td>
+                        <td class="amount">{{ card.total_amount }}</td>
+                        <td></td>
+                    </tr>
+                </tbody>
+            </table>
+        </div>
+        {% endfor %}
+
+        <div class="grand-total">
+            Totalsumma:<span>{{ customer.summary.grand_total }} Kr</span>
+        </div>
+    </body>
+</html>

templates/index.html

@@ -0,0 +1,87 @@
+<!DOCTYPE html>
+<html lang="sv">
+<head>
+    <meta charset="UTF-8">
+    <title>Fakturaöversikt</title>
+    <style>
+        @page {
+            size: A4;
+            margin: 15mm;
+        }
+        * {
+            box-sizing: border-box;
+        }
+        body {
+            font-family: Arial, sans-serif;
+            font-size: 12px;
+            margin: 0;
+            padding: 20px;
+            background: white;
+        }
+        @media print {
+            body { padding: 0; }
+        }
+        h1 {
+            margin: 0 0 15px 0;
+            font-size: 18px;
+            border-bottom: 2px solid #333;
+            padding-bottom: 10px;
+        }
+        .period {
+            margin-bottom: 15px;
+            font-size: 11px;
+            color: #666;
+        }
+        table {
+            width: 100%;
+            border-collapse: collapse;
+            font-size: 11px;
+        }
+        th, td {
+            padding: 8px 10px;
+            text-align: left;
+            border: 1px solid #ccc;
+        }
+        th {
+            background: #f0f0f0;
+            font-weight: bold;
+        }
+        tr:nth-child(even) {
+            background: #fafafa;
+        }
+        a {
+            color: #000;
+            text-decoration: none;
+        }
+        a:hover {
+            text-decoration: underline;
+        }
+    </style>
+</head>
+<body>
+    <h1>Fakturaöversikt</h1>
+    
+    <div class="period">
+        <strong>Period:</strong> {{ period }}
+    </div>
+
+    <table>
+        <thead>
+            <tr>
+                <th>Kundnummer</th>
+                <th>Kort</th>
+                <th>Faktura</th>
+            </tr>
+        </thead>
+        <tbody>
+            {% for (num, card_count) in customers %}
+            <tr>
+                <td>{{ num }}</td>
+                <td>{{ card_count }}</td>
+                <td><a href="customer_{{ num }}.html">Visa</a></td>
+            </tr>
+            {% endfor %}
+        </tbody>
+    </table>
+</body>
+</html>

tests/common/fixtures.rs

@@ -0,0 +1,80 @@
+//! Test fixtures for CSV parsing tests.
+//!
+//! AI AGENT NOTE: These fixtures provide sample data for testing CSV parsing
+//! and other components without requiring real files.
+
+/// Header row for CSV files.
+pub const CSV_HEADER: &str = "Date\tBatch number\tAmount\tVolume\tPrice\tQuality\tQualityName\tCard number\tCard type\tCustomer number\tStation\tTerminal\tPump\tReceipt\tCard report group number\tControl number";
+
+/// A valid CSV row with a known customer (fleet account).
+///
+/// AI AGENT NOTE: This represents a typical fleet customer transaction.
+/// - Customer number: "1861" (known customer)
+/// - Card number: Full card number (not anonymized)
+/// - Amount: Positive (should be imported)
+pub const CSV_ROW_KNOWN_CUSTOMER: &str = "2026-02-01 10:15:16\t409\t559.26\t35.85\t15.60\t1001\t95 Oktan\t7825017523017000642\t7825017523017000642\t1861\t97254\t1\t2\t000910\t1\t";
+
+/// A valid CSV row with an anonymized card (retail customer).
+///
+/// AI AGENT NOTE: This represents a retail transaction.
+/// - Customer number: "" (empty - anonymized)
+/// - Card number: Contains asterisks (partially masked)
+/// - Amount: Positive (should be imported)
+pub const CSV_ROW_ANONYMIZED: &str = "2026-02-01 06:40:14\t409\t267.23\t17.13\t15.60\t1001\t95 Oktan\t554477******9952\t554477******9952\t\t97254\t1\t2\t000898\t4\t756969";
+
+/// A CSV row with zero amount (should be filtered out).
+///
+/// AI AGENT NOTE: Zero amounts typically represent authorizations
+/// that were never completed.
+pub const CSV_ROW_ZERO_AMOUNT: &str = "2026-02-01 06:40:14\t409\t0.00\t0.00\t15.60\t1001\t95 Oktan\t554477******9952\t554477******9952\t\t97254\t1\t2\t000898\t4\t756969";
+
+/// A CSV row with negative amount (should be filtered out).
+///
+/// AI AGENT NOTE: Negative amounts typically represent cancellations
+/// or refunds.
+pub const CSV_ROW_NEGATIVE_AMOUNT: &str = "2026-02-01 06:40:14\t409\t-50.00\t-3.00\t15.60\t1001\t95 Oktan\t7825017523017000642\t7825017523017000642\t1861\t97254\t1\t2\t000898\t1\t";
+
+/// A CSV row with US date format (MM/DD/YYYY).
+///
+/// AI AGENT NOTE: Some source files may use US date format.
+pub const CSV_ROW_US_DATE: &str = "02/01/2026 10:15:16 AM\t409\t559.26\t35.85\t15.60\t1001\t95 Oktan\t7825017523017000642\t7825017523017000642\t1861\t97254\t1\t2\t000910\t1\t";
+
+/// Creates a multi-row CSV string for testing.
+///
+/// AI AGENT NOTE: Combines header and multiple data rows for
+/// testing full CSV parsing.
+pub fn create_test_csv(rows: &[&str]) -> String {
+    let mut csv = CSV_HEADER.to_string();
+    csv.push('\n');
+    for row in rows {
+        csv.push_str(row);
+        csv.push('\n');
+    }
+    csv
+}
+
+/// Sample CSV with mixed transactions (known, anonymized, etc.).
+pub fn sample_csv_mixed() -> String {
+    create_test_csv(&[
+        CSV_ROW_ANONYMIZED,
+        CSV_ROW_KNOWN_CUSTOMER,
+        CSV_ROW_ZERO_AMOUNT,
+    ])
+}
+
+/// Sample CSV with only known customer transactions.
+pub fn sample_csv_known_only() -> String {
+    create_test_csv(&[
+        CSV_ROW_KNOWN_CUSTOMER,
+        "2026-02-01 10:32:18\t409\t508.40\t32.59\t15.60\t1001\t95 Oktan\t7825017523017000717\t7825017523017000717\t1861\t97254\t1\t2\t000912\t1\t",
+        "2026-02-01 10:57:33\t409\t174.41\t11.18\t15.60\t1001\t95 Oktan\t7825017523017001053\t7825017523017001053\t1980\t97254\t1\t1\t000913\t1\t",
+    ])
+}
+
+/// Sample CSV with Diesel transaction.
+pub fn sample_csv_diesel() -> String {
+    create_test_csv(&[
+        "2026-02-01 10:05:16\t409\t543.22\t31.40\t17.30\t4\tDiesel\t673706*********0155\t673706*********0155\t\t97254\t1\t2\t000909\t4\tD00824",
+        "2026-02-01 11:10:21\t409\t612.25\t35.39\t17.30\t4\tDiesel\t7825017523017000873\t7825017523017000873\t1866\t97254\t1\t1\t000916\t1\t",
+    ])
+}

tests/common/mod.rs

@@ -0,0 +1,10 @@
+//! Common test utilities.
+//! 
+//! AI AGENT NOTE: This module provides shared test infrastructure
+//! including database helpers and sample data fixtures.
+
+pub mod fixtures;
+pub mod test_db;
+
+pub use fixtures::*;
+pub use test_db::*;

tests/common/test_db.rs

@@ -0,0 +1,122 @@
+//! Test database utilities.
+//! 
+//! AI AGENT NOTE: These helpers manage the test database connection pool.
+//! Uses rusty_petroleum_test database for all tests.
+
+use sqlx::mysql::{MySqlPool, MySqlPoolOptions};
+use std::time::Duration;
+
+/// Creates a connection pool to the test database.
+/// 
+/// AI AGENT NOTE: Uses config.toml or config.test.toml for connection details.
+/// The test database should be separate from dev/prod to avoid data conflicts.
+pub async fn create_test_pool() -> MySqlPool {
+    let config = crate::config::Config::load(crate::config::Env::Test)
+        .expect("Failed to load test config");
+    
+    MySqlPoolOptions::new()
+        .max_connections(1)
+        .acquire_timeout(Duration::from_secs(10))
+        .connect(&config.database.connection_url())
+        .await
+        .expect("Failed to connect to test database")
+}
+
+/// Resets the test database by dropping and recreating all tables.
+/// 
+/// AI AGENT NOTE: This is used before running tests to ensure a clean state.
+/// It uses the `rusty_petroleum_test` database.
+pub async fn reset_test_database() -> anyhow::Result<()> {
+    let config = crate::config::Config::load(crate::config::Env::Test)?;
+    let database_url = config.database.connection_url();
+    let base_url = database_url.trim_end_matches(config.env.database_name());
+
+    let setup_pool = MySqlPoolOptions::new()
+        .max_connections(1)
+        .connect(base_url)
+        .await?;
+
+    // Drop database if exists
+    sqlx::query(&format!("DROP DATABASE IF EXISTS {}", config.env.database_name()))
+        .execute(&setup_pool)
+        .await?;
+
+    // Create fresh database
+    sqlx::query(&format!("CREATE DATABASE {}", config.env.database_name()))
+        .execute(&setup_pool)
+        .await?;
+
+    drop(setup_pool);
+
+    // Now create tables
+    let pool = create_test_pool().await;
+
+    // Create customers table
+    sqlx::query(
+        r#"
+        CREATE TABLE customers (
+            id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+            customer_number VARCHAR(50) NOT NULL UNIQUE,
+            card_report_group TINYINT UNSIGNED NOT NULL DEFAULT 0,
+            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+            updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+            INDEX idx_customer_number (customer_number)
+        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
+        "#,
+    )
+    .execute(&pool)
+    .await?;
+
+    // Create cards table
+    sqlx::query(
+        r#"
+        CREATE TABLE cards (
+            id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+            card_number VARCHAR(50) NOT NULL UNIQUE,
+            customer_id INT UNSIGNED NOT NULL,
+            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+            updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+            INDEX idx_card_number (card_number),
+            INDEX idx_customer_id (customer_id),
+            FOREIGN KEY (customer_id) REFERENCES customers(id)
+        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
+        "#,
+    )
+    .execute(&pool)
+    .await?;
+
+    // Create transactions table
+    sqlx::query(
+        r#"
+        CREATE TABLE transactions (
+            id BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+            transaction_date DATETIME NOT NULL,
+            batch_number VARCHAR(20) NOT NULL,
+            amount DECIMAL(10,2) NOT NULL,
+            volume DECIMAL(10,3) NOT NULL,
+            price DECIMAL(8,4) NOT NULL,
+            quality_code INT NOT NULL,
+            quality_name VARCHAR(50) NOT NULL,
+            card_number VARCHAR(50) NOT NULL,
+            station VARCHAR(20) NOT NULL,
+            terminal VARCHAR(10) NOT NULL,
+            pump VARCHAR(10) NOT NULL,
+            receipt VARCHAR(20) NOT NULL,
+            control_number VARCHAR(20),
+            customer_id INT UNSIGNED NULL,
+            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+            INDEX idx_transaction_date (transaction_date),
+            INDEX idx_batch_number (batch_number),
+            INDEX idx_customer_id (customer_id),
+            INDEX idx_card_number (card_number),
+            INDEX idx_station (station)
+        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
+        "#,
+    )
+    .execute(&pool)
+    .await?;
+
+    drop(pool);
+
+    Ok(())
+}

tests/config_test.rs

@@ -0,0 +1,105 @@
+//! Tests for the config module.
+//!
+//! AI AGENT NOTE: These tests verify configuration loading, environment
+//! parsing, and database connection URL generation.
+
+use invoice_generator::config::{Config, DatabaseConfig, Env};
+
+/// Tests that Env::default() returns Prod.
+#[test]
+fn env_default_is_prod() {
+    assert_eq!(Env::default(), Env::Prod);
+}
+
+/// Tests Env::from_str with valid short forms.
+#[test]
+fn env_from_str_valid_short() {
+    assert_eq!("prod".parse::<Env>().unwrap(), Env::Prod);
+    assert_eq!("dev".parse::<Env>().unwrap(), Env::Dev);
+    assert_eq!("test".parse::<Env>().unwrap(), Env::Test);
+}
+
+/// Tests Env::from_str with valid long forms (aliases).
+#[test]
+fn env_from_str_valid_aliases() {
+    assert_eq!("production".parse::<Env>().unwrap(), Env::Prod);
+    assert_eq!("development".parse::<Env>().unwrap(), Env::Dev);
+    assert_eq!("testing".parse::<Env>().unwrap(), Env::Test);
+}
+
+/// Tests Env::from_str is case-insensitive.
+#[test]
+fn env_from_str_case_insensitive() {
+    assert_eq!("PROD".parse::<Env>().unwrap(), Env::Prod);
+    assert_eq!("Dev".parse::<Env>().unwrap(), Env::Dev);
+    assert_eq!("TEST".parse::<Env>().unwrap(), Env::Test);
+}
+
+/// Tests Env::from_str with invalid value returns error.
+#[test]
+fn env_from_str_invalid() {
+    let result: Result<Env, _> = "invalid".parse();
+    assert!(result.is_err());
+    assert!(result.unwrap_err().contains("Unknown environment"));
+}
+
+/// Tests Env::as_str returns correct string.
+#[test]
+fn env_as_str() {
+    assert_eq!(Env::Prod.as_str(), "prod");
+    assert_eq!(Env::Dev.as_str(), "dev");
+    assert_eq!(Env::Test.as_str(), "test");
+}
+
+/// Tests Env::database_name returns correct database names.
+#[test]
+fn env_database_name() {
+    assert_eq!(Env::Prod.database_name(), "rusty_petroleum");
+    assert_eq!(Env::Dev.database_name(), "rusty_petroleum_dev");
+    assert_eq!(Env::Test.database_name(), "rusty_petroleum_test");
+}
+
+/// Tests DatabaseConfig::connection_url without password.
+#[test]
+fn db_connection_url_without_password() {
+    let config = DatabaseConfig {
+        host: "localhost".to_string(),
+        port: 3306,
+        user: "test_user".to_string(),
+        password: "".to_string(),
+        name: "test_db".to_string(),
+    };
+
+    let url = config.connection_url();
+    assert_eq!(url, "mysql://test_user@localhost:3306/test_db");
+}
+
+/// Tests DatabaseConfig::connection_url with password.
+#[test]
+fn db_connection_url_with_password() {
+    let config = DatabaseConfig {
+        host: "localhost".to_string(),
+        port: 3306,
+        user: "test_user".to_string(),
+        password: "secret".to_string(),
+        name: "test_db".to_string(),
+    };
+
+    let url = config.connection_url();
+    assert_eq!(url, "mysql://test_user:secret@localhost:3306/test_db");
+}
+
+/// Tests DatabaseConfig::connection_url with custom port.
+#[test]
+fn db_connection_url_custom_port() {
+    let config = DatabaseConfig {
+        host: "127.0.0.1".to_string(),
+        port: 3307,
+        user: "user".to_string(),
+        password: "pass".to_string(),
+        name: "mydb".to_string(),
+    };
+
+    let url = config.connection_url();
+    assert_eq!(url, "mysql://user:pass@127.0.0.1:3307/mydb");
+}

tests/import_test.rs

@@ -0,0 +1,316 @@
+//! Integration tests for CSV parsing.
+//!
+//! AI AGENT NOTE: These tests verify full CSV parsing with actual files.
+
+use invoice_generator::commands::import::{is_anonymized_card, parse_csv_fields, CsvTransaction};
+use std::io::Write;
+use tempfile::NamedTempFile;
+
+/// Tests parsing a CSV file with multiple rows.
+#[test]
+fn parse_csv_file_known_customers() {
+    let csv_content = r#"Date	Batch number	Amount	Volume	Price	Quality	QualityName	Card number	Card type	Customer number	Station	Terminal	Pump	Receipt	Card report group number	Control number
+2026-02-01 10:15:16	409	559.26	35.85	15.60	1001	95 Oktan	7825017523017000642	7825017523017000642	1861	97254	1	2	000910	1	
+2026-02-01 10:32:18	409	508.40	32.59	15.60	1001	95 Oktan	7825017523017000717	7825017523017000717	1861	97254	1	2	000912	1	
+2026-02-01 10:57:33	409	174.41	11.18	15.60	1001	95 Oktan	7825017523017001053	7825017523017001053	1980	97254	1	1	000913	1	
+"#;
+
+    let file = NamedTempFile::with_suffix(".csv").unwrap();
+    file.as_file().write_all(csv_content.as_bytes()).unwrap();
+
+    // Just verify the file was created and has content
+    let metadata = std::fs::metadata(file.path()).unwrap();
+    assert!(metadata.len() > 0);
+}
+
+/// Tests that anonymized cards are correctly identified.
+#[test]
+fn anonymized_card_detection() {
+    // Known card (full number)
+    assert!(!is_anonymized_card("7825017523017000642"));
+    assert!(!is_anonymized_card("7825017523017000717"));
+
+    // Anonymized cards (with asterisks)
+    assert!(is_anonymized_card("554477******9952"));
+    assert!(is_anonymized_card("673706*********0155"));
+    assert!(is_anonymized_card("404776******7006"));
+
+    // Edge cases
+    assert!(!is_anonymized_card("")); // Empty
+}
+
+/// Tests parsing with mixed transactions (known and anonymized).
+#[test]
+fn parse_mixed_transactions() {
+    let known_fields = [
+        "2026-02-01 10:15:16",
+        "409",
+        "559.26",
+        "35.85",
+        "15.60",
+        "1001",
+        "95 Oktan",
+        "7825017523017000642",
+        "type",
+        "1861",
+        "97254",
+        "1",
+        "2",
+        "000910",
+        "1",
+        "",
+    ];
+
+    let anonymized_fields = [
+        "2026-02-01 06:40:14",
+        "409",
+        "267.23",
+        "17.13",
+        "15.60",
+        "1001",
+        "95 Oktan",
+        "554477******9952",
+        "type",
+        "",
+        "97254",
+        "1",
+        "2",
+        "000898",
+        "4",
+        "756969",
+    ];
+
+    let known_result = parse_csv_fields(&known_fields).unwrap();
+    let anonymized_result = parse_csv_fields(&anonymized_fields).unwrap();
+
+    assert!(known_result.is_some());
+    assert!(anonymized_result.is_some());
+
+    let known_tx = known_result.unwrap();
+    let anonymized_tx = anonymized_result.unwrap();
+
+    // Known customer has customer_number
+    assert_eq!(known_tx.customer_number, "1861");
+    assert!(!is_anonymized_card(&known_tx.card_number));
+
+    // Anonymized transaction has empty customer_number
+    assert_eq!(anonymized_tx.customer_number, "");
+    assert!(is_anonymized_card(&anonymized_tx.card_number));
+}
+
+/// Tests that transactions are counted correctly.
+#[test]
+fn transaction_counting() {
+    let fields_1 = [
+        "2026-02-01 10:15:16",
+        "409",
+        "559.26",
+        "35.85",
+        "15.60",
+        "1001",
+        "95 Oktan",
+        "7825017523017000642",
+        "type",
+        "1861",
+        "97254",
+        "1",
+        "2",
+        "000910",
+        "1",
+        "",
+    ];
+
+    let fields_2 = [
+        "2026-02-01 10:32:18",
+        "409",
+        "508.40",
+        "32.59",
+        "15.60",
+        "1001",
+        "95 Oktan",
+        "7825017523017000717",
+        "type",
+        "1861",
+        "97254",
+        "1",
+        "2",
+        "000912",
+        "1",
+        "",
+    ];
+
+    let fields_3 = [
+        "2026-02-01 06:40:14",
+        "409",
+        "267.23",
+        "17.13",
+        "15.60",
+        "1001",
+        "95 Oktan",
+        "554477******9952",
+        "type",
+        "",
+        "97254",
+        "1",
+        "2",
+        "000898",
+        "4",
+        "756969",
+    ];
+
+    // All three should parse successfully
+    assert!(parse_csv_fields(&fields_1).unwrap().is_some());
+    assert!(parse_csv_fields(&fields_2).unwrap().is_some());
+    assert!(parse_csv_fields(&fields_3).unwrap().is_some());
+}
+
+/// Tests that duplicate customers are handled.
+#[test]
+fn duplicate_customers_tracked_once() {
+    let fields = [
+        "2026-02-01 10:15:16",
+        "409",
+        "559.26",
+        "35.85",
+        "15.60",
+        "1001",
+        "95 Oktan",
+        "7825017523017000642",
+        "type",
+        "1861",
+        "97254",
+        "1",
+        "2",
+        "000910",
+        "1",
+        "",
+    ];
+
+    let result = parse_csv_fields(&fields).unwrap().unwrap();
+
+    // Customer 1861 should be tracked
+    assert_eq!(result.customer_number, "1861");
+
+    // Same customer with different card
+    let fields_2 = [
+        "2026-02-01 10:32:18",
+        "409",
+        "508.40",
+        "32.59",
+        "15.60",
+        "1001",
+        "95 Oktan",
+        "7825017523017000717",
+        "type",
+        "1861",
+        "97254",
+        "1",
+        "2",
+        "000912",
+        "1",
+        "",
+    ];
+
+    let result_2 = parse_csv_fields(&fields_2).unwrap().unwrap();
+
+    // Same customer, different card
+    assert_eq!(result_2.customer_number, "1861");
+    assert_ne!(result.card_number, result_2.card_number);
+}
+
+/// Tests diesel product parsing.
+#[test]
+fn diesel_product_parsing() {
+    let fields = [
+        "2026-02-01 10:05:16",
+        "409",
+        "543.22",
+        "31.40",
+        "17.30",
+        "4",
+        "Diesel",
+        "673706*********0155",
+        "type",
+        "",
+        "97254",
+        "1",
+        "2",
+        "000909",
+        "4",
+        "D00824",
+    ];
+
+    let result = parse_csv_fields(&fields).unwrap().unwrap();
+
+    assert_eq!(result.quality_name, "Diesel");
+    assert_eq!(result.quality, 4);
+    assert_eq!(result.price, 17.30);
+    assert_eq!(result.control_number, "D00824");
+}
+
+/// Tests that amount > 0 filter works.
+#[test]
+fn amount_filter_excludes_zero_and_negative() {
+    // Zero amount should be filtered
+    let zero_amount_fields = [
+        "2026-02-01 10:15:16",
+        "409",
+        "0.00",
+        "0.00",
+        "15.60",
+        "1001",
+        "95 Oktan",
+        "7825017523017000642",
+        "type",
+        "1861",
+        "97254",
+        "1",
+        "2",
+        "000910",
+        "1",
+        "",
+    ];
+    assert!(parse_csv_fields(&zero_amount_fields).unwrap().is_none());
+
+    // Negative amount should be filtered
+    let neg_amount_fields = [
+        "2026-02-01 10:15:16",
+        "409",
+        "-50.00",
+        "-3.00",
+        "15.60",
+        "1001",
+        "95 Oktan",
+        "7825017523017000642",
+        "type",
+        "1861",
+        "97254",
+        "1",
+        "2",
+        "000910",
+        "1",
+        "",
+    ];
+    assert!(parse_csv_fields(&neg_amount_fields).unwrap().is_none());
+
+    // Small positive amount should pass
+    let small_amount_fields = [
+        "2026-02-01 10:15:16",
+        "409",
+        "0.01",
+        "0.001",
+        "15.60",
+        "1001",
+        "95 Oktan",
+        "7825017523017000642",
+        "type",
+        "1861",
+        "97254",
+        "1",
+        "2",
+        "000910",
+        "1",
+        "",
+    ];
+    assert!(parse_csv_fields(&small_amount_fields).unwrap().is_some());
+}

tests/models_test.rs

@@ -0,0 +1,141 @@
+//! Tests for the database models.
+//!
+//! AI AGENT NOTE: These tests verify model serialization and data integrity.
+
+use chrono::NaiveDateTime;
+use invoice_generator::db::models::{NewCard, NewCustomer, NewTransaction};
+
+/// Tests that NewCustomer can be created with valid data.
+#[test]
+fn new_customer_creation() {
+    let customer = NewCustomer {
+        customer_number: "12345".to_string(),
+        card_report_group: 1,
+    };
+
+    assert_eq!(customer.customer_number, "12345");
+    assert_eq!(customer.card_report_group, 1);
+}
+
+/// Tests that NewCard can be created with valid data.
+#[test]
+fn new_card_creation() {
+    let card = NewCard {
+        card_number: "7825017523017000642".to_string(),
+        customer_id: 42,
+    };
+
+    assert_eq!(card.card_number, "7825017523017000642");
+    assert_eq!(card.customer_id, 42);
+}
+
+/// Tests that NewTransaction can be created with all fields.
+#[test]
+fn new_transaction_creation() {
+    let date = NaiveDateTime::parse_from_str("2026-02-01 10:15:16", "%Y-%m-%d %H:%M:%S").unwrap();
+
+    let tx = NewTransaction {
+        transaction_date: date,
+        batch_number: "409".to_string(),
+        amount: 559.26,
+        volume: 35.85,
+        price: 15.60,
+        quality_code: 1001,
+        quality_name: "95 Oktan".to_string(),
+        card_number: "7825017523017000642".to_string(),
+        station: "97254".to_string(),
+        terminal: "1".to_string(),
+        pump: "2".to_string(),
+        receipt: "000910".to_string(),
+        control_number: None,
+        customer_id: Some(1),
+    };
+
+    assert_eq!(tx.batch_number, "409");
+    assert_eq!(tx.amount, 559.26);
+    assert_eq!(tx.volume, 35.85);
+    assert_eq!(tx.quality_name, "95 Oktan");
+    assert_eq!(tx.customer_id, Some(1));
+    assert!(tx.control_number.is_none());
+}
+
+/// Tests that NewTransaction can be created with control number.
+#[test]
+fn new_transaction_with_control_number() {
+    let date = NaiveDateTime::parse_from_str("2026-02-01 06:40:14", "%Y-%m-%d %H:%M:%S").unwrap();
+
+    let tx = NewTransaction {
+        transaction_date: date,
+        batch_number: "409".to_string(),
+        amount: 267.23,
+        volume: 17.13,
+        price: 15.60,
+        quality_code: 1001,
+        quality_name: "95 Oktan".to_string(),
+        card_number: "554477******9952".to_string(),
+        station: "97254".to_string(),
+        terminal: "1".to_string(),
+        pump: "2".to_string(),
+        receipt: "000898".to_string(),
+        control_number: Some("756969".to_string()),
+        customer_id: None,
+    };
+
+    assert_eq!(tx.control_number, Some("756969".to_string()));
+    assert!(tx.customer_id.is_none());
+}
+
+/// Tests decimal precision for monetary values.
+#[test]
+fn transaction_decimal_precision() {
+    let date = NaiveDateTime::parse_from_str("2026-02-01 10:15:16", "%Y-%m-%d %H:%M:%S").unwrap();
+
+    let tx = NewTransaction {
+        transaction_date: date,
+        batch_number: "409".to_string(),
+        amount: 123.45,
+        volume: 7.891,
+        price: 15.625,
+        quality_code: 1001,
+        quality_name: "95 Oktan".to_string(),
+        card_number: "CARD123".to_string(),
+        station: "1".to_string(),
+        terminal: "1".to_string(),
+        pump: "1".to_string(),
+        receipt: "001".to_string(),
+        control_number: None,
+        customer_id: None,
+    };
+
+    // Verify precision is maintained
+    assert_eq!(tx.amount, 123.45);
+    assert_eq!(tx.volume, 7.891);
+    assert_eq!(tx.price, 15.625);
+}
+
+/// Tests that anonymized transactions have no customer.
+#[test]
+fn anonymized_transaction_has_no_customer() {
+    let date = NaiveDateTime::parse_from_str("2026-02-01 06:40:14", "%Y-%m-%d %H:%M:%S").unwrap();
+
+    let tx = NewTransaction {
+        transaction_date: date,
+        batch_number: "409".to_string(),
+        amount: 267.23,
+        volume: 17.13,
+        price: 15.60,
+        quality_code: 1001,
+        quality_name: "95 Oktan".to_string(),
+        card_number: "554477******9952".to_string(),
+        station: "97254".to_string(),
+        terminal: "1".to_string(),
+        pump: "2".to_string(),
+        receipt: "000898".to_string(),
+        control_number: Some("756969".to_string()),
+        customer_id: None,
+    };
+
+    assert!(tx.customer_id.is_none());
+    // Card number is still stored
+    assert_eq!(tx.card_number, "554477******9952");
+}

tests/repository_test.rs

@@ -0,0 +1,449 @@
+//! Tests for the repository module.
+//! 
+//! AI AGENT NOTE: These tests verify database operations using the test database.
+//! Each test uses a transaction that is rolled back after the test completes.
+
+use sqlx::Row;
+
+async fn create_test_pool() -> sqlx::MySqlPool {
+    invoice_generator::db::create_pool(&std::env::var("DATABASE_URL").unwrap_or_else(|_| {
+        let config = invoice_generator::config::Config::load(invoice_generator::config::Env::Test).unwrap();
+        config.database.connection_url()
+    })).await.unwrap()
+}
+
+// ===== Customer Tests =====
+
+#[tokio::test]
+async fn customer_insert_returns_id() {
+    let pool = create_test_pool().await;
+    let mut tx = pool.begin().await.unwrap();
+    
+    sqlx::query(
+        "INSERT INTO customers (customer_number, card_report_group) VALUES (?, ?)",
+    )
+    .bind("TEST001")
+    .bind(1u8)
+    .execute(&mut *tx)
+    .await
+    .unwrap();
+
+    let row = sqlx::query("SELECT LAST_INSERT_ID() as id")
+        .fetch_one(&mut *tx)
+        .await
+        .unwrap();
+
+    let id: u64 = row.get("id");
+    assert!(id > 0);
+}
+
+#[tokio::test]
+async fn customer_find_existing() {
+    let pool = create_test_pool().await;
+    let mut tx = pool.begin().await.unwrap();
+    
+    sqlx::query(
+        "INSERT INTO customers (customer_number, card_report_group) VALUES (?, ?)",
+    )
+    .bind("TEST002")
+    .bind(1u8)
+    .execute(&mut *tx)
+    .await
+    .unwrap();
+
+    let customer = sqlx::query_as::<_, invoice_generator::db::models::Customer>(
+        "SELECT id, customer_number, card_report_group, created_at, updated_at 
+         FROM customers WHERE customer_number = ?",
+    )
+    .bind("TEST002")
+    .fetch_one(&mut *tx)
+    .await
+    .unwrap();
+
+    assert_eq!(customer.customer_number, "TEST002");
+    assert_eq!(customer.card_report_group, 1);
+}
+
+#[tokio::test]
+async fn customer_find_nonexistent() {
+    let pool = create_test_pool().await;
+    let mut tx = pool.begin().await.unwrap();
+    
+    let customer = sqlx::query_as::<_, invoice_generator::db::models::Customer>(
+        "SELECT id, customer_number, card_report_group, created_at, updated_at 
+         FROM customers WHERE customer_number = ?",
+    )
+    .bind("NONEXISTENT")
+    .fetch_optional(&mut *tx)
+    .await
+    .unwrap();
+
+    assert!(customer.is_none());
+}
+
+#[tokio::test]
+async fn customer_multiple_cards() {
+    let pool = create_test_pool().await;
+    let mut tx = pool.begin().await.unwrap();
+    
+    sqlx::query(
+        "INSERT INTO customers (customer_number, card_report_group) VALUES (?, ?)",
+    )
+    .bind("TEST003")
+    .bind(1u8)
+    .execute(&mut *tx)
+    .await
+    .unwrap();
+
+    let customer_row = sqlx::query("SELECT LAST_INSERT_ID() as id")
+        .fetch_one(&mut *tx)
+        .await
+        .unwrap();
+    let customer_id: u32 = customer_row.get("id");
+
+    sqlx::query("INSERT INTO cards (card_number, customer_id) VALUES (?, ?)")
+        .bind("CARD001")
+        .bind(customer_id)
+        .execute(&mut *tx)
+        .await
+        .unwrap();
+
+    sqlx::query("INSERT INTO cards (card_number, customer_id) VALUES (?, ?)")
+        .bind("CARD002")
+        .bind(customer_id)
+        .execute(&mut *tx)
+        .await
+        .unwrap();
+
+    let row = sqlx::query("SELECT COUNT(*) as count FROM cards WHERE customer_id = ?")
+        .bind(customer_id)
+        .fetch_one(&mut *tx)
+        .await
+        .unwrap();
+
+    let count: i64 = row.get("count");
+    assert_eq!(count, 2);
+}
+
+// ===== Card Tests =====
+
+#[tokio::test]
+async fn card_insert_with_customer() {
+    let pool = create_test_pool().await;
+    let mut tx = pool.begin().await.unwrap();
+    
+    sqlx::query(
+        "INSERT INTO customers (customer_number, card_report_group) VALUES (?, ?)",
+    )
+    .bind("TEST004")
+    .bind(1u8)
+    .execute(&mut *tx)
+    .await
+    .unwrap();
+
+    let customer_row = sqlx::query("SELECT LAST_INSERT_ID() as id")
+        .fetch_one(&mut *tx)
+        .await
+        .unwrap();
+    let customer_id: u32 = customer_row.get("id");
+
+    sqlx::query("INSERT INTO cards (card_number, customer_id) VALUES (?, ?)")
+        .bind("TESTCARD001")
+        .bind(customer_id)
+        .execute(&mut *tx)
+        .await
+        .unwrap();
+
+    let card_row = sqlx::query("SELECT LAST_INSERT_ID() as id")
+        .fetch_one(&mut *tx)
+        .await
+        .unwrap();
+
+    let id: u64 = card_row.get("id");
+    assert!(id > 0);
+}
+
+#[tokio::test]
+async fn card_find_by_number() {
+    let pool = create_test_pool().await;
+    let mut tx = pool.begin().await.unwrap();
+    
+    sqlx::query(
+        "INSERT INTO customers (customer_number, card_report_group) VALUES (?, ?)",
+    )
+    .bind("TEST005")
+    .bind(1u8)
+    .execute(&mut *tx)
+    .await
+    .unwrap();
+
+    let customer_row = sqlx::query("SELECT LAST_INSERT_ID() as id")
+        .fetch_one(&mut *tx)
+        .await
+        .unwrap();
+    let customer_id: u32 = customer_row.get("id");
+
+    sqlx::query("INSERT INTO cards (card_number, customer_id) VALUES (?, ?)")
+        .bind("TESTCARD002")
+        .bind(customer_id)
+        .execute(&mut *tx)
+        .await
+        .unwrap();
+
+    let card = sqlx::query_as::<_, invoice_generator::db::models::Card>(
+        "SELECT id, card_number, customer_id, created_at, updated_at 
+         FROM cards WHERE card_number = ?",
+    )
+    .bind("TESTCARD002")
+    .fetch_one(&mut *tx)
+    .await
+    .unwrap();
+
+    assert_eq!(card.card_number, "TESTCARD002");
+}
+
+// ===== Transaction Tests =====
+
+#[tokio::test]
+async fn transaction_insert_single() {
+    let pool = create_test_pool().await;
+    let mut tx = pool.begin().await.unwrap();
+    
+    sqlx::query(
+        "INSERT INTO customers (customer_number, card_report_group) VALUES (?, ?)",
+    )
+    .bind("TEST006")
+    .bind(1u8)
+    .execute(&mut *tx)
+    .await
+    .unwrap();
+
+    let customer_row = sqlx::query("SELECT LAST_INSERT_ID() as id")
+        .fetch_one(&mut *tx)
+        .await
+        .unwrap();
+    let customer_id: u32 = customer_row.get("id");
+
+    sqlx::query(
+        "INSERT INTO transactions (transaction_date, batch_number, amount, volume, price, quality_code, quality_name, card_number, station, terminal, pump, receipt, customer_id) VALUES ('2026-02-01 10:00:00', 'TEST', 100.50, 10.5, 9.57, 1001, '95 Oktan', 'CARD123', 'S001', 'T1', 'P1', 'R001', ?)",
+    )
+    .bind(customer_id)
+    .execute(&mut *tx)
+    .await
+    .unwrap();
+
+    let tx_row = sqlx::query("SELECT LAST_INSERT_ID() as id")
+        .fetch_one(&mut *tx)
+        .await
+        .unwrap();
+
+    let id: u64 = tx_row.get("id");
+    assert!(id > 0);
+}
+
+#[tokio::test]
+async fn transaction_insert_anonymized() {
+    let pool = create_test_pool().await;
+    let mut tx = pool.begin().await.unwrap();
+    
+    sqlx::query(
+        "INSERT INTO transactions (transaction_date, batch_number, amount, volume, price, quality_code, quality_name, card_number, station, terminal, pump, receipt, customer_id) VALUES ('2026-02-01 10:00:00', 'TEST', 100.50, 10.5, 9.57, 1001, '95 Oktan', 'ANON******1234', 'S001', 'T1', 'P1', 'R002', NULL)",
+    )
+    .execute(&mut *tx)
+    .await
+    .unwrap();
+
+    let tx_row = sqlx::query("SELECT LAST_INSERT_ID() as id")
+        .fetch_one(&mut *tx)
+        .await
+        .unwrap();
+
+    let id: u64 = tx_row.get("id");
+    assert!(id > 0);
+}
+
+#[tokio::test]
+async fn transaction_count() {
+    let pool = create_test_pool().await;
+    let mut tx = pool.begin().await.unwrap();
+    
+    sqlx::query(
+        "INSERT INTO customers (customer_number, card_report_group) VALUES (?, ?)",
+    )
+    .bind("TEST007")
+    .bind(1u8)
+    .execute(&mut *tx)
+    .await
+    .unwrap();
+
+    let customer_row = sqlx::query("SELECT LAST_INSERT_ID() as id")
+        .fetch_one(&mut *tx)
+        .await
+        .unwrap();
+    let customer_id: u32 = customer_row.get("id");
+
+    for i in 0..5 {
+        sqlx::query(&format!(
+            "INSERT INTO transactions (transaction_date, batch_number, amount, volume, price, quality_code, quality_name, card_number, station, terminal, pump, receipt, customer_id) VALUES ('2026-02-01 10:00:00', 'TEST', {}, 10.0, 10.0, 1001, '95 Oktan', 'CARD{}', 'S001', 'T1', 'P1', 'R00{}', ?)",
+            100.0 + i as f64,
+            i,
+            i
+        ))
+        .bind(customer_id)
+        .execute(&mut *tx)
+        .await
+        .unwrap();
+    }
+
+    let row = sqlx::query("SELECT COUNT(*) as count FROM transactions WHERE customer_id = ?")
+        .bind(customer_id)
+        .fetch_one(&mut *tx)
+        .await
+        .unwrap();
+
+    let count: i64 = row.get("count");
+    assert_eq!(count, 5);
+}
+
+// ===== Query Tests =====
+
+#[tokio::test]
+async fn query_transactions_by_customer() {
+    let pool = create_test_pool().await;
+    let mut tx = pool.begin().await.unwrap();
+    
+    sqlx::query(
+        "INSERT INTO customers (customer_number, card_report_group) VALUES (?, ?)",
+    )
+    .bind("TEST008")
+    .bind(1u8)
+    .execute(&mut *tx)
+    .await
+    .unwrap();
+
+    let customer_row = sqlx::query("SELECT LAST_INSERT_ID() as id")
+        .fetch_one(&mut *tx)
+        .await
+        .unwrap();
+    let customer_id: u32 = customer_row.get("id");
+
+    for i in 0..3 {
+        sqlx::query(&format!(
+            "INSERT INTO transactions (transaction_date, batch_number, amount, volume, price, quality_code, quality_name, card_number, station, terminal, pump, receipt, customer_id) VALUES ('2026-02-01 {}:00:00', 'TEST', 100.0, 10.0, 10.0, 1001, '95 Oktan', 'CARD{}', 'S001', 'T1', 'P1', 'R00{}', ?)",
+            10 + i,
+            i,
+            i
+        ))
+        .bind(customer_id)
+        .execute(&mut *tx)
+        .await
+        .unwrap();
+    }
+
+    let transactions = sqlx::query_as::<_, invoice_generator::db::models::Transaction>(
+        "SELECT t.id, t.transaction_date, t.batch_number, t.amount, t.volume, t.price, t.quality_code, t.quality_name, t.card_number, t.station, t.terminal, t.pump, t.receipt, t.control_number, t.customer_id, t.created_at
+         FROM transactions t
+         WHERE t.customer_id = ?",
+    )
+    .bind(customer_id)
+    .fetch_all(&mut *tx)
+    .await
+    .unwrap();
+
+    assert_eq!(transactions.len(), 3);
+}
+
+#[tokio::test]
+async fn query_excludes_anonymous_from_customer_invoice() {
+    let pool = create_test_pool().await;
+    let mut tx = pool.begin().await.unwrap();
+    
+    sqlx::query(
+        "INSERT INTO customers (customer_number, card_report_group) VALUES (?, ?)",
+    )
+    .bind("TEST009")
+    .bind(1u8)
+    .execute(&mut *tx)
+    .await
+    .unwrap();
+
+    let customer_row = sqlx::query("SELECT LAST_INSERT_ID() as id")
+        .fetch_one(&mut *tx)
+        .await
+        .unwrap();
+    let customer_id: u32 = customer_row.get("id");
+
+    sqlx::query(
+        "INSERT INTO transactions (transaction_date, batch_number, amount, volume, price, quality_code, quality_name, card_number, station, terminal, pump, receipt, customer_id) VALUES ('2026-02-01 10:00:00', 'TEST', 100.0, 10.0, 10.0, 1001, '95 Oktan', 'KNOWNCARD', 'S001', 'T1', 'P1', 'R001', ?)",
+    )
+    .bind(customer_id)
+    .execute(&mut *tx)
+    .await
+    .unwrap();
+
+    sqlx::query(
+        "INSERT INTO transactions (transaction_date, batch_number, amount, volume, price, quality_code, quality_name, card_number, station, terminal, pump, receipt, customer_id) VALUES ('2026-02-01 11:00:00', 'TEST', 50.0, 5.0, 10.0, 1001, '95 Oktan', 'ANON******9999', 'S001', 'T1', 'P1', 'R002', NULL)",
+    )
+    .execute(&mut *tx)
+    .await
+    .unwrap();
+
+    let row = sqlx::query(
+        "SELECT COUNT(*) as count FROM transactions WHERE customer_id = ?",
+    )
+    .bind(customer_id)
+    .fetch_one(&mut *tx)
+    .await
+    .unwrap();
+
+    let count: i64 = row.get("count");
+    assert_eq!(count, 1); // Only the known transaction
+}
+
+#[tokio::test]
+async fn sales_summary_by_product() {
+    let pool = create_test_pool().await;
+    let mut tx = pool.begin().await.unwrap();
+    
+    sqlx::query(
+        "INSERT INTO customers (customer_number, card_report_group) VALUES (?, ?)",
+    )
+    .bind("TEST010")
+    .bind(1u8)
+    .execute(&mut *tx)
+    .await
+    .unwrap();
+
+    let customer_row = sqlx::query("SELECT LAST_INSERT_ID() as id")
+        .fetch_one(&mut *tx)
+        .await
+        .unwrap();
+    let customer_id: u32 = customer_row.get("id");
+
+    sqlx::query(
+        "INSERT INTO transactions (transaction_date, batch_number, amount, volume, price, quality_code, quality_name, card_number, station, terminal, pump, receipt, customer_id) VALUES ('2026-02-01 10:00:00', 'TEST', 100.0, 10.0, 10.0, 1001, '95 Oktan', 'CARD001', 'S001', 'T1', 'P1', 'R001', ?)",
+    )
+    .bind(customer_id)
+    .execute(&mut *tx)
+    .await
+    .unwrap();
+
+    sqlx::query(
+        "INSERT INTO transactions (transaction_date, batch_number, amount, volume, price, quality_code, quality_name, card_number, station, terminal, pump, receipt, customer_id) VALUES ('2026-02-01 11:00:00', 'TEST', 50.0, 5.0, 10.0, 4, 'Diesel', 'CARD001', 'S001', 'T1', 'P1', 'R002', ?)",
+    )
+    .bind(customer_id)
+    .execute(&mut *tx)
+    .await
+    .unwrap();
+
+    let summaries = sqlx::query_as::<_, invoice_generator::db::repository::ProductSummary>(
+        "SELECT quality_name, COUNT(*) as tx_count, SUM(amount) as total_amount, SUM(volume) as total_volume
+         FROM transactions
+         GROUP BY quality_name",
+    )
+    .fetch_all(&mut *tx)
+    .await
+    .unwrap();
+
+    assert_eq!(summaries.len(), 2); // Two products: 95 Oktan and Diesel
+}