# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Project Overview

Single-script Python tool that extracts credit card transactions from BAC Costa Rica statement PDFs. Parses sections B (purchases), D (other charges), and E (voluntary services) and outputs JSON.

## Dependencies

- pdfplumber (>=0.10.0)

## Commands

```bash
# Run tests
python testStatements/run_tests.py

# Run extractor
python bac_extract.py <pdf_file> [options]

# Examples
python bac_extract.py EstadodeCuenta.pdf --pretty
python bac_extract.py statement.pdf -o output.json -v
```

Options:
- `-o, --output`: Output JSON path (default: transactions.json)
- `--pretty`: Pretty-print JSON
- `-v, --verbose`: Enable debug logging

## Architecture

The extraction pipeline:
1. Validates PDF is a BAC statement (`is_bac_statement`)
2. Iterates pages line-by-line, detecting section boundaries via `SECTIONS` dict patterns
3. Parses transactions matching `TRANSACTION_PATTERN` regex
4. Outputs card holders, transactions by section, and summaries

Key data structures:
- `SECTIONS`: Maps section IDs (B/D/E) to start/end regex patterns and output keys
- `SPANISH_MONTHS`: Spanish month abbreviations for date parsing

Key parsing functions:
- `parse_spanish_date`: Converts "15-ENE-25" to "2025-01-15"
- `parse_amount`: Handles "1,234.56" and trailing negatives "100.00-"
- `matches_patterns`: Generic regex pattern matcher for section detection