#!/usr/bin/env python3

import csv
from decimal import Decimal, InvalidOperation
import sys
from pathlib import Path


def convert(in_path, out_path):
    # Read Halifax CSV and write a cleaned CSV for Actual
    with open(in_path, newline="", encoding="utf-8-sig") as f_in, \
         open(out_path, "w", newline="", encoding="utf-8") as f_out:

        reader = csv.DictReader(f_in)

        # Output columns tailored for Actual’s CSV import
        fieldnames = ["Date", "Payee", "Description", "Amount"]
        writer = csv.DictWriter(f_out, fieldnames=fieldnames)
        writer.writeheader()

        for row in reader:
            if not row:
                continue

            # Date in Halifax export (dd/mm/yyyy)
            date = (row.get("Transaction Date") or "").strip()
            if not date:
                # Skip lines without a date
                continue

            desc = (row.get("Transaction Description") or "").strip()
            payee = desc or (row.get("Transaction Type") or "").strip()

            # Halifax has separate Debit / Credit columns
            debit_str = (row.get("Debit Amount") or "").replace(",", "").strip()
            credit_str = (row.get("Credit Amount") or "").replace(",", "").strip()

            amount = None

            # Debits (money going out) → negative
            if debit_str:
                try:
                    amount = -Decimal(debit_str)
                except InvalidOperation:
                    amount = None

            # Credits (money coming in) → positive
            elif credit_str:
                try:
                    amount = Decimal(credit_str)
                except InvalidOperation:
                    amount = None

            # If we still don't have an amount, skip the row
            if amount is None:
                continue

            writer.writerow({
                "Date": date,
                "Payee": payee,
                "Description": desc,
                "Amount": f"{amount:.2f}",
            })


def main():
    if len(sys.argv) < 2:
        print("Usage: python clean_halifax_actual.py input.csv [output.csv]")
        sys.exit(1)

    in_path = Path(sys.argv[1])

    if len(sys.argv) >= 3:
        out_path = Path(sys.argv[2])
    else:
        # Default to inputname_actual.csv
        out_path = in_path.with_name(in_path.stem + "_actual.csv")

    convert(in_path, out_path)
    print(f"Written cleaned file to {out_path}")


if __name__ == "__main__":
    main()