#!/usr/bin/env python3

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


RAW_DIR = Path("~/master-folder/attachments/bank-statements/halifax/raw").expanduser()
CLEANED_DIR = Path("~/master-folder/attachments/bank-statements/halifax/cleaned").expanduser()


def convert(in_path: Path, out_path: Path):
    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)

        fieldnames = ["Date", "Payee", "Description", "Amount"]
        writer = csv.DictWriter(f_out, fieldnames=fieldnames)
        writer.writeheader()

        for row in reader:
            if not row:
                continue

            date = (row.get("Transaction Date") or "").strip()
            if not date:
                continue

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

            debit_str = (row.get("Debit Amount") or "").replace(",", "").strip()
            credit_str = (row.get("Credit Amount") or "").replace(",", "").strip()

            amount = None

            if debit_str:
                try:
                    amount = -Decimal(debit_str)
                except InvalidOperation:
                    continue
            elif credit_str:
                try:
                    amount = Decimal(credit_str)
                except InvalidOperation:
                    continue

            if amount is None:
                continue

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


def select_file(files: list[Path]) -> Path:
    print("\nSelect a Halifax CSV to clean:\n")
    for i, f in enumerate(files, start=1):
        print(f"[{i}] {f.name}")

    try:
        choice = int(input("\nEnter number: ").strip())
        return files[choice - 1]
    except (ValueError, IndexError):
        print("Invalid selection.")
        sys.exit(1)


def main():
    if not RAW_DIR.exists():
        print(f"Raw directory does not exist: {RAW_DIR}")
        sys.exit(1)

    CLEANED_DIR.mkdir(parents=True, exist_ok=True)

    csv_files = sorted(RAW_DIR.glob("*.csv"))

    if not csv_files:
        print("No CSV files found in raw directory.")
        sys.exit(0)

    in_path = select_file(csv_files)

    out_name = f"{in_path.stem}-cleaned.csv"
    out_path = CLEANED_DIR / out_name

    convert(in_path, out_path)
    print(f"\n✔ Written cleaned file to:\n{out_path}\n")


if __name__ == "__main__":
    main()