#!/bin/python3

import sys
import csv
import re
from pathlib import Path

whitelist_cards = ["7756"]

def usage():
    print('Usage: ynab.py <filename>')


def is_reserved(row):
    return '(Reservert)' in row[1]

def convert_memo(original):
    original = re.match(r'="[ ]?(.+)"', original).groups()[0]
    original = original.replace(" Kurs: 1.0000", "")
    words = original.split(" ")

    for i in range(20):
        if words[0] == "":
            # It's empty
            del words[0]
        elif m := re.match(r'\*(\d{4})', words[0]):
            # It's the last four digits of a card
            if m.groups()[0] in whitelist_cards:
                # It's an expected card, ignore it
                del words[0]
            else:
                # It's an unexpected card, move it to the end
                words.append(words.pop(0))
        elif m := re.match(r'\d{2}\.\d{2}', words[0]):
            # It's the date. Move it to the end
            words.append(words.pop(0))
        elif (m1 := re.match(r'^[A-Z]{3}$', words[0])) and (m2 := re.match(r'[\d]+\.[\d]+', words[1])):
            # It's the original currency
            if words[0] == "NOK":
                # It's Norwegian kroner, ignoring
                del words[0]
                del words[0]
            else:
                # It's some other currency, move it to the end
                words.append(words.pop(0))
                words.append(words.pop(0))
        else:
            break
    else:
        raise Exception(f"Infinite loop while parsing \"{original}\"")


    return " ".join(words)


def convert(reader, writer):
    header = ['Date', 'Payee', 'Memo', 'Outflow', 'Inflow']

    writer.writerow(header)

    # Ignore header
    reader.__next__()

    for row in reader:
        if is_reserved(row):
            continue

        money_out = 0
        money_in = 0

        if (isinstance(row[3], str)):
            moneystr = row[3].replace(',', '.')

            try:
                money = float(moneystr) if moneystr else 0
            except ValueError as e:
                print(f'Error in row {row}')
                raise e
        else:
            money = float(row[3])

        if money >= 0:
            money_in = money
        else:
            money_out = -money

        memo = convert_memo(row[2])

        new_row = [*row[:2], memo, money_out, money_in]
        writer.writerow(new_row)


def main():
    if len(sys.argv) != 2:
        usage()
        exit(1)

    filepath = Path(sys.argv[1])

    new_basename = f'ynab-{filepath.name}'
    new_filepath = filepath.parent / new_basename

    with filepath.open(mode='r') as old_file:
        reader = csv.reader(old_file, delimiter=';')

        with new_filepath.open(mode='w') as new_file:
            writer = csv.writer(new_file)
            convert(reader, writer)


if __name__ == '__main__':
    main()