from datetime import date
from decimal import Decimal

import pytest

from app.parsers.base import (ParsedStatement, ParsedTransaction, ParserError,
                              parse_german_amount, parse_german_date)
from app.parsers.detect import detect_bank
from app.parsers.validate import balance_difference, dedup_hash


def test_parse_german_amount():
    assert parse_german_amount("1.234,56") == Decimal("1234.56")
    assert parse_german_amount("1.234,56-") == Decimal("-1234.56")
    assert parse_german_amount("12,00 S") == Decimal("-12.00")
    assert parse_german_amount("12,00 H") == Decimal("12.00")
    assert parse_german_amount("1\xa0234,56") == Decimal("1234.56")


def test_parse_german_date():
    assert parse_german_date("03.06.2026") == date(2026, 6, 3)
    assert parse_german_date("03.06.", default_year=2026) == date(2026, 6, 3)


def test_parse_german_date_invalid():
    with pytest.raises(ParserError):
        parse_german_date("31.02.2026")


def test_detect_bank():
    assert detect_bank("... Volksbank Musterstadt eG ...") == "vr"
    assert detect_bank("... Raiffeisenbank ...") == "vr"
    assert detect_bank("... HypoVereinsbank ...") == "hvb"
    assert detect_bank("... UniCredit Bank ...") == "hvb"
    assert detect_bank("... Deutsche Kreditbank AG ...") == "dkb"
    assert detect_bank("... DKB ...") == "dkb"
    assert detect_bank("irgendwas") is None


def _stmt(txs, opening, closing):
    return ParsedStatement(bank="vr", iban=None, period_start=None,
                           period_end=None, opening_balance=opening,
                           closing_balance=closing, transactions=txs)


def test_balance_difference():
    txs = [ParsedTransaction(date(2026, 6, 1), None, Decimal("-50"), "Miete", "V"),
           ParsedTransaction(date(2026, 6, 2), None, Decimal("20"), "Gutschrift", "K")]
    assert balance_difference(_stmt(txs, Decimal("100"), Decimal("70"))) == Decimal("0")
    assert balance_difference(_stmt(txs, Decimal("100"), Decimal("75"))) == Decimal("5")


def test_dedup_hash_normalizes_whitespace():
    a = dedup_hash(1, date(2026, 6, 1), Decimal("-50.00"), "Miete  Juni")
    b = dedup_hash(1, date(2026, 6, 1), Decimal("-50.00"), "Miete Juni")
    assert a == b and len(a) == 64