from __future__ import annotations

from datetime import date
from pathlib import Path
import unittest

from bank_importer.parser import UnknownTemplateError, detect_header, parse_directory


ROOT = Path(__file__).resolve().parents[1]
SAMPLES = ROOT / "流水模板"


class StatementParserTests(unittest.TestCase):
    @classmethod
    def setUpClass(cls) -> None:
        cls.batches = parse_directory(SAMPLES)
        cls.by_file = {batch.source_file.name: batch for batch in cls.batches}

    def test_all_current_bank_samples_are_recognized(self) -> None:
        expected = {
            "中信银行账户流水.xlsx": ("中信银行", 16, 4),
            "中国农业银行账户流水.xls": ("中国农业银行", 3, 4),
            "中国工商银行账户流水.xlsx": ("中国工商银行", 2, 5),
            "中国建设银行账户流水.xls": ("中国建设银行", 1, 1),
            "河南农商银行账户流水.xlsx": ("河南农商银行", 11, 1),
            "郑州银行账户流水.xls": ("郑州银行", 7, 5),
        }
        self.assertEqual(set(expected), set(self.by_file))
        for filename, (bank, header_row, transaction_count) in expected.items():
            with self.subTest(filename=filename):
                batch = self.by_file[filename]
                self.assertEqual(bank, batch.bank_name)
                self.assertEqual(header_row, batch.header_row)
                self.assertEqual(transaction_count, len(batch.transactions))

    def test_known_statement_periods_are_extracted(self) -> None:
        expected = {
            "中信银行账户流水.xlsx": (date(2026, 4, 26), date(2026, 5, 23)),
            "中国农业银行账户流水.xls": (date(2025, 11, 26), date(2025, 12, 27)),
            "河南农商银行账户流水.xlsx": (date(2026, 2, 24), date(2026, 3, 28)),
            "郑州银行账户流水.xls": (date(2026, 2, 24), date(2026, 3, 27)),
        }
        for filename, period in expected.items():
            with self.subTest(filename=filename):
                batch = self.by_file[filename]
                self.assertEqual(period, (batch.period_start, batch.period_end))

    def test_normalized_transactions_have_one_cash_direction(self) -> None:
        for batch in self.batches:
            for transaction in batch.transactions:
                with self.subTest(
                    filename=batch.source_file.name, row=transaction.source_row
                ):
                    self.assertNotEqual(transaction.income > 0, transaction.expense > 0)

    def test_current_samples_reconcile_by_running_balance(self) -> None:
        for batch in self.batches:
            with self.subTest(filename=batch.source_file.name):
                self.assertEqual((), batch.warnings)

    def test_column_order_does_not_affect_header_detection(self) -> None:
        header = (
            "余额",
            "对方单位名称",
            "贷方发生额",
            "交易时间",
            "本方账号",
            "借方发生额",
            "凭证号",
        )
        template, row_index, columns = detect_header((header,))
        self.assertEqual("icbc-history-detail-v1", template.template_id)
        self.assertEqual(0, row_index)
        self.assertEqual(3, columns["transaction_at"])

    def test_unknown_header_is_rejected(self) -> None:
        with self.assertRaises(UnknownTemplateError) as raised:
            detect_header((("日期", "金额", "备注"),))
        message = str(raised.exception)
        self.assertIn("未识别到受支持的银行表头", message)
        self.assertIn("第 1 行", message)
        self.assertIn("日期、金额、备注", message)


if __name__ == "__main__":
    unittest.main()