import feed_file_exporter as ffe
from constants import database as db_consts, files as file_consts


def _rows_for_file(file_name='Res.txt'):
    return [
        {
            db_consts.RECORD_TYPE: 'H',
            db_consts.BODY_CONTENT: 'HEADER',
            db_consts.FILE_NAME: file_name,
        },
        {
            db_consts.RECORD_TYPE: 'N',
            db_consts.BODY_CONTENT: 'BODY1',
            db_consts.FILE_NAME: file_name,
        },
        {
            db_consts.RECORD_TYPE: 'T',
            db_consts.BODY_CONTENT: 'TAIL',
            db_consts.FILE_NAME: file_name,
        },
    ]


def test_split_rows_to_files_spy_write(tmp_path, mocker):
    rows = _rows_for_file('Res.txt')
    spy = mocker.spy(ffe, 'write_rows_to_file')
    count, upload_list, gen_list = ffe.split_rows_to_files(rows, str(tmp_path))
    assert count == 3
    assert upload_list == ['Res.txt']
    assert len(gen_list) == 1
    spy.assert_called_once()
    # Verify content written
    with open(gen_list[0], 'r', encoding='utf8') as f:
        content = f.read()
    expected = 'HEADER' + file_consts.LINE_TERMINATOR
    expected += 'BODY1' + file_consts.LINE_TERMINATOR
    expected += 'TAIL'
    assert content.replace('\r\n', '\n') == expected.replace('\r\n', '\n')


def test_split_rows_to_files_mismatch_tail_raises(tmp_path, mocker):
    rows = _rows_for_file('A.txt')
    rows[-1][db_consts.FILE_NAME] = 'B.txt'
    spy = mocker.spy(ffe, 'write_rows_to_file')
    try:
        ffe.split_rows_to_files(rows, str(tmp_path))
        assert False, 'Expected ValueError for mismatched tail'
    except ValueError:
        pass
    # write should not occur on mismatch
    assert spy.call_count == 0


class _Row:
    def __init__(self, d):
        self._d = d

    def keys(self):
        return list(self._d.keys())

    def __iter__(self):
        return iter(self._d.values())


class _RP:
    def __init__(self, rows):
        self._rows = rows

    def fetchone(self):
        return _Row(self._rows[0])

    def __iter__(self):
        for r in self._rows[1:]:
            yield _Row(r)


def test_split_res_to_files_creates_file(tmp_path, mocker):
    rows = _rows_for_file('Z.txt')
    rp = _RP(rows)
    log_spy = mocker.spy(ffe.logger, 'info')
    count, gen_list = ffe.split_res_to_files(rp, str(tmp_path))
    assert count == 3
    assert len(gen_list) == 1
    # Logger informed writing
    assert any(
        'Writing File' in str(c.args[0]) for c in log_spy.call_args_list
    )
    with open(gen_list[0], 'r', encoding='utf8') as f:
        content = f.read()
    expected = 'HEADER' + file_consts.LINE_TERMINATOR
    expected += 'BODY1' + file_consts.LINE_TERMINATOR
    expected += 'TAIL'
    assert content.replace('\r\n', '\n') == expected.replace('\r\n', '\n')


def test_split_res_to_files_mismatch_raises(tmp_path):
    rows = _rows_for_file('A.txt')
    rows[-1][db_consts.FILE_NAME] = 'B.txt'
    rp = _RP(rows)
    try:
        ffe.split_res_to_files(rp, str(tmp_path))
        assert False, 'Expected ValueError for mismatched tail'
    except ValueError:
        pass