import csv
import logging
from typing import Any, Collection, Generator, TextIO

from .base import BaseBatchReader, BaseRowReader

CsvDictReaderT = dict[str, str]


logger = logging.getLogger('users_cleanup')


class StringReader(BaseRowReader[str]):
    def _get_row(self) -> Generator[str, None, None]:
        assert self._fp is not None, 'File is not opened. Probably you forgot to use context manager.'
        yield self._fp.readline()


class CsvDictReaderMixin:
    _fp: TextIO | None

    def __init__(self, *, ensure_keys: Collection[str] | None = None, **kwargs: Any) -> None:
        self.ensure_keys = set(ensure_keys) if ensure_keys else None
        super().__init__(**kwargs)

    def _get_row(self) -> Generator[Any, None, None]:
        assert self._fp is not None, 'File is not opened. Probably you forgot to use context manager.'
        reader = csv.DictReader(self._fp)

        if self.ensure_keys:
            if reader.fieldnames is None:
                raise KeyError('Ensure keys are presented in csv')

            diff = self.ensure_keys.difference(reader.fieldnames)
            if diff:
                raise KeyError(f'"{", ".join(diff)}" keys are not present in csv')

        for row in reader:
            yield row


class CsvDictReader(CsvDictReaderMixin, BaseRowReader[CsvDictReaderT]):
    pass


class BatchCsvDictReader(CsvDictReaderMixin, BaseBatchReader[list[CsvDictReaderT]]):
    pass