from collections.abc import Callable, Generator
from typing import Any, Protocol

from config import app_logger as logger
from src.constants import ACCOUNT_BATCH_SIZE


class FetchPageReturnType[T](Protocol):
    items: list[T]
    total_count: int


def fetch_all[T](
    fetch_page: Callable[..., FetchPageReturnType[T]],
    *fetch_args: Any,
    limit: int = ACCOUNT_BATCH_SIZE,
    **fetch_kwargs: Any,
) -> Generator[T, None, None]:
    """
    Generic offset/limit paginator.
    `fetch_page` must return an object with `.items` and `.total_count`.
    """
    offset = 0

    fetch_page_name = (
        getattr(fetch_page, '__qualname__', None)
        or getattr(fetch_page, '__name__', None)
        or type(fetch_page).__name__
    )
    fetch_page_module = getattr(fetch_page, '__module__', None)
    log_prefix = (
        f'{fetch_page_module}.{fetch_page_name}'
        if fetch_page_module
        else fetch_page_name
    )

    logger.debug('%s started.', log_prefix)

    while True:
        batch = fetch_page(*fetch_args, limit=limit, offset=offset, **fetch_kwargs)

        items = batch.items or []
        for item in items:
            yield item

        offset += limit

        logger.debug(
            '%s fetched %d of %d entries.',
            log_prefix,
            min(offset, batch.total_count),
            batch.total_count,
        )

        if offset >= batch.total_count:
            break

    logger.debug('%s completed.', log_prefix)