from collections.abc import Generator
from unittest.mock import patch

import fakeredis
import pytest
from freezegun import freeze_time

from assets import rate_limiting
from assets.rate_limiting import RateLimitedResource


@pytest.fixture
def use_fake_redis_client() -> Generator[fakeredis.FakeRedis, None, None]:
    fake_client = fakeredis.FakeRedis()
    with patch(
        "assets.rate_limiting.redis_connector.client",
        new=fake_client,
    ):
        rate_limiting.get_rate_limiter.cache_clear()
        yield fake_client
        rate_limiting.get_rate_limiter.cache_clear()


def test_unconfigured_resources_allow_all_requests() -> None:
    rate_limiter = rate_limiting.get_rate_limiter()

    # Should allow unlimited calls
    for _ in range(100):
        assert rate_limiter.hit("asdf", "qwer") == rate_limiting.Allowed()  # type: ignore[arg-type]
        assert rate_limiter.hit("asdf", "oa:179") == rate_limiting.Allowed()  # type: ignore[arg-type]


def test_rate_limiter_enforces_limit(
    use_fake_redis_client: fakeredis.FakeRedis,
) -> None:
    rate_limiter = rate_limiting.get_rate_limiter()
    limit = rate_limiting.RATE_LIMITS[
        (rate_limiting.RateLimitedResource.UPLOAD, "oa:179")
    ]

    with freeze_time("2025-10-29 01:01:00") as frozen_time:
        # Calls within the limit should succeed
        for _ in range(limit.amount):
            assert (
                rate_limiter.hit(RateLimitedResource.UPLOAD, "oa:179")
                == rate_limiting.Allowed()
            )

        # Next call should fail
        assert rate_limiter.hit(
            RateLimitedResource.UPLOAD, "oa:179"
        ) == rate_limiting.Exceeded(f"Rate limit exceeded. Limit: {limit}.")

        # Advance time to 1 second before the next rate limit window
        frozen_time.tick(limit.get_expiry())
        # Should still fail
        assert rate_limiter.hit(
            RateLimitedResource.UPLOAD, "oa:179"
        ) == rate_limiting.Exceeded(f"Rate limit exceeded. Limit: {limit}.")

        # Advance time by 1 more second to enter the next rate limit window
        frozen_time.tick(1)
        # Calls within the limit should succeed
        for _ in range(limit.amount):
            assert (
                rate_limiter.hit(RateLimitedResource.UPLOAD, "oa:179")
                == rate_limiting.Allowed()
            )

        # Next call should fail
        assert rate_limiter.hit(
            RateLimitedResource.UPLOAD, "oa:179"
        ) == rate_limiting.Exceeded(f"Rate limit exceeded. Limit: {limit}.")


def test_rate_limiter_error() -> None:
    rate_limiter = rate_limiting.get_rate_limiter()

    with patch.object(rate_limiter._rate_limiter, "hit") as mock_hit:
        mock_hit.side_effect = Exception("some error")

        assert rate_limiter.hit(
            RateLimitedResource.UPLOAD, "oa:179"
        ) == rate_limiting.Error("Exception: some error")