"""The podcast poll loop itself: cadence, error resilience, and client lifecycle."""

from __future__ import annotations

import asyncio
from pathlib import Path

import httpx2
import pytest

import musicmouse.services.podcasts as podcasts_module
from musicmouse.services.podcasts import PodcastFeedService


class _FakeLibrary:
    def __init__(self, root: Path) -> None:
        self.root = root


async def _run_briefly(service: PodcastFeedService) -> None:
    """Let `run()` complete a few fast-interval passes, then cancel it like shutdown does."""
    task = asyncio.create_task(service.run())
    await asyncio.sleep(0.05)
    task.cancel()
    with pytest.raises(asyncio.CancelledError):
        await task


@pytest.mark.asyncio
async def test_run_checks_immediately_and_calls_on_change_only_when_something_changed(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    calls = 0

    async def fake_sync_all_shows(
        client: httpx2.AsyncClient, root: Path, *, keep: int | None = None
    ) -> bool:
        nonlocal calls
        calls += 1
        return calls == 1  # only the very first pass finds something new

    monkeypatch.setattr(podcasts_module, "sync_all_shows", fake_sync_all_shows)

    changes = 0

    async def on_change() -> None:
        nonlocal changes
        changes += 1

    client = httpx2.AsyncClient(transport=httpx2.MockTransport(lambda _r: httpx2.Response(200)))
    service = PodcastFeedService(
        _FakeLibrary(tmp_path), client=client, on_change=on_change, interval=0.01
    )

    await _run_briefly(service)

    assert changes == 1
    assert calls >= 2
    assert client.is_closed


@pytest.mark.asyncio
async def test_run_survives_a_failing_pass(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    calls = 0

    async def fake_sync_all_shows(
        client: httpx2.AsyncClient, root: Path, *, keep: int | None = None
    ) -> bool:
        nonlocal calls
        calls += 1
        if calls == 1:
            raise RuntimeError("boom")
        return False

    monkeypatch.setattr(podcasts_module, "sync_all_shows", fake_sync_all_shows)

    async def on_change() -> None:
        pytest.fail("on_change must not run when nothing changed")

    client = httpx2.AsyncClient(transport=httpx2.MockTransport(lambda _r: httpx2.Response(200)))
    service = PodcastFeedService(
        _FakeLibrary(tmp_path), client=client, on_change=on_change, interval=0.01
    )

    await _run_briefly(service)

    # The RuntimeError from the first pass must not have ended the loop.
    assert calls >= 2
    assert client.is_closed