import asyncio
import logging
from typing import cast

import pytest

from transcription.errors import AppError
from transcription.errors import ErrorCategory
from transcription.services import ServiceBundle
from transcription.services.sources import SourceService
from transcription.worker import WorkerHealth
from transcription.worker import process_next_queued_job
from transcription.worker import run_worker_loop


@pytest.mark.asyncio
async def test_run_worker_loop_stops_on_non_retriable_exception(monkeypatch, caplog):
    """A programming error before a job is claimed stops the loop instead of spinning.

    Regression guard for review log [8]. This previously spun at the poll interval
    forever: the fault was classified non-retriable, logged, and then discarded, and
    it never reached the per-job retry machinery so nothing capped it. Measured at 20
    iterations in 1.2s before the fix.
    """
    calls = 0
    stop_event = asyncio.Event()
    worker_health = WorkerHealth()

    async def _fake_process_next_queued_job(*, session=None, session_factory=None, services=None):
        nonlocal calls
        _ = (session, session_factory, services)
        calls += 1
        raise RuntimeError("boom")

    monkeypatch.setattr("transcription.worker.process_next_queued_job", _fake_process_next_queued_job)

    with caplog.at_level(logging.CRITICAL):
        await asyncio.wait_for(
            run_worker_loop(stop_event=stop_event, poll_interval_seconds=0, worker_health=worker_health),
            timeout=5,
        )

    assert calls == 1
    assert "Worker loop stopped after a non-retriable error" in caplog.text
    snapshot = worker_health.snapshot()
    assert snapshot.state == "failed"
    assert snapshot.error_id is not None
    assert snapshot.error_category == ErrorCategory.INTERNAL_UNEXPECTED.value


@pytest.mark.asyncio
async def test_run_worker_loop_survives_retriable_exception(monkeypatch, caplog):
    """A retriable fault is still suppressed so transient conditions do not stop work."""
    calls = 0
    stop_event = asyncio.Event()
    worker_health = WorkerHealth()

    async def _fake_process_next_queued_job(*, session=None, session_factory=None, services=None):
        nonlocal calls
        _ = (session, session_factory, services)
        calls += 1
        if calls == 1:
            raise AppError(
                "transient",
                category=ErrorCategory.EXTERNAL_PROVIDER,
                suggestion="retry",
                retriable=True,
            )
        stop_event.set()
        return False

    monkeypatch.setattr("transcription.worker.process_next_queued_job", _fake_process_next_queued_job)

    with caplog.at_level(logging.ERROR):
        await run_worker_loop(stop_event=stop_event, poll_interval_seconds=0, worker_health=worker_health)

    assert calls == 2
    assert "Worker loop exception" in caplog.text
    assert worker_health.snapshot().state == "stopped"


@pytest.mark.asyncio
async def test_run_worker_loop_reuses_one_bundle_across_jobs(monkeypatch):
    """HIGH-02: the provider client is built once per loop, not once per job."""
    stop_event = asyncio.Event()
    seen: list[object] = []
    closed = False

    class _Sources:
        async def aclose(self):
            nonlocal closed
            closed = True

    bundle = ServiceBundle(sources=cast("SourceService", _Sources()))
    monkeypatch.setattr(
        "transcription.worker.ServiceBundle.from_session_factory",
        classmethod(lambda _cls, _factory=None, **_kwargs: bundle),
    )

    async def _fake_process_next_queued_job(*, session=None, session_factory=None, services=None):
        _ = (session, session_factory)
        seen.append(services)
        if len(seen) >= 3:
            stop_event.set()
            return False
        return True

    monkeypatch.setattr("transcription.worker.process_next_queued_job", _fake_process_next_queued_job)

    await run_worker_loop(stop_event=stop_event, poll_interval_seconds=0)

    assert len(seen) == 3
    assert all(item is bundle for item in seen)
    assert closed is True


@pytest.mark.asyncio
async def test_process_next_closes_provider_for_the_bundle_it_owns(monkeypatch):
    closed = False

    class _Sources:
        async def aclose(self):
            nonlocal closed
            closed = True

    bundle = ServiceBundle(sources=cast("SourceService", _Sources()))
    monkeypatch.setattr(
        "transcription.worker.ServiceBundle.from_session_factory",
        classmethod(lambda _cls, _factory=None, **_kwargs: bundle),
    )

    async def _no_job(*, services, session):
        _ = (services, session)
        return False

    monkeypatch.setattr("transcription.worker.process_next_queued_job_workflow", _no_job)

    assert await process_next_queued_job() is False
    assert closed is True


@pytest.mark.asyncio
async def test_process_next_leaves_a_caller_owned_bundle_open(monkeypatch):
    """A bundle passed in belongs to the caller and must outlive one job."""
    closed = False

    class _Sources:
        async def aclose(self):
            nonlocal closed
            closed = True

    bundle = ServiceBundle(sources=cast("SourceService", _Sources()))

    async def _no_job(*, services, session):
        _ = (services, session)
        return False

    monkeypatch.setattr("transcription.worker.process_next_queued_job_workflow", _no_job)

    assert await process_next_queued_job(services=bundle) is False
    assert closed is False