from collections.abc import AsyncIterator

from gargi_ai.main import app
from gargi_ai.providers import LLMProvider, TTSProvider
from gargi_ai.schemas import TeachingPayload


class FailingLLM(LLMProvider):
    async def stream_explanation(self, prompt: str) -> AsyncIterator[str]:
        raise RuntimeError("provider unavailable")
        yield

    async def generate_artifact(self, prompt: str) -> TeachingPayload:
        raise RuntimeError("not reached")


class FailingTTS(TTSProvider):
    async def synthesize(self, text: str, voice: str):
        raise RuntimeError("tts unavailable")


class FailingArtifactLLM(LLMProvider):
    async def stream_explanation(self, prompt: str) -> AsyncIterator[str]:
        yield "The teacher response still works."

    async def generate_artifact(self, prompt: str) -> TeachingPayload:
        raise RuntimeError("artifact model overloaded")


def create_lesson(client):
    return client.post(
        "/api/v1/sessions", json={"topic": "Physics"}
    ).json()["id"]


def test_gemini_failure_is_a_recoverable_sse_error(client):
    session_id = create_lesson(client)
    app.state.llm = FailingLLM()
    response = client.post(
        f"/api/v1/sessions/{session_id}/teach",
        json={"text": "Teach me."},
    )
    assert response.status_code == 200
    assert "PROVIDER_ERROR" in response.text
    assert '"ok": false' in response.text


def test_tts_failure_keeps_lesson_payload(client):
    session_id = create_lesson(client)
    app.state.tts = FailingTTS()
    response = client.post(
        f"/api/v1/sessions/{session_id}/teach",
        json={"text": "Teach me."},
    )
    assert "event: lesson_payload" in response.text
    assert "TTS_GENERATION_FAILED" in response.text
    assert 'event: done' in response.text


def test_live_artifact_failure_returns_fallback_payload(client):
    session_id = create_lesson(client)
    app.state.llm = FailingArtifactLLM()
    with client.websocket_connect(
        f"/api/v1/sessions/{session_id}/live"
    ) as websocket:
        assert websocket.receive_json()["type"] == "ready"

        websocket.send_bytes(b"fake-microphone-pcm")
        assert websocket.receive_json()["type"] == "input_transcription"
        assert websocket.receive_json()["type"] == "output_transcription"
        assert websocket.receive_bytes() == b"fake-live-pcm"
        lesson_payload = websocket.receive_json()
        turn_complete = websocket.receive_json()

        assert lesson_payload["type"] == "lesson_payload"
        assert lesson_payload["fallback"] is True
        assert len(lesson_payload["quiz"]) == 3
        assert turn_complete["type"] == "turn_complete"