"""Unit tests for the WhisperSTT source plumbing.

These do NOT load a model or spawn the worker (that needs the whisper312 venv and
is exercised by the manual TTS->STT round trip). They pin the SpeechToText
contract: how `utterances()` turns an audio source into Utterances, and how it
behaves with no source wired yet.
"""

import asyncio
from typing import AsyncIterator

from wsai.backends.whisper import WhisperSTT
from wsai.interfaces import SpeechToText, Utterance


def _collect(stt: WhisperSTT) -> list[Utterance]:
    async def run():
        return [u async for u in stt.utterances()]

    return asyncio.run(asyncio.wait_for(run(), timeout=5))


async def _paths(items) -> AsyncIterator[str]:
    for it in items:
        yield it


def test_is_speech_to_text():
    assert isinstance(WhisperSTT(), SpeechToText)


def test_no_audio_source_yields_nothing():
    # Discord voice receiver not wired yet -> the loop idles and returns.
    assert _collect(WhisperSTT(audio_source=None)) == []


def test_utterances_transcribes_each_chunk(monkeypatch):
    stt = WhisperSTT(audio_source=_paths(["a.wav", "b.wav"]))

    async def fake_transcribe(wav_path, *, language=None):
        return f"text::{wav_path}"

    monkeypatch.setattr(stt, "transcribe", fake_transcribe)

    utts = _collect(stt)
    assert [u.text for u in utts] == ["text::a.wav", "text::b.wav"]
    assert all(u.source == "voice" for u in utts)


def test_empty_transcript_is_skipped(monkeypatch):
    # Silence / VAD-filtered audio transcribes to "" and must not become a turn.
    stt = WhisperSTT(audio_source=_paths(["silent.wav", "real.wav"]))

    async def fake_transcribe(wav_path, *, language=None):
        return "" if wav_path == "silent.wav" else "안녕"

    monkeypatch.setattr(stt, "transcribe", fake_transcribe)

    utts = _collect(stt)
    assert [u.text for u in utts] == ["안녕"]