from __future__ import annotations

import unittest
from unittest.mock import patch

from owner_voice_pet.config import AppConfig
from owner_voice_pet.full_duplex_audio import (
    CaptureRingBuffer,
    FakeWebRtcAudioProcessingProvider,
    NoopAudioProcessingProvider,
    RenderReferenceRingBuffer,
    build_audio_processing_provider,
    webrtc_apm_probe,
)
from owner_voice_pet.models import AudioFrame, ErrorCode, ProviderError


def frame(
    frame_id: int,
    timestamp_ms: int,
    *,
    duration_ms: int = 20,
    pcm: bytes = b"\x01\x00" * 160,
    sample_rate: int = 16000,
    channels: int = 1,
    metadata: dict[str, object] | None = None,
) -> AudioFrame:
    data = {"duration_ms": duration_ms}
    if metadata:
        data.update(metadata)
    return AudioFrame(
        pcm=pcm,
        sample_rate=sample_rate,
        channels=channels,
        timestamp_ms=timestamp_ms,
        frame_id=frame_id,
        metadata=data,
    )


class FullDuplexAudioTests(unittest.TestCase):
    def test_audio_frame_duration_and_fixture_roundtrip(self) -> None:
        original = frame(7, 140, metadata={"speech": True})

        self.assertEqual(original.duration_ms, 20)
        restored = AudioFrame.from_fixture(original.to_fixture())

        self.assertEqual(restored, original)
        self.assertTrue(restored.metadata["speech"])

    def test_capture_ring_buffer_drops_oldest_frames_on_overrun(self) -> None:
        buffer = CaptureRingBuffer(capacity_ms=40)

        first = buffer.write(frame(1, 0))
        second = buffer.write(frame(2, 20))
        third = buffer.write(frame(3, 40))

        self.assertFalse(first.overrun)
        self.assertFalse(second.overrun)
        self.assertTrue(third.overrun)
        self.assertEqual([item.frame_id for item in third.dropped], [1])
        self.assertEqual([item.frame_id for item in buffer.frames()], [2, 3])
        self.assertEqual(buffer.duration_ms, 40)

    def test_render_reference_window_uses_timestamps(self) -> None:
        buffer = RenderReferenceRingBuffer(capacity_ms=100)
        for idx, timestamp in enumerate([0, 20, 40, 60], start=1):
            buffer.write(frame(idx, timestamp))

        window = buffer.latest_window(timestamp_ms=60, window_ms=30)

        self.assertEqual([item.frame_id for item in window], [3, 4])

    def test_fake_webrtc_apm_suppresses_assistant_echo(self) -> None:
        provider = FakeWebRtcAudioProcessingProvider(sample_rate=16000, channels=1)
        provider.process_render(frame(1, 0, metadata={"assistant_audio": True}))

        processed = provider.process_capture(frame(2, 20, metadata={"assistant_echo": True, "speech": True}))

        self.assertEqual(processed.pcm, b"\x00" * len(processed.pcm))
        self.assertTrue(processed.metadata["echo_suppressed"])
        self.assertFalse(processed.metadata["speech"])

    def test_fake_webrtc_apm_rejects_format_mismatch(self) -> None:
        provider = FakeWebRtcAudioProcessingProvider(sample_rate=16000, channels=1)

        with self.assertRaises(ProviderError) as raised:
            provider.process_capture(frame(1, 0, sample_rate=8000))

        self.assertEqual(raised.exception.code, ErrorCode.AUDIO_APM_FORMAT_MISMATCH)

    def test_fake_webrtc_apm_can_report_processing_failure(self) -> None:
        provider = FakeWebRtcAudioProcessingProvider(fail_processing=True)

        with self.assertRaises(ProviderError) as raised:
            provider.process_capture(frame(1, 0))

        self.assertEqual(raised.exception.code, ErrorCode.AUDIO_APM_PROCESS_FAILED)

    def test_audio_processing_provider_uses_fake_provider(self) -> None:
        provider = build_audio_processing_provider(AppConfig(audio_apm_provider="fake"))

        self.assertIsInstance(provider, FakeWebRtcAudioProcessingProvider)
        self.assertTrue(provider.health_check().available)

    def test_required_webrtc_provider_fails_when_probe_is_unavailable(self) -> None:
        with patch("owner_voice_pet.full_duplex_audio.webrtc_apm_probe") as probe:
            probe.return_value = type(
                "Health",
                (),
                {"available": False, "message": "missing binding"},
            )()
            with self.assertRaises(ProviderError) as raised:
                build_audio_processing_provider(
                    AppConfig(audio_apm_provider="webrtc", audio_apm_required=True)
                )

        self.assertEqual(raised.exception.code, ErrorCode.AUDIO_APM_UNAVAILABLE)

    def test_webrtc_provider_can_fallback_when_not_required(self) -> None:
        with patch("owner_voice_pet.full_duplex_audio.webrtc_apm_probe") as probe:
            probe.return_value = type(
                "Health",
                (),
                {"available": False, "message": "missing binding"},
            )()
            provider = build_audio_processing_provider(
                AppConfig(audio_apm_provider="webrtc", audio_apm_required=False)
            )

        self.assertIsInstance(provider, NoopAudioProcessingProvider)
        self.assertTrue(provider.health_check().fallback_active)

    def test_webrtc_probe_reports_unavailable_without_binding(self) -> None:
        with patch("importlib.util.find_spec", return_value=None):
            health = webrtc_apm_probe()

        self.assertFalse(health.available)
        self.assertEqual(health.provider, "webrtc")


if __name__ == "__main__":
    unittest.main()