import io
import logging
import time

from fastapi import APIRouter, HTTPException, Request, Response
from pydantic import BaseModel, Field
from pydub import AudioSegment

from .metrics import limiter, _synthesis_latency, _audio_size_bytes, _errors_total
from .engine import get_model
from .pipeline import process_tts
from .validators import validate_text, validate_speaker

logger = logging.getLogger(__name__)
router = APIRouter()

# Доступные голоса v5_5_ru (5 голосов для русского языка)
SPEAKERS = {
    "aidar": "Мужской, нейтральный",
    "baya": "Женский, мягкий",
    "kseniya": "Женский, энергичный",
    "eugene": "Мужской, спокойный",
    "xenia": "Женский, молодой",
}

# Маппинг OpenAI голосов → Silero голоса
# Модель v5_5_ru поддерживает: aidar, baya, kseniya, eugene, xenia
OPENAI_VOICE_MAP = {
    "alloy": "aidar",        # мужской, нейтральный
    "echo": "eugene",        # мужской, спокойный
    "fable": "baya",         # женский, мягкий
    "onyx": "aidar",         # fallback на aidar (нет ruslan в v5_5_ru)
    "nova": "kseniya",       # женский, энергичный
    "shimmer": "xenia",      # женский, молодой
}


# ─── Модели ────────────────────────────────────────────────────────


class TTSRequest(BaseModel):
    text: str = Field(..., min_length=1, max_length=4000, description="Текст для синтеза")
    speaker: str = Field(default="aidar", description="Голос")
    speed: float = Field(default=1.0, ge=0.5, le=2.0, description="Скорость (0.5x - 2.0x)")


class VoicesResponse(BaseModel):
    speakers: dict
    sample_rate: int = 48000


class OpenAITTSRequest(BaseModel):
    """OpenAI-совместимый TTS запрос"""
    model: str = "tts-1"
    input: str = Field(..., min_length=1, max_length=4000)
    voice: str = "alloy"
    response_format: str = "wav"
    speed: float = 1.0


# ─── Роуты ─────────────────────────────────────────────────────────


@router.get("/v1/models", tags=["openai"])
async def list_openai_models():
    """OpenAI-совместимый список моделей"""
    return {
        "object": "list",
        "data": [
            {"id": "tts-1", "object": "model", "created": 1700000000, "owned_by": "silero"},
            {"id": "tts-1-hd", "object": "model", "created": 1700000000, "owned_by": "silero"},
        ]
    }


@router.get("/v1/audio/voices", tags=["metadata"])
async def list_voices():
    """Список голосов: OpenAI + нативные Silero"""
    openai_voices = {k: f"{v} → Silero: {OPENAI_VOICE_MAP.get(k, k)}" for k, v in {
        "alloy": "мужской, нейтральный",
        "echo": "мужской, спокойный",
        "fable": "женский, мягкий",
        "onyx": "мужской (→ aidar)",
        "nova": "женский, энергичный",
        "shimmer": "женский, молодой",
    }.items()}
    return {"voices": {**openai_voices, **SPEAKERS}}


@router.get("/v1/voices", response_model=VoicesResponse, tags=["metadata"])
async def list_voices_legacy():
    """Список голосов (совместимость с Silero API)"""
    return VoicesResponse(speakers=SPEAKERS)


@router.get("/v1/health", tags=["metadata"])
async def health_check():
    """Проверка здоровья сервиса"""
    try:
        model, device = get_model()
        return {
            "status": "healthy",
            "model_loaded": True,
            "device": str(device),
        }
    except Exception as e:
        return {
            "status": "unhealthy",
            "model_loaded": False,
            "error": str(e),
        }


@router.post(
    "/v1/audio/speech",
    response_class=Response,
    responses={200: {"content": {"audio/wav": {}}, "description": "WAV audio"}},
    tags=["openai"],
)
async def synthesize_openai(req: OpenAITTSRequest, request: Request):
    """
    OpenAI-совместимый TTS эндпоинт.

    Принимает голоса двумя способами:
    1. OpenAI: alloy, echo, fable, onyx, nova, shimmer → автоматический маппинг
    2. Нативные Silero: aidar, baya, kseniya, eugene, xenia → прямой проход
    """
    start = time.time()

    # Сначала проверяем нативный Silero голос, потом маппинг OpenAI
    if req.voice in SPEAKERS:
        speaker = req.voice
    elif req.voice in OPENAI_VOICE_MAP:
        speaker = OPENAI_VOICE_MAP[req.voice]
    else:
        raise HTTPException(
            status_code=400,
            detail=f"Неизвестный голос '{req.voice}'. "
                   f"OpenAI: {', '.join(OPENAI_VOICE_MAP.keys())} | "
                   f"Silero: {', '.join(SPEAKERS.keys())}",
        )

    try:
        validate_speaker(speaker, SPEAKERS)
        text = validate_text(req.input)

        settings = request.app.state.config

        wav_data = await process_tts(
            text=text,
            speaker=speaker,
            sample_rate=settings.sample_rate,
        )

        duration = time.time() - start
        _synthesis_latency.labels(voice=speaker).observe(duration)
        _audio_size_bytes.labels(voice=speaker).observe(len(wav_data))

        # OpenAI API возвращает audio/wav по умолчанию
        return Response(
            content=wav_data,
            media_type="audio/wav",
            headers={
                "Content-Disposition": 'attachment; filename="tts.wav"',
            },
        )

    except HTTPException:
        _errors_total.labels(error_type="validation").inc()
        raise
    except Exception as e:
        _errors_total.labels(error_type="synthesis").inc()
        logger.error("Ошибка синтеза: %s", str(e), exc_info=True)
        raise HTTPException(
            status_code=500,
            detail=f"Ошибка синтеза: {str(e)}",
        )


@router.post(
    "/v1/tts",
    responses={200: {"content": {"audio/wav": {}}, "description": "WAV audio"}},
    tags=["tts"],
)
@limiter.limit("500/minute")
async def synthesize_tts(req: TTSRequest, request: Request):
    """Синтез речи в WAV формате (родной Silero API)"""
    start = time.time()

    try:
        validate_speaker(req.speaker, SPEAKERS)
        text = validate_text(req.text)

        settings = request.app.state.config

        wav_data = await process_tts(
            text=text,
            speaker=req.speaker,
            sample_rate=settings.sample_rate,
        )

        duration = time.time() - start
        _synthesis_latency.labels(voice=req.speaker).observe(duration)
        _audio_size_bytes.labels(voice=req.speaker).observe(len(wav_data))

        return Response(
            content=wav_data,
            media_type="audio/wav",
            headers={
                "Content-Disposition": 'attachment; filename="tts.wav"',
            },
        )

    except HTTPException:
        _errors_total.labels(error_type="validation").inc()
        raise
    except Exception as e:
        _errors_total.labels(error_type="synthesis").inc()
        logger.error("Ошибка синтеза: %s", str(e), exc_info=True)
        raise HTTPException(
            status_code=500,
            detail=f"Ошибка синтеза: {str(e)}",
        )


@router.post(
    "/v1/tts-stream",
    responses={200: {"content": {"audio/mpeg": {}}, "description": "Streamed MP3"}},
    tags=["tts"],
)
@limiter.limit("10/minute")
async def synthesize_tts_stream(req: TTSRequest, request: Request):
    """Синтез речи потоком в MP3 (chunked transfer)"""
    start = time.time()

    if req.speaker != "aidar":
        raise HTTPException(status_code=400, detail="Стриминг поддерживает только голос 'aidar'")

    if len(req.text) > 500:
        raise HTTPException(status_code=400, detail="Максимум 500 символов для стрима")

    try:
        settings = request.app.state.config

        wav_data = await process_tts(
            text=validate_text(req.text),
            speaker=req.speaker,
            sample_rate=settings.sample_rate,
        )

        audio_segment = AudioSegment(
            wav_data,
            sample_width=2,
            channels=1,
            frame_rate=48000,
        )
        mp3_data = io.BytesIO()
        audio_segment.export(mp3_data, format="mp3", bitrate="192k")
        mp3_data.seek(0)
        mp3_bytes = mp3_data.read()

        duration = time.time() - start
        _synthesis_latency.labels(voice="aidar").observe(duration)
        _audio_size_bytes.labels(voice="aidar").observe(len(mp3_bytes))

        return Response(
            content=mp3_bytes,
            media_type="audio/mpeg",
            headers={
                "Transfer-Encoding": "chunked",
                "Content-Disposition": 'inline; filename="tts.mp3"',
            },
        )

    except HTTPException:
        _errors_total.labels(error_type="stream_validation").inc()
        raise
    except Exception as e:
        _errors_total.labels(error_type="stream_synthesis").inc()
        logger.error("Ошибка стриминга: %s", str(e), exc_info=True)
        raise HTTPException(
            status_code=500,
            detail=f"Ошибка стриминга: {str(e)}",
        )