"""
TTS 服务集成模块

提供高层 TTS 服务接口，直接使用配置文件中的 TTS 设置。
"""

from io import BytesIO
from typing import Optional
from config.settings import settings
from tts.factory import TTSEngineFactory
from tts.base import TTSEngine
from utils.logger import logger


class TTSService:
    """
    TTS 服务
    
    提供统一的 TTS 调用接口，自动使用配置文件中的引擎和参数。
    """

    _engine: Optional[TTSEngine] = None

    @classmethod
    def _get_engine(cls) -> TTSEngine:
        """
        获取 TTS 引擎实例

        Returns:
            TTSEngine 实例
        """
        if cls._engine is None:
            cls._engine = TTSEngineFactory.create(settings.TTS_ENGINE)
            logger.info(
                f"TTS Service initialized with engine: {settings.TTS_ENGINE}"
            )
        return cls._engine

    @classmethod
    async def synthesize(
        cls,
        text: str,
        language: Optional[str] = None,
        voice: Optional[str] = None,
        rate: Optional[float] = None,
        pitch: Optional[float] = None,
    ) -> BytesIO:
        """
        将文本合成为语音

        Args:
            text: 要合成的文本
            language: 语言代码，默认使用配置文件中的 TTS_LANGUAGE
            voice: 声音 ID，默认使用配置文件中的 TTS_VOICE
            rate: 语速，默认使用配置文件中的 TTS_RATE
            pitch: 音调，默认使用配置文件中的 TTS_PITCH

        Returns:
            BytesIO 对象，包含合成后的音频数据
        """
        engine = cls._get_engine()

        # 使用配置文件中的默认值
        language = language or settings.TTS_LANGUAGE
        voice = voice or settings.TTS_VOICE or None
        rate = rate or settings.TTS_RATE
        pitch = pitch or settings.TTS_PITCH

        logger.debug(f"Synthesizing text with TTS Service: {text[:50]}...")

        return await engine.synthesize(
            text=text,
            language=language,
            voice=voice,
            rate=rate,
            pitch=pitch,
        )

    @classmethod
    async def get_supported_voices(cls, language: Optional[str] = None) -> list[dict]:
        """
        获取支持的声音列表

        Args:
            language: 语言代码，默认使用配置文件中的 TTS_LANGUAGE

        Returns:
            声音列表
        """
        engine = cls._get_engine()
        language = language or settings.TTS_LANGUAGE
        return await engine.get_supported_voices(language)

    @classmethod
    def get_engine_info(cls) -> dict:
        """
        获取当前 TTS 引擎信息

        Returns:
            包含引擎名称、版本、当前配置等信息的字典
        """
        engine = cls._get_engine()
        return {
            "engine_name": engine.get_engine_name(),
            "engine_version": engine.get_engine_version(),
            "config": {
                "language": settings.TTS_LANGUAGE,
                "voice": settings.TTS_VOICE or "default",
                "rate": settings.TTS_RATE,
                "pitch": settings.TTS_PITCH,
            },
        }

    @classmethod
    def reset_engine(cls) -> None:
        """重置 TTS 引擎实例（仅在切换引擎时需要调用）"""
        cls._engine = None
        TTSEngineFactory.clear_instances()
        logger.info("TTS Service engine reset")