"""
TTS 服务：文字转语音
"""
import base64
import os
from io import BytesIO

from openai import OpenAI


class TTSService:
    """TTS 服务（文字转语音）"""
    
    def __init__(self):
        api_key = os.getenv("OPENAI_API_KEY", "")
        if api_key:
            self.client = OpenAI(api_key=api_key)
        else:
            self.client = None
    
    async def synthesize(self, text: str) -> str:
        """
        将文字转换为语音
        
        Args:
            text: 要转换的文字
        
        Returns:
            Base64 编码的音频数据
        """
        if not self.client:
            # 如果没有配置 API Key，返回空字符串
            return ""
        
        try:
            # 调用 OpenAI TTS API
            response = self.client.audio.speech.create(
                model="tts-1",
                voice="alloy",  # 可选: alloy, echo, fable, onyx, nova, shimmer
                input=text
            )
            
            # 读取音频数据
            audio_bytes = BytesIO()
            for chunk in response.iter_bytes():
                audio_bytes.write(chunk)
            
            # 转换为 Base64
            audio_data = audio_bytes.getvalue()
            audio_base64 = base64.b64encode(audio_data).decode('utf-8')
            return audio_base64
        except Exception as e:
            # 出错时返回空字符串
            print(f"TTS 生成失败: {str(e)}")
            return ""


# 全局实例
tts_service = TTSService()