"""
ASR 服务：语音转文字
"""
import base64
import os

from openai import OpenAI


class ASRService:
    """ASR 服务（语音转文字）"""
    
    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 transcribe(self, audio_base64: str) -> str | None:
        """
        转写音频为文字
        
        Args:
            audio_base64: Base64 编码的音频数据
        
        Returns:
            转写文本
        """
        if not self.client:
            # 如果没有配置 API Key，返回模拟数据
            return "这是模拟的转写文本（请配置 OPENAI_API_KEY 以使用实际 ASR 功能）"
        
        try:
            # 解码 Base64 音频
            audio_bytes = base64.b64decode(audio_base64)
            
            # 保存临时文件
            import tempfile
            with tempfile.NamedTemporaryFile(suffix=".m4a", delete=False) as tmp_file:
                tmp_file.write(audio_bytes)
                tmp_file_path = tmp_file.name
            
            try:
                # 调用 OpenAI Whisper API
                with open(tmp_file_path, "rb") as audio_file:
                    transcript = self.client.audio.transcriptions.create(
                        model="whisper-1",
                        file=audio_file,
                        language="zh"  # 中文
                    )
                return transcript.text
            finally:
                # 清理临时文件
                import os
                if os.path.exists(tmp_file_path):
                    os.remove(tmp_file_path)
        except Exception as e:
            # 出错时返回错误信息
            return f"转写失败: {str(e)}"


# 全局实例
asr_service = ASRService()