import os
import requests

def synthesize_cosyvoice(text, speed=1.0, pitch=0, volume=1.0, instruction=None):
    """调用阿里云百炼CosyVoice API"""
    api_key = os.getenv('DASHSCOPE_API_KEY', '')
    if not api_key:
        raise ValueError('DASHSCOPE_API_KEY未设置')
    
    url = 'https://dashscope.aliyuncs.com/api/v1/services/audio/tts/SpeechSynthesizer'
    headers = {
        'Authorization': f'Bearer {api_key}',
        'Content-Type': 'application/json'
    }
    
    # 前端 pitch: -12~12 → API rate: 0.5~2.0（以1.0为中心）
    pitch_ratio = max(0.5, min(2.0, 1.0 + pitch / 24))
    # 前端 volume: 0~10 → API volume: 0~100
    volume_int = int(max(0, min(100, volume * 10)))

    payload = {
        'model': 'cosyvoice-v3.5-flash',
        'input': {
            'text': text,
            'voice': 'cosyvoice-v3.5-flash-bailian-e859a6e87823419f9c6b3eefb1a97dc3',
            'format': 'mp3',
            'sample_rate': 32000
        },
        'parameters': {
            'rate': max(0.5, min(2.0, speed)),
            'pitch': pitch_ratio,
            'volume': volume_int
        }
    }
    
    response = requests.post(url, json=payload, headers=headers, timeout=60)
    
    if response.status_code == 402 or response.status_code == 403:
        raise Exception('CosyVoice 账户欠费或权限不足，请联系管理员')
    if response.status_code == 401:
        raise Exception('CosyVoice API密钥无效，请联系管理员')
    if response.status_code == 429:
        raise Exception('CosyVoice 请求过于频繁，请稍后再试')
    if response.status_code != 200:
        raise Exception(f'CosyVoice 服务异常({response.status_code})，请稍后再试')
    
    result = response.json()
    
    # 阿里云返回JSON格式，音频数据在 output.audio.url 字段
    if 'output' in result and 'audio' in result['output']:
        audio_url = result['output']['audio'].get('url')
        if audio_url:
            # 从URL下载实际音频
            audio_response = requests.get(audio_url, timeout=60)
            if audio_response.status_code == 200:
                return audio_response.content
            raise Exception(f'下载音频失败: {audio_response.status_code}')
    
    raise Exception(f'CosyVoice返回格式异常: {result}')