"""
音频处理辅助工具
支持格式转换、音频切片等
"""

import os
import subprocess
from typing import Tuple, Optional
import numpy as np


def get_audio_info(audio_path: str) -> dict:
    """
    获取音频文件信息
    
    Returns:
        dict: {
            "duration": float,  # 秒
            "sample_rate": int,
            "channels": int,
            "format": str
        }
    """
    try:
        import soundfile as sf
        info = sf.info(audio_path)
        return {
            "duration": info.duration,
            "sample_rate": info.samplerate,
            "channels": info.channels,
            "format": info.format
        }
    except ImportError:
        # 降级方案：使用 ffprobe
        import json
        cmd = [
            "ffprobe", "-v", "quiet",
            "-print_format", "json",
            "-show_format", "-show_streams",
            audio_path
        ]
        result = subprocess.run(cmd, capture_output=True, text=True)
        data = json.loads(result.stdout)
        
        audio_stream = next((s for s in data.get("streams", []) if s.get("codec_type") == "audio"), {})
        duration = float(data.get("format", {}).get("duration", 0))
        
        return {
            "duration": duration,
            "sample_rate": int(audio_stream.get("sample_rate", 16000)),
            "channels": int(audio_stream.get("channels", 1)),
            "format": audio_stream.get("codec_name", "unknown")
        }


def convert_to_wav(input_path: str, output_path: Optional[str] = None, sample_rate: int = 16000) -> str:
    """
    转换音频为 WAV 格式（16kHz 单声道）
    
    Args:
        input_path: 输入文件路径
        output_path: 输出文件路径（可选）
        sample_rate: 采样率，默认 16000
    
    Returns:
        输出文件路径
    """
    if output_path is None:
        output_path = tempfile.NamedTemporaryFile(suffix=".wav", delete=False).name
    
    cmd = [
        "ffmpeg", "-y",  # 覆盖已存在的文件
        "-i", input_path,
        "-ar", str(sample_rate),  # 采样率
        "-ac", "1",  # 单声道
        "-acodec", "pcm_s16le",  # 16bit PCM
        output_path
    ]
    
    subprocess.run(cmd, capture_output=True, check=True)
    return output_path


def slice_audio(audio_path: str, start: float, end: float, output_path: Optional[str] = None) -> str:
    """
    切片音频
    
    Args:
        audio_path: 输入文件路径
        start: 开始时间（秒）
        end: 结束时间（秒）
        output_path: 输出文件路径
    
    Returns:
        输出文件路径
    """
    if output_path is None:
        output_path = tempfile.NamedTemporaryFile(suffix=".wav", delete=False).name
    
    cmd = [
        "ffmpeg", "-y",
        "-i", audio_path,
        "-ss", str(start),
        "-to", str(end),
        "-c", "copy",  # 无损复制
        output_path
    ]
    
    subprocess.run(cmd, capture_output=True, check=True)
    return output_path


def merge_audio(audio_paths: list, output_path: Optional[str] = None) -> str:
    """
    合并多个音频文件
    
    Args:
        audio_paths: 音频文件路径列表
        output_path: 输出文件路径
    
    Returns:
        输出文件路径
    """
    if output_path is None:
        output_path = tempfile.NamedTemporaryFile(suffix=".wav", delete=False).name
    
    # 创建临时文件列表
    list_file = tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False)
    for path in audio_paths:
        list_file.write(f"file '{path}'\n")
    list_file.close()
    
    cmd = [
        "ffmpeg", "-y",
        "-f", "concat",
        "-safe", "0",
        "-i", list_file.name,
        "-c", "copy",
        output_path
    ]
    
    subprocess.run(cmd, capture_output=True, check=True)
    
    # 清理临时文件
    os.unlink(list_file.name)
    
    return output_path


def is_ffmpeg_available() -> bool:
    """检查 ffmpeg 是否可用"""
    try:
        subprocess.run(["ffmpeg", "-version"], capture_output=True, check=True)
        return True
    except (subprocess.CalledProcessError, FileNotFoundError):
        return False


if __name__ == "__main__":
    # 测试
    print("FFmpeg 可用:", is_ffmpeg_available())