import { useCallback, useEffect, useRef, useState } from 'react';

interface AudioActivityConfig {
  threshold?: number; // 音频阈值，默认 30
  sampleRate?: number; // 采样率，默认 100ms
  smoothingTimeConstant?: number; // 平滑常数，默认 0.8
  fftSize?: number; // FFT 大小，默认 1024
}

interface UseAudioActivityDetectionReturn {
  isDetecting: boolean;
  isSpeaking: boolean;
  audioLevel: number;
  startDetection: (stream: MediaStream) => void;
  stopDetection: () => void;
  error: string | null;
}

export function useAudioActivityDetection(
  config: AudioActivityConfig = {}
): UseAudioActivityDetectionReturn {
  const {
    threshold = 30,
    sampleRate = 100,
    smoothingTimeConstant = 0.8,
    fftSize = 1024,
  } = config;

  const [isDetecting, setIsDetecting] = useState(false);
  const [isSpeaking, setIsSpeaking] = useState(false);
  const [audioLevel, setAudioLevel] = useState(0);
  const [error, setError] = useState<string | null>(null);

  const audioContextRef = useRef<AudioContext | null>(null);
  const analyserRef = useRef<AnalyserNode | null>(null);
  const microphoneRef = useRef<MediaStreamAudioSourceNode | null>(null);
  const animationFrameRef = useRef<number | null>(null);
  const intervalRef = useRef<NodeJS.Timeout | null>(null);

  // 音频分析函数
  const analyzeAudio = useCallback(() => {
    if (!analyserRef.current) return;

    const analyser = analyserRef.current;
    const bufferLength = analyser.frequencyBinCount;
    const dataArray = new Uint8Array(bufferLength);

    const checkAudioLevel = () => {
      if (!analyser) return;

      analyser.getByteFrequencyData(dataArray);

      // 计算平均音量
      let sum = 0;
      for (let i = 0; i < bufferLength; i++) {
        sum += dataArray[i];
      }
      const average = sum / bufferLength;

      setAudioLevel(average);

      // 判断是否在说话
      const currentlySpeaking = average > threshold;
      setIsSpeaking(currentlySpeaking);

      // 调试日志
      if (process.env.NODE_ENV === 'development') {
        // console.log('Audio Level:', average, 'Speaking:', currentlySpeaking);
      }
    };

    // 使用定时器而不是 requestAnimationFrame 以确保稳定的采样率
    intervalRef.current = setInterval(checkAudioLevel, sampleRate);
  }, [threshold, sampleRate]);

  // 开始检测
  const startDetection = useCallback(async (stream: MediaStream) => {
    try {
      setError(null);
      
      // 创建音频上下文
      if (!audioContextRef.current) {
        audioContextRef.current = new (window.AudioContext || (window as any).webkitAudioContext)();
      }

      const audioContext = audioContextRef.current;

      // 确保音频上下文处于运行状态
      if (audioContext.state === 'suspended') {
        await audioContext.resume();
      }

      // 创建分析器
      const analyser = audioContext.createAnalyser();
      analyser.smoothingTimeConstant = smoothingTimeConstant;
      analyser.fftSize = fftSize;

      // 创建音频源
      const microphone = audioContext.createMediaStreamSource(stream);
      microphone.connect(analyser);

      analyserRef.current = analyser;
      microphoneRef.current = microphone;

      setIsDetecting(true);
      analyzeAudio();

      console.log('音频活动检测已启动');
    } catch (err) {
      console.error('启动音频检测失败:', err);
      setError(err instanceof Error ? err.message : '启动音频检测失败');
    }
  }, [analyzeAudio, smoothingTimeConstant, fftSize]);

  // 停止检测
  const stopDetection = useCallback(() => {
    // 清除定时器
    if (intervalRef.current) {
      clearInterval(intervalRef.current);
      intervalRef.current = null;
    }

    // 清除动画帧
    if (animationFrameRef.current) {
      cancelAnimationFrame(animationFrameRef.current);
      animationFrameRef.current = null;
    }

    // 断开音频连接
    if (microphoneRef.current) {
      microphoneRef.current.disconnect();
      microphoneRef.current = null;
    }

    // 清理分析器
    analyserRef.current = null;

    // 关闭音频上下文
    if (audioContextRef.current && audioContextRef.current.state !== 'closed') {
      audioContextRef.current.close();
      audioContextRef.current = null;
    }

    setIsDetecting(false);
    setIsSpeaking(false);
    setAudioLevel(0);
    setError(null);

    console.log('音频活动检测已停止');
  }, []);

  // 组件卸载时清理
  useEffect(() => {
    return () => {
      stopDetection();
    };
  }, [stopDetection]);

  return {
    isDetecting,
    isSpeaking,
    audioLevel,
    startDetection,
    stopDetection,
    error,
  };
}