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

interface AudioLevelHookResult {
  audioLevel: number; // 0-100 percentage
  isAnalyzing: boolean;
}

export const useAudioLevel = (stream: MediaStream | null): AudioLevelHookResult => {
  const [audioLevel, setAudioLevel] = useState(0);
  const [isAnalyzing, setIsAnalyzing] = useState(false);
  const audioContextRef = useRef<AudioContext | null>(null);
  const analyserRef = useRef<AnalyserNode | null>(null);
  const sourceRef = useRef<MediaStreamAudioSourceNode | null>(null);
  const animationFrameRef = useRef<number | null>(null);

  useEffect(() => {
    if (!stream) {
      // Clean up when stream is null
      if (animationFrameRef.current) {
        cancelAnimationFrame(animationFrameRef.current);
        animationFrameRef.current = null;
      }
      if (sourceRef.current) {
        sourceRef.current.disconnect();
        sourceRef.current = null;
      }
      if (audioContextRef.current) {
        audioContextRef.current.close();
        audioContextRef.current = null;
      }
      analyserRef.current = null;
      setIsAnalyzing(false);
      setAudioLevel(0);
      return;
    }

    const audioTracks = stream.getAudioTracks();
    if (audioTracks.length === 0) {
      setIsAnalyzing(false);
      setAudioLevel(0);
      return;
    }

    try {
      // Create audio context and analyser
      const audioContext = new (window.AudioContext || (window as Window & { webkitAudioContext?: typeof AudioContext }).webkitAudioContext)();
      const analyser = audioContext.createAnalyser();
      const source = audioContext.createMediaStreamSource(stream);

      // Configure analyser
      analyser.fftSize = 256;
      analyser.smoothingTimeConstant = 0.8;
      
      // Connect nodes
      source.connect(analyser);

      // Store references
      audioContextRef.current = audioContext;
      analyserRef.current = analyser;
      sourceRef.current = source;

      const dataArray = new Uint8Array(analyser.frequencyBinCount);

      const updateLevel = () => {
        if (!analyserRef.current) return;

        analyserRef.current.getByteFrequencyData(dataArray);
        
        // Calculate RMS (Root Mean Square) for more accurate level representation
        let sum = 0;
        for (const value of dataArray) {
          sum += value * value;
        }
        const rms = Math.sqrt(sum / dataArray.length);
        
        // Convert to percentage (0-100)
        const level = Math.min(100, (rms / 255) * 100);
        setAudioLevel(level);

        animationFrameRef.current = requestAnimationFrame(updateLevel);
      };

      setIsAnalyzing(true);
      updateLevel();

    } catch (error) {
      console.error('Failed to create audio level analyzer:', error);
      setIsAnalyzing(false);
      setAudioLevel(0);
    }

    // Cleanup function
    return () => {
      if (animationFrameRef.current) {
        cancelAnimationFrame(animationFrameRef.current);
        animationFrameRef.current = null;
      }
      if (sourceRef.current) {
        sourceRef.current.disconnect();
        sourceRef.current = null;
      }
      if (audioContextRef.current) {
        audioContextRef.current.close();
        audioContextRef.current = null;
      }
      analyserRef.current = null;
      setIsAnalyzing(false);
      setAudioLevel(0);
    };
  }, [stream]);

  return { audioLevel, isAnalyzing };
};