Recordly/src/hooks/useAudioLevelMeter.ts

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

export interface AudioLevelMeterOptions {
  enabled: boolean
  deviceId?: string
  smoothingFactor?: number
}

export function useAudioLevelMeter(options: AudioLevelMeterOptions) {
  const [level, setLevel] = useState(0)
  const audioContextRef = useRef<AudioContext | null>(null)
  const analyserRef = useRef<AnalyserNode | null>(null)
  const streamRef = useRef<MediaStream | null>(null)
  const animationFrameRef = useRef<number | null>(null)

  useEffect(() => {
    const cleanup = () => {
      if (animationFrameRef.current) {
        cancelAnimationFrame(animationFrameRef.current)
        animationFrameRef.current = null
      }
      if (streamRef.current) {
        streamRef.current.getTracks().forEach((track) => track.stop())
        streamRef.current = null
      }
      if (audioContextRef.current) {
        audioContextRef.current.close().catch(() => {})
        audioContextRef.current = null
      }
      analyserRef.current = null
    }

    if (!options.enabled) {
      cleanup()
      setLevel(0)
      return cleanup
    }

    let mounted = true

    const startMonitoring = async () => {
      try {
        const constraints: MediaStreamConstraints = {
          audio: options.deviceId ? { deviceId: { exact: options.deviceId } } : true,
          video: false,
        }

        const stream = await navigator.mediaDevices.getUserMedia(constraints)
        if (!mounted) {
          stream.getTracks().forEach((track) => track.stop())
          return
        }

        streamRef.current = stream

        const audioContext = new AudioContext()
        if (audioContext.state === 'suspended') {
          await audioContext.resume()
        }
        audioContextRef.current = audioContext

        const analyser = audioContext.createAnalyser()
        analyser.fftSize = 256
        analyser.smoothingTimeConstant = options.smoothingFactor ?? 0.8
        analyserRef.current = analyser

        const source = audioContext.createMediaStreamSource(stream)
        source.connect(analyser)

        const dataArray = new Uint8Array(analyser.frequencyBinCount)

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

          analyser.getByteFrequencyData(dataArray)

          let sum = 0
          for (let index = 0; index < dataArray.length; index++) {
            sum += dataArray[index] * dataArray[index]
          }

          const rms = Math.sqrt(sum / dataArray.length)
          const normalizedLevel = Math.min(100, (rms / 255) * 100 * 2)
          setLevel(normalizedLevel)
          animationFrameRef.current = requestAnimationFrame(updateLevel)
        }

        updateLevel()
      } catch (error) {
        console.error('Error starting audio level monitoring:', error)
        if (mounted) {
          setLevel(0)
        }
      }
    }

    void startMonitoring()

    return () => {
      mounted = false
      cleanup()
    }
  }, [options.deviceId, options.enabled, options.smoothingFactor])

  return { level }
}