/// <reference types="@types/dom-speech-recognition" />
'use client'

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

type VoiceState = 'idle' | 'listening' | 'processing' | 'error'

interface UseVoiceTranscriptionOptions {
  onTranscript: (text: string) => void
  onError?: (message: string) => void
  lang?: string
}

export function useVoiceTranscription({ onTranscript, onError, lang = 'fr-FR' }: UseVoiceTranscriptionOptions) {
  const [state, setState] = useState<VoiceState>('idle')
  const recognitionRef = useRef<SpeechRecognition | null>(null)
  const accumulatedRef = useRef<string>('')

  const isSupported =
    typeof window !== 'undefined' &&
    ('SpeechRecognition' in window || 'webkitSpeechRecognition' in window)

  const start = useCallback(() => {
    if (!isSupported) {
      onError?.('La reconnaissance vocale n\'est pas disponible sur ce navigateur.')
      setState('error')
      return
    }

    const SR = (window as any).SpeechRecognition || (window as any).webkitSpeechRecognition
    const rec: SpeechRecognition = new SR()
    rec.lang = lang
    rec.continuous = true
    rec.interimResults = false
    accumulatedRef.current = ''

    rec.onstart = () => setState('listening')

    rec.onresult = (event: SpeechRecognitionEvent) => {
      let transcript = ''
      for (let i = event.resultIndex; i < event.results.length; i++) {
        if (event.results[i].isFinal) {
          transcript += event.results[i][0].transcript
        }
      }
      if (transcript) accumulatedRef.current += (accumulatedRef.current ? ' ' : '') + transcript
    }

    rec.onerror = (event: SpeechRecognitionErrorEvent) => {
      console.error('[voice] SpeechRecognition error:', event.error)
      onError?.(event.error === 'not-allowed' ? 'Microphone non autorisé.' : `Erreur: ${event.error}`)
      setState('error')
    }

    rec.onend = () => {
      setState('idle')
      if (accumulatedRef.current.trim()) {
        onTranscript(accumulatedRef.current.trim())
        accumulatedRef.current = ''
      }
    }

    recognitionRef.current = rec
    rec.start()
  }, [isSupported, lang, onTranscript, onError])

  const stop = useCallback(() => {
    recognitionRef.current?.stop()
    recognitionRef.current = null
  }, [])

  const toggle = useCallback(() => {
    if (state === 'listening') {
      stop()
    } else {
      start()
    }
  }, [state, start, stop])

  useEffect(() => {
    return () => {
      recognitionRef.current?.stop()
    }
  }, [])

  return { state, toggle, start, stop, isSupported }
}