import React, { useState, useRef, useCallback, useEffect } from 'react'
import { Avatar } from '../components/Avatar'
import { RecordButton } from '../components/RecordButton'
import { ModeBadge } from '../components/ModeBadge'
import { Stats } from '../components/Stats'
import { useWebSocket } from '../hooks/useWebSocket'
import { useMediaRecorder } from '../hooks/useMediaRecorder'
import { useUDPDetection, ICE_SERVERS } from '../hooks/useUDPDetection'
import { useH264Decoder } from '../hooks/useH264Decoder'

export function AutoPage() {
  // Refs
  const rtcVideoRef = useRef(null)
  const canvasRef = useRef(null)
  const audioRef = useRef(null)
  const pcRef = useRef(null)

  // State
  const [mode, setMode] = useState('detecting')
  const [responseText, setResponseText] = useState('Verificando conectividade...')
  const [wsStatusDot, setWsStatusDot] = useState(null)
  const [rtcStatusDot, setRtcStatusDot] = useState(null)
  const [udpStatusDot, setUdpStatusDot] = useState(null)
  const [showRtcVideo, setShowRtcVideo] = useState(false)
  const [showCanvas, setShowCanvas] = useState(false)
  const [stats, setStats] = useState({ frameCount: 0, fps: null, latency: null })
  const [modeInfo, setModeInfo] = useState('Detectando automaticamente o melhor modo de streaming...')

  // Timing refs
  const startTimeRef = useRef(0)
  const frameCountRef = useRef(0)
  const totalBytesRef = useRef(0)

  // Hooks
  const { udpAvailable, detecting } = useUDPDetection()
  const { isSupported: webCodecsSupported, initDecoder, decodeFrame, close: closeDecoder } = useH264Decoder(canvasRef)

  // Determine best mode after UDP detection
  useEffect(() => {
    if (!detecting) {
      if (udpAvailable) {
        setMode('webrtc')
        setModeInfo('UDP detectado! Usando WebRTC para latencia minima.')
        setRtcStatusDot('connected')
      } else if (webCodecsSupported) {
        setMode('h264')
        setModeInfo('UDP nao disponivel. Usando H.264 via WebSocket.')
        setUdpStatusDot('warning')
      } else {
        setMode('jpeg')
        setModeInfo('WebCodecs nao suportado. Usando JPEG.')
        setUdpStatusDot('error')
      }
    }
  }, [detecting, udpAvailable, webCodecsSupported])

  // Update stats display
  const updateStats = useCallback(() => {
    const elapsed = (Date.now() - startTimeRef.current) / 1000
    setStats(prev => ({
      ...prev,
      frameCount: frameCountRef.current,
      fps: elapsed > 0 ? (frameCountRef.current / elapsed).toFixed(1) : null
    }))
  }, [])

  // Handle WebRTC offer
  const handleRTCOffer = useCallback(async (data, send) => {
    if (mode !== 'webrtc') return

    const pc = new RTCPeerConnection({ iceServers: ICE_SERVERS })
    pcRef.current = pc

    pc.ontrack = (event) => {
      console.log('[WebRTC] Got track:', event.track.kind)
      if (event.track.kind === 'video') {
        if (rtcVideoRef.current) {
          rtcVideoRef.current.srcObject = event.streams[0]
        }
        setShowRtcVideo(true)
        setRtcStatusDot('streaming')
      }
    }

    pc.onicecandidate = (event) => {
      if (event.candidate) {
        send({ type: 'rtc_candidate', candidate: event.candidate })
      }
    }

    pc.oniceconnectionstatechange = () => {
      console.log('[WebRTC] ICE state:', pc.iceConnectionState)
      if (pc.iceConnectionState === 'connected') {
        setRtcStatusDot('connected')
      } else if (pc.iceConnectionState === 'failed') {
        setRtcStatusDot('error')
        // Fallback
        const fallbackMode = webCodecsSupported ? 'h264' : 'jpeg'
        setMode(fallbackMode)
      }
    }

    await pc.setRemoteDescription(new RTCSessionDescription(data.offer))
    const answer = await pc.createAnswer()
    await pc.setLocalDescription(answer)

    send({ type: 'rtc_answer', answer })
  }, [mode, webCodecsSupported])

  // WebSocket message handler
  const handleMessage = useCallback(async (data) => {
    if (data.type === 'binary') {
      // H.264 binary frame
      if (mode !== 'h264') return
      const view = new Uint8Array(data.data)
      const frameType = view[0]
      const frameData = view.slice(1)

      if (frameType === 0x00) {
        console.log('[H264] Codec config:', frameData.length, 'bytes')
        return
      }

      const isKeyframe = frameType === 0x01
      totalBytesRef.current += frameData.length
      decodeFrame(frameData, isKeyframe)
      frameCountRef.current++
      updateStats()
      return
    }

    switch (data.type) {
      case 'status':
        setResponseText(data.message)
        break

      case 'transcription':
        setResponseText(`"${data.text}"`)
        break

      case 'response':
        setResponseText(data.text)
        break

      case 'audio':
        if (audioRef.current) {
          // Use root path for API URLs
          audioRef.current.src = data.url.startsWith('/') ? data.url : '/' + data.url
          audioRef.current.load()
        }
        break

      case 'info':
        frameCountRef.current = 0
        totalBytesRef.current = 0
        startTimeRef.current = Date.now()
        setStats(prev => ({ ...prev, frameCount: 0 }))

        if (mode === 'h264' && data.codec === 'h264') {
          setShowCanvas(true)
          await initDecoder(256, 256, () => {
            frameCountRef.current++
            updateStats()
          })
        } else if (mode === 'jpeg') {
          setShowCanvas(true)
        }

        audioRef.current?.play().catch(e => console.log('[Audio] Autoplay blocked'))
        break

      case 'frame':
        // JPEG mode
        if (mode === 'jpeg' && canvasRef.current) {
          const img = new Image()
          img.onload = () => {
            const canvas = canvasRef.current
            const ctx = canvas.getContext('2d')
            if (canvas.width !== img.width) {
              canvas.width = img.width
              canvas.height = img.height
            }
            ctx.drawImage(img, 0, 0)
            frameCountRef.current++
            updateStats()
          }
          img.src = 'data:image/jpeg;base64,' + data.frame
          totalBytesRef.current += data.frame.length * 0.75
        }
        break

      case 'done':
        setStats(prev => ({ ...prev, latency: Date.now() - startTimeRef.current }))
        setTimeout(() => {
          setShowCanvas(false)
          setShowRtcVideo(false)
          closeDecoder()
        }, 1000)
        setWsStatusDot('connected')
        break

      case 'rtc_offer':
        await handleRTCOffer(data, wsSend)
        break

      case 'rtc_candidate':
        if (pcRef.current && data.candidate) {
          await pcRef.current.addIceCandidate(new RTCIceCandidate(data.candidate))
        }
        break

      case 'error':
        console.error('[Server] Error:', data.message)
        setResponseText('Erro: ' + data.message)
        break
    }
  }, [mode, initDecoder, decodeFrame, closeDecoder, updateStats, handleRTCOffer])

  // WebSocket connection
  const { status: wsStatus, send: wsSend } = useWebSocket(handleMessage)

  useEffect(() => {
    if (wsStatus === 'connected') {
      setWsStatusDot('connected')
      setResponseText('Pressione e fale')
    } else if (wsStatus === 'error') {
      setWsStatusDot('error')
    } else {
      setWsStatusDot(null)
    }
  }, [wsStatus])

  // Handle recording complete
  const handleRecordingComplete = useCallback((base64Audio) => {
    const codec = mode === 'webrtc' ? 'webrtc' : mode === 'h264' ? 'h264' : 'jpeg'

    wsSend({
      type: 'start',
      audio_base64: base64Audio,
      codec,
      resolution: 256,
      batch_size: 16
    })

    setResponseText('Processando...')
    setWsStatusDot('streaming')
  }, [mode, wsSend])

  // Media recorder
  const { isRecording, error: micError, startRecording, stopRecording } = useMediaRecorder(handleRecordingComplete)

  useEffect(() => {
    if (micError) {
      setResponseText('Erro: ' + micError)
    }
  }, [micError])

  const isDisabled = wsStatus !== 'connected' || detecting

  return (
    <div className="app-container">
      <ModeBadge mode={mode} />

      <Avatar
        ref={{ rtcVideoRef, canvasRef }}
        wsStatus={wsStatusDot}
        rtcStatus={rtcStatusDot}
        udpStatus={udpStatusDot}
        showRtcVideo={showRtcVideo}
        showCanvas={showCanvas}
      />

      <div className="controls">
        <RecordButton
          disabled={isDisabled}
          isRecording={isRecording}
          onStart={startRecording}
          onStop={stopRecording}
          text={detecting ? 'Detectando...' : 'Falar'}
        />
        <p className="response-text">{responseText}</p>
      </div>

      <Stats
        mode={mode}
        latency={stats.latency}
        frameCount={stats.frameCount}
        fps={stats.fps}
      />

      <div className="mode-info">{modeInfo}</div>

      <audio ref={audioRef} preload="none" />
    </div>
  )
}