import React, { useEffect, useRef, useState } from 'react'
import Hls from 'hls.js'
import { whepUrl, hlsUrl } from './api.js'
import { audio, effectiveMuted } from './useAudio.js'
import { names } from './names.js'

// WebRTC (WHEP) first, HLS fallback. Mute/volume come from the shared audio store.
export default function Player({ params, api }) {
  const { id, user, title } = params
  const custom = names.use(s => s.streams[id])      // viewer-side rename (tab double-click)
  const whep = params.whep || id                       // Opus audio mirror path when the source audio is AAC
  const videoRef = useRef(null)
  const [status, setStatus] = useState('connecting…')
  const [viewers, setViewers] = useState(params.viewers ?? 0)
  const wrapRef = useRef(null)
  const [dims, setDims] = useState(null)              // {w, h, gameH}: video size + game height (h minus the timecode band)
  const [box, setBox] = useState(null)                // {W, H}: game-aspect frame fitted into the panel; video overflows it at the bottom
  const state = audio.use()
  const muted = effectiveMuted(state, id)
  const volume = state.streams[id]?.volume ?? 0.8
  const override = state.streams[id]?.override
  const focused = state.focused === id

  useEffect(() => { audio.ensure(id) }, [id])
  // size the frame: fit a box of the GAME aspect (video width / height-without-band) into the panel, letterboxed.
  // The video is laid across the full box width, so its band rows fall below the box and are clipped.
  useEffect(() => {
    const el = wrapRef.current; if (!el) return
    const fit = () => {
      if (!dims) { setBox(null); return }
      const cw = el.clientWidth, ch = el.clientHeight; if (!cw || !ch) return
      const a = dims.w / dims.gameH
      const W = cw / ch > a ? Math.floor(ch * a) : cw
      setBox({ W, H: Math.floor(W / a) })
    }
    fit(); const ro = new ResizeObserver(fit); ro.observe(el); return () => ro.disconnect()
  }, [dims])
  const onSize = e => {
    const v = e.currentTarget; const w = v.videoWidth, h = v.videoHeight; if (!w || !h) return
    let band = Math.round(w / 160); band += band % 2
    // only treat the extra rows as a band if what remains is a standard game height
    const gameH = [720, 1080, 1440, 2160].includes(h - band) ? h - band : h
    setDims(d => (d && d.w === w && d.h === h) ? d : { w, h, gameH })
  }
  useEffect(() => { const d = api.onDidActiveChange?.(() => {}) ; return () => d?.dispose?.() }, [api])
  useEffect(() => { const t = setInterval(() => setViewers(params.viewers ?? 0), 2000); return () => clearInterval(t) }, [params.viewers])

  // apply audio state to the element
  useEffect(() => {
    const v = videoRef.current; if (!v) return
    v.muted = muted; v.volume = volume
    if (!muted && v.paused) v.play().catch(() => {})
  }, [muted, volume])

  // connect
  useEffect(() => {
    const v = videoRef.current; if (!v) return
    let pc, hls, cancelled = false
    const startHls = () => {
      if (cancelled) return
      setStatus('hls')
      if (Hls.isSupported()) {
        hls = new Hls({ lowLatencyMode: true, liveSyncDurationCount: 2, enableWorker: true })
        hls.loadSource(hlsUrl(id)); hls.attachMedia(v)
        hls.on(Hls.Events.MANIFEST_PARSED, () => v.play().catch(() => {}))
        hls.on(Hls.Events.ERROR, (_, d) => { if (d.fatal) setStatus('hls error: ' + d.details) })
      } else if (v.canPlayType('application/vnd.apple.mpegurl')) {
        v.src = hlsUrl(id); v.play().catch(() => {})
      } else setStatus('no playback method')
    }
    const startWhep = async () => {
      try {
        pc = new RTCPeerConnection({ iceServers: [{ urls: 'stun:stun.l.google.com:19302' }] })
        pc.addTransceiver('video', { direction: 'recvonly' })
        pc.addTransceiver('audio', { direction: 'recvonly' })
        pc.ontrack = e => { if (v.srcObject !== e.streams[0]) { v.srcObject = e.streams[0]; v.play().catch(() => {}) } }
        pc.onconnectionstatechange = () => {
          if (pc.connectionState === 'connected') setStatus('')
          if (['failed', 'disconnected', 'closed'].includes(pc.connectionState) && !cancelled) { pc.close(); startHls() }
        }
        const offer = await pc.createOffer()
        await pc.setLocalDescription(offer)
        await new Promise(res => { if (pc.iceGatheringState === 'complete') return res(); const t = setTimeout(res, 1500); pc.onicegatheringstatechange = () => { if (pc.iceGatheringState === 'complete') { clearTimeout(t); res() } } })
        const r = await fetch(whepUrl(whep), { method: 'POST', headers: { 'Content-Type': 'application/sdp' }, body: pc.localDescription.sdp, credentials: 'same-origin' })
        if (!r.ok) throw new Error('whep ' + r.status)
        await pc.setRemoteDescription({ type: 'answer', sdp: await r.text() })
        setStatus('webrtc')
      } catch (e) {
        if (cancelled) return
        try { pc?.close() } catch {}
        startHls()
      }
    }
    startWhep()
    return () => { cancelled = true; try { pc?.close() } catch {}; try { hls?.destroy() } catch {}; v.srcObject = null; v.removeAttribute('src') }
  }, [id, whep])

  const icon = muted ? '🔇' : volume === 0 ? '🔈' : volume < 0.5 ? '🔉' : '🔊'
  return (
    <div className={'player' + (focused ? ' focused' : '')} onMouseDown={() => api.setActive?.()}>
      <div className="vwrap" ref={wrapRef}>
        <div className="frame" style={box ? { width: box.W, height: box.H } : undefined}>
          <video ref={videoRef} autoPlay playsInline muted onLoadedMetadata={onSize} onResize={onSize} />
        </div>
      </div>
      {status && <div className="status">{status}</div>}
      <div className="bar">
        <span className="live">LIVE</span>
        <span className="who">{user}</span>
        <span className="title" title={title}>{custom || title}</span>
        <span className="viewers">👁 {viewers}</span>
        <button className={'mute' + (!muted ? ' on' : '') + (override === 'unmuted' && !focused ? ' pinned' : '')}
                title={override ? (override === 'unmuted' ? 'audio pinned on (click to mute)' : 'muted (click to unmute)') : (focused ? 'focused: audio on (click to mute)' : 'muted: click to pin audio on')}
                onMouseDown={e => e.stopPropagation()} onClick={() => audio.toggleMute(id)}>{icon}</button>
        <input type="range" min="0" max="1" step="0.02" value={volume} onMouseDown={e => e.stopPropagation()}
               onChange={e => audio.setVolume(id, parseFloat(e.target.value))} />
      </div>
    </div>
  )
}