'use client'

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

const API_URL = process.env.NEXT_PUBLIC_API_URL ?? 'http://localhost:8080'

interface RemoteQueueItem {
  title: string
  owner: string
  color_bg: string
  color_text: string
  img?: string
}

interface RemoteVersion {
  title: string
  artist: string
  duration: string
  img?: string
}

interface RemoteState {
  title: string
  artist: string
  cover: string
  is_playing: boolean
  volume: number
  progress: number
  duration: number
  queue_len: number
  cur_idx: number
  queue: RemoteQueueItem[]
  versions: RemoteVersion[]
  active_version: number
}

function formatTime(s: number) {
  if (!s || isNaN(s)) return '0:00'
  return `${Math.floor(s / 60)}:${Math.floor(s % 60).toString().padStart(2, '0')}`
}

async function cmd(id: string, c: string, value?: number, text?: string) {
  await fetch(`${API_URL}/api/remote/${id}/command`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ cmd: c, value: value ?? 0, text }),
  }).catch(() => {})
}

export default function RemotePage({ params }: { params: Promise<{ id: string }> }) {
  const { id } = use(params)
  const [state, setState] = useState<RemoteState | null>(null)
  const [notFound, setNotFound] = useState(false)
  const [volume, setVolume] = useState(1)
  const [addText, setAddText] = useState('')
  const [tab, setTab] = useState<'player' | 'queue'>('player')
  const [versionsOpen, setVersionsOpen] = useState(false)
  const [savedVersions, setSavedVersions] = useState<Record<string, { title: string; artist: string; duration: string }>>({})
  const [localProgress, setLocalProgress] = useState(0)
  const [connected, setConnected] = useState(true)
  const [seeking, setSeeking] = useState(false)
  const lastPollRef = useRef<{ progress: number; ts: number; playing: boolean }>({ progress: 0, ts: Date.now(), playing: false })
  const lastSuccessRef = useRef(Date.now())
  const progressBarRef = useRef<HTMLDivElement>(null)
  const volumeDebounce = useRef<ReturnType<typeof setTimeout> | null>(null)

  useEffect(() => {
    try {
      const s = typeof window !== 'undefined' ? localStorage.getItem('pm_versions') : null
      if (s) setSavedVersions(JSON.parse(s))
    } catch {}
  }, [])

  useEffect(() => {
    let active = true
    const poll = async () => {
      try {
        const res = await fetch(`${API_URL}/api/remote/${id}/state`)
        if (res.status === 404) { setNotFound(true); return }
        if (!res.ok) return
        const data: RemoteState = await res.json()
        if (active) {
          setState(data)
          if (!seeking) {
            lastPollRef.current = { progress: data.progress ?? 0, ts: Date.now(), playing: data.is_playing }
            setLocalProgress(data.progress ?? 0)
          }
          setVolume(v => Math.abs(v - (data.volume ?? 1)) > 0.05 ? (data.volume ?? 1) : v)
          lastSuccessRef.current = Date.now()
          setConnected(true)
        }
      } catch {
        if (active) setConnected(false)
      }
    }
    poll()
    const iv = setInterval(poll, 2000)
    return () => { active = false; clearInterval(iv) }
  }, [id, seeking])

  useEffect(() => {
    const iv = setInterval(() => {
      if (seeking) return
      const { progress, ts, playing } = lastPollRef.current
      if (playing) setLocalProgress(progress + (Date.now() - ts) / 1000)
    }, 250)
    return () => clearInterval(iv)
  }, [seeking])

  const getSeekPct = useCallback((clientX: number) => {
    const bar = progressBarRef.current
    if (!bar || !state?.duration) return null
    const rect = bar.getBoundingClientRect()
    return Math.max(0, Math.min(1, (clientX - rect.left) / rect.width))
  }, [state?.duration])

  const handleSeekStart = useCallback((clientX: number) => {
    const pct = getSeekPct(clientX)
    if (pct === null) return
    setSeeking(true)
    const seekTo = pct * (state?.duration ?? 0)
    setLocalProgress(seekTo)
  }, [getSeekPct, state?.duration])

  const handleSeekMove = useCallback((clientX: number) => {
    if (!seeking) return
    const pct = getSeekPct(clientX)
    if (pct === null) return
    setLocalProgress(pct * (state?.duration ?? 0))
  }, [seeking, getSeekPct, state?.duration])

  const handleSeekEnd = useCallback((clientX: number) => {
    if (!seeking) return
    const pct = getSeekPct(clientX)
    if (pct !== null && state) {
      const seekTo = pct * state.duration
      lastPollRef.current = { progress: seekTo, ts: Date.now(), playing: state.is_playing }
      setLocalProgress(seekTo)
      cmd(id, 'seek', seekTo)
    }
    setSeeking(false)
  }, [seeking, getSeekPct, state, id])

  useEffect(() => {
    const onMouseMove = (e: MouseEvent) => handleSeekMove(e.clientX)
    const onMouseUp = (e: MouseEvent) => handleSeekEnd(e.clientX)
    const onTouchMove = (e: TouchEvent) => { if (e.touches[0]) handleSeekMove(e.touches[0].clientX) }
    const onTouchEnd = (e: TouchEvent) => { const t = e.changedTouches[0]; if (t) handleSeekEnd(t.clientX) }
    if (seeking) {
      window.addEventListener('mousemove', onMouseMove)
      window.addEventListener('mouseup', onMouseUp)
      window.addEventListener('touchmove', onTouchMove, { passive: true })
      window.addEventListener('touchend', onTouchEnd)
    }
    return () => {
      window.removeEventListener('mousemove', onMouseMove)
      window.removeEventListener('mouseup', onMouseUp)
      window.removeEventListener('touchmove', onTouchMove)
      window.removeEventListener('touchend', onTouchEnd)
    }
  }, [seeking, handleSeekMove, handleSeekEnd])

  if (notFound) return (
    <div className="min-h-screen flex flex-col items-center justify-center text-center px-6 gap-4">
      <div className="w-16 h-16 rounded-full bg-surface2 flex items-center justify-center mb-2">
        <svg width="28" height="28" viewBox="0 0 24 24" fill="none" stroke="#333" strokeWidth="1.5">
          <path d="M9 18V5l12-2v13" /><circle cx="6" cy="18" r="3" /><circle cx="18" cy="16" r="3" />
        </svg>
      </div>
      <div>
        <p className="text-app-text font-display font-bold text-[15px] mb-1">Сессия не найдена</p>
        <p className="text-muted text-[12px]">Ссылка устарела или сессия завершена</p>
      </div>
    </div>
  )

  if (!state) return (
    <div className="min-h-screen flex items-center justify-center">
      <div className="w-5 h-5 rounded-full border-2 border-surface2 border-t-accent animate-spin" />
    </div>
  )

  const clampedProgress = Math.min(localProgress, state.duration || localProgress)
  const progressPct = state.duration > 0 ? (clampedProgress / state.duration) * 100 : 0
  const queue = state.queue ?? []
  const versions = state.versions ?? []
  const trackTitle = queue[state.cur_idx]?.title ?? ''
  const currentOwner = queue[state.cur_idx]

  const isSavedLocally = (v: RemoteVersion) => {
    const s = savedVersions[trackTitle]
    return !!s && s.title === v.title && s.artist === v.artist && s.duration === v.duration
  }

  const handleSaveVersion = (i: number) => {
    const v = versions[i]
    if (!v || !trackTitle) return
    const alreadySaved = isSavedLocally(v)
    const next = { ...savedVersions }
    if (alreadySaved) delete next[trackTitle]
    else next[trackTitle] = { title: v.title, artist: v.artist, duration: v.duration }
    setSavedVersions(next)
    try { localStorage.setItem('pm_versions', JSON.stringify(next)) } catch {}
    cmd(id, 'save_version', i)
  }

  return (
    <main className="min-h-screen flex flex-col max-w-sm mx-auto px-4 pt-5 pb-8">

      {/* Header */}
      <div className="flex items-center justify-between mb-5">
        <div className="flex items-center gap-2">
          <span
            className="w-1.5 h-1.5 rounded-full shrink-0 transition-all duration-500"
            style={{ background: connected ? '#5cc87a' : '#ff6b6b', boxShadow: connected ? '0 0 5px #5cc87a99' : 'none' }}
          />
          <span className="text-[11px] font-display font-bold tracking-[1.5px] uppercase text-muted">Party Mix · Пульт</span>
        </div>
        <div className="flex items-center gap-1 bg-surface2 rounded-[9px] p-0.5">
          {(['player', 'queue'] as const).map(t => (
            <button
              key={t}
              onClick={() => setTab(t)}
              className="px-3 py-1.5 text-[11px] font-display font-bold rounded-[7px] transition-all cursor-pointer flex items-center gap-1"
              style={{ background: tab === t ? 'rgba(var(--accent-rgb),0.12)' : 'transparent', color: tab === t ? 'var(--accent)' : '#555' }}
            >
              {t === 'player' ? 'Плеер' : 'Очередь'}
              {t === 'queue' && queue.length > 0 && (
                <span className="text-[9px] opacity-60 font-display tabular-nums">{queue.length}</span>
              )}
            </button>
          ))}
        </div>
      </div>

      {tab === 'player' && (
        <div className="flex flex-col gap-6 items-center flex-1">

          {/* Cover */}
          <div
            className="w-full aspect-square rounded-[24px] overflow-hidden bg-surface2 shrink-0"
            style={{ boxShadow: state.cover ? '0 20px 60px rgba(var(--accent-rgb),0.18), 0 8px 20px rgba(0,0,0,0.4)' : '0 8px 20px rgba(0,0,0,0.3)' }}
          >
            {state.cover ? (
              <img src={state.cover} alt="" className="w-full h-full object-cover" />
            ) : (
              <div className="w-full h-full flex items-center justify-center">
                <svg width="56" height="56" viewBox="0 0 24 24" fill="none" stroke="#222" strokeWidth="1">
                  <path d="M9 18V5l12-2v13" /><circle cx="6" cy="18" r="3" /><circle cx="18" cy="16" r="3" />
                </svg>
              </div>
            )}
          </div>

          {/* Track info */}
          <div className="w-full">
            <div className="flex items-start justify-between gap-2">
              <div className="min-w-0 flex-1">
                <div className="font-display text-[20px] font-extrabold tracking-tight leading-tight truncate">
                  {state.title || '—'}
                </div>
                {state.artist && (
                  <div className="text-[13px] text-muted mt-1 truncate">{state.artist}</div>
                )}
              </div>
              <div className="flex flex-col items-end gap-1 shrink-0">
                {currentOwner && (
                  <span className="text-[10px] px-2 py-0.5 rounded-[5px] font-medium" style={{ background: currentOwner.color_bg, color: currentOwner.color_text }}>
                    {currentOwner.owner}
                  </span>
                )}
                {state.queue_len > 0 && (
                  <span className="text-[11px] text-muted font-display tabular-nums">{state.cur_idx + 1} / {state.queue_len}</span>
                )}
              </div>
            </div>
          </div>

          {/* Progress bar */}
          <div className="w-full select-none">
            <div
              ref={progressBarRef}
              className="relative h-4 flex items-center cursor-pointer group"
              onMouseDown={(e) => { e.preventDefault(); handleSeekStart(e.clientX) }}
              onTouchStart={(e) => { if (e.touches[0]) handleSeekStart(e.touches[0].clientX) }}
            >
              <div className="absolute inset-y-0 flex items-center w-full">
                <div className="relative w-full h-1.5 bg-white/[0.08] rounded-full">
                  <div
                    className="absolute inset-y-0 left-0 rounded-full transition-none"
                    style={{ width: `${progressPct}%`, background: 'var(--accent)' }}
                  />
                  <div
                    className="absolute top-1/2 -translate-y-1/2 -translate-x-1/2 w-3.5 h-3.5 rounded-full bg-white shadow transition-none"
                    style={{ left: `${progressPct}%`, opacity: seeking ? 1 : 0, transition: seeking ? 'none' : 'opacity 0.15s' }}
                  />
                </div>
              </div>
            </div>
            <div className="flex justify-between text-[11px] text-muted font-display tabular-nums -mt-0.5">
              <span>{formatTime(clampedProgress)}</span>
              <span>{formatTime(state.duration)}</span>
            </div>
          </div>

          {/* Controls */}
          <div className="flex items-center justify-between w-full px-2">
            <button
              onClick={() => cmd(id, 'prev')}
              className="w-12 h-12 rounded-full flex items-center justify-center text-muted hover:text-app-text active:scale-90 transition-all cursor-pointer"
            >
              <svg width="28" height="28" viewBox="0 0 24 24" fill="currentColor">
                <path d="M6 6h2v12H6zm3.5 6 8.5 6V6z" />
              </svg>
            </button>

            <button
              onClick={() => cmd(id, state.is_playing ? 'pause' : 'play')}
              className="w-18 h-18 rounded-full flex items-center justify-center active:scale-90 transition-all cursor-pointer hover:brightness-110"
              style={{
                width: 72,
                height: 72,
                background: 'var(--accent)',
                color: '#0a0a0f',
                boxShadow: '0 6px 24px rgba(var(--accent-rgb),0.45)',
              }}
            >
              {state.is_playing ? (
                <svg width="24" height="24" viewBox="0 0 24 24" fill="currentColor">
                  <rect x="6" y="4" width="4" height="16" rx="1" /><rect x="14" y="4" width="4" height="16" rx="1" />
                </svg>
              ) : (
                <svg width="24" height="24" viewBox="0 0 24 24" fill="currentColor" style={{ marginLeft: 3 }}>
                  <path d="M8 5v14l11-7z" />
                </svg>
              )}
            </button>

            <button
              onClick={() => cmd(id, 'next')}
              className="w-12 h-12 rounded-full flex items-center justify-center text-muted hover:text-app-text active:scale-90 transition-all cursor-pointer"
            >
              <svg width="28" height="28" viewBox="0 0 24 24" fill="currentColor">
                <path d="M6 18l8.5-6L6 6v12z" /><rect x="16" y="6" width="2" height="12" rx="1" />
              </svg>
            </button>
          </div>

          {/* Volume */}
          <div className="w-full flex items-center gap-3">
            <svg width="15" height="15" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" className="text-muted shrink-0">
              <polygon points="11 5 6 9 2 9 2 15 6 15 11 19 11 5" />
            </svg>
            <input
              type="range"
              min="0"
              max="1"
              step="0.02"
              value={volume}
              onChange={(e) => {
                const v = parseFloat(e.target.value)
                setVolume(v)
                if (volumeDebounce.current) clearTimeout(volumeDebounce.current)
                volumeDebounce.current = setTimeout(() => cmd(id, 'volume', v), 150)
              }}
              className="flex-1 cursor-pointer h-1.5"
              style={{ accentColor: 'var(--accent)' }}
            />
            <svg width="15" height="15" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" className="text-muted shrink-0">
              <polygon points="11 5 6 9 2 9 2 15 6 15 11 19 11 5" />
              <path d="M15.54 8.46a5 5 0 0 1 0 7.07M19.07 4.93a10 10 0 0 1 0 14.14" />
            </svg>
          </div>

          {/* Versions */}
          {versions.length > 1 && (
            <div className="w-full">
              <button
                onClick={() => setVersionsOpen(v => !v)}
                className="w-full flex items-center justify-between px-3 py-2.5 rounded-[10px] bg-surface2 border border-white/[0.07] hover:border-white/[0.12] transition-colors cursor-pointer"
              >
                <span className="text-[12px] font-display font-bold tracking-[0.5px] text-muted">Версии трека</span>
                <span className="flex items-center gap-2">
                  <span className="text-[11px] text-muted opacity-60">{versions.length}</span>
                  <svg width="11" height="11" viewBox="0 0 24 24" fill="none" stroke="#555" strokeWidth="2.5" className={`transition-transform duration-200 ${versionsOpen ? 'rotate-180' : ''}`}>
                    <polyline points="6 9 12 15 18 9" />
                  </svg>
                </span>
              </button>
              {versionsOpen && (
                <div className="mt-1.5 border border-white/[0.07] rounded-[10px] overflow-hidden bg-surface2/50">
                  {versions.map((v, i) => {
                    const active = i === state.active_version
                    const saved = isSavedLocally(v)
                    return (
                      <div
                        key={i}
                        className="flex items-center gap-2.5 px-3 py-2.5 border-b border-white/[0.05] last:border-b-0"
                        style={{ background: active ? 'rgba(var(--accent-rgb),0.05)' : undefined }}
                      >
                        <span className="text-[10px] text-muted w-4 text-right shrink-0 font-display tabular-nums">{i + 1}</span>
                        {v.img ? (
                          <img src={v.img} alt="" className="w-8 h-8 rounded-[6px] object-cover shrink-0 bg-surface2" onError={(e) => ((e.target as HTMLImageElement).style.display = 'none')} />
                        ) : (
                          <div className="w-8 h-8 rounded-[6px] bg-surface2 shrink-0" />
                        )}
                        <div className="flex-1 min-w-0 cursor-pointer" onClick={() => { cmd(id, 'version', i); setVersionsOpen(false) }}>
                          <div className="text-[12px] text-app-text truncate">{v.title}</div>
                          <div className="text-[11px] text-muted mt-px truncate">{v.artist}</div>
                        </div>
                        <span className="text-[11px] text-muted shrink-0 font-display tabular-nums">{v.duration}</span>
                        <button
                          onClick={(e) => { e.stopPropagation(); handleSaveVersion(i) }}
                          className="w-7 h-7 rounded-full border flex items-center justify-center shrink-0 transition-all cursor-pointer"
                          style={{ borderColor: saved ? 'rgba(var(--accent-rgb),0.4)' : 'rgba(255,255,255,0.07)', background: saved ? 'rgba(var(--accent-rgb),0.08)' : 'transparent' }}
                        >
                          <svg width="10" height="10" viewBox="0 0 24 24" fill={saved ? 'var(--accent)' : 'none'} stroke={saved ? 'var(--accent)' : '#555'} strokeWidth="2">
                            <path d="M19 21l-7-5-7 5V5a2 2 0 0 1 2-2h10a2 2 0 0 1 2 2z" />
                          </svg>
                        </button>
                        <button
                          onClick={() => { cmd(id, 'version', i); setVersionsOpen(false) }}
                          className="w-7 h-7 rounded-full border flex items-center justify-center shrink-0 transition-all cursor-pointer"
                          style={{ background: active ? 'var(--accent)' : 'transparent', borderColor: active ? 'var(--accent)' : 'rgba(255,255,255,0.07)' }}
                        >
                          <svg width="9" height="9" viewBox="0 0 24 24" fill={active ? '#0a0a0f' : '#555'}><path d="M8 5v14l11-7z" /></svg>
                        </button>
                      </div>
                    )
                  })}
                </div>
              )}
            </div>
          )}
        </div>
      )}

      {tab === 'queue' && (
        <div className="flex flex-col gap-3 flex-1">

          {/* Add track */}
          <div className="flex gap-2">
            <input
              type="text"
              value={addText}
              onChange={(e) => setAddText(e.target.value)}
              onKeyDown={(e) => {
                if (e.key === 'Enter' && addText.trim()) {
                  cmd(id, 'add', 0, addText.trim())
                  setAddText('')
                }
              }}
              placeholder="Исполнитель — Название"
              className="flex-1 min-w-0 text-[13px] bg-surface2 border border-white/[0.07] rounded-[10px] px-3 py-2.5 text-app-text outline-none focus:border-accent/35 placeholder:text-muted transition-colors"
            />
            <button
              onClick={() => {
                if (!addText.trim()) return
                cmd(id, 'add', 0, addText.trim())
                setAddText('')
              }}
              className="shrink-0 w-11 rounded-[10px] flex items-center justify-center bg-accent text-bg font-display font-bold text-[18px] cursor-pointer hover:brightness-110 active:scale-95 transition-all"
              style={{ color: '#0a0a0f' }}
            >
              +
            </button>
          </div>

          {/* Queue list */}
          {queue.length === 0 ? (
            <div className="flex-1 flex flex-col items-center justify-center text-center py-16 gap-3">
              <svg width="32" height="32" viewBox="0 0 24 24" fill="none" stroke="#2a2a2a" strokeWidth="1.5">
                <line x1="8" y1="6" x2="21" y2="6" /><line x1="8" y1="12" x2="21" y2="12" />
                <line x1="8" y1="18" x2="21" y2="18" />
                <circle cx="3" cy="6" r="1" fill="#2a2a2a" stroke="none" />
                <circle cx="3" cy="12" r="1" fill="#2a2a2a" stroke="none" />
                <circle cx="3" cy="18" r="1" fill="#2a2a2a" stroke="none" />
              </svg>
              <p className="text-[13px] text-muted">Очередь пуста</p>
            </div>
          ) : (
            <div className="flex flex-col">
              {queue.map((item, i) => {
                const active = i === state.cur_idx
                return (
                  <div
                    key={i}
                    onClick={() => cmd(id, 'goto', i)}
                    className="flex items-center gap-2.5 px-2 py-2.5 border-b border-white/[0.05] last:border-b-0 cursor-pointer rounded-[8px] transition-colors active:bg-surface2"
                    style={{ background: active ? 'rgba(var(--accent-rgb),0.05)' : undefined }}
                  >
                    {/* Index / playing indicator */}
                    <div className="w-5 flex items-center justify-center shrink-0">
                      {active ? (
                        <div className="flex items-end gap-[1.5px] h-3.5">
                          <div className="queue-bar" /><div className="queue-bar" /><div className="queue-bar" />
                        </div>
                      ) : (
                        <span className="text-[11px] text-muted font-display tabular-nums">{i + 1}</span>
                      )}
                    </div>

                    {/* Cover */}
                    {item.img ? (
                      <img src={item.img} alt="" className="w-9 h-9 rounded-[7px] object-cover shrink-0 bg-surface2" onError={(e) => ((e.target as HTMLImageElement).style.display = 'none')} />
                    ) : (
                      <div className="w-9 h-9 rounded-[7px] bg-surface2 shrink-0 flex items-center justify-center">
                        <svg width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="#333" strokeWidth="1.5">
                          <path d="M9 18V5l12-2v13" /><circle cx="6" cy="18" r="3" /><circle cx="18" cy="16" r="3" />
                        </svg>
                      </div>
                    )}

                    {/* Title + owner */}
                    <div className="flex-1 min-w-0">
                      <span className="text-[13px] text-app-text truncate block leading-tight"
                        style={{ color: active ? 'var(--accent)' : undefined }}
                      >{item.title}</span>
                      <span className="text-[10px] px-1.5 py-0.5 rounded-[4px] font-medium inline-block mt-0.5" style={{ background: item.color_bg, color: item.color_text }}>
                        {item.owner}
                      </span>
                    </div>

                    {/* Remove */}
                    <button
                      onClick={(e) => { e.stopPropagation(); cmd(id, 'remove', i) }}
                      className="w-7 h-7 rounded-full flex items-center justify-center text-muted hover:text-[#ff6b6b] hover:bg-[rgba(255,107,107,0.08)] transition-all cursor-pointer shrink-0"
                    >
                      <svg width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5" strokeLinecap="round">
                        <line x1="18" y1="6" x2="6" y2="18" /><line x1="6" y1="6" x2="18" y2="18" />
                      </svg>
                    </button>
                  </div>
                )
              })}
            </div>
          )}
        </div>
      )}

    </main>
  )
}