import { useState, useEffect, useRef, useCallback } from 'react'
import type { ScatSegment } from './scatTypes'

interface ScatTimelineProps {
  segments: ScatSegment[]
  currentIdx: number
  onSeek: (idx: number) => void
}

function ScatTimeline({
  segments,
  currentIdx,
  onSeek,
}: ScatTimelineProps) {
  const [playing, setPlaying] = useState(false)
  const [speed, setSpeed] = useState(1)
  const intervalRef = useRef<ReturnType<typeof setInterval> | null>(null)

  const total = Math.min(segments.length, 12)
  const displaySegs = segments.slice(0, total)
  const pct = ((currentIdx + 1) / total) * 100

  const stop = useCallback(() => {
    if (intervalRef.current) {
      clearInterval(intervalRef.current)
      intervalRef.current = null
    }
    setPlaying(false)
  }, [])

  const play = useCallback(() => {
    stop()
    setPlaying(true)
    intervalRef.current = setInterval(() => {
      onSeek(-1) // signal to advance
    }, 800 / speed)
  }, [speed, stop, onSeek])

  const togglePlay = () => {
    if (playing) stop()
    else play()
  }

  useEffect(() => {
    if (playing && intervalRef.current) {
      clearInterval(intervalRef.current)
      intervalRef.current = setInterval(() => {
        onSeek(-1)
      }, 800 / speed)
    }
  }, [speed, playing, onSeek])

  useEffect(() => {
    return () => { if (intervalRef.current) clearInterval(intervalRef.current) }
  }, [])

  const cycleSpeed = () => {
    const speeds = [1, 2, 4]
    setSpeed(s => speeds[(speeds.indexOf(s) + 1) % speeds.length])
  }

  const doneCount = segments.filter(s => s.status === '완료').length
  const progCount = segments.filter(s => s.status === '진행중').length
  const totalLen = segments.reduce((a, s) => a + s.lengthM, 0)

  return (
    <div className="absolute bottom-0 left-0 right-0 h-[72px] bg-[rgba(15,21,36,0.95)] backdrop-blur-2xl border-t border-border flex items-center px-5 gap-4 z-[40]">
      {/* Controls */}
      <div className="flex gap-1 flex-shrink-0">
        <button onClick={() => onSeek(0)} className="w-[34px] h-[34px] rounded-sm border border-border bg-bg-3 text-text-2 flex items-center justify-center cursor-pointer hover:bg-bg-hover text-sm">⏮</button>
        <button onClick={() => onSeek(Math.max(0, currentIdx - 1))} className="w-[34px] h-[34px] rounded-sm border border-border bg-bg-3 text-text-2 flex items-center justify-center cursor-pointer hover:bg-bg-hover text-sm">◀</button>
        <button onClick={togglePlay} className={`w-[34px] h-[34px] rounded-sm border flex items-center justify-center cursor-pointer text-sm ${playing ? 'bg-status-green text-black border-status-green' : 'border-border bg-bg-3 text-text-2 hover:bg-bg-hover'}`}>
          {playing ? '⏸' : '▶'}
        </button>
        <button onClick={() => onSeek(Math.min(total - 1, currentIdx + 1))} className="w-[34px] h-[34px] rounded-sm border border-border bg-bg-3 text-text-2 flex items-center justify-center cursor-pointer hover:bg-bg-hover text-sm">▶</button>
        <button onClick={() => onSeek(total - 1)} className="w-[34px] h-[34px] rounded-sm border border-border bg-bg-3 text-text-2 flex items-center justify-center cursor-pointer hover:bg-bg-hover text-sm">⏭</button>
        <div className="w-2" />
        <button onClick={cycleSpeed} className="w-[34px] h-[34px] rounded-sm border border-border bg-bg-3 text-text-2 flex items-center justify-center cursor-pointer hover:bg-bg-hover text-xs font-mono font-bold">{speed}×</button>
      </div>

      {/* Progress */}
      <div className="flex-1 flex flex-col gap-1.5">
        <div className="flex justify-between px-1">
          {displaySegs.map((s, i) => (
            <span
              key={i}
              className={`text-[10px] font-mono cursor-pointer ${i === currentIdx ? 'text-status-green font-semibold' : 'text-text-3'}`}
              onClick={() => onSeek(i)}
            >
              {s.code}
            </span>
          ))}
        </div>
        <div className="relative h-6 flex items-center">
          <div className="w-full h-1 bg-border rounded relative">
            <div className="absolute top-0 left-0 h-full rounded transition-all duration-300" style={{ width: `${pct}%`, background: 'linear-gradient(90deg, var(--green), #4ade80)' }} />
            {/* Markers */}
            {displaySegs.map((s, i) => {
              const x = ((i + 0.5) / total) * 100
              return (
                <div key={i} className="absolute w-0.5 bg-border-light" style={{ left: `${x}%`, top: -3, height: i % 3 === 0 ? 14 : 10 }}>
                  {s.status === '완료' && (
                    <span className="absolute -top-[18px] left-1/2 -translate-x-1/2 text-[10px] cursor-pointer" style={{ filter: 'drop-shadow(0 0 4px rgba(34,197,94,0.5))' }}>✅</span>
                  )}
                  {s.status === '진행중' && (
                    <span className="absolute -top-[18px] left-1/2 -translate-x-1/2 text-[10px]">⏳</span>
                  )}
                </div>
              )
            })}
          </div>
          {/* Thumb */}
          <div
            className="absolute top-1/2 -translate-y-1/2 w-4 h-4 bg-status-green border-[3px] border-bg-0 rounded-full cursor-grab shadow-[0_0_10px_rgba(34,197,94,0.4)] z-[2] transition-all duration-300"
            style={{ left: `${pct}%`, transform: `translate(-50%, -50%)` }}
          />
        </div>
      </div>

      {/* Info */}
      <div className="flex flex-col items-end gap-1 flex-shrink-0 min-w-[210px]">
        <span className="text-sm font-semibold text-status-green font-mono">
          구간 {displaySegs[currentIdx]?.code || 'S-001'} / {total}개
        </span>
        <div className="flex gap-3.5">
          <span className="flex items-center gap-1.5 text-[11px]">
            <span className="text-text-2 font-korean">완료</span>
            <span className="text-text-1 font-semibold font-mono text-status-green">{doneCount}/{segments.length}</span>
          </span>
          <span className="flex items-center gap-1.5 text-[11px]">
            <span className="text-text-2 font-korean">진행중</span>
            <span className="text-text-1 font-semibold font-mono text-status-orange">{progCount}/{segments.length}</span>
          </span>
          <span className="flex items-center gap-1.5 text-[11px]">
            <span className="text-text-2 font-korean">총 해안선</span>
            <span className="text-text-1 font-semibold font-mono">{(totalLen / 1000).toFixed(1)} km</span>
          </span>
        </div>
      </div>
    </div>
  )
}

export default ScatTimeline