Runway LoaderAn airplane taxis down a runway progress bar, nose tilting up and taking off at 100%.

'use client'

// npm install framer-motion

import { useLayoutEffect, useEffect, useRef, useState } from 'react'
import { motion, AnimatePresence } from 'framer-motion'
const useIsomorphicLayoutEffect = typeof window !== 'undefined' ? useLayoutEffect : useEffect


// ─── Airplane SVG — top-down view, pointing right ─────────────────────────────

function Airplane({ isDark }: { isDark: boolean }) {
  // Light mode uses darker greys so the plane reads against sand-100
  const bodyTop    = isDark ? '#ececec' : '#c8c8c8'
  const bodyMid    = isDark ? '#ffffff' : '#dedede'
  const bodyBot    = isDark ? '#d0d0d0' : '#b4b4b4'
  const wingLight  = isDark ? '#f8f8f8' : '#d8d8d8'
  const wingDark   = isDark ? '#bababa' : '#909090'
  const tail       = isDark ? '#c8c8c8' : '#a8a8a8'
  const nose       = isDark ? '#f4f4f4' : '#d8d8d8'

  return (
    <svg
      className="w-[52px] sm:w-[72px] h-auto"
      viewBox="0 0 72 46"
      fill="none"
      style={{
        filter: isDark
          ? 'drop-shadow(0 4px 12px rgba(0,0,0,0.75)) drop-shadow(0 2px 4px rgba(0,0,0,0.5))'
          : 'drop-shadow(0 2px 8px rgba(0,0,0,0.35)) drop-shadow(0 1px 3px rgba(0,0,0,0.2))',
      }}
    >
      <defs>
        <linearGradient id="rl-body" x1="0" y1="0" x2="0" y2="1">
          <stop offset="0%"   stopColor={bodyTop} />
          <stop offset="40%"  stopColor={bodyMid} />
          <stop offset="100%" stopColor={bodyBot} />
        </linearGradient>
        <linearGradient id="rl-wing-t" x1="0" y1="1" x2="1" y2="0">
          <stop offset="0%"   stopColor={wingLight} />
          <stop offset="100%" stopColor={wingDark} />
        </linearGradient>
        <linearGradient id="rl-wing-b" x1="0" y1="0" x2="1" y2="1">
          <stop offset="0%"   stopColor={wingLight} />
          <stop offset="100%" stopColor={wingDark} />
        </linearGradient>
      </defs>

      {/* Top wing — root centred on body, thicker chord */}
      <path d="M44,21 L28,21 L8,2 L18,0 Z" fill="url(#rl-wing-t)" />
      {/* Bottom wing */}
      <path d="M44,25 L28,25 L8,44 L18,46 Z" fill="url(#rl-wing-b)" />

      {/* Horizontal tail stabilisers */}
      <path d="M8,21 L2,14 L6,14 L12,21 Z" fill={tail} />
      <path d="M8,25 L2,32 L6,32 L12,25 Z" fill={tail} />

      {/* Fuselage */}
      <ellipse cx="34" cy="23" rx="29" ry="7" fill="url(#rl-body)" />

      {/* Nose taper */}
      <path
        d="M61,19.5 C66,21.5 67.5,23 67,23 C67.5,23 66,24.5 61,26.5 L58,23 Z"
        fill={nose}
      />

      {/* Cockpit window */}
      <ellipse cx="57" cy="23" rx="4" ry="3" fill="#7ec8e8" opacity="0.9" />
    </svg>
  )
}

// ─── RunwayLoader ─────────────────────────────────────────────────────────────

type Phase = 'taxiing' | 'takeoff' | 'resetting'

export default function RunwayLoader() {
  const containerRef = useRef<HTMLDivElement>(null)
  const [isDark, setIsDark] = useState(() => typeof window !== 'undefined' ? document.documentElement.classList.contains('dark') : false)

  useIsomorphicLayoutEffect(() => {
    const el = containerRef.current
    if (!el) return
    const check = () => {
      const card = el.closest('[data-card-theme]')
      setIsDark(card ? card.classList.contains('dark') : document.documentElement.classList.contains('dark'))
    }
    check()
    const observer = new MutationObserver(check)
    observer.observe(document.documentElement, { attributes: true, attributeFilter: ['class'] })
    const cardWrapper = el.closest('[data-card-theme]')
    if (cardWrapper) observer.observe(cardWrapper, { attributes: true, attributeFilter: ['class'] })
    return () => observer.disconnect()
  }, [])

  const [progress, setProgress] = useState(0)
  const [phase, setPhase] = useState<Phase>('taxiing')
  const [cycle, setCycle] = useState(0)

  const rafRef         = useRef<number>(0)
  const startRef       = useRef<number | undefined>(undefined)
  const aliveRef       = useRef(true)
  const disappearedRef = useRef(false)

  // Nose tip touches the right wall when the plane centre reaches this %
  const WALL_PCT = 91

  useEffect(() => {
    aliveRef.current = true
    disappearedRef.current = false
    const TAXI_MS = 5500

    function tick(ts: number) {
      if (!aliveRef.current) return
      if (!startRef.current) startRef.current = ts
      const t = Math.min((ts - startRef.current) / TAXI_MS, 1)
      // Realistic curve: fast to ~82% in first 75% of time, then slows
      const eased = t <= 0.75
        ? (t / 0.75) * 82
        : 82 + (1 - Math.pow(1 - (t - 0.75) / 0.25, 2)) * 18
      const p = Math.min(eased, 100)
      setProgress(p)

      // Trigger disappear exactly when nose tip hits the right wall
      if (p >= WALL_PCT && !disappearedRef.current) {
        disappearedRef.current = true
        setPhase('takeoff')
      }

      if (p < 100) {
        rafRef.current = requestAnimationFrame(tick)
      } else {
        // Bar is full — wait for disappear animation then reset
        setTimeout(() => {
          if (!aliveRef.current) return
          setPhase('resetting')
          setTimeout(() => {
            if (!aliveRef.current) return
            disappearedRef.current = false
            startRef.current = undefined
            setProgress(0)
            setPhase('taxiing')
            setCycle((c) => c + 1)
            rafRef.current = requestAnimationFrame(tick)
          }, 400)
        }, 600)
      }
    }

    rafRef.current = requestAnimationFrame(tick)
    return () => {
      aliveRef.current = false
      if (rafRef.current) cancelAnimationFrame(rafRef.current)
    }
  }, [])


  // Plane sits at the fill boundary, clamped so nose tip doesn't pass the right wall
  const planePct = Math.min(progress, WALL_PCT)

  // Theme-responsive track colours
  const trackBg = isDark
    ? 'linear-gradient(to bottom, #404040, #252525)'
    : 'linear-gradient(to bottom, #bab7b2, #a09d98)'
  const trackShadow = isDark
    ? 'inset 0 4px 12px rgba(0,0,0,0.85), inset 0 -1px 3px rgba(255,255,255,0.04), 0 2px 8px rgba(0,0,0,0.5)'
    : 'inset 0 3px 8px rgba(0,0,0,0.22), inset 0 -1px 3px rgba(255,255,255,0.28), 0 2px 5px rgba(0,0,0,0.12)'
  const dashColor = isDark
    ? 'rgba(255,255,255,0.22)'
    : 'rgba(255,255,255,0.42)'

  return (
    <div ref={containerRef} className="flex min-h-screen w-full items-center justify-center" style={{ background: isDark ? '#110F0C' : '#F5F1EA' }}>
      <div className="flex w-full max-w-[440px] flex-col items-center gap-4 px-4 sm:gap-6 sm:px-6">

        {/* ── Runway track ── */}
        <div
          className="relative h-11 w-full overflow-visible rounded-full sm:h-14"
          style={{ background: trackBg, boxShadow: trackShadow }}
        >

          {/* Runway centreline dashes — static full-width, sits behind the fill */}
          <div
            className="pointer-events-none absolute top-1/2 -translate-y-px"
            style={{
              left: 18,
              right: 18,
              height: 2,
              backgroundImage: `repeating-linear-gradient(to right, ${dashColor} 0, ${dashColor} 10px, transparent 10px, transparent 24px)`,
            }}
          />

          {/* Red fill — painted on top of dashes, revealing only the right portion */}
          <div
            className="absolute inset-y-0 left-0 rounded-full"
            style={{
              width: `${progress}%`,
              background: 'linear-gradient(to right, #6b0000, #be1c1c 50%, #e03030)',
              boxShadow: 'inset 0 1px 3px rgba(255,255,255,0.1)',
            }}
          />

          {/* Heat-shimmer exhaust behind the engines */}
          {phase === 'taxiing' && progress > 30 && (
            <motion.div
              className="pointer-events-none absolute top-1/2 -translate-y-1/2 rounded-full"
              style={{
                right: `calc(${100 - planePct}% + 26px)`,
                width: Math.min(((progress - 30) / 70) * 56, 56),
                height: 22,
                background:
                  'radial-gradient(ellipse at right, rgba(255,140,20,0.3), transparent)',
                filter: 'blur(8px)',
              }}
              animate={{ opacity: [0.3, 0.75, 0.2, 0.65, 0.3] }}
              transition={{ duration: 0.2, repeat: Infinity }}
            />
          )}

          {/* ── Airplane ── */}
          <AnimatePresence>
            {phase !== 'resetting' && (
              <div
                key={`plane-${cycle}`}
                className="pointer-events-none absolute top-1/2 z-20"
                style={{
                  left: `${planePct}%`,
                  transform: 'translateX(-50%) translateY(-50%)',
                }}
              >
                {phase === 'taxiing' ? (
                  <Airplane isDark={isDark} />
                ) : (
                  // Liftoff: grows and slides right past the edge, then fades
                  <motion.div
                    initial={{ opacity: 1, x: 0, scale: 1 }}
                    animate={{ opacity: 0, x: 120, scale: 1.8 }}
                    transition={{ duration: 0.7, ease: 'easeIn' }}
                  >
                    <Airplane isDark={isDark} />
                  </motion.div>
                )}
              </div>
            )}
          </AnimatePresence>
        </div>

        {/* ── Progress readout ── */}
        <div className="flex flex-col items-center gap-1">
          <div className="flex items-baseline gap-1">
            <span
              className="text-2xl font-bold tabular-nums sm:text-[28px]"
              style={{ color: isDark ? '#FAF7F2' : '#1C1916' }}
            >
              {Math.round(progress)}
            </span>
            <span className="text-sm font-semibold sm:text-base" style={{ color: '#9E9890' }}>%</span>
          </div>
          <span
            className="text-[10px] font-semibold uppercase tracking-widest sm:text-[11px]"
            style={{ color: isDark ? '#736D65' : '#9E9890' }}
          >
            {phase === 'takeoff'
              ? 'Taking off!'
              : phase === 'resetting'
                ? '—'
                : 'Preparing for takeoff'}
          </span>
        </div>

      </div>
    </div>
  )
}