'use client';

import { useEffect, useRef, useState } from 'react';
import { Play, Pause, RotateCcw, Square, Circle, Type } from 'lucide-react';
import { cn, iconBtn } from '@/lib/utils';
import { buildCSS } from '@/lib/animate/cssBuilder';
import type { AnimationConfig, PreviewElement } from '@/types/animate';

interface Props {
  config: AnimationConfig;
  element: PreviewElement;
  onElementChange: (e: PreviewElement) => void;
}

type AnimState = 'playing' | 'paused' | 'ended';

const SPEEDS: { label: string; value: string }[] = [
  { label: '0.25×', value: '0.25' },
  { label: '0.5×', value: '0.5' },
  { label: '1×', value: '1' },
  { label: '2×', value: '2' },
];

const ELEMENTS: { value: PreviewElement; icon: React.ReactNode; title: string }[] = [
  { value: 'box', icon: <Square className="w-3 h-3" />, title: 'Box' },
  { value: 'circle', icon: <Circle className="w-3 h-3" />, title: 'Circle' },
  { value: 'text', icon: <Type className="w-3 h-3" />, title: 'Text' },
];

const previewBtn = cn(iconBtn, 'w-7 h-7');

const pillCls = (active: boolean) =>
  cn(
    'px-2 py-0.5 rounded text-[10px] font-mono transition-all',
    active ? 'text-primary bg-primary/10' : 'text-muted-foreground/50 hover:text-muted-foreground'
  );

export function AnimationPreview({ config, element, onElementChange }: Props) {
  const styleRef = useRef<HTMLStyleElement | null>(null);
  const [restartKey, setRestartKey] = useState(0);
  const [animState, setAnimState] = useState<AnimState>('playing');
  const [speed, setSpeed] = useState('1');

  useEffect(() => {
    if (!styleRef.current) {
      styleRef.current = document.createElement('style');
      styleRef.current.id = 'kit-animate-preview';
      document.head.appendChild(styleRef.current);
    }
    styleRef.current.textContent = buildCSS(config);
    setAnimState('playing');
    setRestartKey((k) => k + 1);
  }, [config]);

  useEffect(() => {
    return () => { styleRef.current?.remove(); };
  }, []);

  const restart = () => { setAnimState('playing'); setRestartKey((k) => k + 1); };

  const scaledDuration = Math.round(config.duration / Number(speed));
  const isInfinite = config.iterationCount === 'infinite';

  return (
    <div className="glass rounded-xl p-4 shrink-0 flex flex-col gap-3">
      {/* Header: speed pills */}
      <div className="flex items-center justify-between shrink-0">
        <span className="text-[10px] font-semibold text-muted-foreground uppercase tracking-widest">Preview</span>
        <div className="flex items-center glass rounded-md border border-border/30 px-1 gap-0.5">
          {SPEEDS.map((s) => (
            <button key={s.value} onClick={() => setSpeed(s.value)} className={pillCls(speed === s.value)}>
              {s.label}
            </button>
          ))}
        </div>
      </div>

      {/* Canvas */}
      <div
        className="h-44 rounded-xl flex items-center justify-center relative overflow-hidden"
        style={{
          background: 'linear-gradient(135deg, rgba(255,255,255,0.02) 0%, rgba(139,92,246,0.04) 100%)',
          backgroundImage: [
            'linear-gradient(135deg, rgba(255,255,255,0.02) 0%, rgba(139,92,246,0.04) 100%)',
            'linear-gradient(var(--border) 1px, transparent 1px)',
            'linear-gradient(90deg, var(--border) 1px, transparent 1px)',
          ].join(', '),
          backgroundSize: 'auto, 32px 32px, 32px 32px',
        }}
      >
        <div
          key={restartKey}
          className="animated relative z-10"
          style={{
            animationDuration: `${scaledDuration}ms`,
            animationPlayState: animState === 'paused' ? 'paused' : 'running',
          }}
          onAnimationEnd={() => !isInfinite && setAnimState('ended')}
        >
          {element === 'box' && (
            <div className="w-16 h-16 rounded-xl bg-gradient-to-br from-violet-500 to-purple-600 shadow-lg shadow-purple-500/30" />
          )}
          {element === 'circle' && (
            <div className="w-16 h-16 rounded-full bg-gradient-to-br from-cyan-400 to-violet-500 shadow-lg shadow-cyan-500/30" />
          )}
          {element === 'text' && (
            <span className="text-3xl font-bold bg-gradient-to-r from-violet-400 via-pink-400 to-cyan-400 bg-clip-text text-transparent select-none">
              Hello
            </span>
          )}
        </div>
      </div>

      {/* Controls: element selector + playback */}
      <div className="flex items-center justify-between shrink-0">
        {/* Element picker */}
        <div className="flex items-center glass rounded-md border border-border/30 p-0.5 gap-0.5">
          {ELEMENTS.map(({ value, icon, title }) => (
            <button
              key={value}
              onClick={() => onElementChange(value)}
              title={title}
              className={cn(
                'w-7 h-7 flex items-center justify-center rounded transition-all',
                element === value
                  ? 'bg-primary text-primary-foreground'
                  : 'text-muted-foreground hover:text-foreground'
              )}
            >
              {icon}
            </button>
          ))}
        </div>

        {/* Playback */}
        <div className="flex items-center gap-1">
          <button
            onClick={() => animState === 'ended' ? restart() : setAnimState('playing')}
            disabled={animState === 'playing'}
            title={animState === 'ended' ? 'Replay' : 'Play'}
            className={previewBtn}
          >
            <Play className="w-3 h-3" />
          </button>
          <button
            onClick={() => setAnimState('paused')}
            disabled={animState !== 'playing'}
            title="Pause"
            className={previewBtn}
          >
            <Pause className="w-3 h-3" />
          </button>
          <button onClick={restart} title="Restart" className={previewBtn}>
            <RotateCcw className="w-3 h-3" />
          </button>
        </div>
      </div>
    </div>
  );
}
