Animated icons

'use client';

import { cn, round } from '@/lib/kit';
import { SCENE_CSS, keyframes, useSceneId, useScenePlay } from '@/components/ui/motion-scene';

/*
 * Icons that move with meaning: the bell swings, the arrow leaves the tray,
 * the plane takes off, the heart beats. Drawn on the 24 px grid of the kit
 * icons (1.6 px stroke, round caps), animated with transform, opacity and
 * stroke-dashoffset only. Hover plays them on the icon itself or on its
 * parent (a button or link), focus-visible too, so keyboard users see the
 * same. A still icon is always complete.
 */

export type AnimatedIconName = 'bell' | 'upload' | 'download' | 'send' | 'heart' | 'check' | 'refresh' | 'search' | 'mail' | 'star' | 'trash' | 'copy' | 'lock' | 'eye' | 'cart' | 'sparkle';

interface Part {
  d: string;
  /** Which motion this part follows */
  m?: string;
  /** Filled when active (heart, star) */
  fill?: boolean;
  origin?: string;
  /** Draw on with stroke-dashoffset */
  draw?: boolean;
  /** Hidden when still, only shows while the motion plays */
  hidden?: boolean;
}

interface Def {
  parts: Part[];
  /** Motions in percent of one play: name -> frames */
  motions: Record<string, [number, string][]>;
  /** Seconds of one play */
  dur: number;
}

const ICONS: Record<AnimatedIconName, Def> = {
  bell: {
    dur: 1,
    parts: [
      { d: 'M6.5 16.5V11a5.5 5.5 0 0 1 11 0v5.5l1.5 2h-14Z', m: 'swing', origin: '12px 3.5px' },
      { d: 'M10 20.5a2 2 0 0 0 4 0', m: 'clap', origin: '12px 3.5px' },
      { d: 'M12 3.5v2', m: 'swing', origin: '12px 3.5px' },
    ],
    motions: {
      swing: [[0, 'transform:rotate(0)'], [15, 'transform:rotate(16deg)'], [32, 'transform:rotate(-13deg)'], [48, 'transform:rotate(9deg)'], [64, 'transform:rotate(-5deg)'], [80, 'transform:rotate(2deg)'], [100, 'transform:rotate(0)']],
      clap: [[0, 'transform:rotate(0)'], [20, 'transform:rotate(-12deg)'], [38, 'transform:rotate(16deg)'], [55, 'transform:rotate(-9deg)'], [72, 'transform:rotate(5deg)'], [100, 'transform:rotate(0)']],
    },
  },
  upload: {
    dur: 0.9,
    parts: [
      { d: 'M4.5 14.5v3a2 2 0 0 0 2 2h11a2 2 0 0 0 2-2v-3' },
      { d: 'M12 15V4.5M7.5 9 12 4.5 16.5 9', m: 'up' },
    ],
    motions: { up: [[0, 'transform:translateY(0);opacity:1'], [40, 'transform:translateY(-7px);opacity:0'], [41, 'transform:translateY(7px);opacity:0'], [100, 'transform:translateY(0);opacity:1']] },
  },
  download: {
    dur: 0.9,
    parts: [
      { d: 'M4.5 14.5v3a2 2 0 0 0 2 2h11a2 2 0 0 0 2-2v-3' },
      { d: 'M12 4.5V15M7.5 10.5 12 15l4.5-4.5', m: 'down' },
    ],
    motions: { down: [[0, 'transform:translateY(0);opacity:1'], [40, 'transform:translateY(7px);opacity:0'], [41, 'transform:translateY(-7px);opacity:0'], [100, 'transform:translateY(0);opacity:1']] },
  },
  send: {
    dur: 1,
    parts: [{ d: 'M20.5 3.5 3.5 10.5l7 3 3 7Zm0 0-10 10', m: 'fly' }],
    motions: {
      fly: [[0, 'transform:translate(0,0) scale(1);opacity:1'], [12, 'transform:translate(-1.5px,1.5px) scale(.95);opacity:1'], [42, 'transform:translate(12px,-12px) scale(.8);opacity:0'], [43, 'transform:translate(-12px,12px) scale(.8);opacity:0'], [100, 'transform:translate(0,0) scale(1);opacity:1']],
    },
  },
  heart: {
    dur: 0.9,
    parts: [{ d: 'M12 19.5s-7.5-4.3-7.5-9.6A4.1 4.1 0 0 1 12 7.6a4.1 4.1 0 0 1 7.5 2.3c0 5.3-7.5 9.6-7.5 9.6Z', m: 'beat', fill: true, origin: '12px 13px' }],
    motions: { beat: [[0, 'transform:scale(1)'], [18, 'transform:scale(1.22)'], [34, 'transform:scale(.94)'], [52, 'transform:scale(1.1)'], [72, 'transform:scale(.98)'], [100, 'transform:scale(1)']] },
  },
  check: {
    dur: 0.7,
    parts: [{ d: 'M5 12.5 10 17.5 19.5 7', draw: true, m: 'draw' }],
    motions: { draw: [[0, 'stroke-dashoffset:1'], [100, 'stroke-dashoffset:0']] },
  },
  refresh: {
    dur: 0.9,
    parts: [{ d: 'M19.5 12a7.5 7.5 0 1 1-2.2-5.3M19.5 4v4.5H15', m: 'turn', origin: '12px 12px' }],
    motions: { turn: [[0, 'transform:rotate(0)'], [100, 'transform:rotate(360deg)']] },
  },
  search: {
    dur: 1.1,
    parts: [{ d: 'M10.5 17a6.5 6.5 0 1 0 0-13 6.5 6.5 0 0 0 0 13Zm4.6-1.9 4.4 4.4', m: 'scan' }],
    motions: { scan: [[0, 'transform:translate(0,0)'], [25, 'transform:translate(-1.5px,-1px)'], [50, 'transform:translate(1px,-2px)'], [75, 'transform:translate(1.5px,.5px)'], [100, 'transform:translate(0,0)']] },
  },
  mail: {
    dur: 1,
    parts: [
      { d: 'M4 7.5h16v11H4Z' },
      { d: 'M4.5 8 12 13.5 19.5 8', m: 'flap', origin: '12px 8px' },
      { d: 'M8 11.5V5h8v6.5', m: 'letter', hidden: true },
    ],
    motions: {
      flap: [[0, 'transform:scaleY(1)'], [30, 'transform:scaleY(-1)'], [70, 'transform:scaleY(-1)'], [100, 'transform:scaleY(1)']],
      letter: [[0, 'transform:translateY(4px);opacity:0'], [30, 'transform:translateY(4px);opacity:0'], [50, 'transform:translateY(-1px);opacity:1'], [70, 'transform:translateY(-1px);opacity:1'], [90, 'transform:translateY(4px);opacity:0'], [100, 'transform:translateY(4px);opacity:0']],
    },
  },
  star: {
    dur: 0.9,
    parts: [{ d: 'm12 4 2.4 5 5.4.7-4 3.7 1 5.4L12 16.2l-4.8 2.6 1-5.4-4-3.7 5.4-.7Z', m: 'spin', fill: true, origin: '12px 12px' }],
    motions: { spin: [[0, 'transform:rotate(0) scale(1)'], [45, 'transform:rotate(72deg) scale(1.2)'], [100, 'transform:rotate(72deg) scale(1)']] },
  },
  trash: {
    dur: 0.9,
    parts: [
      { d: 'M6.5 8.5h11l-.8 10.2a1.5 1.5 0 0 1-1.5 1.3H8.8a1.5 1.5 0 0 1-1.5-1.3Z' },
      { d: 'M4.5 6.5h15M9.5 6.5V4.5h5v2', m: 'lid', origin: '19.5px 6.5px' },
      { d: 'M10.5 11.5v5M13.5 11.5v5' },
    ],
    motions: { lid: [[0, 'transform:rotate(0) translateY(0)'], [35, 'transform:rotate(14deg) translateY(-2px)'], [65, 'transform:rotate(14deg) translateY(-2px)'], [100, 'transform:rotate(0) translateY(0)']] },
  },
  copy: {
    dur: 0.8,
    parts: [
      { d: 'M8.5 8.5h10v11h-10Z', m: 'front' },
      { d: 'M15.5 8.5V4.5h-10v11h3', m: 'back' },
    ],
    motions: {
      front: [[0, 'transform:translate(0,0)'], [45, 'transform:translate(1.5px,1.5px)'], [100, 'transform:translate(0,0)']],
      back: [[0, 'transform:translate(0,0)'], [45, 'transform:translate(-1.5px,-1.5px)'], [100, 'transform:translate(0,0)']],
    },
  },
  lock: {
    dur: 1,
    parts: [
      { d: 'M6 11h12v9H6Z' },
      { d: 'M8.5 11V8a3.5 3.5 0 0 1 7 0v3', m: 'open', origin: '15.5px 11px' },
      { d: 'M12 14.5v2' },
    ],
    motions: { open: [[0, 'transform:translateY(0) rotate(0)'], [30, 'transform:translateY(-2px) rotate(0)'], [50, 'transform:translateY(-2px) rotate(25deg)'], [75, 'transform:translateY(-2px) rotate(25deg)'], [100, 'transform:translateY(0) rotate(0)']] },
  },
  eye: {
    dur: 0.8,
    parts: [
      { d: 'M2.5 12s3.5-6.5 9.5-6.5S21.5 12 21.5 12s-3.5 6.5-9.5 6.5S2.5 12 2.5 12Z', m: 'blink', origin: '12px 12px' },
      { d: 'M12 14.6a2.6 2.6 0 1 0 0-5.2 2.6 2.6 0 0 0 0 5.2Z', m: 'blink', origin: '12px 12px' },
    ],
    motions: { blink: [[0, 'transform:scaleY(1)'], [30, 'transform:scaleY(.08)'], [55, 'transform:scaleY(1)'], [100, 'transform:scaleY(1)']] },
  },
  cart: {
    dur: 0.9,
    parts: [
      { d: 'M3.5 4.5h2l2 10.5h10l2-7.5H7', m: 'roll' },
      { d: 'M9 19.5a1 1 0 1 0 0-2 1 1 0 0 0 0 2Zm8 0a1 1 0 1 0 0-2 1 1 0 0 0 0 2Z', m: 'roll' },
      { d: 'M12.5 3v4M10.5 5h4', m: 'add' },
    ],
    motions: {
      roll: [[0, 'transform:translateX(0)'], [30, 'transform:translateX(2.5px)'], [55, 'transform:translateX(-1px)'], [100, 'transform:translateX(0)']],
      add: [[0, 'transform:translateY(-4px);opacity:0'], [40, 'transform:translateY(1px);opacity:1'], [60, 'transform:translateY(0);opacity:1'], [100, 'transform:translateY(0);opacity:1']],
    },
  },
  sparkle: {
    dur: 1.1,
    parts: [
      { d: 'M11 3.5c.6 4.2 2.3 5.9 6.5 6.5-4.2.6-5.9 2.3-6.5 6.5-.6-4.2-2.3-5.9-6.5-6.5 4.2-.6 5.9-2.3 6.5-6.5Z', m: 'big', fill: true, origin: '11px 10px' },
      { d: 'M18 15.5c.3 1.8 1 2.5 2.8 2.8-1.8.3-2.5 1-2.8 2.8-.3-1.8-1-2.5-2.8-2.8 1.8-.3 2.5-1 2.8-2.8Z', m: 'small', origin: '18px 18.3px' },
    ],
    motions: {
      big: [[0, 'transform:scale(1) rotate(0)'], [35, 'transform:scale(1.15) rotate(15deg)'], [70, 'transform:scale(.95) rotate(0)'], [100, 'transform:scale(1) rotate(0)']],
      small: [[0, 'transform:scale(1);opacity:1'], [25, 'transform:scale(0);opacity:0'], [55, 'transform:scale(1.3);opacity:1'], [100, 'transform:scale(1);opacity:1']],
    },
  },
};

export const ANIMATED_ICON_NAMES = Object.keys(ICONS) as AnimatedIconName[];

export interface AnimatedIconProps {
  name: AnimatedIconName;
  /** Size in px. Default 24. */
  size?: number;
  /** hover: plays when the icon or its parent is hovered or focused (default). loop: plays on its own with a rest. in-view: once when it appears. */
  trigger?: 'hover' | 'loop' | 'in-view';
  /** Filled state for heart, star and sparkle, and the accent color for all */
  active?: boolean;
  /** 1 is the designed tempo */
  speed?: number;
  strokeWidth?: number;
  /** Read to screen readers. Without it the icon is decorative, which is right inside a labelled button. */
  label?: string;
  className?: string;
}

/**
 *   <button className="…"><AnimatedIcon name="bell" /> Notify me</button>
 *   <AnimatedIcon name="heart" active trigger="in-view" />
 */
export function AnimatedIcon({ name, size = 24, trigger = 'hover', active = false, speed = 1, strokeWidth = 1.6, label, className }: AnimatedIconProps) {
  const sid = useSceneId('kvai');
  const play = useScenePlay<HTMLSpanElement>(trigger === 'hover' ? 'off' : 'in-view');
  const def = ICONS[name];
  const sp = Math.max(0.1, speed);
  const dur = round(def.dur / sp, 3);
  const cycle = round(dur + 1.6 / sp, 3);
  const share = dur / cycle;
  const css = [
    SCENE_CSS,
    ...Object.entries(def.motions).map(([m, frames]) => keyframes(`${sid}-${m}`, frames)),
    ...Object.entries(def.motions).map(([m, frames]) => keyframes(`${sid}-${m}-l`, [...frames.map(([p, d]) => [round(p * share, 2), d] as [number, string]), [100, frames[frames.length - 1][1]]])),
    ...Object.keys(def.motions).map((m) => {
      const on = trigger === 'hover'
        ? `.${sid}:hover .${sid}-${m}, :hover > .${sid} .${sid}-${m}, :focus-visible > .${sid} .${sid}-${m}, [data-icon-host]:hover .${sid} .${sid}-${m}, [data-icon-host]:focus-visible .${sid} .${sid}-${m}`
        : `.${sid}:not([data-kv="off"]) .${sid}-${m}`;
      const value = trigger === 'loop' ? `${sid}-${m}-l ${cycle}s cubic-bezier(.4,0,.2,1) infinite both` : `${sid}-${m} ${dur}s cubic-bezier(.4,0,.2,1) 1 both`;
      return `${on} { animation: ${value}; }`;
    }),
    `@media (prefers-reduced-motion: reduce) { .${sid} * { animation: none !important; } }`,
  ].join('\n');
  const fillOn = active ? 'var(--primary)' : 'none';
  return (
    <span
      ref={play.ref}
      data-kv={trigger === 'hover' ? undefined : play.state}
      role={label ? 'img' : undefined}
      aria-label={label}
      aria-hidden={label ? undefined : true}
      className={cn(sid, 'inline-grid shrink-0 place-items-center', active && 'text-primary', className)}
      style={{ width: size, height: size }}
    >
      <style dangerouslySetInnerHTML={{ __html: css }} />
      <svg viewBox="0 0 24 24" width={size} height={size} fill="none" stroke="currentColor" strokeWidth={strokeWidth} strokeLinecap="round" strokeLinejoin="round" className="overflow-visible">
        {def.parts.map((p, i) => (
          <path
            key={i}
            d={p.d}
            className={p.m ? `${sid}-${p.m}` : undefined}
            fill={p.fill ? fillOn : 'none'}
            {...(p.draw ? { pathLength: 1, strokeDasharray: '1 1' } : null)}
            style={{ transformOrigin: p.origin ?? '12px 12px', transformBox: 'view-box', transition: 'fill .3s', opacity: p.hidden ? 0 : undefined }}
          />
        ))}
      </svg>
    </span>
  );
}