Checkbox

:root {
  --size-control-sm: 2rem;
  --size-control-md: 2.25rem;
  --size-control-lg: 2.5rem;
  --size-icon-sm: 0.875rem;
  --size-icon-md: 1rem;
  --size-icon-lg: 1.25rem;
  --size-roll-fade: 0.25em;
  --size-roll-fade-x: 0.5em;
  --duration-instant: 80ms;
  --duration-fast: 150ms;
  --duration-base: 220ms;
  --duration-slow: 350ms;
  --duration-slower: 500ms;
  --z-overlay: 1200;
  --z-modal: 1300;
  --z-popover: 1400;
  --z-toast: 1500;
  --z-tooltip: 1600;
  --focus-ring-width: 2px;
  --focus-ring-offset: 2px;
  --opacity-disabled: 0.5;
  --ease-spring: linear(0, 0.157, 0.48, 0.77, 0.97, 1.07, 1.1, 1.09, 1.05, 1.02, 1, 0.995, 1);
  --destructive-foreground: oklch(1 0 0);
  --overlay: color-mix(in oklch, oklch(0 0 0) 40%, transparent);
}

.dark {
  --destructive-foreground: oklch(1 0 0);
  --overlay: color-mix(in oklch, oklch(0 0 0) 60%, transparent);
}

@theme inline {
  --animate-popover-in: popover-in var(--duration-fast) cubic-bezier(0.22, 1, 0.36, 1) both;
  --animate-popover-out: popover-out var(--duration-instant) cubic-bezier(0.55, 0, 1, 0.45) both;
  --animate-collapsible-open: collapsible-open var(--duration-slow) cubic-bezier(0.22, 1, 0.36, 1);
  --animate-collapsible-close: collapsible-close var(--duration-base) cubic-bezier(0.55, 0, 1, 0.45) both;
  --color-destructive-foreground: var(--destructive-foreground);
  --color-overlay: var(--overlay);
  @keyframes popover-in {
    from {
      opacity: 0;
      filter: blur(6px);
      transform: scale(0.96);
    }
    to {
      opacity: 1;
      filter: blur(0);
      transform: scale(1);
    }
  }
  @keyframes popover-out {
    from {
      opacity: 1;
      filter: blur(0);
      transform: scale(1);
    }
    to {
      opacity: 0;
      filter: blur(6px);
      transform: scale(0.96);
    }
  }
  @keyframes collapsible-open {
    from {
      height: 0;
      opacity: 0;
      filter: blur(6px);
    }
    to {
      height: var(--collapsible-height);
      opacity: 1;
      filter: blur(0);
    }
  }
  @keyframes collapsible-close {
    from {
      height: var(--collapsible-height);
      opacity: 1;
      filter: blur(0);
    }
    to {
      height: 0;
      opacity: 0;
      filter: blur(6px);
    }
  }
}

@media (prefers-reduced-motion: reduce) {
  :root {
    --duration-instant: 1ms;
    --duration-fast: 1ms;
    --duration-base: 1ms;
    --duration-slow: 1ms;
    --duration-slower: 1ms;
  }
}

import type { Transition } from "motion/react";

/*
 * Motion tokens for JavaScript animations (motion/react).
 * Durations and easings mirror the CSS tokens in src/styles/tokens.css;
 * `pnpm check:tokens` fails if the two drift apart.
 */

/** Durations in seconds. Mirrors --duration-* in tokens.css. */
export const duration = {
  instant: 0.08,
  fast: 0.15,
  base: 0.22,
  slow: 0.35,
  slower: 0.5,
} as const;

/** Cubic-bezier easings. Mirrors --ease-* in tokens.css. */
export const ease = {
  out: [0.22, 1, 0.36, 1],
  in: [0.55, 0, 1, 0.45],
  inOut: [0.65, 0, 0.35, 1],
} as const;

/**
 * Named springs: the library's motion voice.
 * - snappy: quick, almost no overshoot. Toggles, tabs, small controls.
 * - smooth: slow and settled. Panels, sidebars, page sections.
 * - bouncy: playful overshoot. Rare, for moments of delight.
 */
export const spring = {
  snappy: { type: "spring", stiffness: 520, damping: 38, mass: 1 },
  smooth: { type: "spring", stiffness: 120, damping: 20, mass: 1 },
  bouncy: { type: "spring", stiffness: 300, damping: 15, mass: 1 },
} as const satisfies Record<string, Transition>;

export type SpringName = keyof typeof spring;

/**
 * The blur (owner, 2026-10-15): content that appears, leaves or swaps sharpens in from a 6px blur as it
 * fades, instead of only fading. Pair it with the movement the pattern already has. Not for fills,
 * highlights, hover or anything full-screen (those still fade), and with reduced motion it's opacity only.
 * The CSS keyframes in tokens.css use the same 6px (checked by `pnpm check:tokens`).
 */
export const blur = { hidden: "blur(6px)", shown: "blur(0px)" } as const;

/** Swapping content in place (Loading Button, Copy Button): the new rises 6px from blurred; the old lifts away blurring */
export const swap = {
  initial: { opacity: 0, filter: blur.hidden, y: 6 },
  animate: { opacity: 1, filter: blur.shown, y: 0 },
  exit: { opacity: 0, filter: blur.hidden, y: -6 },
} as const;

/**
 * The flow of a changing number (Number Ticker): a spring for the characters' moves, the width and the digits'
 * spin, sampled into CSS linear(), and a fade for characters coming and going. Web Animations timings, in
 * milliseconds. The curve is from number-flow, © 2024 Maxwell Barvian, MIT licence (its full notice is in
 * components/number-ticker/number-ticker.tsx).
 */
export const flow = {
  transform: {
    duration: 900,
    easing:
      "linear(0,.005,.019,.039,.066,.096,.129,.165,.202,.24,.278,.316,.354,.39,.426,.461,.494,.526,.557,.586,.614,.64,.665,.689,.711,.731,.751,.769,.786,.802,.817,.831,.844,.856,.867,.877,.887,.896,.904,.912,.919,.925,.931,.937,.942,.947,.951,.955,.959,.962,.965,.968,.971,.973,.976,.978,.98,.981,.983,.984,.986,.987,.988,.989,.99,.991,.992,.992,.993,.994,.994,.995,.995,.996,.996,.9963,.9967,.9969,.9972,.9975,.9977,.9979,.9981,.9982,.9984,.9985,.9987,.9988,.9989,1)",
  },
  opacity: { duration: 450, easing: "ease-out" },
} as const satisfies Record<string, EffectTiming>;

"use client";

import { duration, ease } from "@/lib/motion";
import { cn } from "@/lib/utils";
import { cva, type VariantProps } from "class-variance-authority";
import { motion, useReducedMotion } from "motion/react";
import { Checkbox as CheckboxPrimitive } from "radix-ui";
import { type ComponentProps, useState } from "react";

/*
 * A checkbox on Radix Checkbox (owner, 2026-10-15).
 * - Motion (.agents/rules/motion.md): the fill grows from the centre as it fades in (CSS, the same `before:`
 *   layer as Button's tint) and the check draws itself in (pathLength, the tiny-stroke exception).
 *   Unchecking is checking played backwards: the check erases, then the fill shrinks and fades. Indeterminate is a dash that draws in the same way;
 *   between checked and indeterminate the fill stays and one mark erases as the other draws.
 * - Nothing animates on first paint. With reduced motion the marks appear and go at once.
 * - The state is held here and always passed to Radix, controlled or not, so the marks know what to draw.
 *   When its form resets, Radix restores the first state through onCheckedChange, so that still works.
 * - Sizes match Switch's track heights (16 and 20px), so the two line up in a form. Flat, no shadow.
 */

const checkboxVariants = cva(
  [
    "peer relative isolate inline-flex shrink-0 cursor-pointer items-center justify-center border border-input bg-transparent text-primary-foreground",
    "transition-colors duration-(--duration-fast) ease-out enabled:hover:border-ring",
    // The fill covers the border, so checked is one solid shape. It grows from 60% as it fades in (owner,
    // 2026-10-15: "the BG can also animate a little"). Unchecking, it waits for the check to start erasing, then
    // shrinks and fades a little quicker.
    "before:pointer-events-none before:absolute before:-inset-px before:-z-10 before:bg-primary before:opacity-0 before:scale-60",
    "before:transition before:duration-(--duration-fast) before:ease-in data-[state=unchecked]:before:delay-(--duration-instant)",
    "not-data-[state=unchecked]:before:scale-100 not-data-[state=unchecked]:before:opacity-100 not-data-[state=unchecked]:before:duration-(--duration-base) not-data-[state=unchecked]:before:ease-out",
    "outline-ring focus-visible:outline-(length:--focus-ring-width) focus-visible:outline-offset-(--focus-ring-offset)",
    "aria-invalid:border-destructive aria-invalid:outline-destructive",
    "disabled:cursor-not-allowed disabled:opacity-(--opacity-disabled)",
  ],
  {
    variants: {
      size: {
        sm: "size-4 rounded-xs before:rounded-xs",
        md: "size-5 rounded-sm before:rounded-sm",
      },
    },
    defaultVariants: { size: "md" },
  },
);

/** The same check as Copy Button and Loading Button, and a dash for indeterminate */
const CHECK = "M5 12.5l4.5 4.5L19 7.5";
const DASH = "M7 12h10";

/**
 * A mark that draws itself in, after the fill has started, and erases the way it came. Its opacity goes
 * with it, so a round cap never leaves a dot behind.
 */
function Mark({ d, shown, reduce }: { d: string; shown: boolean; reduce: boolean }) {
  return (
    <motion.path
      d={d}
      stroke="currentColor"
      strokeWidth="2.5"
      strokeLinecap="round"
      strokeLinejoin="round"
      initial={false}
      animate={{ pathLength: shown ? 1 : 0, opacity: shown ? 1 : 0 }}
      transition={
        reduce
          ? { duration: 0 }
          : shown
            ? {
                pathLength: { duration: duration.base, ease: ease.out, delay: duration.instant },
                opacity: { duration: 0, delay: duration.instant },
              }
            : { duration: duration.fast, ease: ease.in }
      }
    />
  );
}

export type CheckboxProps = ComponentProps<typeof CheckboxPrimitive.Root> &
  VariantProps<typeof checkboxVariants>;

/**
 * A checkbox for choices submitted with a form, built on Radix Checkbox (role="checkbox", Space toggles).
 * Set `checked` to "indeterminate" for a select-all box when only some are picked. Give it a visible label
 * (`<label htmlFor>`).
 */
function Checkbox({ className, size, checked, defaultChecked, onCheckedChange, ...props }: CheckboxProps) {
  const [uncontrolled, setUncontrolled] = useState(defaultChecked ?? false);
  const state = checked ?? uncontrolled;
  const reduce = useReducedMotion() ?? false;

  return (
    <CheckboxPrimitive.Root
      data-slot="checkbox"
      data-size={size ?? "md"}
      checked={state}
      onCheckedChange={(value) => {
        if (checked === undefined) setUncontrolled(value);
        onCheckedChange?.(value);
      }}
      className={cn(checkboxVariants({ size }), className)}
      {...props}
    >
      <svg data-slot="checkbox-indicator" viewBox="0 0 24 24" fill="none" aria-hidden className="size-full">
        <Mark d={CHECK} shown={state === true} reduce={reduce} />
        <Mark d={DASH} shown={state === "indeterminate"} reduce={reduce} />
      </svg>
    </CheckboxPrimitive.Root>
  );
}

export { Checkbox, checkboxVariants };