Sheet

: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 { Button } from "@/components/ui/button";
import { duration, ease, spring } from "@/lib/motion";
import { cn } from "@/lib/utils";
import { cva } from "class-variance-authority";
import { XIcon } from "lucide-react";
import { AnimatePresence, motion, useReducedMotion } from "motion/react";
import { Dialog as SheetPrimitive } from "radix-ui";
import { type ComponentProps, createContext, useCallback, useContext, useState } from "react";

/*
 * Sheet: a panel that slides in from an edge of the screen, for forms, filters, navigation or details beside
 * the page. Built on Radix Dialog, so it's a modal: focus moves in and stays there, Escape and the backdrop
 * close it, and focus goes back to the trigger.
 * - The root keeps the open state, controlled (`open`) or not (`defaultOpen`), so the panel can slide out:
 *   the portal stays mounted (forceMount) inside AnimatePresence until the exit ends.
 * - Motion (.agents/rules/motion.md): a drawer slides. The panel comes in from its edge on spring.snappy and
 *   leaves on a timed duration.base + ease.in. No blur: it's a surface moving, not content appearing. The
 *   backdrop only fades. With reduced motion, both only fade.
 * - An 8px band in the panel's own colour lies just past the screen edge, so the spring's slight overshoot
 *   never opens a gap between the panel and the edge.
 * - While it leaves, clicks go through to the page, so the page is usable again at once. Focus then goes
 *   back to the trigger, unless the person has already focused something else there.
 */

type Side = "top" | "right" | "bottom" | "left";

const SheetContext = createContext<boolean | null>(null);

function useSheetOpen(part: string) {
  const open = useContext(SheetContext);
  if (open === null) throw new Error(`${part} must be used inside Sheet`);
  return open;
}

/** Leaving is timed rather than a spring, so it's over quickly */
const leave = { duration: duration.base, ease: ease.in };

/** Where the panel waits off-screen, beyond its edge */
const offscreen = {
  top: { y: "-100%" },
  right: { x: "100%" },
  bottom: { y: "100%" },
  left: { x: "-100%" },
} as const satisfies Record<Side, object>;

const sheetVariants = cva(
  [
    "fixed z-(--z-modal) flex flex-col gap-4 overflow-y-auto bg-background p-6 text-foreground shadow-lg outline-hidden",
    // Leaving, it no longer catches clicks
    "data-[state=closed]:pointer-events-none",
  ],
  {
    variants: {
      // Each side sits 8px past its edge with an 8px border in the panel's colour there (the overshoot band),
      // and a hairline on the side facing the page
      side: {
        top: "inset-x-0 -top-2 max-h-full border-t-8 border-b border-t-background border-b-border",
        right:
          "inset-y-0 -right-2 h-full w-3/4 border-r-8 border-l border-r-background border-l-border sm:max-w-sm",
        bottom: "inset-x-0 -bottom-2 max-h-full border-t border-b-8 border-t-border border-b-background",
        left: "inset-y-0 -left-2 h-full w-3/4 border-r border-l-8 border-r-border border-l-background sm:max-w-sm",
      },
    },
    defaultVariants: { side: "right" },
  },
);

function Sheet({ open, defaultOpen, onOpenChange, ...props }: ComponentProps<typeof SheetPrimitive.Root>) {
  const [own, setOwn] = useState(defaultOpen ?? false);
  const current = open ?? own;
  const setOpen = useCallback(
    (next: boolean) => {
      setOwn(next);
      onOpenChange?.(next);
    },
    [onOpenChange],
  );
  return (
    <SheetContext.Provider value={current}>
      <SheetPrimitive.Root data-slot="sheet" open={current} onOpenChange={setOpen} {...props} />
    </SheetContext.Provider>
  );
}

function SheetTrigger(props: ComponentProps<typeof SheetPrimitive.Trigger>) {
  return <SheetPrimitive.Trigger data-slot="sheet-trigger" {...props} />;
}

function SheetClose(props: ComponentProps<typeof SheetPrimitive.Close>) {
  return <SheetPrimitive.Close data-slot="sheet-close" {...props} />;
}

/** Stays mounted while the sheet is open and while its exit plays */
function SheetPortal({
  children,
  ...props
}: Omit<ComponentProps<typeof SheetPrimitive.Portal>, "forceMount">) {
  const open = useSheetOpen("SheetPortal");
  return (
    // initial={false}: a sheet that starts open is simply there, with no entrance
    <AnimatePresence initial={false}>
      {open ? (
        <SheetPrimitive.Portal data-slot="sheet-portal" {...props} forceMount>
          {children}
        </SheetPrimitive.Portal>
      ) : null}
    </AnimatePresence>
  );
}

function SheetOverlay({ className, style, ...props }: ComponentProps<typeof SheetPrimitive.Overlay>) {
  const open = useSheetOpen("SheetOverlay");
  return (
    <SheetPrimitive.Overlay
      data-slot="sheet-overlay"
      className={cn("fixed inset-0 z-(--z-overlay) bg-overlay", className)}
      // Radix keeps the backdrop clickable; while it fades out, clicks go through to the page
      style={{ pointerEvents: open ? "auto" : "none", ...style }}
      {...props}
      asChild
      forceMount
    >
      {/* The backdrop only fades: a full-screen blur would cost too much (ADR 0011) */}
      <motion.div
        initial={{ opacity: 0 }}
        animate={{ opacity: 1, transition: { duration: duration.base, ease: ease.out } }}
        exit={{ opacity: 0, transition: leave }}
      />
    </SheetPrimitive.Overlay>
  );
}

export type SheetContentProps = ComponentProps<typeof SheetPrimitive.Content> & {
  /** The edge it slides in from */
  side?: Side;
  /** Show a close button in the top corner */
  showCloseButton?: boolean;
};

function SheetContent({
  className,
  children,
  side = "right",
  showCloseButton = true,
  onCloseAutoFocus,
  ...props
}: SheetContentProps) {
  const reduce = useReducedMotion() ?? false;
  const hidden = reduce ? { opacity: 0 } : offscreen[side];
  return (
    <SheetPortal>
      <SheetOverlay />
      <SheetPrimitive.Content
        data-slot="sheet-content"
        data-side={side}
        className={cn(
          sheetVariants({ side }),
          // The header stops short of the close button, so a long title never runs under it
          showCloseButton && "**:data-[slot=sheet-header]:pe-8",
          className,
        )}
        onCloseAutoFocus={(event) => {
          onCloseAutoFocus?.(event);
          // Once the panel is gone, focus goes back to the trigger, unless the person has already focused
          // something on the page (clicks reach it while the panel leaves)
          if (document.activeElement !== document.body) event.preventDefault();
        }}
        {...props}
        asChild
        forceMount
      >
        <motion.div
          initial={hidden}
          animate={
            reduce
              ? { opacity: 1, transition: { duration: duration.base, ease: ease.out } }
              : { x: 0, y: 0, transition: spring.snappy }
          }
          exit={{ ...hidden, transition: leave }}
        >
          {children}
          {showCloseButton ? (
            <SheetPrimitive.Close asChild>
              {/* Centred on the title's line, its icon lined up with the panel's padding */}
              <Button
                data-slot="sheet-close"
                variant="ghost"
                size="icon-sm"
                aria-label="Close"
                className="absolute end-4 top-5 text-muted-foreground hover:text-foreground"
              >
                <XIcon />
              </Button>
            </SheetPrimitive.Close>
          ) : null}
        </motion.div>
      </SheetPrimitive.Content>
    </SheetPortal>
  );
}

function SheetHeader({ className, ...props }: ComponentProps<"div">) {
  return <div data-slot="sheet-header" className={cn("grid gap-1.5", className)} {...props} />;
}

/** Actions at the panel's foot: stacked on phones with the main one on top, in a row at the end from sm */
function SheetFooter({ className, ...props }: ComponentProps<"div">) {
  return (
    <div
      data-slot="sheet-footer"
      className={cn("mt-auto flex flex-col-reverse gap-2 sm:flex-row sm:justify-end", className)}
      {...props}
    />
  );
}

function SheetTitle({ className, ...props }: ComponentProps<typeof SheetPrimitive.Title>) {
  return (
    <SheetPrimitive.Title
      data-slot="sheet-title"
      className={cn("text-base font-semibold", className)}
      {...props}
    />
  );
}

function SheetDescription({ className, ...props }: ComponentProps<typeof SheetPrimitive.Description>) {
  return (
    <SheetPrimitive.Description
      data-slot="sheet-description"
      className={cn("text-sm text-muted-foreground", className)}
      {...props}
    />
  );
}

export {
  Sheet,
  SheetClose,
  SheetContent,
  SheetDescription,
  SheetFooter,
  SheetHeader,
  SheetTitle,
  SheetTrigger,
  sheetVariants,
};