FAQ Section

// Shared motion tokens. Easing curves mirror the CSS custom properties in
// globals.css; springs are the canonical physics used across components.
// Strong custom variants — defaults like `ease-in`/`ease-out` feel weak.

export const EASE_OUT = [0.16, 1, 0.3, 1] as const;
export const EASE_IN_OUT = [0.77, 0, 0.175, 1] as const;
export const EASE_DRAWER = [0.32, 0.72, 0, 1] as const;

/** CSS string form of EASE_OUT for inline style transitions. */
export const EASE_OUT_CSS = "cubic-bezier(0.16, 1, 0.3, 1)";

/** Press feedback on buttons and other tappable surfaces. */
export const SPRING_PRESS = {
  type: "spring",
  stiffness: 500,
  damping: 30,
  mass: 0.6,
} as const;

/** Content swaps — label/icon slots trading places inside a control. */
export const SPRING_SWAP = {
  type: "spring",
  stiffness: 460,
  damping: 30,
  mass: 0.55,
} as const;

/** Overlay panel entrances — modals and sheets summoned by pointer. */
export const SPRING_PANEL = {
  type: "spring",
  stiffness: 420,
  damping: 40,
  mass: 0.5,
} as const;

/** Shared-layout glides — pills, indicators and panels morphing between positions. */
export const SPRING_LAYOUT = {
  type: "spring",
  stiffness: 360,
  damping: 32,
  mass: 0.6,
} as const;

/** Cursor-follow physics for decorative mouse tracking (magnetic, tilt, dock). */
export const SPRING_MOUSE = {
  stiffness: 200,
  damping: 15,
  mass: 0.3,
} as const;

/** Dragged handles and fills (sliders) — critically damped `useSpring` config,
 * so the value follows the pointer butterily and never rebounds off an end. */
export const SPRING_GLIDE = {
  stiffness: 700,
  damping: 50,
  mass: 0.5,
} as const;

import { clsx, type ClassValue } from "clsx"
import { twMerge } from "tailwind-merge"

export function cn(...inputs: ClassValue[]) {
  return twMerge(clsx(inputs))
}

"use client";

import { useEffect, useState } from "react";

/**
 * Returns true only on devices that have a true hover (mouse / trackpad).
 * Touch devices fire phantom `:hover` on tap that sticks until tap-elsewhere
 * — gate hover-only effects (scale lifts, magnetic pulls) behind this.
 */
export function useHoverCapable() {
  const [canHover, setCanHover] = useState(false);

  useEffect(() => {
    if (typeof window === "undefined" || !window.matchMedia) return;
    const mq = window.matchMedia("(hover: hover) and (pointer: fine)");
    const update = () => setCanHover(mq.matches);
    update();
    mq.addEventListener?.("change", update);
    return () => mq.removeEventListener?.("change", update);
  }, []);

  return canHover;
}

// Shared touch primitives. iOS and iPadOS run their own gestures on top of the
// page — the long-press selection callout and the selection it drags in with
// it — and they win: once the platform claims a touch it cancels ours
// mid-gesture, so a press-and-hold or a drag simply dies. Surfaces that own
// their gesture have to opt out.
//
// What the two classes below cover, precisely:
// - `-webkit-touch-callout: none` stops iOS's long-press callout. WebKit-only:
//   it is not a property other engines have, so it is inert everywhere else.
// - `user-select: none` stops the long-press selection on every engine,
//   Android included, and stops a drag from painting a selection under the
//   cursor. It is inherited, so it reaches every descendant — which is why the
//   two classes differ only in whether they apply it unconditionally.
// What neither covers:
// - Chrome for Android's long-press menu on a link or an image. No CSS
//   suppresses it; a gesture surface that wraps one needs its own
//   `onContextMenu` with `preventDefault()`.
// - The native drag of an `<img>` or `<a>` descendant. `-webkit-user-drag` is
//   not inherited and plain divs and buttons are not drag sources, so setting
//   it on the surface does nothing — the child itself needs `draggable={false}`.

/**
 * Classes for a surface that *is* the control: a thumb, a drum, a stage, a
 * handle, a hold button. Selection is suppressed on every input, because a
 * drag that highlights the control's own label is wrong on a mouse too.
 * Compose with `touch-none` when the surface also owns the scroll axis — leave
 * it off when the page must still scroll from there.
 */
export const TOUCH_GESTURE_CLASS = "select-none [-webkit-touch-callout:none]";

/**
 * The same opt-out for a gesture surface that wraps content the consumer owns:
 * a scroller, a context-menu trigger, a sheet header, a list row. Selection is
 * suppressed only where the platform runs its own press gestures — a coarse
 * pointer — so a mouse user can still select and copy that content. If the
 * gesture itself would paint a selection under the cursor, add `select-none`
 * for the duration of the gesture rather than reaching for
 * `TOUCH_GESTURE_CLASS`.
 *
 * `pointer: coarse` describes the *primary* pointer and nothing else, so a
 * hybrid machine reads it wrong in both directions: a tablet with a mouse
 * plugged in keeps touch as primary and loses mouse selection, and a laptop
 * with a touchscreen keeps the mouse as primary and leaves selection live
 * under a finger. No media query can answer per interaction — the query is
 * about the device, and the question is about the gesture in progress. The
 * default stays here because it is right on the machines that are one thing or
 * the other, and losing a selection is a nuisance; where the miss costs a
 * *gesture* instead, the surface pairs it with `holdSelection` on the press.
 */
export const TOUCH_GESTURE_CONTENT_CLASS =
  "[-webkit-touch-callout:none] pointer-coarse:select-none";

/**
 * Grow a small control's *hit area* to at least 44×44px (WCAG 2.5.5, Apple
 * HIG) on a coarse pointer, without changing what it looks like or the space
 * it takes in layout. An invisible `::after` box, centered on the control and
 * `max(100%, 2.75rem)` on each axis, catches the taps: a 32px icon button
 * reaches 6px past each edge, a wide 40px button only grows vertically, and a
 * control already 44px or larger is left as it is. Hit-testing a pseudo
 * element lands on its owner, so handlers, focus and `:active` all behave.
 *
 * Mouse and trackpad rendering is untouched — nothing here applies outside
 * `pointer: coarse`. Requirements on the element it goes on:
 * - It must be the containing block: add `relative` (and keep it mergeable, so
 *   a consumer's `absolute` still wins through `cn`).
 * - It must not clip itself (`overflow-hidden`), or the overhang is clipped
 *   away along with its hit area.
 * - It must render children: `<input>` and other void elements have no
 *   `::after`. Put it on the wrapper or label instead.
 * - It must not already use `::after` for something visible.
 *
 * Centered 44px means two 32px buttons with a 4px gap overlap by 8px; the
 * later one wins that strip, which still ends well short of the earlier
 * button's visual center. Below a ~32px pitch the later neighbour starts
 * eating into that center — use `TOUCH_TARGET_Y_CLASS` for such dense rows.
 *
 * The overhang is real geometry: inside a scroll container it counts as
 * scrollable overflow, so a control flush against a scroller's edge can add a
 * few pixels of scroll on touch screens. Give such a scroller a little padding
 * on that side.
 */
export const TOUCH_TARGET_CLASS =
  "pointer-coarse:after:absolute pointer-coarse:after:top-1/2 pointer-coarse:after:left-1/2 pointer-coarse:after:size-[max(100%,2.75rem)] pointer-coarse:after:-translate-x-1/2 pointer-coarse:after:-translate-y-1/2 pointer-coarse:after:content-['']";

/**
 * `TOUCH_TARGET_CLASS` on the vertical axis only, for controls packed tighter
 * than ~32px apart in a row (pagination dots, dense swatches), where growing
 * sideways would hand most of each control to its neighbour. Same rules.
 */
export const TOUCH_TARGET_Y_CLASS =
  "pointer-coarse:after:absolute pointer-coarse:after:inset-x-0 pointer-coarse:after:top-1/2 pointer-coarse:after:h-[max(100%,2.75rem)] pointer-coarse:after:-translate-y-1/2 pointer-coarse:after:content-['']";

/**
 * Suppress selection on `element` for as long as a gesture is running on it,
 * whatever the primary pointer of the machine happens to be. Returns the
 * release. Inline, so it wins over the class above and is gone again the
 * moment the gesture ends.
 *
 * For the press gestures a native selection would otherwise steal — a
 * long-press that opens a menu. Elsewhere prefer the classes: a surface that
 * takes selection away for the whole session is a surface whose text nobody
 * can copy.
 */
export function holdSelection(element: HTMLElement) {
  element.style.setProperty("user-select", "none");
  element.style.setProperty("-webkit-user-select", "none");
  return () => {
    element.style.removeProperty("user-select");
    element.style.removeProperty("-webkit-user-select");
  };
}

/**
 * Pointer capture, best effort. WebKit throws `NotFoundError` when the pointer
 * is already gone by the time the handler runs — routine on iOS, where the
 * system can claim the touch first — and an uncaught throw takes the rest of
 * the handler, the gesture included, down with it. Touch pointers carry
 * implicit capture anyway, so losing it is never fatal.
 */
export function capturePointer(element: Element, pointerId: number) {
  try {
    element.setPointerCapture(pointerId);
  } catch {
    // Pointer is no longer active — implicit capture still applies on touch.
  }
}

/** Release a capture taken with `capturePointer`, ignoring a stale pointer. */
export function releasePointer(element: Element, pointerId: number) {
  try {
    if (element.hasPointerCapture(pointerId)) {
      element.releasePointerCapture(pointerId);
    }
  } catch {
    // Capture was already dropped by the browser.
  }
}

/**
 * Whether this event came from a pointer that is *hovering*: not a touch, and
 * not currently pressed. Which input the user is holding right now is not
 * something a device capability can answer — a touchscreen laptop hovers and
 * taps, and iPadOS reports a fine hovering pointer for a finger — so both
 * paths stay live and each handler branches on the event it was given.
 *
 * A pen resting on the glass is making contact, not hovering: `buttons` is the
 * tell, and it sends a pen tap down the same route a finger takes.
 *
 * This answers what an *enter* asks. A leave is the other half of a pair and
 * has to be read against the enter that started it — `useHoverGesture` in
 * `lib/hooks/use-hover-gesture` does that, and hover surfaces should use it
 * rather than asking this question twice.
 */
export const isHoveringPointer = (event: {
  pointerType: string;
  buttons: number;
}) => event.pointerType !== "touch" && event.buttons === 0;

"use client";
// karaui.kamisama-v0.my.id/components/blocks/faq-section

import { Plus, Search, X } from "lucide-react";
import {
  AnimatePresence,
  motion,
  type Transition,
  useReducedMotion,
} from "motion/react";
import {
  type ReactNode,
  useCallback,
  useEffect,
  useId,
  useMemo,
  useRef,
  useState,
} from "react";
import { EASE_OUT, SPRING_LAYOUT, SPRING_SWAP } from "@/lib/ease";
import { cn } from "@/lib/utils";

export interface FaqItem {
  /** Stable id. Also the element id / URL hash when `deepLink` is on. */
  id: string;
  question: string;
  answer: ReactNode;
  /**
   * Plain-text version of `answer` used for search when `answer` is not a
   * string. String answers are searched (and highlighted) directly.
   */
  searchText?: string;
}

export interface FaqSectionProps {
  items: FaqItem[];
  eyebrow?: ReactNode;
  heading?: ReactNode;
  description?: ReactNode;
  /** "single" keeps one answer open at a time; "multiple" lets several stay open. */
  type?: "single" | "multiple";
  /** Controlled open item ids. */
  value?: string[];
  /** Uncontrolled initial open item ids. */
  defaultValue?: string[];
  onValueChange?: (value: string[]) => void;
  /** Show a search field that narrows and highlights questions. */
  searchable?: boolean;
  searchPlaceholder?: string;
  /** Rendered when the search matches nothing. Receives the query. */
  emptyState?: (query: string) => ReactNode;
  /** "Still have questions?" slot under the header column. */
  cta?: ReactNode;
  /**
   * Give each item `id={item.id}`, open the item named by `location.hash`
   * (on mount and on hashchange) and write the hash when an item opens.
   */
  deepLink?: boolean;
  className?: string;
}

const PANEL_TRANSITION: Transition = { duration: 0.32, ease: EASE_OUT };
const PANEL_EXIT_TRANSITION: Transition = { duration: 0.22, ease: EASE_OUT };

function escapeRegExp(value: string) {
  return value.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
}

/** Wrap every case-insensitive occurrence of `query` in a <mark>. */
function highlight(text: string, query: string): ReactNode {
  const q = query.trim();
  if (!q) return text;
  const parts = text.split(new RegExp(`(${escapeRegExp(q)})`, "gi"));
  const lower = q.toLowerCase();
  let offset = 0;
  return parts.map((part) => {
    const key = `${offset}-${part}`;
    offset += part.length;
    return part.toLowerCase() === lower ? (
      <mark
        key={key}
        className="rounded-[4px] bg-primary/15 px-0.5 text-foreground"
      >
        {part}
      </mark>
    ) : (
      part
    );
  });
}

function matches(item: FaqItem, query: string) {
  const q = query.trim().toLowerCase();
  if (!q) return true;
  const answerText =
    typeof item.answer === "string" ? item.answer : (item.searchText ?? "");
  return (
    item.question.toLowerCase().includes(q) ||
    answerText.toLowerCase().includes(q)
  );
}

/**
 * FAQ page section: a header column (eyebrow, heading, description, optional
 * search and a CTA slot) beside an accordion of questions. Searching narrows
 * the list with layout animation and highlights matches; items can be
 * deep-linked by hash. Columns sit side by side once the section's own
 * container is wide enough and stack below that.
 */
export function FaqSection({
  items,
  eyebrow = "FAQ",
  heading = "Frequently asked questions",
  description,
  type = "single",
  value,
  defaultValue = [],
  onValueChange,
  searchable = false,
  searchPlaceholder = "Search questions",
  emptyState,
  cta,
  deepLink = false,
  className,
}: FaqSectionProps) {
  const reduce = useReducedMotion();
  const baseId = useId();
  const [internal, setInternal] = useState<string[]>(defaultValue);
  const open = value ?? internal;
  const [query, setQuery] = useState("");

  const setOpen = useCallback(
    (next: string[]) => {
      if (value === undefined) setInternal(next);
      onValueChange?.(next);
    },
    [value, onValueChange],
  );

  const toggle = useCallback(
    (id: string) => {
      const isOpen = open.includes(id);
      const next = isOpen
        ? open.filter((x) => x !== id)
        : type === "single"
          ? [id]
          : [...open, id];
      setOpen(next);
      if (deepLink && !isOpen && typeof window !== "undefined") {
        window.history.replaceState(null, "", `#${id}`);
      }
    },
    [open, type, setOpen, deepLink],
  );

  // Latest state for the hash listener, read through a ref so the listener
  // subscribes once and never re-scrolls to the hash item on every toggle.
  const latest = useRef({ open, type, setOpen, reduce });
  latest.current = { open, type, setOpen, reduce };

  // Deep links: read the hash after mount (never during render) and follow
  // later hash changes.
  useEffect(() => {
    if (!deepLink) return;
    const openFromHash = () => {
      const id = decodeURIComponent(window.location.hash.slice(1));
      if (!id || !items.some((item) => item.id === id)) return;
      const { open: current, type: mode, setOpen: set, reduce: still } =
        latest.current;
      if (!current.includes(id)) {
        set(mode === "single" ? [id] : [...current, id]);
      }
      document.getElementById(id)?.scrollIntoView({
        block: "nearest",
        behavior: still ? "auto" : "smooth",
      });
    };
    openFromHash();
    window.addEventListener("hashchange", openFromHash);
    return () => window.removeEventListener("hashchange", openFromHash);
  }, [deepLink, items]);

  const filtered = useMemo(
    () => items.filter((item) => matches(item, query)),
    [items, query],
  );

  const layoutTransition = reduce ? { duration: 0 } : SPRING_LAYOUT;

  return (
    <section
      className={cn(
        "@container w-full text-foreground",
        className,
      )}
    >
      <div className="grid gap-8 @xl:grid-cols-[minmax(0,2fr)_minmax(0,3fr)] @xl:gap-10">
        <div className="flex flex-col gap-4">
          <div className="flex flex-col gap-3">
            {eyebrow ? (
              <p className="text-xs font-medium uppercase tracking-[0.2em] text-muted-foreground">
                {eyebrow}
              </p>
            ) : null}
            {heading ? (
              <h2 className="text-balance text-2xl font-semibold leading-tight tracking-tight @3xl:text-3xl">
                {heading}
              </h2>
            ) : null}
            {description ? (
              <p className="text-pretty text-sm leading-6 text-muted-foreground">
                {description}
              </p>
            ) : null}
          </div>

          {searchable ? (
            <div className="relative">
              <label htmlFor={`${baseId}-search`} className="sr-only">
                {searchPlaceholder}
              </label>
              <Search
                aria-hidden
                className="pointer-events-none absolute top-1/2 left-3.5 size-4 -translate-y-1/2 text-muted-foreground"
              />
              <input
                id={`${baseId}-search`}
                type="search"
                value={query}
                onChange={(event) => setQuery(event.target.value)}
                placeholder={searchPlaceholder}
                autoComplete="off"
                className="h-10 w-full rounded-full border border-border bg-card pr-10 pl-10 text-sm text-foreground outline-none transition-colors placeholder:text-muted-foreground focus-visible:border-border-strong focus-visible:ring-2 focus-visible:ring-ring/40 [&::-webkit-search-cancel-button]:appearance-none"
              />
              <AnimatePresence initial={false}>
                {query ? (
                  <motion.button
                    key="clear"
                    type="button"
                    aria-label="Clear search"
                    onClick={() => setQuery("")}
                    initial={{ opacity: 0, scale: reduce ? 1 : 0.6 }}
                    animate={{ opacity: 1, scale: 1 }}
                    exit={{ opacity: 0, scale: reduce ? 1 : 0.6 }}
                    transition={SPRING_SWAP}
                    className="absolute top-1/2 right-2 grid size-7 -translate-y-1/2 place-items-center rounded-full text-muted-foreground outline-none hover:bg-muted hover:text-foreground focus-visible:ring-2 focus-visible:ring-ring/40"
                  >
                    <X className="size-3.5" />
                  </motion.button>
                ) : null}
              </AnimatePresence>
              <p aria-live="polite" className="sr-only">
                {query
                  ? `${filtered.length} of ${items.length} questions shown`
                  : ""}
              </p>
            </div>
          ) : null}

          {cta ? <div className="hidden @xl:block">{cta}</div> : null}
        </div>

        <div className="flex flex-col gap-4">
          {/* layoutRoot keeps the rows' layout animation measured relative to
              this list, so page scroll never replays as movement. */}
          <motion.div layoutRoot className="relative flex flex-col gap-2">
            <AnimatePresence initial={false} mode="popLayout">
              {filtered.map((item) => (
                <FaqRow
                  key={item.id}
                  item={item}
                  baseId={baseId}
                  open={open.includes(item.id)}
                  query={query}
                  deepLink={deepLink}
                  reduce={reduce}
                  layoutTransition={layoutTransition}
                  onToggle={() => toggle(item.id)}
                />
              ))}
              {filtered.length === 0 ? (
                <motion.div
                  key="empty"
                  layout
                  initial={{ opacity: 0 }}
                  animate={{ opacity: 1 }}
                  exit={{ opacity: 0 }}
                  transition={{ duration: 0.2, ease: EASE_OUT }}
                  className="rounded-2xl border border-dashed border-border-strong px-5 py-8 text-center text-sm text-muted-foreground"
                >
                  {emptyState ? (
                    emptyState(query)
                  ) : (
                    <>
                      No questions match &ldquo;{query.trim()}&rdquo;.{" "}
                      <button
                        type="button"
                        onClick={() => setQuery("")}
                        className="font-medium text-foreground underline underline-offset-4 outline-none focus-visible:ring-2 focus-visible:ring-ring/40"
                      >
                        Clear search
                      </button>
                    </>
                  )}
                </motion.div>
              ) : null}
            </AnimatePresence>
          </motion.div>

          {cta ? <div className="@xl:hidden">{cta}</div> : null}
        </div>
      </div>
    </section>
  );
}

function FaqRow({
  item,
  baseId,
  open,
  query,
  deepLink,
  reduce,
  layoutTransition,
  onToggle,
}: {
  item: FaqItem;
  baseId: string;
  open: boolean;
  query: string;
  deepLink: boolean;
  reduce: boolean | null;
  layoutTransition: Transition;
  onToggle: () => void;
}) {
  const triggerId = `${baseId}-${item.id}-trigger`;
  const panelId = `${baseId}-${item.id}-panel`;

  return (
    // Layout animation is the point here: rows glide into the gaps left by
    // filtered-out questions and by answers opening/closing.
    <motion.div
      layout="position"
      id={deepLink ? item.id : undefined}
      initial={{ opacity: 0, scale: reduce ? 1 : 0.97 }}
      animate={{ opacity: 1, scale: 1 }}
      exit={{
        opacity: 0,
        scale: reduce ? 1 : 0.97,
        transition: { duration: 0.15, ease: EASE_OUT },
      }}
      transition={{ layout: layoutTransition, duration: 0.22, ease: EASE_OUT }}
      data-state={open ? "open" : "closed"}
      className={cn(
        "scroll-mt-6 overflow-hidden rounded-2xl border bg-card text-card-foreground transition-colors",
        open ? "border-border-strong" : "border-border",
      )}
    >
      <h3 className="m-0">
        <button
          id={triggerId}
          type="button"
          aria-expanded={open}
          aria-controls={panelId}
          onClick={onToggle}
          className="flex min-h-[52px] w-full items-center gap-4 px-5 py-3 text-left text-[15px] font-medium text-foreground outline-none transition-colors hover:bg-muted/40 focus-visible:bg-muted/40"
        >
          <span className="min-w-0 flex-1 text-pretty">
            {highlight(item.question, query)}
          </span>
          <motion.span
            aria-hidden
            initial={false}
            animate={{ rotate: open ? 45 : 0 }}
            transition={reduce ? { duration: 0 } : SPRING_SWAP}
            className={cn(
              "grid size-6 shrink-0 place-items-center rounded-full transition-colors",
              open
                ? "bg-primary text-primary-foreground"
                : "bg-muted text-muted-foreground",
            )}
          >
            <Plus className="size-3.5" />
          </motion.span>
        </button>
      </h3>
      {/* Height is animated on purpose: the accordion's job is to disclose
          content in flow, which has to push the following rows down. */}
      <motion.div
        id={panelId}
        role="region"
        aria-labelledby={triggerId}
        inert={!open}
        initial={false}
        animate={{ height: open ? "auto" : 0, opacity: open ? 1 : 0 }}
        transition={
          reduce
            ? { duration: 0 }
            : open
              ? PANEL_TRANSITION
              : PANEL_EXIT_TRANSITION
        }
        className="overflow-hidden"
      >
        <div className="px-5 pb-4 text-sm leading-6 text-muted-foreground">
          {typeof item.answer === "string"
            ? highlight(item.answer, query)
            : item.answer}
        </div>
      </motion.div>
    </motion.div>
  );
}

export type {
  ButtonLinkProps,
  ButtonProps,
  ButtonSize,
  ButtonVariant,
} from "./base";
export { Button, ButtonLink } from "./base";
export type { MagneticButtonProps } from "./magnetic";
export { MagneticButton } from "./magnetic";
export type { ButtonState, StatefulButtonProps } from "./stateful";
export { StatefulButton } from "./stateful";

"use client";

import {
  AnimatePresence,
  type HTMLMotionProps,
  motion,
  useReducedMotion,
} from "motion/react";
import {
  forwardRef,
  type PointerEvent,
  type ReactNode,
  useCallback,
  useRef,
  useState,
} from "react";
import { EASE_OUT, SPRING_PRESS } from "@/lib/ease";
import { useHoverCapable } from "@/lib/hooks/use-hover-capable";
import { TOUCH_TARGET_CLASS } from "@/lib/touch";
import { cn } from "@/lib/utils";

export type ButtonVariant = "primary" | "secondary" | "ghost" | "outline";
export type ButtonSize = "sm" | "md" | "lg" | "icon";

export interface ButtonProps extends Omit<
  HTMLMotionProps<"button">,
  "children"
> {
  variant?: ButtonVariant;
  size?: ButtonSize;
  pressScale?: number;
  /** Spawn a Material-style ripple from the press point. Off by default. */
  ripple?: boolean;
  children?: ReactNode;
}

export interface ButtonLinkProps extends Omit<
  HTMLMotionProps<"a">,
  "children"
> {
  variant?: ButtonVariant;
  size?: ButtonSize;
  pressScale?: number;
  children?: ReactNode;
}

type Ripple = { id: number; x: number; y: number; size: number };

const VARIANT_CLASS: Record<ButtonVariant, string> = {
  primary: "bg-primary text-primary-foreground hover:bg-primary/90",
  secondary: "border border-border bg-card text-foreground hover:border-border",
  ghost: "text-muted-foreground hover:text-foreground hover:bg-primary/5",
  outline:
    "border border-border bg-transparent text-foreground hover:bg-primary/5",
};

const SIZE_CLASS: Record<ButtonSize, string> = {
  sm: "h-8 px-3 text-xs gap-1.5 rounded-full",
  md: "h-10 px-5 text-sm gap-2 rounded-full",
  lg: "h-12 px-6 text-base gap-2 rounded-full",
  icon: "h-8 w-8 rounded-lg",
};

export const Button = forwardRef<HTMLButtonElement, ButtonProps>(
  function Button(
    {
      variant = "primary",
      size = "md",
      pressScale = 0.93,
      ripple = false,
      className,
      children,
      onPointerDown,
      ...rest
    },
    ref,
  ) {
    const reduce = useReducedMotion();
    const canHover = useHoverCapable();
    const [ripples, setRipples] = useState<Ripple[]>([]);
    const nextId = useRef(0);

    const handlePointerDown = useCallback(
      (event: PointerEvent<HTMLButtonElement>) => {
        if (ripple && !reduce) {
          const rect = event.currentTarget.getBoundingClientRect();
          const size = Math.max(rect.width, rect.height) * 2;
          const id = nextId.current++;
          setRipples((prev) => [
            ...prev,
            {
              id,
              x: event.clientX - rect.left,
              y: event.clientY - rect.top,
              size,
            },
          ]);
        }
        onPointerDown?.(event);
      },
      [ripple, reduce, onPointerDown],
    );

    return (
      <motion.button
        ref={ref}
        type="button"
        whileTap={reduce ? undefined : { scale: pressScale }}
        whileHover={reduce || !canHover ? undefined : { scale: 1.02 }}
        transition={SPRING_PRESS}
        onPointerDown={handlePointerDown}
        className={cn(
          "relative inline-flex items-center justify-center font-medium select-none",
          "transition-colors",
          "disabled:pointer-events-none disabled:opacity-50",
          // The ripple layer clips itself, so on a touch screen the button can
          // stop clipping and let its enlarged hit area overhang.
          ripple && "overflow-hidden pointer-coarse:overflow-visible",
          TOUCH_TARGET_CLASS,
          VARIANT_CLASS[variant],
          SIZE_CLASS[size],
          className,
        )}
        {...rest}
      >
        {ripple && !reduce ? (
          <span className="pointer-events-none absolute inset-0 overflow-hidden rounded-[inherit]">
            <AnimatePresence>
              {ripples.map((r) => (
                <motion.span
                  key={r.id}
                  className="absolute rounded-full bg-current"
                  style={{
                    left: r.x,
                    top: r.y,
                    width: r.size,
                    height: r.size,
                    x: "-50%",
                    y: "-50%",
                  }}
                  initial={{ scale: 0.05, opacity: 0.3 }}
                  animate={{ scale: 1, opacity: 0 }}
                  exit={{ opacity: 0 }}
                  transition={{ duration: 1.6, ease: EASE_OUT }}
                  onAnimationComplete={() =>
                    setRipples((prev) => prev.filter((x) => x.id !== r.id))
                  }
                />
              ))}
            </AnimatePresence>
          </span>
        ) : null}
        {children}
      </motion.button>
    );
  },
);

export const ButtonLink = forwardRef<HTMLAnchorElement, ButtonLinkProps>(
  function ButtonLink(
    {
      variant = "primary",
      size = "md",
      pressScale = 0.93,
      className,
      children,
      ...rest
    },
    ref,
  ) {
    const reduce = useReducedMotion();
    const canHover = useHoverCapable();

    return (
      <motion.a
        ref={ref}
        whileTap={reduce ? undefined : { scale: pressScale }}
        whileHover={reduce || !canHover ? undefined : { scale: 1.02 }}
        transition={SPRING_PRESS}
        className={cn(
          "relative inline-flex items-center justify-center font-medium select-none",
          "transition-colors",
          TOUCH_TARGET_CLASS,
          VARIANT_CLASS[variant],
          SIZE_CLASS[size],
          className,
        )}
        {...rest}
      >
        {children}
      </motion.a>
    );
  },
);

"use client";

import { forwardRef } from "react";
import { Magnetic } from "../magnetic";
import { Button, type ButtonProps } from "./base";

export interface MagneticButtonProps extends ButtonProps {
  /** Magnetic pull strength. Default 0.25. */
  strength?: number;
  /** Class applied to the magnetic wrapper. */
  magneticClassName?: string;
}

export const MagneticButton = forwardRef<HTMLButtonElement, MagneticButtonProps>(function MagneticButton(
  { strength = 0.25, magneticClassName, children, ...rest },
  ref,
) {
  return (
    <Magnetic strength={strength} className={magneticClassName}>
      <Button ref={ref} {...rest}>
        {children}
      </Button>
    </Magnetic>
  );
});

"use client";

import { Check, Loader2, X } from "lucide-react";
import {
  AnimatePresence,
  motion,
  useReducedMotion,
  type Variants,
} from "motion/react";
import {
  forwardRef,
  type ReactNode,
  useLayoutEffect,
  useRef,
  useState,
} from "react";
import { EASE_OUT, SPRING_SWAP } from "@/lib/ease";
import { Button, type ButtonProps } from "./base";

export type ButtonState = "idle" | "loading" | "success" | "error";

export interface StatefulButtonProps extends Omit<ButtonProps, "children"> {
  state?: ButtonState;
  children: ReactNode;
  loadingText?: ReactNode;
  successText?: ReactNode;
  errorText?: ReactNode;
  icon?: ReactNode;
}

const CASCADE_STAGGER = 0.025;
const ROLL_BLUR = "blur(6px)";

const CASCADE_LETTER_VARIANTS: Variants = {
  initial: { opacity: 0, y: "105%", filter: ROLL_BLUR },
  animate: (delay: number = 0) => ({
    opacity: 1,
    y: "0%",
    filter: "blur(0px)",
    transition: { ...SPRING_SWAP, delay },
  }),
  exit: (delay: number = 0) => ({
    opacity: 0,
    y: "-105%",
    filter: ROLL_BLUR,
    transition: { duration: 0.16, ease: EASE_OUT, delay: delay * 0.5 },
  }),
};

const ICON_VARIANTS: Variants = {
  // Width collapses too, so the icon adds/removes its own space smoothly
  // instead of popping the row width in a single frame.
  initial: { opacity: 0, width: 0, scale: 0.7, filter: ROLL_BLUR },
  animate: {
    opacity: 1,
    width: "1.5rem",
    scale: 1,
    filter: "blur(0px)",
    transition: SPRING_SWAP,
  },
  exit: {
    opacity: 0,
    width: 0,
    scale: 0.7,
    filter: ROLL_BLUR,
    transition: { duration: 0.16, ease: EASE_OUT },
  },
};

function IconSlot({ keyId, children }: { keyId: string; children: ReactNode }) {
  const reduce = useReducedMotion();
  return (
    <motion.span
      key={keyId}
      variants={ICON_VARIANTS}
      initial={reduce ? { opacity: 0 } : "initial"}
      animate={reduce ? { opacity: 1 } : "animate"}
      exit={reduce ? { opacity: 0 } : "exit"}
      transition={reduce ? { duration: 0.15 } : undefined}
      className="inline-grid shrink-0 place-items-center overflow-hidden"
    >
      {children}
    </motion.span>
  );
}

function TextSlot({
  value,
  children,
}: {
  value: string;
  children: ReactNode;
}) {
  const reduce = useReducedMotion();
  const measureRef = useRef<HTMLSpanElement>(null);
  const [width, setWidth] = useState<number>();
  const label = typeof children === "string" ? children : null;
  const cascade = label !== null && !reduce;

  // Measure strings with the same per-letter layout as the cascade. Measuring
  // the whole string preserves kerning, which can make it narrower than the
  // inline-block letters and clip the final glyph during the width animation.
  useLayoutEffect(() => {
    const nextWidth = measureRef.current?.offsetWidth;
    if (!nextWidth) return;
    setWidth((current) => (current === nextWidth ? current : nextWidth));
  });

  return (
    <motion.span
      initial={false}
      animate={{ width }}
      transition={reduce ? { duration: 0 } : SPRING_SWAP}
      className="relative inline-block overflow-hidden whitespace-nowrap align-bottom"
    >
      <span
        ref={measureRef}
        aria-hidden
        className="invisible inline-block whitespace-nowrap"
      >
        {cascade
          ? label.split("").map((char, index) => (
              <span
                // biome-ignore lint/suspicious/noArrayIndexKey: position is the slot identity.
                key={index}
                className="inline-block whitespace-pre"
              >
                {char}
              </span>
            ))
          : children}
      </span>

      {cascade ? (
        <>
          <span className="sr-only">{label}</span>
          <AnimatePresence initial={false}>
            <motion.span
              key={`cascade-${value}`}
              aria-hidden
              initial="initial"
              animate="animate"
              exit="exit"
              className="absolute left-0 top-0 inline-block whitespace-pre"
            >
              {label.split("").map((char, index) => (
                <motion.span
                  // biome-ignore lint/suspicious/noArrayIndexKey: position is the slot identity.
                  key={index}
                  custom={index * CASCADE_STAGGER}
                  variants={CASCADE_LETTER_VARIANTS}
                  className="inline-block whitespace-pre will-change-[opacity,filter,transform]"
                >
                  {char}
                </motion.span>
              ))}
            </motion.span>
          </AnimatePresence>
        </>
      ) : (
        <AnimatePresence initial={false}>
          <motion.span
            key={`text-${value}`}
            initial={reduce ? { opacity: 0 } : { opacity: 0, y: 14, filter: ROLL_BLUR }}
            animate={reduce ? { opacity: 1 } : { opacity: 1, y: 0, filter: "blur(0px)" }}
            exit={reduce ? { opacity: 0 } : { opacity: 0, y: -14, filter: ROLL_BLUR }}
            transition={reduce ? { duration: 0.15 } : SPRING_SWAP}
            className="absolute left-0 top-0 inline-block will-change-[opacity,filter,transform]"
          >
            {children}
          </motion.span>
        </AnimatePresence>
      )}
    </motion.span>
  );
}

export const StatefulButton = forwardRef<HTMLButtonElement, StatefulButtonProps>(function StatefulButton(
  {
    state = "idle",
    children,
    loadingText = "Loading",
    successText = "Done",
    errorText = "Try again",
    icon,
    disabled,
    ...rest
  },
  ref,
) {
  const isBusy = state === "loading";
  const stateText =
    state === "loading"
      ? loadingText
      : state === "success"
        ? successText
        : state === "error"
        ? errorText
        : children;
  const textKey =
    typeof stateText === "string" ? `${state}-${stateText}` : state;

  return (
    <Button ref={ref} disabled={disabled || isBusy} aria-busy={isBusy} whileHover={undefined} {...rest}>
      <span
        aria-live="polite"
        className="relative inline-flex items-center justify-center overflow-hidden"
      >
        <AnimatePresence initial={false}>
          {state === "loading" ? (
            <IconSlot keyId="loading-icon">
              <Loader2 className="h-4 w-4 animate-spin" />
            </IconSlot>
          ) : null}
          {state === "success" ? (
            <IconSlot keyId="success-icon">
              <Check className="h-4 w-4" />
            </IconSlot>
          ) : null}
          {state === "error" ? (
            <IconSlot keyId="error-icon">
              <X className="h-4 w-4" />
            </IconSlot>
          ) : null}
        </AnimatePresence>

        <TextSlot value={textKey}>{stateText}</TextSlot>

        <AnimatePresence initial={false}>
          {state === "idle" && icon ? (
            <IconSlot keyId="idle-icon">{icon}</IconSlot>
          ) : null}
        </AnimatePresence>
      </span>
    </Button>
  );
});

"use client";

import { motion, useMotionValue, useReducedMotion, useSpring } from "motion/react";
import { useRef, type ReactNode } from "react";
import { SPRING_MOUSE } from "@/lib/ease";
import { useHoverCapable } from "@/lib/hooks/use-hover-capable";
import { cn } from "@/lib/utils";

export interface MagneticProps {
  children: ReactNode;
  strength?: number;
  className?: string;
}

export function Magnetic({ children, strength = 0.35, className }: MagneticProps) {
  const ref = useRef<HTMLDivElement>(null);
  const reduce = useReducedMotion();
  const canHover = useHoverCapable();
  // Decorative cursor-follow: skip on touch (phantom hover) and reduced motion.
  const enabled = !reduce && canHover;
  const x = useMotionValue(0);
  const y = useMotionValue(0);
  const sx = useSpring(x, SPRING_MOUSE);
  const sy = useSpring(y, SPRING_MOUSE);

  const onMove = (e: React.MouseEvent<HTMLDivElement>) => {
    const el = ref.current;
    if (!el || !enabled) return;
    const rect = el.getBoundingClientRect();
    x.set((e.clientX - rect.left - rect.width / 2) * strength);
    y.set((e.clientY - rect.top - rect.height / 2) * strength);
  };

  const onLeave = () => {
    x.set(0);
    y.set(0);
  };

  return (
    <motion.div
      ref={ref}
      onMouseMove={onMove}
      onMouseLeave={onLeave}
      style={{ x: sx, y: sy }}
      className={cn("inline-block", className)}
    >
      {children}
    </motion.div>
  );
}