Kanban

'use client';import {  closestCenter,  closestCorners,  DndContext,  DragOverlay,  KeyboardSensor,  MouseSensor,  pointerWithin,  TouchSensor,  useSensor,  useSensors,  type Announcements,  type CollisionDetection,  type DragEndEvent,  type DragMoveEvent,  type DragOverEvent,  type DragStartEvent,  type KeyboardCoordinateGetter,} from '@dnd-kit/core';import { SortableContext } from '@dnd-kit/sortable';import { PlusIcon } from 'lucide-react';import {  AnimatePresence,  domMax,  LayoutGroup,  LazyMotion,  m,  MotionConfig,  useMotionValue,  useReducedMotion,  useSpring,} from 'motion/react';import * as React from 'react';import { Button } from '@/components/ui/button';import { cn } from '@/lib/utils';import { DraggedCard } from './card';import { CardSheet } from './card-sheet';import { Column } from './column';import { KanbanContext, type KanbanActions, type KanbanContextValue } from './context';import { ACCENTS, createSampleBoard, DEFAULT_LABELS, DEFAULT_MEMBERS } from './data';import { DROP_ANIMATION, ENTER, EXIT, INTRO_MS, LAYOUT, MAX_TILT } from './motion';import { createState, findColumnId, kanbanReducer } from './store';import { Toolbar } from './toolbar';import type { KanbanCard, KanbanData, KanbanLabel, KanbanMember } from './types';import { matchesQuery, parseQuery, uid } from './utils';export { createSampleBoard, DEFAULT_LABELS, DEFAULT_MEMBERS } from './data';export type * from './types';export interface KanbanProps {  /** Initial board. Defaults to a small sample board. */  defaultValue?: KanbanData;  /** Called with the new board after every change (not during a drag). */  onValueChange?: (data: KanbanData) => void;  /** Persist the board in `localStorage` under this key. */  storageKey?: string;  labels?: KanbanLabel[];  members?: KanbanMember[];  /** `n` new card, `/` filter, `⌘Z` / `⇧⌘Z` undo and redo. Scoped to the board. Default `true`. */  hotkeys?: boolean;  className?: string;}const noStrategy = () => null;/* ------------------------------ collision ------------------------------ */const collision: CollisionDetection = (args) => {  const kind = args.active.data.current?.type;  const typeOf = (id: string | number) =>    args.droppableContainers.find((c) => c.id === id)?.data.current?.type;  if (kind === 'column') {    return closestCenter({      ...args,      droppableContainers: args.droppableContainers.filter(        (c) => c.data.current?.type === 'column',      ),    });  }  const pool = args.droppableContainers.filter((c) => {    const t = c.data.current?.type;    return t === 'card' || t === 'body';  });  const hits = pointerWithin({ ...args, droppableContainers: pool });  const candidates = hits.length ? hits : closestCorners({ ...args, droppableContainers: pool });  // A card under the pointer beats the column body that contains it.  const card = candidates.find((c) => typeOf(c.id) === 'card');  return card ? [card] : candidates.slice(0, 1);};/** Arrow keys while a keyboard drag is active: small steps vertically, one column per press sideways. */const keyboardCoordinates: KeyboardCoordinateGetter = (event, { currentCoordinates }) => {  switch (event.code) {    case 'ArrowDown':      return { ...currentCoordinates, y: currentCoordinates.y + 72 };    case 'ArrowUp':      return { ...currentCoordinates, y: currentCoordinates.y - 72 };    case 'ArrowRight':      return { ...currentCoordinates, x: currentCoordinates.x + 304 };    case 'ArrowLeft':      return { ...currentCoordinates, x: currentCoordinates.x - 304 };  }  return undefined;};const clamp = (n: number, min: number, max: number) => Math.min(max, Math.max(min, n));function isKanbanData(value: unknown): value is KanbanData {  const v = value as Partial<KanbanData> | null;  return (    !!v &&    typeof v.cards === 'object' &&    typeof v.columns === 'object' &&    Array.isArray(v.columnOrder) &&    v.columnOrder.length > 0 &&    v.columnOrder.every((id) => Array.isArray(v.columns?.[id]?.cardIds))  );}/* ------------------------------- component ------------------------------ *//** * `LazyMotion` + `m.*` keep the bundle small; `domMax` is required for layout animations. * `reducedMotion="user"` drops transforms (and keeps fades) for people who ask for less motion. */export function Kanban(props: KanbanProps) {  return (    <LazyMotion features={domMax} strict>      <MotionConfig reducedMotion="user">        <KanbanBoard {...props} />      </MotionConfig>    </LazyMotion>  );}function KanbanBoard({  defaultValue,  onValueChange,  storageKey,  labels = DEFAULT_LABELS,  members = DEFAULT_MEMBERS,  hotkeys = true,  className,}: KanbanProps) {  const id = React.useId();  const reduceMotion = useReducedMotion();  const [state, dispatch] = React.useReducer(kanbanReducer, undefined, () =>    createState(defaultValue ?? createSampleBoard()),  );  const { data } = state;  const stateRef = React.useRef(state);  stateRef.current = state;  /* ------------------------- persistence + callbacks ------------------------- */  const hydrated = React.useRef(false);  React.useEffect(() => {    if (storageKey) {      try {        const raw = localStorage.getItem(storageKey);        const parsed: unknown = raw ? JSON.parse(raw) : null;        if (isKanbanData(parsed)) dispatch({ type: 'data/replace', data: parsed });      } catch {        // unreadable storage: keep the initial board      }    }    hydrated.current = true;  }, [storageKey]);  const firstRun = React.useRef(true);  React.useEffect(() => {    if (firstRun.current) {      firstRun.current = false;      return;    }    if (!hydrated.current) return;    onValueChange?.(data);    if (!storageKey) return;    try {      localStorage.setItem(storageKey, JSON.stringify(data));    } catch {      // quota / private mode: persistence is best-effort    }  }, [data, onValueChange, storageKey]);  /* --------------------------------- actions --------------------------------- */  const actions = React.useMemo<KanbanActions>(    () => ({      addCard: (columnId, draft) =>        dispatch({          type: 'card/add',          columnId,          card: {            id: uid(),            description: '',            labelId: null,            priority: 'medium',            due: null,            assigneeId: null,            checklist: [],            ...draft,          },        }),      updateCard: (cardId, patch) => dispatch({ type: 'card/update', id: cardId, patch }),      deleteCard: (cardId) => dispatch({ type: 'card/delete', id: cardId }),      addColumn: () =>        dispatch({          type: 'column/add',          column: {            id: uid(),            title: 'New column',            accent:              ACCENTS[stateRef.current.data.columnOrder.length % ACCENTS.length] ?? ACCENTS[0]!,            wip: null,            collapsed: false,            done: false,            art: 'spark',            cardIds: [],          },        }),      updateColumn: (columnId, patch) => dispatch({ type: 'column/update', id: columnId, patch }),      deleteColumn: (columnId) => dispatch({ type: 'column/delete', id: columnId }),      moveCard: (cardId, toColumnId, toIndex) =>        dispatch({ type: 'card/move', id: cardId, toColumnId, toIndex }),      moveColumn: (columnId, toIndex) => dispatch({ type: 'column/move', id: columnId, toIndex }),      undo: () => dispatch({ type: 'undo' }),      redo: () => dispatch({ type: 'redo' }),      commitDrag: (base) => dispatch({ type: 'history/commit', base }),      restore: (restored) => dispatch({ type: 'history/restore', data: restored }),    }),    [],  );  /* ---------------------------------- UI state ---------------------------------- */  const [query, setQuery] = React.useState('');  const [openId, setOpenId] = React.useState<string | null>(null);  const [composerFor, setComposerFor] = React.useState<string | null>(null);  const [activeId, setActiveId] = React.useState<string | null>(null);  const [activeType, setActiveType] = React.useState<'card' | 'column' | null>(null);  const [settledId, setSettledId] = React.useState<string | null>(null);  const [intro, setIntro] = React.useState(true);  const [toast, setToast] = React.useState<{ key: number; message: string } | null>(null);  const rootRef = React.useRef<HTMLDivElement>(null);  const scrollerRef = React.useRef<HTMLDivElement>(null);  const searchRef = React.useRef<HTMLInputElement>(null);  const dragBase = React.useRef<KanbanData | null>(null);  const parsed = React.useMemo(() => parseQuery(query), [query]);  const filtering = parsed.active;  React.useEffect(() => {    const t = window.setTimeout(() => setIntro(false), INTRO_MS);    return () => window.clearTimeout(t);  }, []);  // New column: bring it into view.  const columnCount = React.useRef(data.columnOrder.length);  React.useEffect(() => {    const el = scrollerRef.current;    if (el && data.columnOrder.length > columnCount.current) {      el.scrollTo({ left: el.scrollWidth, behavior: reduceMotion ? 'auto' : 'smooth' });    }    columnCount.current = data.columnOrder.length;  }, [data.columnOrder.length, reduceMotion]);  // Deleting shows an undo toast; any other change dismisses it.  const toastCount = React.useRef({    cards: Object.keys(data.cards).length,    columns: data.columnOrder.length,  });  React.useEffect(() => {    const prev = toastCount.current;    toastCount.current = {      cards: Object.keys(data.cards).length,      columns: data.columnOrder.length,    };    if (state.lastOp === 'delete') {      setToast({        key: Date.now(),        message: data.columnOrder.length < prev.columns ? 'Column deleted' : 'Card deleted',      });    } else {      setToast(null);    }  }, [data, state.lastOp]);  const dismissToast = React.useCallback(() => setToast(null), []);  const openComposer = (columnId: string) => {    if (stateRef.current.data.columns[columnId]?.collapsed) {      actions.updateColumn(columnId, { collapsed: false });    }    setComposerFor(columnId);  };  /* ---------------------------------- hotkeys ---------------------------------- */  const onKeyDown = (e: React.KeyboardEvent<HTMLDivElement>) => {    if (!hotkeys || e.defaultPrevented) return;    if (!e.currentTarget.contains(e.target as Node)) return; // events bubbling out of portals    const t = e.target as HTMLElement;    if (t.isContentEditable || /^(INPUT|TEXTAREA|SELECT)$/.test(t.tagName)) return;    const mod = e.metaKey || e.ctrlKey;    const key = e.key.toLowerCase();    if (mod && key === 'z') {      e.preventDefault();      if (e.shiftKey) actions.redo();      else actions.undo();    } else if (mod && key === 'y') {      e.preventDefault();      actions.redo();    } else if (!mod && !e.altKey && key === 'n') {      const first = stateRef.current.data.columnOrder[0];      if (!first) return;      e.preventDefault();      scrollerRef.current?.scrollTo({ left: 0 });      openComposer(first);    } else if (!mod && !e.altKey && key === '/') {      e.preventDefault();      searchRef.current?.focus();    }  };  /* ------------------------------ drag and drop ------------------------------ */  const tiltTarget = useMotionValue(0);  const tilt = useSpring(tiltTarget, { stiffness: 300, damping: 30 });  const lastDx = React.useRef(0);  const tiltTimer = React.useRef<number | undefined>(undefined);  const sensors = useSensors(    useSensor(MouseSensor, { activationConstraint: { distance: 6 } }),    useSensor(TouchSensor, { activationConstraint: { delay: 180, tolerance: 8 } }),    useSensor(KeyboardSensor, {      keyboardCodes: { start: ['Space'], cancel: ['Escape'], end: ['Space'] },      coordinateGetter: keyboardCoordinates,    }),  );  const titleOf = (itemId: string | number) => {    const d = stateRef.current.data;    return d.cards[String(itemId)]?.title ?? d.columns[String(itemId)]?.title ?? 'item';  };  const columnNameAt = (overId: string | number, type: unknown, columnId?: string) => {    const d = stateRef.current.data;    if (type === 'column') return d.columns[String(overId)]?.title;    if (type === 'body') return d.columns[columnId ?? '']?.title;    const col = findColumnId(d, String(overId));    return col ? d.columns[col]?.title : undefined;  };  const announcements: Announcements = {    onDragStart: ({ active }) =>      `Picked up ${titleOf(active.id)}. Use the arrow keys to move, space to drop, escape to cancel.`,    onDragOver: ({ active, over }) => {      if (!over) return undefined;      const name = columnNameAt(over.id, over.data.current?.type, over.data.current?.columnId);      return name ? `${titleOf(active.id)} is over ${name}.` : undefined;    },    onDragEnd: ({ active }) => `Dropped ${titleOf(active.id)}.`,    onDragCancel: ({ active }) => `Cancelled. ${titleOf(active.id)} returned to where it started.`,  };  const onDragStart = ({ active }: DragStartEvent) => {    dragBase.current = stateRef.current.data;    lastDx.current = 0;    setActiveId(String(active.id));    setActiveType(active.data.current?.type === 'column' ? 'column' : 'card');    setSettledId(null);  };  const onDragMove = ({ delta }: DragMoveEvent) => {    const vx = delta.x - lastDx.current;    lastDx.current = delta.x;    tiltTarget.set(clamp(vx * 0.6, -MAX_TILT, MAX_TILT));    window.clearTimeout(tiltTimer.current);    tiltTimer.current = window.setTimeout(() => tiltTarget.set(0), 70);  };  const onDragOver = ({ active, over }: DragOverEvent) => {    if (!over) return;    const d = stateRef.current.data;    const overType = over.data.current?.type;    if (active.data.current?.type === 'column') {      if (overType !== 'column' || over.id === active.id) return;      actions.moveColumn(String(active.id), d.columnOrder.indexOf(String(over.id)));      return;    }    const cardId = String(active.id);    const from = findColumnId(d, cardId);    if (!from) return;    let toColumn: string;    let toIndex: number;    if (overType === 'card') {      if (over.id === active.id) return;      toColumn = findColumnId(d, String(over.id)) ?? from;      const overIndex = d.columns[toColumn]?.cardIds.indexOf(String(over.id)) ?? 0;      if (toColumn === from) {        toIndex = overIndex;      } else {        const rect = active.rect.current.translated;        const below = !!rect && rect.top > over.rect.top + over.rect.height / 2;        toIndex = overIndex + (below ? 1 : 0);      }    } else if (overType === 'body') {      toColumn = over.data.current?.columnId;      if (!toColumn || toColumn === from) return;      toIndex = d.columns[toColumn]?.cardIds.length ?? 0;    } else {      return;    }    actions.moveCard(cardId, toColumn, toIndex);  };  const endDrag = (settled: string | null) => {    window.clearTimeout(tiltTimer.current);    tiltTarget.set(0);    setActiveId(null);    setActiveType(null);    dragBase.current = null;    if (settled) {      setSettledId(settled);      window.setTimeout(() => setSettledId((cur) => (cur === settled ? null : cur)), 700);    }  };  const onDragEnd = ({ active }: DragEndEvent) => {    // The whole drag (many live moves) becomes a single undo step.    if (dragBase.current) actions.commitDrag(dragBase.current);    endDrag(activeType === 'card' ? String(active.id) : null);  };  const onDragCancel = () => {    if (dragBase.current) actions.restore(dragBase.current);    endDrag(null);  };  /* ---------------------------------- derived ---------------------------------- */  const visible = React.useMemo(() => {    const map: Record<string, KanbanCard[]> = {};    for (const columnId of data.columnOrder) {      map[columnId] = (data.columns[columnId]?.cardIds ?? [])        .map((cardId) => data.cards[cardId])        .filter((c): c is KanbanCard => !!c && matchesQuery(c, parsed, labels, members));    }    return map;  }, [data, parsed, labels, members]);  const stats = React.useMemo(() => {    let total = 0;    let done = 0;    let matches = 0;    for (const columnId of data.columnOrder) {      const col = data.columns[columnId];      if (!col) continue;      total += col.cardIds.length;      if (col.done) done += col.cardIds.length;      matches += visible[columnId]?.length ?? 0;    }    return { total, done, matches };  }, [data, visible]);  const activeCard = activeType === 'card' && activeId ? data.cards[activeId] : undefined;  const activeColumnId = activeCard && activeId ? findColumnId(data, activeId) : null;  const activeColumn = activeType === 'column' && activeId ? data.columns[activeId] : undefined;  const fresh = state.lastOp !== 'move';  const deleting = state.lastOp === 'delete';  const context = React.useMemo<KanbanContextValue>(    () => ({ labels, members, actions, openCard: setOpenId }),    [labels, members, actions],  );  return (    <KanbanContext.Provider value={context}>      <div        ref={rootRef}        tabIndex={-1}        onKeyDown={onKeyDown}        className={cn(          'relative flex h-[640px] min-h-0 flex-col overflow-hidden rounded-xl border bg-background text-foreground outline-none',          className,        )}      >        <Toolbar          query={query}          onQuery={setQuery}          inputRef={searchRef}          matches={stats.matches}          total={stats.total}          done={stats.done}          canUndo={state.past.length > 0}          canRedo={state.future.length > 0}          onUndo={actions.undo}          onRedo={actions.redo}          onNewCard={() => data.columnOrder[0] && openComposer(data.columnOrder[0])}          hotkeys={hotkeys}        />        <DndContext          id={id}          sensors={sensors}          collisionDetection={collision}          onDragStart={onDragStart}          onDragMove={onDragMove}          onDragOver={onDragOver}          onDragEnd={onDragEnd}          onDragCancel={onDragCancel}          accessibility={{            announcements,            screenReaderInstructions: {              draggable:                'To pick up a card or column, press space. Use the arrow keys to move it, space to drop it, or escape to cancel.',            },          }}        >          <LayoutGroup id={id}>            <m.div              ref={scrollerRef}              layoutScroll              role="region"              aria-label="Kanban board"              data-dragging={activeId ? '' : undefined}              className="flex min-h-0 flex-1 snap-x snap-mandatory items-start gap-3 overflow-x-auto overflow-y-hidden p-3 data-[dragging]:snap-none md:snap-none"            >              <SortableContext items={data.columnOrder} strategy={noStrategy}>                {data.columnOrder.map((columnId, i) => {                  const column = data.columns[columnId];                  if (!column) return null;                  return (                    <Column                      key={columnId}                      column={column}                      index={i}                      cards={visible[columnId] ?? []}                      filtering={filtering}                      intro={intro}                      fresh={fresh}                      deleting={deleting}                      isTarget={activeColumnId === columnId}                      canDelete={data.columnOrder.length > 1}                      composerOpen={composerFor === columnId}                      settledId={settledId}                      onOpenComposer={() => openComposer(columnId)}                      onCloseComposer={() =>                        setComposerFor((cur) => (cur === columnId ? null : cur))                      }                    />                  );                })}              </SortableContext>              <m.div layout="position" transition={{ layout: LAYOUT }} className="shrink-0">                <Button                  variant="outline"                  className="h-10 w-44 justify-center border-dashed text-muted-foreground"                  onClick={actions.addColumn}                >                  <PlusIcon /> New column                </Button>              </m.div>            </m.div>          </LayoutGroup>          <DragOverlay zIndex={60} dropAnimation={reduceMotion ? null : DROP_ANIMATION}>            {activeCard && activeColumnId && (              <DraggedCard                card={activeCard}                done={data.columns[activeColumnId]?.done ?? false}                tilt={tilt}              />            )}            {activeColumn && (              <m.div                className="flex w-full items-center gap-2 rounded-xl border bg-card px-3 py-2.5 shadow-xl"                initial={{ scale: 1 }}                animate={{ scale: 1.03 }}                transition={ENTER}              >                <span className="size-2 rounded-full" style={{ background: activeColumn.accent }} />                <span className="text-sm font-semibold">{activeColumn.title}</span>                <span className="ml-auto rounded-md bg-muted px-1.5 text-xs leading-5 text-muted-foreground tabular-nums">                  {activeColumn.cardIds.length}                </span>              </m.div>            )}          </DragOverlay>        </DndContext>        <div className="pointer-events-none absolute inset-x-0 bottom-3 flex justify-center">          <AnimatePresence>            {toast && (              <m.div                key={toast.key}                role="status"                initial={{ opacity: 0, scale: 0.95 }}                animate={{ opacity: 1, scale: 1 }}                exit={{ opacity: 0, transition: EXIT }}                transition={ENTER}                className="pointer-events-auto flex items-center gap-3 rounded-lg border bg-popover py-1.5 pr-1.5 pl-3 text-sm text-popover-foreground shadow-lg"              >                <Toast message={toast.message} onExpire={dismissToast} />                <Button size="xs" variant="secondary" onClick={actions.undo}>                  Undo                </Button>              </m.div>            )}          </AnimatePresence>        </div>        <CardSheet          card={openId ? (data.cards[openId] ?? null) : null}          onClose={() => setOpenId(null)}        />      </div>    </KanbanContext.Provider>  );}function Toast({ message, onExpire }: { message: string; onExpire: () => void }) {  React.useEffect(() => {    const t = window.setTimeout(onExpire, 5000);    return () => window.clearTimeout(t);  }, [onExpire]);  return <span>{message}</span>;}