// ── Bucket management ──

import { $, esc, api } from './util.js';
import { state, CARD_COLORS, setActiveBucket, ensureActiveBucketValid } from './state.js';
import { showDialog } from './dialog.js';
import { pushUndo } from './undo.js';

// ── Bucket context menu ──

const ctxMenu = document.createElement('div');
ctxMenu.id = 'bucket-ctx';
ctxMenu.className = 'fixed z-[85] bg-t-surface border border-t-border shadow-2xl hidden';
ctxMenu.style.minWidth = '170px';
document.body.appendChild(ctxMenu);

let ctxBucketId = null;

function hideBucketCtx() { ctxMenu.classList.add('hidden'); ctxBucketId = null; }
document.addEventListener('click', hideBucketCtx);

async function showBucketCtx(x, y, bucket) {
    ctxBucketId = bucket.id;
    // Move-left / move-right operates within the bucket's siblings —
    // top-level peers if the bucket is top-level, dropdown peers if it's
    // a super-bucket child. This keeps reordering scoped to where the
    // user actually sees the bucket in the UI.
    const siblings = state.buckets
        .filter(b => (b.parent_id || null) === (bucket.parent_id || null))
        .sort((a, b) => (a.position || 0) - (b.position || 0));
    const idx = siblings.findIndex(b => b.id == bucket.id);
    const canLeft = idx > 0;
    const canRight = idx >= 0 && idx < siblings.length - 1;
    const hasCards = state.cards.some(c => c.bucket_id == bucket.id);

    const isCollab = !!bucket.collab_uid;
    ctxMenu.innerHTML = `<div class="py-1">
        <button class="ctx-item" data-baction="rename"><i class="ph ph-pencil-simple text-sm"></i><span class="font-pixel text-[10px]">Rename</span></button>
        <button class="ctx-item" data-baction="color"><i class="ph ph-palette text-sm"></i><span class="font-pixel text-[10px]">Color</span><i class="ph ph-caret-right text-xs ml-auto"></i></button>
        ${isCollab && typeof window._collabBucketsEditDialog === 'function'
            ? `<button class="ctx-item" data-baction="collab-manage"><i class="ph ph-users-three text-sm"></i><span class="font-pixel text-[10px]">Members &amp; owner…</span></button>`
            : ''
        }
        ${!isCollab && typeof window._collabBucketsUpgradeDialog === 'function'
            ? `<button class="ctx-item" data-baction="collab-upgrade"><i class="ph ph-users-three text-sm"></i><span class="font-pixel text-[10px]">Make collaborative…</span></button>`
            : ''
        }
        <div style="height:1px;background:var(--t-border);margin:2px 0"></div>
        <button class="ctx-item ${!canLeft ? 'opacity-30 pointer-events-none' : ''}" data-baction="move-left"><i class="ph ph-arrow-left text-sm"></i><span class="font-pixel text-[10px]">Move left</span></button>
        <button class="ctx-item ${!canRight ? 'opacity-30 pointer-events-none' : ''}" data-baction="move-right"><i class="ph ph-arrow-right text-sm"></i><span class="font-pixel text-[10px]">Move right</span></button>
        <div style="height:1px;background:var(--t-border);margin:2px 0"></div>
        ${hasCards
            ? `<button class="ctx-item" data-baction="delete-keep"><i class="ph ph-trash text-sm"></i><span class="font-pixel text-[10px]">Delete (keep cards)</span></button>
               <button class="ctx-item danger" data-baction="delete-all"><i class="ph ph-trash text-sm"></i><span class="font-pixel text-[10px]">Delete + cards</span></button>`
            : `<button class="ctx-item danger" data-baction="delete-keep"><i class="ph ph-trash text-sm"></i><span class="font-pixel text-[10px]">Delete</span></button>`
        }
    </div>
    <div id="bctx-colors" class="hidden px-3 py-2 border-t border-t-border">
        <div class="flex flex-wrap gap-1.5">
            ${CARD_COLORS.map(c => `<button class="w-5 h-5 rounded-sm border-2 transition-all hover:scale-125 ${c.hex === (bucket.color || '#64748b') ? 'border-t-bright' : 'border-transparent'}" style="background:${c.hex}" data-bctx-color="${c.hex}"></button>`).join('')}
        </div>
    </div>`;

    ctxMenu.style.left = Math.min(x, innerWidth - 178) + 'px';
    ctxMenu.style.top = Math.min(y, innerHeight - 250) + 'px';
    ctxMenu.classList.remove('hidden');

    ctxMenu.querySelectorAll('[data-baction]').forEach(btn => btn.addEventListener('click', async e => {
        e.stopPropagation();
        const a = btn.dataset.baction;

        if (a === 'color') {
            e.stopPropagation();
            document.getElementById('bctx-colors').classList.toggle('hidden');
            return;
        }
        else if (a === 'collab-manage') {
            hideBucketCtx();
            if (typeof window._collabBucketsEditDialog === 'function') {
                const changed = await window._collabBucketsEditDialog(bucket.collab_uid);
                if (changed) await window._reloadAll();
            }
            return;
        }
        else if (a === 'collab-upgrade') {
            hideBucketCtx();
            if (typeof window._collabBucketsUpgradeDialog === 'function') {
                const changed = await window._collabBucketsUpgradeDialog(bucket.id);
                if (changed) await window._reloadAll();
            }
            return;
        }
        else if (a === 'rename') {
            hideBucketCtx();
            const name = await showDialog({ title: 'rename_bucket', input: true, placeholder: bucket.name });
            if (!name || !name.trim()) return;
            // Collab buckets: push name change through the plugin (relay +
            // mirror). The next poll pulls the new name into the local row.
            if (bucket.collab_uid && typeof window._collabBucketsPatch === 'function') {
                const res = await window._collabBucketsPatch(bucket.collab_uid, { name: name.trim() });
                if (!res?.ok) { alert(res?.error || 'rename failed'); return; }
            } else {
                await api(`api/buckets/${bucket.id}`, { method: 'PATCH', body: { name: name.trim() } });
            }
            await window._reloadAll();
        }
        else if (a === 'move-left' || a === 'move-right') {
            hideBucketCtx();
            const other = siblings[a === 'move-left' ? idx - 1 : idx + 1];
            if (!other) return;
            // Swap positions of two siblings — works for both top-level
            // and dropdown reordering since `siblings` is scoped above.
            await api(`api/buckets/${bucket.id}`, { method: 'PATCH', body: { position: other.position ?? 0 } });
            await api(`api/buckets/${other.id}`, { method: 'PATCH', body: { position: bucket.position ?? 0 } });
            await loadBuckets(); window._renderBoard();
        }
        else if (a === 'delete-keep') {
            hideBucketCtx();
            const cards = state.cards.filter(c => c.bucket_id == bucket.id);
            if (cards.length > 0 || localStorage.getItem('hyprcrd-confirm-delete') !== '0') {
                const msg = bucket.collab_uid
                    ? (cards.length ? `Leave / delete "${bucket.name}"? ${cards.length} card(s) will be kept locally.` : `Leave / delete "${bucket.name}"?`)
                    : (cards.length ? `Delete "${bucket.name}"? ${cards.length} card(s) will be kept.` : `Delete "${bucket.name}"?`);
                const ok = await showDialog({ title: 'delete_bucket', message: msg, danger: true, okLabel: bucket.collab_uid ? 'Leave / delete' : 'Delete' });
                if (!ok) return;
            }
            if (state.activeBucket == bucket.id) setActiveBucket('all');
            // Collab bucket: route through plugin so the relay is notified
            // (owner = delete for everyone; member = just leave).
            if (bucket.collab_uid && typeof window._collabBucketsDelete === 'function') {
                const res = await window._collabBucketsDelete(bucket.collab_uid);
                if (!res?.ok) { alert(res?.error || 'delete failed'); return; }
                // Undo is intentionally NOT wired for collab deletes/leaves
                // — restoring would require re-creating on the relay and
                // re-attaching cards under a new uid. Too messy for MVP.
            } else {
                // Snapshot the row + affected card ids before deleting so
                // the undo entry can restore them.
                const snapshot = { name: bucket.name, color: bucket.color, position: bucket.position };
                const affected = cards.map(c => c.id);
                await api(`api/buckets/${bucket.id}`, { method: 'DELETE' });
                pushUndo(`delete bucket "${bucket.name}"`, async () => {
                    const created = await api('api/buckets', { method: 'POST', body: { name: snapshot.name } });
                    if (created?.id) {
                        await api(`api/buckets/${created.id}`, { method: 'PATCH', body: { color: snapshot.color, position: snapshot.position } });
                        // Re-attach cards to the recreated bucket
                        await Promise.all(affected.map(id => api(`api/cards/${id}`, { method: 'PATCH', body: { bucket_id: created.id } })));
                    }
                });
            }
            await window._reloadAll();
        }
        else if (a === 'delete-all') {
            hideBucketCtx();
            const cards = state.cards.filter(c => c.bucket_id == bucket.id);
            const ok = await showDialog({ title: 'delete_bucket', message: `Delete "${bucket.name}" and ${cards.length} card(s)?`, danger: true, okLabel: 'Delete all' });
            if (!ok) return;
            for (const c of cards) await api(`api/cards/${c.id}`, { method: 'DELETE' });
            if (state.activeBucket == bucket.id) setActiveBucket('all');
            if (bucket.collab_uid && typeof window._collabBucketsDelete === 'function') {
                const res = await window._collabBucketsDelete(bucket.collab_uid);
                if (!res?.ok) { alert(res?.error || 'delete failed'); return; }
            } else {
                await api(`api/buckets/${bucket.id}`, { method: 'DELETE' });
            }
            await window._reloadAll();
        }
    }));

    // Bucket color clicks
    ctxMenu.querySelectorAll('[data-bctx-color]').forEach(btn => btn.addEventListener('click', async e => {
        e.stopPropagation();
        hideBucketCtx();
        const newColor = btn.dataset.bctxColor;
        if (bucket.collab_uid && typeof window._collabBucketsPatch === 'function') {
            const res = await window._collabBucketsPatch(bucket.collab_uid, { color: newColor });
            if (!res?.ok) { alert(res?.error || 'color change failed'); return; }
        } else {
            await api(`api/buckets/${bucket.id}`, { method: 'PATCH', body: { color: newColor } });
        }
        await window._reloadAll();
    }));
}

const bar = $('bucket-bar');
const inpBucket = $('inp-bucket');
const searchFilter = $('search-bucket-filter');
const tasksFilter = $('tasks-bucket-filter');

/** Switch the active bucket without going through the click path —
 *  used by the number-key hotkeys (and any other code that wants to
 *  activate a bucket programmatically without triggering the super-
 *  bucket dropdown). Persists via setActiveBucket and re-renders the
 *  bar + board so the active highlight tracks. */
export function activateBucket(idOrSpecial) {
    setActiveBucket(idOrSpecial);
    state.activeGroup = null;
    renderBar();
    window._renderBoard?.();
}

export async function loadBuckets() {
    state.buckets = await api('api/buckets');
    // The persisted activeBucket may point to a bucket that no longer
    // exists (deleted in another tab, removed via import, etc.). Reset
    // to 'all' in that case before rendering.
    ensureActiveBucketValid();
    renderBar();
    populateSelects();
}

export function populateSelects() {
    const bucketOpts = state.buckets.map(b => `<option value="${b.id}">${esc(b.name)}</option>`).join('');
    if (inpBucket) inpBucket.innerHTML = `<option value="">no bucket</option>` + bucketOpts;
    if (searchFilter) searchFilter.innerHTML = `<option value="">all buckets</option><option value="none">unsorted</option>` + bucketOpts;
    if (tasksFilter) {
        const cur = tasksFilter.value;
        tasksFilter.innerHTML = `<option value="">all buckets</option><option value="none">unsorted</option>` + bucketOpts;
        const valid = cur === '' || cur === 'none' || state.buckets.some(b => String(b.id) === cur);
        tasksFilter.value = valid ? cur : '';
    }
}

function autoBucketNameFromCard(card) {
    const existing = new Set(state.buckets.map(b => String(b.name || '').trim().toLowerCase()).filter(Boolean));
    const base = String(card?.title || '').trim().replace(/\s+/g, ' ').slice(0, 40) || 'bucket';
    if (!existing.has(base.toLowerCase())) return base;
    let i = 2;
    while (existing.has(`${base} ${i}`.toLowerCase())) i++;
    return `${base} ${i}`;
}

function updateHeaderTint() {
    const header = $('main-header');
    if (!header) return;
    const bucket = state.buckets.find(b => b.id == state.activeBucket);
    if (bucket && bucket.color) {
        header.style.borderBottomWidth = '4px';
        header.style.borderBottomColor = bucket.color;
    } else {
        header.style.borderBottomWidth = '';
        header.style.borderBottomColor = '';
    }
}

// Remembers the last active member per super-bucket so the tile doesn't
// fall back to the parent label when the user navigates away and comes
// back. Keyed by parent bucket id → last selected member id (could be
// the parent itself or any child).
const lastSuperSelection = new Map();

function renderBar() {
    if (!bar) return;
    const tab = (active) => `bucket-tab ${active ? 'active' : ''} flex items-center gap-1.5 px-2.5 py-1 text-xs border border-t-border text-t-muted hover:border-t-accent hover:text-t-accent transition-colors shrink-0`;

    // Top-level buckets only — children are rendered inside their parent's
    // dropdown popover, not directly in the bar.
    const topLevel = state.buckets.filter(b => !b.parent_id);
    const childrenOf = (parentId) => state.buckets
        .filter(b => b.parent_id == parentId)
        .sort((a, b) => (a.position || 0) - (b.position || 0));

    // Track which super-bucket member is active NOW so we can recall it
    // later when the user comes back from a different bucket.
    for (const b of topLevel) {
        const kids = childrenOf(b.id);
        if (!kids.length) continue;
        if (state.activeBucket == b.id) lastSuperSelection.set(b.id, b.id);
        const activeKid = kids.find(c => c.id == state.activeBucket);
        if (activeKid) lastSuperSelection.set(b.id, activeKid.id);
    }

    // Resolve which child / parent to *show* on a super-bucket tile.
    // Priority: currently active member → last selected member → parent.
    const tileFor = (parent) => {
        const kids = childrenOf(parent.id);
        if (!kids.length) return null; // not a super-bucket
        const activeChild = kids.find(c => c.id == state.activeBucket);
        if (activeChild) return activeChild;
        if (state.activeBucket == parent.id) return parent;
        // Fall back to the last selection rather than the parent
        const lastId = lastSuperSelection.get(parent.id);
        if (lastId) {
            if (lastId == parent.id) return parent;
            const lastKid = kids.find(c => c.id == lastId);
            if (lastKid) return lastKid;
        }
        return parent;
    };

    // Show an unread dot on the fixed `all` tab when state.unseenCardIds
    // has anything in it AND the user isn't currently looking at the
    // all view. board.js drives the unseen set; we just read it here so
    // the dot survives bar re-renders that aren't followed by a board
    // render (e.g. bucket reorder, plain renderBar() call).
    const allUnread = state.activeBucket !== 'all' && state.unseenCardIds.size > 0;
    bar.innerHTML = `
        <button class="${tab(state.activeBucket === 'all')}${allUnread ? ' has-unread' : ''}" data-bucket="all" data-tip="all"><i class="ph ph-squares-four text-sm"></i>${allUnread ? '<span class="bar-unread-dot"></span>' : ''}</button>
        <button class="${tab(state.activeBucket === 'current')}" data-bucket="current" data-tip="current"><i class="ph ph-lightning text-sm"></i></button>
        <button class="${tab(state.activeBucket === 'favorites')}" data-bucket="favorites" data-tip="favorites"><i class="ph ph-star text-sm"></i></button>
        <button class="${tab(state.activeBucket === 'journal')}" data-bucket="journal" data-tip="journal"><i class="ph ph-notebook text-sm"></i></button>
        <button class="${tab(state.activeBucket === 'none')}" data-bucket="none" data-tip="unsorted"><i class="ph ph-tray text-sm"></i></button>
        ${topLevel.map(b => {
            const kids = childrenOf(b.id);
            const isSuper = kids.length > 0;
            if (isSuper) {
                // Super-bucket tile: shows the active member's name + a stack icon.
                // The shown member's id goes on `data-super-shown` so we can
                // highlight + recolor without taking over the dropdown click.
                const shown = tileFor(b);
                const c = shown.color || '#64748b';
                const groupActive = state.activeBucket == b.id || kids.some(k => k.id == state.activeBucket);
                return `<button class="${tab(groupActive)} bucket-super" data-bucket-super="${b.id}" data-super-shown="${shown.id}" draggable="true" data-bucket-drag="${b.id}" style="border-top:3px solid ${c};${groupActive ? `background:${c};color:var(--t-bg);border-color:${c}` : ''}"><i class="ph ph-stack text-sm"></i><span class="font-pixel text-[10px]">${esc(shown.name)}</span><span class="super-caret" data-super-caret="${b.id}"><i class="ph ph-caret-down text-[10px]"></i></span></button>`;
            }
            const c = b.color || '#64748b';
            const active = state.activeBucket == b.id;
            return `<button class="${tab(active)}" data-bucket="${b.id}" draggable="true" data-bucket-drag="${b.id}" style="border-top:3px solid ${c};${active ? `background:${c};color:var(--t-bg);border-color:${c}` : ''}"><i class="ph ph-folder text-sm"></i><span class="font-pixel text-[10px]">${esc(b.name)}</span></button>`;
        }).join('')}
        <button id="add-bucket-btn" class="bucket-add flex items-center gap-1 px-2 py-1 text-xs text-t-dim hover:text-t-accent transition-colors shrink-0"><i class="ph ph-plus text-sm"></i><span class="font-pixel text-[10px]">Bucket</span></button>`;

    updateHeaderTint();

    let draggingBucketId = null;

    // Single insertion-cursor element shared by all bucket tabs. Lives
    // inside #bucket-bar (which is `position: relative` so absolute
    // children align to its scroll-aware coord space) and gets repositioned
    // by the dragover handlers below. The cursor sits *between* tiles,
    // not as a border on the target tile, so it stays unambiguous when
    // we add the super-bucket nest gesture later.
    let dropCursor = bar.querySelector('#bucket-drop-cursor');
    if (!dropCursor) {
        dropCursor = document.createElement('div');
        dropCursor.id = 'bucket-drop-cursor';
        bar.appendChild(dropCursor);
    }
    function showDropCursor(targetTab, before) {
        // Position the cursor at the gap on the chosen side of the target.
        // offsetLeft / offsetWidth are relative to the offsetParent
        // (#bucket-bar) so they survive horizontal scroll.
        const x = before
            ? targetTab.offsetLeft - 4
            : targetTab.offsetLeft + targetTab.offsetWidth + 1;
        dropCursor.style.left = x + 'px';
        dropCursor.style.display = 'block';
    }
    function hideDropCursor() {
        dropCursor.style.display = 'none';
    }

    /** Can `draggedId` legally become a child of `targetId`?
     *  Rules: 1-level deep only, no self-parenting, target must be a real
     *  user bucket and currently top-level, dragged must not have children. */
    function canNestInto(draggedId, targetId) {
        if (!Number.isFinite(draggedId) || !Number.isFinite(targetId)) return false;
        if (draggedId === targetId) return false;
        const target = state.buckets.find(b => b.id === targetId);
        if (!target || target.parent_id) return false;
        const dragged = state.buckets.find(b => b.id === draggedId);
        if (!dragged) return false;
        // Already a child of the same target → no-op nest
        if (dragged.parent_id === targetId) return false;
        // Dragged has its own children → would create level-2
        if (state.buckets.some(b => b.parent_id === draggedId)) return false;
        return true;
    }

    /** Open a popover under a super-bucket tile, listing parent + every
     *  child. Each entry is a real `.bucket-tab[data-bucket=...]` element
     *  so the collab plugin's MutationObserver still picks them up and
     *  decorates them with the unread dot / users-three icon. */
    function openSuperDropdown(anchorTab, parentId) {
        // Toggle: if a popover is already open for this parent, close it.
        const existing = document.getElementById('bucket-super-popover');
        if (existing) {
            const wasFor = existing.dataset.parentId;
            existing.remove();
            if (wasFor === String(parentId)) return;
        }
        const parent = state.buckets.find(b => b.id === parentId);
        if (!parent) return;
        const kids = state.buckets
            .filter(b => b.parent_id === parentId)
            .sort((a, b) => (a.position || 0) - (b.position || 0));
        const members = [parent, ...kids];

        const pop = document.createElement('div');
        pop.id = 'bucket-super-popover';
        pop.dataset.parentId = String(parentId);
        // Anchor under the tile, clamped to the viewport.
        const rect = anchorTab.getBoundingClientRect();
        pop.style.position = 'fixed';
        pop.style.top = (rect.bottom + 4) + 'px';
        pop.style.left = rect.left + 'px';

        // Highlight the currently active member OR the last remembered
        // selection (so the user sees which child was picked last time
        // even when they're currently on a different bucket).
        const lastId = lastSuperSelection.get(parentId);
        const renderEntry = (m) => {
            const c = m.color || '#64748b';
            const active = state.activeBucket == m.id || (!members.some(x => x.id == state.activeBucket) && lastId == m.id);
            const isParent = m.id === parentId;
            return `<button class="bucket-tab ${active ? 'active' : ''} flex items-center gap-1.5 px-2.5 py-1 text-xs border border-t-border text-t-muted hover:border-t-accent hover:text-t-accent transition-colors w-full" data-bucket="${m.id}" draggable="true" data-bucket-drag="${m.id}" style="border-left:3px solid ${c};${active ? `background:${c};color:var(--t-bg);border-color:${c}` : ''}"><i class="ph ph-folder text-sm"></i><span class="font-pixel text-[10px] flex-1 text-left">${esc(m.name)}</span>${isParent ? '<i class="ph ph-house text-[10px] opacity-60" data-tip="parent"></i>' : ''}</button>`;
        };
        pop.innerHTML = members.map(renderEntry).join('');
        // Append inside #bucket-bar (not document.body) so the collab
        // plugin's MutationObserver on #bucket-bar still picks up these
        // .bucket-tab entries and decorates collab children with the
        // unread dot + users-three icon. Position is `fixed` anyway so
        // the bar's overflow:auto can't clip the popover.
        bar.appendChild(pop);

        // Wire each entry: click selects, contextmenu opens bucket ctx,
        // drag starts a re-parent / re-order operation against the bar.
        pop.querySelectorAll('.bucket-tab[data-bucket]').forEach(entry => {
            const ebid = entry.dataset.bucket;
            entry.addEventListener('click', () => {
                setActiveBucket(ebid);
                state.activeGroup = null;
                pop.remove();
                renderBar();
                window._renderBoard();
            });
            entry.addEventListener('contextmenu', e => {
                e.preventDefault(); e.stopPropagation();
                const bk = state.buckets.find(b => b.id == ebid);
                if (bk) showBucketCtx(e.clientX, e.clientY, bk);
            });
            entry.addEventListener('dragstart', e => {
                draggingBucketId = ebid;
                e.dataTransfer.setData('application/x-bucket', ebid);
                e.dataTransfer.effectAllowed = 'move';
                entry.style.opacity = '0.3';
            });
            entry.addEventListener('dragend', () => {
                entry.style.opacity = '';
                draggingBucketId = null;
                hideDropCursor();
                bar.querySelectorAll('.bucket-nest-target').forEach(x => x.classList.remove('bucket-nest-target'));
            });
        });

        // Click outside the popover closes it.
        setTimeout(() => {
            const onDocClick = (e) => {
                if (!pop.contains(e.target) && !anchorTab.contains(e.target)) {
                    pop.remove();
                    document.removeEventListener('click', onDocClick);
                }
            };
            document.addEventListener('click', onDocClick);
        }, 0);
    }

    bar.querySelectorAll('.bucket-tab').forEach(t => {
        // Super-bucket tile uses `data-bucket-super`; regular tiles use
        // `data-bucket`. The id we resolve here is the parent's id for a
        // super-tile (so drag/contextmenu/etc. operate on the parent).
        const isSuperTile = t.classList.contains('bucket-super');
        const bid = isSuperTile ? t.dataset.bucketSuper : t.dataset.bucket;
        const SPECIAL = ['all', 'current', 'favorites', 'journal', 'none'];
        const isUser = isSuperTile || !SPECIAL.includes(bid);

        if (isSuperTile) {
            // Caret arrow opens the dropdown; clicking the rest of the
            // tab activates the last-shown child (or parent).
            const caret = t.querySelector('[data-super-caret]');
            if (caret) {
                caret.addEventListener('click', (e) => {
                    e.stopPropagation();
                    openSuperDropdown(t, parseInt(bid, 10));
                });
            }
            t.addEventListener('click', () => {
                const shownId = t.dataset.superShown;
                setActiveBucket(shownId || bid);
                state.activeGroup = null;
                renderBar();
                window._renderBoard();
            });
        } else {
            t.addEventListener('click', () => { setActiveBucket(bid); state.activeGroup = null; renderBar(); window._renderBoard(); });
        }

        if (isUser) {
            t.addEventListener('contextmenu', e => {
                e.preventDefault(); e.stopPropagation();
                const bucket = state.buckets.find(b => b.id == bid);
                if (bucket) showBucketCtx(e.clientX, e.clientY, bucket);
            });

            // Bucket drag
            t.addEventListener('dragstart', e => {
                draggingBucketId = bid;
                e.dataTransfer.setData('application/x-bucket', bid);
                e.dataTransfer.effectAllowed = 'move';
                t.style.opacity = '0.3';
            });
            t.addEventListener('dragend', () => {
                t.style.opacity = '';
                draggingBucketId = null;
                hideDropCursor();
                bar.querySelectorAll('.bucket-nest-target').forEach(x => x.classList.remove('bucket-nest-target'));
            });
        }

        t.addEventListener('dragover', e => {
            e.preventDefault();
            if (draggingBucketId && isUser && draggingBucketId !== bid) {
                // Three drop zones along the tile's width:
                //   left  25% → insert before
                //   right 25% → insert after
                //   center 50% → nest into this bucket
                const rect = t.getBoundingClientRect();
                const x = e.clientX - rect.left;
                const isLeft = x < rect.width * 0.25;
                const isRight = x > rect.width * 0.75;
                const isCenter = !isLeft && !isRight;
                if (isCenter && canNestInto(parseInt(draggingBucketId, 10), parseInt(bid, 10))) {
                    hideDropCursor();
                    bar.querySelectorAll('.bucket-nest-target').forEach(x => x.classList.remove('bucket-nest-target'));
                    t.classList.add('bucket-nest-target');
                } else {
                    bar.querySelectorAll('.bucket-nest-target').forEach(x => x.classList.remove('bucket-nest-target'));
                    showDropCursor(t, isLeft);
                }
                t.classList.remove('drag-over');
            } else if (!draggingBucketId) {
                // Card drop on bucket
                t.classList.add('drag-over');
            }
        });
        t.addEventListener('dragleave', () => {
            t.classList.remove('drag-over');
        });
        t.addEventListener('drop', async e => {
            e.preventDefault();
            t.classList.remove('drag-over', 'bucket-nest-target');
            hideDropCursor();

            // Bucket reorder / nest
            const dragBid = e.dataTransfer.getData('application/x-bucket');
            if (dragBid && isUser && dragBid !== bid) {
                const rect = t.getBoundingClientRect();
                const x = e.clientX - rect.left;
                const isLeft = x < rect.width * 0.25;
                const isRight = x > rect.width * 0.75;
                const isCenter = !isLeft && !isRight;
                if (isCenter && canNestInto(parseInt(dragBid, 10), parseInt(bid, 10))) {
                    // Nest: dragged becomes a child of target. Backend
                    // refuses cycles / level-2 with a 400 — bubble that
                    // up via alert so the user knows.
                    const res = await api(`api/buckets/${dragBid}`, { method: 'PATCH', body: { parent_id: parseInt(bid, 10) } });
                    if (res?.error) { alert(res.error); return; }
                    await loadBuckets();
                    renderBar();
                    window._renderBoard();
                    return;
                }
                // Reorder among top-level buckets only.
                const before = isLeft || (!isRight && x < rect.width / 2);
                const topIds = state.buckets.filter(b => !b.parent_id).map(b => String(b.id)).filter(i => i !== dragBid);
                const targetIdx = topIds.indexOf(String(bid));
                if (targetIdx >= 0) {
                    topIds.splice(before ? targetIdx : targetIdx + 1, 0, dragBid);
                    // The dragged bucket also gets un-nested if it was a child.
                    await api(`api/buckets/${dragBid}`, { method: 'PATCH', body: { parent_id: null } });
                    await Promise.all(topIds.map((id, i) => api(`api/buckets/${id}`, { method: 'PATCH', body: { position: i } })));
                    await loadBuckets();
                    window._renderBoard();
                }
                return;
            }

            // Card drop on bucket — move dragged card + all selected
            const cardId = e.dataTransfer.getData('text/plain');
            if (!cardId) return;
            const selected = window._getSelectedIds?.() || [];
            const ids = selected.includes(String(cardId)) ? selected : [String(cardId)];

            if (bid === 'favorites') {
                const { toggleFavorite, isFavorite } = await import('./state.js');
                for (const id of ids) { if (!isFavorite(id)) toggleFavorite(id); }
                window._clearSelection?.();
                window._renderBoard();
                return;
            }
            // Card drop on a super-bucket: card goes into the *currently
            // shown* member of that group, not the parent itself.
            const targetBid = isSuperTile ? (t.dataset.superShown || bid) : bid;
            const bucketId = targetBid === 'none' ? null : (['all','current','journal'].includes(targetBid) ? undefined : targetBid);
            if (bucketId === undefined) return;
            await Promise.all(ids.map(id => api(`api/cards/${id}`, { method: 'PATCH', body: { bucket_id: bucketId, parent_id: null } })));
            window._clearSelection?.();
            await window._reloadAll();
        });
    });

    const addBtn = $('add-bucket-btn');
    addBtn?.addEventListener('click', async () => {
        // Plugins (e.g. collab-buckets) can override the default create
        // dialog by exposing window._collabBucketsCreateDialog. It returns
        // true when a bucket was created, in which case we reload.
        if (typeof window._collabBucketsCreateDialog === 'function') {
            const created = await window._collabBucketsCreateDialog();
            if (created) { await loadBuckets(); window._renderBoard(); }
            return;
        }
        const name = await showDialog({ title: 'new_bucket', input: true, placeholder: '> bucket name...' });
        if (!name || !name.trim()) return;
        await api('api/buckets', { method: 'POST', body: { name: name.trim() } });
        await loadBuckets();
        window._renderBoard();
    });

    const isCardDrag = e => Array.from(e.dataTransfer?.types || []).includes('text/plain');

    addBtn?.addEventListener('dragover', e => {
        if (!isCardDrag(e)) return;
        e.preventDefault();
        e.dataTransfer.dropEffect = 'move';
        addBtn.classList.add('drag-over');
    });
    addBtn?.addEventListener('dragleave', () => addBtn.classList.remove('drag-over'));
    addBtn?.addEventListener('drop', async e => {
        addBtn.classList.remove('drag-over');
        const cardId = e.dataTransfer.getData('text/plain');
        if (!cardId) return;
        e.preventDefault();
        const selected = window._getSelectedIds?.() || [];
        const ids = selected.includes(String(cardId)) ? selected : [String(cardId)];
        const card = state.cards.find(c => String(c.id) === String(cardId));
        const created = await api('api/buckets', { method: 'POST', body: { name: autoBucketNameFromCard(card) } });
        if (!created?.id) return;
        await Promise.all(ids.map(id => api(`api/cards/${id}`, { method: 'PATCH', body: { bucket_id: created.id, parent_id: null } })));
        window._clearSelection?.();
        await loadBuckets();
        await window._reloadAll();
    });

    renderTagBar();
}

export function renderTagBar() {
    let tagBar = $('tag-bar');
    if (!tagBar) {
        tagBar = document.createElement('div');
        tagBar.id = 'tag-bar';
        tagBar.className = 'flex items-center gap-1.5 px-6 py-1';
        const bucketRow = $('bucket-row');
        bucketRow?.parentNode.insertBefore(tagBar, bucketRow.nextSibling);
    }
    if (!state.activeTags.length) {
        tagBar.classList.add('hidden');
        return;
    }
    tagBar.classList.remove('hidden');
    tagBar.innerHTML = `<i class="ph ph-funnel text-xs text-t-accent"></i>` +
        state.activeTags.map(t => `
            <span class="tag-chip" style="font-size:10px;">
                <span class="font-pixel">#${esc(t)}</span>
                <i class="ph ph-x text-[9px] ml-0.5 cursor-pointer hover:text-t-danger" data-remove-tag="${t}"></i>
            </span>`).join('') +
        `<button id="clear-tag-filter" class="flex items-center gap-1 px-1.5 py-0.5 text-[10px] font-pixel text-t-dim hover:text-t-danger transition-colors">
            <i class="ph ph-x text-xs"></i>clear all
        </button>`;
    tagBar.querySelectorAll('[data-remove-tag]').forEach(btn => {
        btn.addEventListener('click', e => {
            e.stopPropagation();
            state.activeTags = state.activeTags.filter(t => t !== btn.dataset.removeTag);
            renderTagBar();
            window._renderBoard();
        });
    });
    $('clear-tag-filter')?.addEventListener('click', () => {
        state.activeTags = [];
        renderTagBar();
        window._renderBoard();
    });
}