// ── Board rendering & card interactions ──

import { $, esc, api } from './util.js';
import { state, sortedCards, parseTags, tagChipHtml, getChildren, getRecent, getFavorites, isFavorite, SORT_MODES, SORT_ICONS, CARD_COLORS } from './state.js';
import { stripMd, getTodos, firstImage, leadingImage } from './markdown.js';
import { pushReorder, pushCardEdit, pushBatch, snapshotCard } from './undo.js';
import { getCalConfig } from './caldav.js';
import { renderMd, addCodeCopyButtons } from './markdown.js';

const board = $('board');
const boardPreview = $('board-preview');
const boardPreviewBody = $('board-preview-body');
const boardPreviewTitle = $('board-preview-title');
const boardPreviewColor = $('board-preview-color');
const boardPreviewTags = $('board-preview-tags');
const boardPreviewMeta = $('board-preview-meta');
let boardSplitOpen = localStorage.getItem('hyprcrd-board-split') === '1';
let boardPreviewCardId = null;
let activeDragEl = null;
let dragGhost = null;

// ── Multi-select ──
const selectedIds = new Set();
const selectBar = $('select-bar');
const selectCount = $('select-count');

function updateSelectBar() {
    if (!selectBar) return;
    if (selectedIds.size) {
        selectBar.classList.remove('hidden');
        selectCount.textContent = `${selectedIds.size} selected`;
    } else {
        selectBar.classList.add('hidden');
    }
}

function toggleSelect(id) {
    const sid = String(id);
    const el = board.querySelector(`[data-id="${id}"]`);
    if (selectedIds.has(sid)) {
        selectedIds.delete(sid);
        el?.classList.remove('card-selected');
        el?.querySelector('.card-select-check')?.remove();
    } else {
        selectedIds.add(sid);
        el?.classList.add('card-selected');
        if (el && !el.querySelector('.card-select-check')) {
            const check = document.createElement('div');
            check.className = 'card-select-check';
            el.appendChild(check);
        }
    }
    updateSelectBar();
}

function clearSelection() {
    selectedIds.clear();
    board.querySelectorAll('.card-selected').forEach(el => {
        el.classList.remove('card-selected');
        el.querySelector('.card-select-check')?.remove();
    });
    updateSelectBar();
}

export function getSelectedIds() { return [...selectedIds]; }
export { clearSelection };

$('select-export')?.addEventListener('click', () => {
    if (!selectedIds.size) return;
    window.location.href = 'api/export?ids=' + [...selectedIds].join(',');
});
$('select-clear')?.addEventListener('click', clearSelection);

// Custom drag ghost that fades near header
document.addEventListener('dragover', e => {
    if (!dragGhost) return;
    const header = document.querySelector('header');
    if (!header) return;
    const headerBottom = header.getBoundingClientRect().bottom;
    const dist = e.clientY - headerBottom;
    const near = dist < 80;
    const op = near ? Math.max(0.08, dist / 80 * 0.5) : 0.5;
    dragGhost.style.opacity = op.toFixed(2);
    dragGhost.style.borderColor = near ? 'var(--t-accent)' : '';
    dragGhost.style.borderWidth = near ? '2px' : '';
    dragGhost.style.boxShadow = near ? '0 0 12px var(--t-accent)' : '';
    dragGhost.style.left = (e.clientX - dragGhost._offsetX) + 'px';
    dragGhost.style.top = (e.clientY - dragGhost._offsetY) + 'px';
});

// ── Sort toggle ──

export function updateSortUI() {
    const btn = $('sort-toggle');
    const label = $('sort-label');
    const icon = document.querySelector('#sort-toggle i');
    const fixedSort = state.activeBucket === 'current' || state.activeBucket === 'journal';
    if (btn) btn.style.display = fixedSort ? 'none' : '';
    if (label) label.textContent = state.sortMode;
    if (icon) icon.className = `ph ${SORT_ICONS[state.sortMode]} text-xs`;
}

// ── Board split preview ──

function showBoardPreview(cardId) {
    const card = state.cards.find(c => c.id == cardId);
    if (!card || !boardSplitOpen) return;
    boardPreviewCardId = cardId;
    $('board-preview-empty')?.classList.add('hidden');
    $('board-preview-content')?.classList.remove('hidden');
    if (boardPreviewColor) boardPreviewColor.style.background = card.color;
    if (boardPreviewTitle) boardPreviewTitle.textContent = card.title;
    if (boardPreviewBody) {
        boardPreviewBody.innerHTML = renderMd(card.body);
        addCodeCopyButtons(boardPreviewBody);
    }
    const tags = parseTags(card);
    if (boardPreviewTags) {
        if (tags.length) {
            boardPreviewTags.classList.remove('hidden');
            boardPreviewTags.innerHTML = tags.map(t => tagChipHtml(t)).join('');
        } else {
            boardPreviewTags.classList.add('hidden');
        }
    }
    if (boardPreviewMeta) {
        boardPreviewMeta.textContent = '> ' + (card.updated_at || card.created_at || '').substring(0, 10) + (card.bucket_name ? '  |  ' + card.bucket_name : '');
    }
    // Highlight active card
    board.querySelectorAll('.board-card').forEach(el => el.classList.toggle('preview-active', el.dataset.id == cardId));
}

function closeBoardPreview() {
    boardPreview?.classList.add('hidden');
    boardSplitOpen = false;
    localStorage.setItem('hyprcrd-board-split', '0');
    const btn = $('board-split-toggle');
    if (btn) btn.classList.remove('text-t-accent');
    board.querySelectorAll('.board-card').forEach(el => el.classList.remove('preview-active'));
    boardPreviewCardId = null;
    resetBoardPreview();
}

function resetBoardPreview() {
    $('board-preview-empty')?.classList.remove('hidden');
    $('board-preview-content')?.classList.add('hidden');
    if (boardPreviewTitle) boardPreviewTitle.textContent = '';
    if (boardPreviewBody) boardPreviewBody.innerHTML = '';
}

function toggleBoardSplit() {
    boardSplitOpen = !boardSplitOpen;
    localStorage.setItem('hyprcrd-board-split', boardSplitOpen ? '1' : '0');
    boardPreview?.classList.toggle('hidden', !boardSplitOpen);
    const btn = $('board-split-toggle');
    if (btn) btn.classList.toggle('text-t-accent', boardSplitOpen);
    if (!boardSplitOpen) {
        board.querySelectorAll('.board-card').forEach(el => el.classList.remove('preview-active'));
        boardPreviewCardId = null;
    }
}

$('board-split-toggle')?.addEventListener('click', toggleBoardSplit);
$('board-preview-close')?.addEventListener('click', closeBoardPreview);
$('board-preview-edit')?.addEventListener('click', () => {
    const card = state.cards.find(c => c.id == boardPreviewCardId);
    if (card) window._openModal(card);
});

// Init split state
if (boardSplitOpen) {
    boardPreview?.classList.remove('hidden');
    const btn = $('board-split-toggle');
    if (btn) btn.classList.add('text-t-accent');
}

$('superview-toggle')?.addEventListener('click', () => {
    state.superView = !state.superView;
    localStorage.setItem('hyprcrd-superview', state.superView ? '1' : '0');
    const btn = $('superview-toggle');
    const icon = btn?.querySelector('i');
    if (icon) icon.className = `ph ${state.superView ? 'ph-squares-four' : 'ph-list'} text-xs`;
    if (btn) btn.classList.toggle('text-t-accent', state.superView);
    renderBoard();
});
if (state.superView) {
    const btn = $('superview-toggle');
    const icon = btn?.querySelector('i');
    if (icon) icon.className = 'ph ph-squares-four text-xs';
    if (btn) btn.classList.add('text-t-accent');
}

$('hide-termine')?.addEventListener('click', () => {
    state.hideTermine = !state.hideTermine;
    localStorage.setItem('hyprcrd-hide-termine', state.hideTermine ? '1' : '0');
    const btn = $('hide-termine');
    const icon = btn?.querySelector('i');
    if (icon) icon.className = `ph ${state.hideTermine ? 'ph-calendar-check' : 'ph-calendar-x'} text-xs`;
    if (btn) btn.classList.toggle('text-t-accent', state.hideTermine);
    renderBoard();
});
// Init toggle state
if (state.hideTermine) {
    const btn = $('hide-termine');
    const icon = btn?.querySelector('i');
    if (icon) icon.className = 'ph ph-calendar-check text-xs';
    if (btn) btn.classList.add('text-t-accent');
}

$('sort-toggle')?.addEventListener('click', () => {
    state.sortMode = SORT_MODES[(SORT_MODES.indexOf(state.sortMode) + 1) % SORT_MODES.length];
    localStorage.setItem('hyprcrd-sort', state.sortMode);
    updateSortUI();
    renderBoard();
});

function renderCardHtml(c, inGroup = false, recent = []) {
    const coverImg = leadingImage(c.body);
    const thumbImg = coverImg ? null : firstImage(c.body);
    const children = getChildren(c.id);
    const isGroup = !inGroup && children.length > 0;
    const todos = getTodos(c.body);
    const todoPct = todos ? Math.round(todos.done / todos.total * 100) : 0;
    const hasCover = !!coverImg;
    const tags = parseTags(c);
    const isTermin = tags.includes('termin') || tags.includes('geburtstag');
    let calCfg = null;
    if (isTermin) { for (const t of tags) { if (t && t !== 'termin' && t !== 'geburtstag') { const cfg = getCalConfig(t); if (cfg) { calCfg = cfg; break; } } } }
    const cardColor = calCfg?.color || c.color;
    const calIcon = isTermin ? (calCfg?.icon || 'calendar-dots') : null;

    return `
    <div class="board-card ${isGroup ? 'card-group ' : ''}card-glow ${hasCover ? 'card-has-cover' : 'bg-t-surface'} border border-t-border cursor-pointer hover:border-t-muted transition-colors relative group"
         style="--glow-color:${cardColor}22;${hasCover ? `background-image:url('${coverImg}')` : ''};${recent.includes(String(c.id)) ? 'border-bottom:3px solid ' + cardColor : ''}" draggable="true" data-id="${c.id}">
        ${hasCover ? '<div class="card-cover-overlay"></div>' : ''}
        <div class="card-bar w-full card-layer" style="background:${cardColor}"></div>
        ${isGroup ? `<div class="card-group-badge cursor-pointer hover:scale-110 transition-transform" style="background:${cardColor};color:#000" data-group="${c.id}">${children.length + 1}</div>` : ''}
        ${thumbImg ? `<div class="card-thumb" style="background-image:url('${thumbImg}')"></div>` : ''}
        <div class="p-4 card-layer flex flex-col h-full ${thumbImg ? 'pr-16' : ''}">
            <div class="flex items-start gap-2 mb-2">
                ${calIcon ? `<i class="ph ph-${calIcon} text-xs mt-0.5 shrink-0" style="color:${cardColor}"></i>` : ''}
                ${isFavorite(c.id) ? `<i class="ph-fill ph-star text-amber-400 text-xs mt-0.5 shrink-0"></i>` : ''}
                ${todos ? `<i class="ph ${todos.done === todos.total ? 'ph-check-square text-t-accent' : 'ph-squares-four text-t-muted'} text-sm mt-0.5 shrink-0"></i>` : ''}
                <h3 class="font-pixel text-xs text-t-bright leading-relaxed line-clamp-2">${esc(c.title)}</h3>
            </div>
            ${todos ? `<div class="mb-2"><div class="flex items-center gap-2 mb-1">
                <div class="flex-1 h-1.5 bg-t-border rounded-full overflow-hidden"><div class="h-full rounded-full transition-all" style="width:${todoPct}%;background:${cardColor}"></div></div>
                <span class="font-pixel text-[9px] ${todos.done === todos.total ? 'text-t-accent' : 'text-t-dim'}">${todos.done}/${todos.total}</span>
            </div></div>` : ''}
            <p class="text-xs ${hasCover ? 'text-t-text' : 'text-t-muted'} leading-relaxed line-clamp-5 flex-1">${esc(stripMd(c.body))}</p>
            ${tags.length ? `<div class="flex flex-wrap gap-1 mt-1.5 card-layer">${tags.slice(0, 5).map(t => tagChipHtml(t)).join('')}${tags.length > 5 ? `<span class="tag-chip tag-chip-more">+${tags.length - 5}</span>` : ''}</div>` : ''}
            <div class="mt-auto pt-2 flex items-center gap-2 text-[10px] ${hasCover ? 'text-t-text' : 'text-t-dim'} font-pixel">
                <span class="flex items-center gap-1"><i class="ph ph-clock text-xs"></i>${(c.updated_at || c.created_at || '').substring(0, 10)}</span>
                ${c.bucket_name ? `<span class="flex items-center gap-1"><i class="ph ph-folder text-xs"></i>${esc(c.bucket_name)}</span>` : ''}
            </div>
        </div>
    </div>`;
}

// ── Render ──

export function renderBoard() {
    let cards;
    if (state.activeGroup) {
        const parent = state.cards.find(c => c.id == state.activeGroup);
        cards = parent ? [parent, ...getChildren(parent.id)] : [];
    } else {
        if (state.activeBucket === 'current') {
            // Current shows ALL recently touched cards, including group children
            const recent = getRecent();
            const now = Date.now();
            const freshMs = 48 * 60 * 60 * 1000;
            cards = state.cards.filter(c => {
                if (recent.includes(String(c.id))) return true;
                const updated = new Date(c.updated_at || c.created_at || 0).getTime();
                return (now - updated) < freshMs;
            });
            cards.sort((a, b) => (b.updated_at || b.created_at || '').localeCompare(a.updated_at || a.created_at || ''));
        } else {
            cards = state.cards.filter(c => !c.parent_id);
            if (state.activeBucket === 'favorites') {
                const favs = getFavorites();
                cards = cards.filter(c => favs.includes(String(c.id)));
            } else if (state.activeBucket === 'journal') {
                const today = new Date().toISOString().substring(0, 10);
                cards = cards.filter(c => /^\d{4}-\d{2}-\d{2}/.test(c.title) && c.title.substring(0, 10) <= today);
                cards.sort((a, b) => b.title.localeCompare(a.title));
            } else if (state.activeBucket === 'none') {
                cards = cards.filter(c => !c.bucket_id && !/^\d{4}-\d{2}-\d{2}/.test(c.title));
            } else if (state.activeBucket !== 'all') {
                cards = cards.filter(c => c.bucket_id == state.activeBucket);
            }
        }
    }
    // Hide appointments
    if (state.hideTermine) {
        cards = cards.filter(c => !parseTags(c).includes('termin'));
    }
    // Tag filter (intersects with bucket filter) — hierarchical: #nase matches #nase/popel
    if (state.activeTags.length) {
        cards = cards.filter(c => {
            const ct = parseTags(c);
            return state.activeTags.every(at => ct.some(t => t === at || t.startsWith(at + '/')));
        });
    }
    // Current and journal have fixed sort order, skip global sort
    if (state.activeBucket !== 'current' && state.activeBucket !== 'journal') {
        cards = sortedCards(cards);
    }
    updateSortUI();
    window._refreshTasks?.();

    hideFan();
    renderGroupBar(cards);

    if (!cards.length) {
        board.style.display = '';
        board.innerHTML = `<div class="col-span-full text-center py-20">
            <i class="ph ph-cards text-4xl text-t-dim mb-4 block"></i>
            <p class="font-pixel text-sm text-t-dim cursor-blink">no cards found</p></div>`;
        const fc = $('footer-count');
        if (fc) fc.textContent = `0 cards · ${state.cards.length} total`;
        return;
    }

    const recent = getRecent();
    const inGroup = !!state.activeGroup;

    if (state.superView) {
        // Compact multi-column list view — override board grid
        board.style.display = 'block';
        const cols = cards.length <= 20 ? 2 : cards.length <= 50 ? 3 : cards.length <= 100 ? 4 : 5;
        board.innerHTML = `<div class="superview-grid" style="column-count:${cols};">` + cards.map(c => {
            const tags = parseTags(c);
            const isTermin = tags.includes('termin') || tags.includes('geburtstag');
            let calCfg = null;
            if (isTermin) { for (const t of tags) { if (t !== 'termin' && t !== 'geburtstag') { const cfg = getCalConfig(t); if (cfg) { calCfg = cfg; break; } } } }
            const dotColor = calCfg?.color || c.color;
            const icon = isTermin ? (calCfg?.icon || 'calendar-dots') : (isFavorite(c.id) ? 'star' : null);
            const iconColor = isTermin ? dotColor : (isFavorite(c.id) ? '#fbbf24' : 'var(--t-dim)');
            return `<div class="superview-item" data-id="${c.id}">
                <span class="superview-dot" style="background:${dotColor}"></span>
                ${icon ? `<i class="ph ph-${icon} superview-icon" style="color:${iconColor}"></i>` : ''}
                <span class="superview-title">${esc(c.title)}</span>
            </div>`;
        }).join('') + '</div>';

        let hoverPopup = null, hoverTimer = null, hoverCloseTimer = null;
        function clearHover() {
            if (hoverTimer) { clearTimeout(hoverTimer); hoverTimer = null; }
            if (hoverCloseTimer) { clearTimeout(hoverCloseTimer); hoverCloseTimer = null; }
            if (hoverPopup) { hoverPopup.remove(); hoverPopup = null; }
        }
        function delayedClose() {
            hoverCloseTimer = setTimeout(clearHover, 150);
        }
        function cancelClose() {
            if (hoverCloseTimer) { clearTimeout(hoverCloseTimer); hoverCloseTimer = null; }
        }

        board.querySelectorAll('.superview-item[data-id]').forEach(el => {
            el.addEventListener('click', () => { clearHover(); if (boardSplitOpen) showBoardPreview(el.dataset.id); else window._openDetail(el.dataset.id); });
            el.addEventListener('dblclick', () => { clearHover(); const card = state.cards.find(c => c.id == el.dataset.id); if (card) window._openModal(card); });
            el.addEventListener('contextmenu', e => { e.preventDefault(); clearHover(); const card = state.cards.find(c => c.id == el.dataset.id); if (card) window._showContextMenu(e.clientX, e.clientY, card); });

            el.addEventListener('mouseenter', () => {
                cancelClose();
                if (hoverTimer) { clearTimeout(hoverTimer); hoverTimer = null; }
                hoverTimer = setTimeout(() => {
                    if (hoverPopup) { hoverPopup.remove(); hoverPopup = null; }
                    const card = state.cards.find(c => c.id == el.dataset.id);
                    if (!card) return;
                    const rect = el.getBoundingClientRect();

                    hoverPopup = document.createElement('div');
                    Object.assign(hoverPopup.style, {
                        position: 'fixed', zIndex: '100',
                        width: '280px',
                        filter: 'drop-shadow(0 8px 24px rgba(0,0,0,0.4))',
                    });
                    const textEnd = el.querySelector('.superview-title');
                    const textRect = textEnd ? textEnd.getBoundingClientRect() : rect;
                    const left = textRect.right + 8;
                    const useLeft = left + 290 < window.innerWidth;
                    hoverPopup.style.left = (useLeft ? left : textRect.left - 288) + 'px';
                    hoverPopup.style.top = Math.min(rect.top - 20, window.innerHeight - 320) + 'px';
                    hoverPopup.innerHTML = renderCardHtml(card);
                    hoverPopup.addEventListener('mouseenter', e => { e.stopPropagation(); cancelClose(); });
                    hoverPopup.addEventListener('mouseleave', delayedClose);
                    hoverPopup.addEventListener('mouseover', e => e.stopPropagation());
                    // Tag clicks inside hover card
                    hoverPopup.querySelectorAll('.tag-seg[data-tag]').forEach(seg => {
                        seg.addEventListener('click', e => {
                            e.stopPropagation();
                            const tag = seg.dataset.tag;
                            if (e.ctrlKey || e.metaKey) {
                                const idx = state.activeTags.indexOf(tag);
                                if (idx >= 0) state.activeTags.splice(idx, 1);
                                else state.activeTags.push(tag);
                            } else {
                                state.activeTags = state.activeTags.length === 1 && state.activeTags[0] === tag ? [] : [tag];
                            }
                            clearHover();
                            window._renderTagBar?.();
                            renderBoard();
                        });
                    });
                    // Click on hover card opens detail
                    hoverPopup.querySelector('.board-card')?.addEventListener('click', () => {
                        clearHover();
                        window._openDetail(card.id);
                    });
                    document.body.appendChild(hoverPopup);
                }, 400);
            });
            el.addEventListener('mouseleave', delayedClose);
        });

        const fc = $('footer-count');
        if (fc) fc.textContent = `${cards.length} cards · ${state.cards.length} total`;
        return;
    }

    board.style.display = '';
    board.innerHTML = cards.map(c => renderCardHtml(c, inGroup, recent)).join('');

    bindCardEvents();

    // Restore selection state
    selectedIds.forEach(id => {
        const el = board.querySelector(`[data-id="${id}"]`);
        if (el) {
            el.classList.add('card-selected');
            if (!el.querySelector('.card-select-check')) {
                const check = document.createElement('div');
                check.className = 'card-select-check';
                el.appendChild(check);
            }
        }
    });
    updateSelectBar();

    // Footer count
    const fc = $('footer-count');
    if (fc) fc.textContent = `${cards.length} card${cards.length !== 1 ? 's' : ''} · ${state.cards.length} total`;
}

// ── Group bar ──

function renderGroupBar(cards) {
    const bar = $('group-bar');
    if (!bar) return;
    if (state.activeGroup) {
        const parent = state.cards.find(c => c.id == state.activeGroup);
        bar.classList.remove('hidden');
        bar.innerHTML = `
            <button id="group-back" class="flex items-center gap-1.5 px-2.5 py-1 text-xs border border-t-border text-t-muted hover:border-t-accent hover:text-t-accent transition-colors">
                <i class="ph ph-arrow-left text-sm"></i><span class="font-pixel text-[10px]">back</span>
            </button>
            <i class="ph ph-stack text-t-accent text-sm"></i>
            <span class="font-pixel text-[10px] text-t-accent">${esc(parent?.title || 'group')}</span>
            <span class="font-pixel text-[9px] text-t-dim">${cards.length} cards</span>`;
        $('group-back')?.addEventListener('click', () => { state.activeGroup = null; renderBoard(); });
    } else {
        bar.classList.add('hidden');
    }
}

// ── Group fan preview ──

let fanEl = null;
let fanTimer = null;
let fanGroupId = null;

function showFan(groupEl, parentId) {
    hideFan();
    const parent = state.cards.find(c => c.id == parentId);
    if (!parent) return;
    const children = getChildren(parentId);
    const all = children;
    const maxShow = 12;
    const visible = all.slice(0, maxShow);
    const hasMore = all.length > maxShow;

    fanGroupId = parentId;
    fanEl = document.createElement('div');
    fanEl.className = 'group-fan';
    const cols = Math.min(6, visible.length);
    fanEl.innerHTML = `<div class="group-fan-grid ${hasMore ? 'has-more' : ''}" style="--fan-cols:${cols}">${visible.map(c => {
        const img = firstImage(c.body);
        return `<div class="group-fan-card" data-fan-id="${c.id}">
            <div class="group-fan-bar" style="background:${c.color}"></div>
            ${img ? `<div class="group-fan-thumb" style="background-image:url('${img}')"></div>` : ''}
            <div class="group-fan-title font-pixel">${esc(c.title)}</div>
        </div>`;
    }).join('')}</div>`;

    document.body.appendChild(fanEl);

    // Position below the group card
    const rect = groupEl.getBoundingClientRect();
    const fanW = fanEl.offsetWidth;
    let left = rect.left + rect.width / 2 - fanW / 2;
    left = Math.max(8, Math.min(left, innerWidth - fanW - 8));
    let top = rect.bottom + 6;
    if (top + fanEl.offsetHeight > innerHeight - 40) top = rect.top - fanEl.offsetHeight - 6;
    fanEl.style.left = left + 'px';
    fanEl.style.top = top + 'px';

    fanEl.querySelectorAll('[data-fan-id]').forEach(card => {
        card.addEventListener('click', () => { hideFan(); window._openDetail(card.dataset.fanId); });
    });

    fanEl.addEventListener('mouseleave', hideFan);
}

function hideFan() {
    if (fanTimer) { clearTimeout(fanTimer); fanTimer = null; }
    if (fanEl) { fanEl.remove(); fanEl = null; }
    fanGroupId = null;
}

// ── Card event binding ──

function bindCardEvents() {
    board.querySelectorAll('[data-group]').forEach(badge => {
        badge.addEventListener('click', e => { e.stopPropagation(); state.activeGroup = badge.dataset.group; renderBoard(); });
    });

    board.querySelectorAll('.tag-seg[data-tag]').forEach(seg => {
        seg.addEventListener('click', e => {
            e.stopPropagation();
            const tag = seg.dataset.tag;
            if (e.ctrlKey || e.metaKey) {
                const idx = state.activeTags.indexOf(tag);
                if (idx >= 0) state.activeTags.splice(idx, 1);
                else state.activeTags.push(tag);
            } else {
                state.activeTags = state.activeTags.length === 1 && state.activeTags[0] === tag ? [] : [tag];
            }
            window._renderTagBar?.();
            renderBoard();
        });
    });

    board.querySelectorAll('[data-id]').forEach(el => {
        const id = el.dataset.id;
        const children = getChildren(id);
        const isGroup = children.length > 0 && !state.activeGroup;
        let clickTimer = null;

        // Group fan on long hover
        if (isGroup) {
            el.addEventListener('mouseenter', () => {
                fanTimer = setTimeout(() => showFan(el, id), 800);
            });
            el.addEventListener('mouseleave', e => {
                // Don't hide if moving to the fan itself
                if (fanEl && fanEl.contains(e.relatedTarget)) return;
                if (fanTimer) { clearTimeout(fanTimer); fanTimer = null; }
                // Delay hiding to allow moving to fan
                if (fanEl && fanGroupId == id) {
                    setTimeout(() => { if (fanGroupId == id && fanEl && !fanEl.matches(':hover')) hideFan(); }, 200);
                }
            });
        }

        el.addEventListener('click', (e) => {
            if (e.ctrlKey || e.metaKey) { e.preventDefault(); toggleSelect(id); return; }
            if (clickTimer) return;
            clickTimer = setTimeout(() => {
                clickTimer = null;
                if (boardSplitOpen) { showBoardPreview(id); }
                else { window._openDetail(id); }
            }, 200);
        });
        el.addEventListener('dblclick', e => {
            e.preventDefault();
            if (clickTimer) { clearTimeout(clickTimer); clickTimer = null; }
            const card = state.cards.find(c => c.id == id);
            if (card) window._openModal(card);
        });
        el.addEventListener('contextmenu', e => {
            e.preventDefault(); e.stopPropagation();
            const card = state.cards.find(c => c.id == id);
            if (card) window._showContextMenu(e.clientX, e.clientY, card);
        });

        // Drag & drop
        el.addEventListener('dragstart', e => {
            e.dataTransfer.setData('text/plain', id);
            e.dataTransfer.effectAllowed = 'move';
            activeDragEl = el;

            // Determine all dragged cards (selected or just this one)
            const isMulti = selectedIds.has(String(id)) && selectedIds.size > 1;
            const dragIds = isMulti ? [...selectedIds] : [String(id)];

            // Ghost all dragged cards
            dragIds.forEach(did => {
                board.querySelector(`[data-id="${did}"]`)?.classList.add('card-dragging');
            });

            // Hide native drag image
            const empty = document.createElement('div');
            empty.style.width = '1px'; empty.style.height = '1px'; empty.style.opacity = '0.01';
            document.body.appendChild(empty);
            e.dataTransfer.setDragImage(empty, 0, 0);
            setTimeout(() => empty.remove(), 0);

            // Create stacked ghost
            const rect = el.getBoundingClientRect();
            const container = document.createElement('div');
            container.style.cssText = `position:fixed;z-index:9998;pointer-events:none;transition:opacity 0.12s;opacity:0.5;`;
            container._offsetX = e.clientX - rect.left;
            container._offsetY = e.clientY - rect.top;

            if (isMulti) {
                // Stack effect: offset layers behind
                const count = Math.min(dragIds.length, 4);
                for (let i = count - 1; i >= 1; i--) {
                    const layer = document.createElement('div');
                    layer.style.cssText = `position:absolute;top:${i * 4}px;left:${i * 4}px;width:${rect.width}px;height:${rect.height}px;background:var(--t-surface);border:1px solid var(--t-border);border-radius:inherit;opacity:${0.3 + (count - i) * 0.15};`;
                    container.appendChild(layer);
                }
                // Badge
                const badge = document.createElement('div');
                badge.textContent = dragIds.length;
                badge.style.cssText = `position:absolute;top:-6px;right:-6px;min-width:20px;height:20px;border-radius:10px;background:var(--t-accent);color:var(--t-bg);font-size:10px;font-weight:700;display:flex;align-items:center;justify-content:center;padding:0 6px;z-index:5;font-family:var(--t-font-pixel,'Silkscreen',cursive);`;
                container.appendChild(badge);
            }

            const clone = el.cloneNode(true);
            clone.style.cssText = `position:relative;width:${rect.width}px;`;
            clone.querySelector('.card-select-check')?.remove();
            container.appendChild(clone);

            container.style.left = (e.clientX - container._offsetX) + 'px';
            container.style.top = (e.clientY - container._offsetY) + 'px';
            document.body.appendChild(container);
            dragGhost = container;
        });
        el.addEventListener('dragend', () => {
            // Remove ghost class from all dragged cards
            board.querySelectorAll('.card-dragging').forEach(c => c.classList.remove('card-dragging'));
            activeDragEl = null;
            if (dragGhost) { dragGhost.remove(); dragGhost = null; }
            board.querySelectorAll('.card-drop-before,.card-drop-after,.card-drop-group').forEach(x =>
                x.classList.remove('card-drop-before', 'card-drop-after', 'card-drop-group'));
        });
        el.addEventListener('dragover', e => {
            e.preventDefault(); e.dataTransfer.dropEffect = 'move';
            const rect = el.getBoundingClientRect();
            const edge = rect.width * 0.25, x = e.clientX - rect.left;
            el.classList.toggle('card-drop-before', x < edge);
            el.classList.toggle('card-drop-after', x > rect.width - edge);
            el.classList.toggle('card-drop-group', x >= edge && x <= rect.width - edge);
        });
        el.addEventListener('dragleave', () => el.classList.remove('card-drop-before', 'card-drop-after', 'card-drop-group'));
        el.addEventListener('drop', e => handleCardDrop(e, el, id));
    });
}

// ── Card drop handler ──

async function handleCardDrop(e, el, targetId) {
    e.preventDefault();
    const wasGroup = el.classList.contains('card-drop-group');
    const wasBefore = el.classList.contains('card-drop-before');
    el.classList.remove('card-drop-before', 'card-drop-after', 'card-drop-group');
    const dragId = e.dataTransfer.getData('text/plain');
    if (!dragId || dragId === targetId) return;

    if (wasGroup) {
        const prev = snapshotCard(state.cards.find(c => c.id == dragId));
        pushCardEdit('group', dragId, { parent_id: prev.parent_id || null });
        await api(`api/cards/${dragId}`, { method: 'PATCH', body: { parent_id: targetId } });
        await window._reloadAll();
        return;
    }

    // Compute new order — must mirror renderBoard's filtering
    let filtered;
    if (state.activeGroup) {
        const parent = state.cards.find(c => c.id == state.activeGroup);
        filtered = parent ? sortedCards([parent, ...getChildren(parent.id)]) : [];
    } else {
        const root = state.cards.filter(c => !c.parent_id);
        if (state.activeBucket === 'favorites') {
            const favs = getFavorites();
            filtered = sortedCards(root.filter(c => favs.includes(String(c.id))));
        } else if (state.activeBucket === 'journal') {
            filtered = root.filter(c => /^\d{4}-\d{2}-\d{2}/.test(c.title));
            filtered.sort((a, b) => b.title.localeCompare(a.title));
        } else if (state.activeBucket === 'none') {
            filtered = sortedCards(root.filter(c => !c.bucket_id && !/^\d{4}-\d{2}-\d{2}/.test(c.title)));
        } else if (state.activeBucket !== 'all' && state.activeBucket !== 'current') {
            filtered = sortedCards(root.filter(c => c.bucket_id == state.activeBucket));
        } else {
            filtered = sortedCards(root);
        }
    }
    const ids = filtered.map(c => String(c.id)).filter(i => i !== String(dragId));
    ids.splice(wasBefore ? ids.indexOf(String(targetId)) : ids.indexOf(String(targetId)) + 1, 0, String(dragId));

    // Ungroup if dragging child to main board
    const dragCard = state.cards.find(c => c.id == dragId);
    if (!state.activeGroup && dragCard?.parent_id) {
        await api(`api/cards/${dragId}`, { method: 'PATCH', body: { parent_id: null } });
    }

    // Undo snapshot before reorder
    pushReorder('reorder', filtered);

    // FLIP capture
    const oldRects = {};
    board.querySelectorAll('[data-id]').forEach(c => { oldRects[c.dataset.id] = c.getBoundingClientRect(); });

    await Promise.all(ids.map((cid, i) => api(`api/cards/${cid}`, { method: 'PATCH', body: { position: i } })));

    // Swap group parent if needed
    if (state.activeGroup && ids[0] !== String(state.activeGroup)) {
        const newP = ids[0], oldP = String(state.activeGroup);
        await api(`api/cards/${newP}`, { method: 'PATCH', body: { parent_id: null } });
        await api(`api/cards/${oldP}`, { method: 'PATCH', body: { parent_id: newP } });
        for (const cid of ids.slice(1)) { if (cid !== oldP) await api(`api/cards/${cid}`, { method: 'PATCH', body: { parent_id: newP } }); }
        state.activeGroup = newP;
    }

    state.sortMode = 'manual';
    localStorage.setItem('hyprcrd-sort', 'manual');
    updateSortUI();
    await window._reloadAll();

    // FLIP animate
    board.querySelectorAll('[data-id]').forEach(card => {
        const old = oldRects[card.dataset.id];
        if (!old) return;
        const nw = card.getBoundingClientRect();
        const dx = old.left - nw.left, dy = old.top - nw.top;
        if (!dx && !dy) return;
        card.style.transition = 'none';
        card.style.transform = `translate(${dx}px,${dy}px)`;
        requestAnimationFrame(() => { card.style.transition = 'transform 0.25s ease'; card.style.transform = ''; });
    });
}