// /home/Autopartes/pos/static/js/catalog.js
// Catalog UI: TecDoc vehicle navigation with local stock enrichment, cart, detail panel.

(function () {
    'use strict';

    var API = '/pos/api/catalog';
    var token = localStorage.getItem('pos_token');
    if (!token) { window.location.href = '/pos/login'; return; }

    var headers = { 'Authorization': 'Bearer ' + token, 'Content-Type': 'application/json' };

    // ─── DOM refs ───
    var breadcrumb    = document.getElementById('breadcrumb');
    var searchInput   = document.getElementById('searchInput');
    var searchDropdown = document.getElementById('searchDropdown');
    var levelTitle    = document.getElementById('levelTitle');
    var levelFilter   = document.getElementById('levelFilter');
    var loading       = document.getElementById('loading');
    var emptyState    = document.getElementById('emptyState');
    var emptyTitle    = document.getElementById('emptyTitle');
    var emptySubtitle = document.getElementById('emptySubtitle');
    var navGrid       = document.getElementById('navGrid');
    var partsGrid     = document.getElementById('partsGrid');
    var paginationNav = document.getElementById('pagination');
    var pageBody      = document.getElementById('pageBody');
    // Detail panel
    var detailPanel   = document.getElementById('detailPanel');
    var detailOverlay = document.getElementById('detailOverlay');
    var detailBody    = document.getElementById('detailBody');
    var detailFooter  = document.getElementById('detailFooter');
    var detailClose   = document.getElementById('detailClose');
    var qtyMinus      = document.getElementById('qtyMinus');
    var qtyPlus       = document.getElementById('qtyPlus');
    var qtyDisplay    = document.getElementById('qtyDisplay');
    var addToCartBtn  = document.getElementById('addToCartBtn');
    // Cart
    var cartSidebar   = document.getElementById('cartSidebar');
    var cartOverlay   = document.getElementById('cartOverlay');
    var cartItemsEl   = document.getElementById('cartItems');
    var cartEmptyEl   = document.getElementById('cartEmpty');
    var cartSubtotalEl= document.getElementById('cartSubtotal');
    var cartTaxEl     = document.getElementById('cartTax');
    var cartTotalEl   = document.getElementById('cartTotal');
    var cartBadge     = document.getElementById('cartBadge');
    var checkoutBtn   = document.getElementById('checkoutBtn');
    var cartFab       = document.getElementById('cartFab');
    var cartCloseBtn  = document.getElementById('cartCloseBtn');

    // ─── Navigation State ───
    var nav = {
        level: 'brands',  // brands|models|years|engines|categories|groups|parts
        brand: null,       // {id, name}
        model: null,       // {id, name}
        year: null,        // {id, year}
        engine: null,      // {id_mye, name}
        category: null,    // {id, name}
        group: null,       // {id, name}
    };

    var currentPage = 1;
    var currentDetailPart = null;
    var detailQty = 1;
    var isOffline = false;

    // ─── Cart State ───
    var cartItems = JSON.parse(localStorage.getItem('pos_cart') || '[]');

    // ─── API helper ───
    function apiFetch(url) {
        return fetch(url, { headers: headers })
            .then(function (resp) {
                if (resp.status === 401) {
                    localStorage.removeItem('pos_token');
                    window.location.href = '/pos/login';
                    return null;
                }
                return resp.json();
            })
            .catch(function (e) {
                console.error('API error:', e);
                return null;
            });
    }

    // ─── UI helpers ───
    function showLoading() { loading.classList.add('is-visible'); navGrid.innerHTML = ''; partsGrid.style.display = 'none'; partsGrid.innerHTML = ''; emptyState.classList.remove('is-visible'); paginationNav.innerHTML = ''; }
    function hideLoading() { loading.classList.remove('is-visible'); }

    function showEmpty(title, subtitle) {
        emptyTitle.textContent = title;
        emptySubtitle.textContent = subtitle || '';
        emptyState.classList.add('is-visible');
        navGrid.innerHTML = '';
        partsGrid.style.display = 'none';
    }

    function fmt(n) { return (parseFloat(n) || 0).toFixed(2); }

    function esc(s) {
        if (!s) return '';
        var d = document.createElement('div');
        d.textContent = s;
        return d.innerHTML;
    }

    // ─── Breadcrumb ───
    function updateBreadcrumb() {
        var parts = [];
        parts.push({ label: 'Catalogo', action: 'loadBrands' });

        if (nav.brand) parts.push({ label: nav.brand.name, action: 'loadModels' });
        if (nav.model) parts.push({ label: nav.model.name, action: 'loadYears' });
        if (nav.year) parts.push({ label: String(nav.year.year), action: 'loadEngines' });
        if (nav.engine) parts.push({ label: nav.engine.name, action: 'loadCategories' });
        if (nav.category) parts.push({ label: nav.category.name, action: 'loadGroups' });
        if (nav.group) parts.push({ label: nav.group.name, action: null });

        var html = '';
        for (var i = 0; i < parts.length; i++) {
            if (i > 0) html += '<span class="breadcrumb__sep" aria-hidden="true">/</span>';
            if (i < parts.length - 1 && parts[i].action) {
                html += '<a class="breadcrumb__link" data-bc-action="' + parts[i].action + '">' + esc(parts[i].label) + '</a>';
            } else {
                html += '<span class="breadcrumb__current">' + esc(parts[i].label) + '</span>';
            }
        }
        breadcrumb.innerHTML = html;

        // Wire breadcrumb clicks
        breadcrumb.querySelectorAll('[data-bc-action]').forEach(function (el) {
            el.addEventListener('click', function () {
                var action = this.dataset.bcAction;
                if (action === 'loadBrands') { resetNav(); loadBrands(); }
                else if (action === 'loadModels') { resetNavFrom('models'); loadModels(); }
                else if (action === 'loadYears') { resetNavFrom('years'); loadYears(); }
                else if (action === 'loadEngines') { resetNavFrom('engines'); loadEngines(); }
                else if (action === 'loadCategories') { resetNavFrom('categories'); loadCategories(); }
                else if (action === 'loadGroups') { resetNavFrom('groups'); loadGroups(); }
            });
        });
    }

    function resetNav() {
        nav.level = 'brands';
        nav.brand = nav.model = nav.year = nav.engine = nav.category = nav.group = null;
    }

    function resetNavFrom(level) {
        var levels = ['brands', 'models', 'years', 'engines', 'categories', 'groups', 'parts'];
        var idx = levels.indexOf(level);
        if (idx <= 0) { resetNav(); return; }
        nav.level = level;
        var keys = [null, 'model', 'year', 'engine', 'category', 'group', null];
        for (var i = idx; i < keys.length; i++) {
            if (keys[i]) nav[keys[i]] = null;
        }
    }

    // ─── Level filter ───
    function setupLevelFilter(show) {
        if (!show) { levelFilter.style.display = 'none'; levelFilter.value = ''; return; }
        levelFilter.style.display = '';
        levelFilter.value = '';
        levelFilter.oninput = function () {
            var q = this.value.toLowerCase();
            var cards = navGrid.querySelectorAll('.nav-card');
            cards.forEach(function (card) {
                var text = card.textContent.toLowerCase();
                card.style.display = text.indexOf(q) >= 0 ? '' : 'none';
            });
        };
    }

    // ─── LEVEL LOADERS ───

    function loadBrands() {
        nav.level = 'brands';
        updateBreadcrumb();
        levelTitle.textContent = 'Selecciona una marca';
        setupLevelFilter(true);
        showLoading();

        apiFetch(API + '/brands').then(function (data) {
            hideLoading();
            if (!data || !data.data || !data.data.length) {
                if (!data) {
                    enterOfflineMode();
                    return;
                }
                showEmpty('Sin marcas', 'El catalogo no tiene marcas con partes disponibles.');
                return;
            }
            navGrid.className = 'nav-grid';
            navGrid.innerHTML = data.data.map(function (b) {
                return '<div class="nav-card" role="listitem" data-brand-id="' + b.id_brand + '" data-name="' + esc(b.name_brand) + '">' +
                    '<div class="nav-card__name">' + esc(b.name_brand) + '</div>' +
                    '</div>';
            }).join('');

            navGrid.querySelectorAll('.nav-card').forEach(function (card) {
                card.addEventListener('click', function () {
                    nav.brand = { id: parseInt(this.dataset.brandId), name: this.dataset.name };
                    loadModels();
                });
            });
        });
    }

    function loadModels() {
        nav.level = 'models';
        updateBreadcrumb();
        levelTitle.textContent = 'Modelos de ' + nav.brand.name;
        setupLevelFilter(true);
        showLoading();

        apiFetch(API + '/models?brand_id=' + nav.brand.id).then(function (data) {
            hideLoading();
            if (!data || !data.data || !data.data.length) { showEmpty('Sin modelos', 'No hay modelos con partes para ' + nav.brand.name); return; }
            navGrid.className = 'nav-grid';
            navGrid.innerHTML = data.data.map(function (m) {
                return '<div class="nav-card" role="listitem" data-model-id="' + m.id_model + '" data-name="' + esc(m.name_model) + '">' +
                    '<div class="nav-card__name">' + esc(m.name_model) + '</div>' +
                    '</div>';
            }).join('');

            navGrid.querySelectorAll('.nav-card').forEach(function (card) {
                card.addEventListener('click', function () {
                    nav.model = { id: parseInt(this.dataset.modelId), name: this.dataset.name };
                    loadYears();
                });
            });
        });
    }

    function loadYears() {
        nav.level = 'years';
        updateBreadcrumb();
        levelTitle.textContent = nav.brand.name + ' ' + nav.model.name + ' — Anios';
        setupLevelFilter(false);
        showLoading();

        apiFetch(API + '/years?model_id=' + nav.model.id).then(function (data) {
            hideLoading();
            if (!data || !data.data || !data.data.length) { showEmpty('Sin anios', 'No hay anios con partes para este modelo.'); return; }
            navGrid.className = 'nav-grid nav-grid--years';
            navGrid.innerHTML = data.data.map(function (y) {
                return '<div class="nav-card nav-card--year" role="listitem" data-year-id="' + y.id_year + '" data-year="' + y.year_car + '">' +
                    '<div class="nav-card__name">' + y.year_car + '</div>' +
                    '</div>';
            }).join('');

            navGrid.querySelectorAll('.nav-card').forEach(function (card) {
                card.addEventListener('click', function () {
                    nav.year = { id: parseInt(this.dataset.yearId), year: parseInt(this.dataset.year) };
                    loadEngines();
                });
            });
        });
    }

    function loadEngines() {
        nav.level = 'engines';
        updateBreadcrumb();
        levelTitle.textContent = nav.brand.name + ' ' + nav.model.name + ' ' + nav.year.year + ' — Motor';
        setupLevelFilter(false);
        showLoading();

        apiFetch(API + '/engines?model_id=' + nav.model.id + '&year_id=' + nav.year.id).then(function (data) {
            hideLoading();
            if (!data || !data.data || !data.data.length) { showEmpty('Sin motores', 'No hay configuraciones de motor para esta combinacion.'); return; }

            // If only one engine, auto-select it
            if (data.data.length === 1) {
                var e = data.data[0];
                nav.engine = { id_mye: e.id_mye, name: e.name_engine + (e.trim_level ? ' ' + e.trim_level : '') };
                loadCategories();
                return;
            }

            navGrid.className = 'nav-grid';
            navGrid.innerHTML = data.data.map(function (e) {
                var label = e.name_engine + (e.trim_level ? ' — ' + e.trim_level : '');
                return '<div class="nav-card" role="listitem" data-mye-id="' + e.id_mye + '" data-name="' + esc(label) + '">' +
                    '<div class="nav-card__name">' + esc(e.name_engine) + '</div>' +
                    (e.trim_level ? '<div class="nav-card__sub">' + esc(e.trim_level) + '</div>' : '') +
                    '</div>';
            }).join('');

            navGrid.querySelectorAll('.nav-card').forEach(function (card) {
                card.addEventListener('click', function () {
                    nav.engine = { id_mye: parseInt(this.dataset.myeId), name: this.dataset.name };
                    loadCategories();
                });
            });
        });
    }

    function loadCategories() {
        nav.level = 'categories';
        updateBreadcrumb();
        levelTitle.textContent = 'Categorias de partes';
        setupLevelFilter(true);
        showLoading();

        apiFetch(API + '/categories?mye_id=' + nav.engine.id_mye).then(function (data) {
            hideLoading();
            if (!data || !data.data || !data.data.length) { showEmpty('Sin categorias', 'No hay partes catalogadas para este vehiculo.'); return; }
            navGrid.className = 'nav-grid';
            navGrid.innerHTML = data.data.map(function (c) {
                return '<div class="nav-card" role="listitem" data-cat-id="' + c.id_part_category + '" data-name="' + esc(c.name) + '">' +
                    '<div class="nav-card__name">' + esc(c.name) + '</div>' +
                    '<div class="nav-card__count">' + c.part_count + ' partes</div>' +
                    '</div>';
            }).join('');

            navGrid.querySelectorAll('.nav-card').forEach(function (card) {
                card.addEventListener('click', function () {
                    nav.category = { id: parseInt(this.dataset.catId), name: this.dataset.name };
                    loadGroups();
                });
            });
        });
    }

    function loadGroups() {
        nav.level = 'groups';
        updateBreadcrumb();
        levelTitle.textContent = nav.category.name;
        setupLevelFilter(true);
        showLoading();

        apiFetch(API + '/groups?mye_id=' + nav.engine.id_mye + '&category_id=' + nav.category.id).then(function (data) {
            hideLoading();
            if (!data || !data.data || !data.data.length) { showEmpty('Sin subcategorias', 'No hay subcategorias para ' + nav.category.name); return; }
            navGrid.className = 'nav-grid';
            navGrid.innerHTML = data.data.map(function (g) {
                return '<div class="nav-card" role="listitem" data-group-id="' + g.id_part_group + '" data-name="' + esc(g.name) + '">' +
                    '<div class="nav-card__name">' + esc(g.name) + '</div>' +
                    '<div class="nav-card__count">' + g.part_count + ' partes</div>' +
                    '</div>';
            }).join('');

            navGrid.querySelectorAll('.nav-card').forEach(function (card) {
                card.addEventListener('click', function () {
                    nav.group = { id: parseInt(this.dataset.groupId), name: this.dataset.name };
                    loadParts(1);
                });
            });
        });
    }

    function loadParts(page) {
        nav.level = 'parts';
        currentPage = page || 1;
        updateBreadcrumb();
        levelTitle.textContent = nav.group.name;
        setupLevelFilter(false);
        showLoading();
        navGrid.innerHTML = '';

        apiFetch(API + '/parts?mye_id=' + nav.engine.id_mye + '&group_id=' + nav.group.id + '&page=' + currentPage + '&per_page=30').then(function (data) {
            hideLoading();
            if (!data || !data.data || !data.data.length) { showEmpty('Sin partes', 'No hay partes en este grupo.'); return; }

            partsGrid.style.display = '';
            partsGrid.innerHTML = data.data.map(function (p) {
                var stockBadge;
                if (p.local_stock > 0) {
                    stockBadge = '<span class="stock-badge stock-badge--local">En stock: ' + p.local_stock + '</span>';
                } else if (p.bodega_count > 0) {
                    stockBadge = '<span class="stock-badge stock-badge--bodega">' + p.bodega_count + ' bodega' + (p.bodega_count > 1 ? 's' : '') + '</span>';
                } else {
                    stockBadge = '<span class="stock-badge stock-badge--none">Sin stock</span>';
                }

                var imgHtml = p.image_url
                    ? '<img src="' + esc(p.image_url) + '" alt="' + esc(p.name) + '">'
                    : '<svg width="48" height="48" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1"><rect x="3" y="3" width="18" height="18" rx="2"/><path d="M8 7h8M8 12h8M8 17h5"/></svg>';

                return '<article class="part-card" role="listitem" data-part-id="' + p.id_part + '">' +
                    '<div class="part-card__image">' + imgHtml + '</div>' +
                    '<div class="part-card__body">' +
                    '<div class="part-card__oem">' + esc(p.oem_part_number) + '</div>' +
                    '<div class="part-card__name">' + esc(p.name) + '</div>' +
                    '</div>' +
                    '<div class="part-card__footer">' +
                    (p.local_price ? '<span class="part-card__price">$' + fmt(p.local_price) + '</span>' : '<span class="part-card__price" style="color:var(--color-text-muted);">Sin precio</span>') +
                    stockBadge +
                    '</div>' +
                    '</article>';
            }).join('');

            // Wire part card clicks → open detail panel
            partsGrid.querySelectorAll('.part-card').forEach(function (card) {
                card.addEventListener('click', function () {
                    openPartDetail(parseInt(this.dataset.partId));
                });
            });

            // Pagination
            if (data.pagination) renderPagination(data.pagination);
        });
    }

    // ─── PAGINATION ───
    function renderPagination(pg) {
        if (!pg || pg.total_pages <= 1) { paginationNav.innerHTML = ''; return; }
        var html = '';

        if (pg.page <= 1) {
            html += '<button class="page-item page-item--wide is-disabled" disabled>Anterior</button>';
        } else {
            html += '<button class="page-item page-item--wide" data-page="' + (pg.page - 1) + '">Anterior</button>';
        }

        var pages = buildPageNumbers(pg.page, pg.total_pages);
        pages.forEach(function (p) {
            if (p === '...') {
                html += '<span style="padding:0 4px;color:var(--color-text-muted);">...</span>';
            } else if (p === pg.page) {
                html += '<button class="page-item is-active">' + p + '</button>';
            } else {
                html += '<button class="page-item" data-page="' + p + '">' + p + '</button>';
            }
        });

        if (pg.page >= pg.total_pages) {
            html += '<button class="page-item page-item--wide is-disabled" disabled>Siguiente</button>';
        } else {
            html += '<button class="page-item page-item--wide" data-page="' + (pg.page + 1) + '">Siguiente</button>';
        }

        paginationNav.innerHTML = html;

        paginationNav.querySelectorAll('[data-page]').forEach(function (btn) {
            btn.addEventListener('click', function () {
                pageBody.scrollTo({ top: 0, behavior: 'smooth' });
                loadParts(parseInt(this.dataset.page));
            });
        });
    }

    function buildPageNumbers(current, total) {
        if (total <= 7) { var a = []; for (var i = 1; i <= total; i++) a.push(i); return a; }
        var p = [1];
        if (current > 3) p.push('...');
        for (var j = Math.max(2, current - 1); j <= Math.min(total - 1, current + 1); j++) p.push(j);
        if (current < total - 2) p.push('...');
        p.push(total);
        return p;
    }

    // ─── DETAIL PANEL ───
    function openPartDetail(partId) {
        detailBody.innerHTML = '<div class="loading is-visible"><div class="spinner"></div></div>';
        detailFooter.style.display = 'none';
        detailPanel.classList.add('is-open');
        detailOverlay.classList.add('is-visible');
        detailQty = 1;
        qtyDisplay.textContent = '1';

        apiFetch(API + '/part/' + partId).then(function (data) {
            if (!data || data.error) {
                detailBody.innerHTML = '<p style="color:var(--color-error);padding:var(--space-4);">Error al cargar detalle.</p>';
                return;
            }

            currentDetailPart = data;
            var p = data.part;
            var local = data.local;
            var bodegas = data.bodegas || [];
            var alts = data.alternatives || [];

            var html = '';

            // Part info
            html += '<div class="detail-section">';
            if (p.category_name) html += '<div style="font-size:var(--text-caption);color:var(--color-text-muted);margin-bottom:var(--space-1);">' + esc(p.category_name) + ' > ' + esc(p.group_name) + '</div>';
            html += '<div class="detail-oem">' + esc(p.oem_part_number) + '</div>';
            html += '<div class="detail-name">' + esc(p.name) + '</div>';
            if (p.description) html += '<div class="detail-desc">' + esc(p.description) + '</div>';
            if (p.image_url) html += '<div style="margin-top:var(--space-3);text-align:center;"><img src="' + esc(p.image_url) + '" alt="" style="max-width:100%;max-height:200px;object-fit:contain;border-radius:var(--radius-sm);"></div>';
            html += '</div>';

            // Local stock
            html += '<div class="detail-section">';
            html += '<div class="detail-section__title">Mi stock</div>';
            if (local && local.stock > 0) {
                html += '<div class="stock-row"><span class="stock-label">Cantidad</span><span class="stock-value stock-value--ok">' + local.stock + ' ' + (local.unit || 'PZA') + '</span></div>';
                html += '<div class="stock-row"><span class="stock-label">Precio publico</span><span class="stock-value">$' + fmt(local.price_1) + '</span></div>';
                if (local.price_2) html += '<div class="stock-row"><span class="stock-label">Precio mayoreo</span><span class="stock-value">$' + fmt(local.price_2) + '</span></div>';
                if (local.price_3) html += '<div class="stock-row"><span class="stock-label">Precio taller</span><span class="stock-value">$' + fmt(local.price_3) + '</span></div>';
                if (local.location) html += '<div class="stock-row"><span class="stock-label">Ubicacion</span><span class="stock-value">' + esc(local.location) + '</span></div>';
            } else {
                html += '<div style="color:var(--color-text-muted);font-size:var(--text-body-sm);">No tienes esta parte en inventario.</div>';
            }
            html += '</div>';

            // Bodegas
            if (bodegas.length) {
                html += '<div class="detail-section">';
                html += '<div class="detail-section__title">Disponible en bodegas</div>';
                html += '<table class="bodega-table"><thead><tr><th>Bodega</th><th>Precio</th><th>Stock</th></tr></thead><tbody>';
                bodegas.forEach(function (b) {
                    html += '<tr><td>' + esc(b.business_name) + '</td><td>' + (b.price ? '$' + fmt(b.price) : '--') + '</td><td>' + b.stock + '</td></tr>';
                });
                html += '</tbody></table></div>';
            }

            // Alternatives
            if (alts.length) {
                html += '<div class="detail-section">';
                html += '<div class="detail-section__title">Alternativas / Cross-references</div>';
                alts.forEach(function (a) {
                    var stockLabel = a.local_stock > 0
                        ? '<span class="stock-badge stock-badge--local">Stock: ' + a.local_stock + '</span>'
                        : (a.bodega_count > 0 ? '<span class="stock-badge stock-badge--bodega">' + a.bodega_count + ' bod.</span>' : '');
                    html += '<div class="alt-item">' +
                        '<div><div class="alt-item__pn">' + esc(a.part_number) + '</div>' +
                        '<div class="alt-item__mfr">' + esc(a.manufacturer) + (a.name ? ' — ' + esc(a.name) : '') + '</div></div>' +
                        '<div class="alt-item__stock">' + stockLabel + '</div>' +
                        '</div>';
                });
                html += '</div>';
            }

            detailBody.innerHTML = html;

            // Show footer only if we have local stock
            if (local && local.stock > 0) {
                detailFooter.style.display = '';
            } else {
                detailFooter.style.display = 'none';
            }
        });
    }

    function closeDetail() {
        detailPanel.classList.remove('is-open');
        detailOverlay.classList.remove('is-visible');
        currentDetailPart = null;
    }

    detailClose.addEventListener('click', closeDetail);
    detailOverlay.addEventListener('click', closeDetail);

    qtyMinus.addEventListener('click', function () { if (detailQty > 1) { detailQty--; qtyDisplay.textContent = detailQty; } });
    qtyPlus.addEventListener('click', function () { detailQty++; qtyDisplay.textContent = detailQty; });

    addToCartBtn.addEventListener('click', function () {
        if (!currentDetailPart) return;
        var p = currentDetailPart.part;
        var local = currentDetailPart.local;
        if (!local) return;

        addToCart({
            id: p.id_part,
            part_number: p.oem_part_number,
            name: p.name,
            brand: '',
            price: local.price_1,
            tax_rate: local.tax_rate || 0.16,
            unit: local.unit || 'PZA',
            stock: local.stock,
            source: 'local',
            inventory_id: local.inventory_id,
        }, detailQty);
        closeDetail();
    });

    // ─── SMART SEARCH ───
    var searchTimeout = null;

    searchInput.addEventListener('input', function () {
        clearTimeout(searchTimeout);
        var q = this.value.trim();
        if (q.length < 2) { searchDropdown.classList.remove('is-visible'); return; }
        searchTimeout = setTimeout(function () { runSearch(q); }, 350);
    });

    searchInput.addEventListener('keydown', function (e) {
        if (e.key === 'Enter') {
            e.preventDefault();
            clearTimeout(searchTimeout);
            var q = this.value.trim();
            if (q.length >= 2) runSearch(q);
        }
        if (e.key === 'Escape') {
            searchDropdown.classList.remove('is-visible');
        }
    });

    // Close dropdown on outside click
    document.addEventListener('click', function (e) {
        if (!searchDropdown.contains(e.target) && e.target !== searchInput) {
            searchDropdown.classList.remove('is-visible');
        }
    });

    function runSearch(q) {
        apiFetch(API + '/search?q=' + encodeURIComponent(q) + '&limit=20').then(function (data) {
            if (!data || !data.data || !data.data.length) {
                searchDropdown.innerHTML = '<div style="padding:var(--space-4);color:var(--color-text-muted);font-size:var(--text-body-sm);">Sin resultados para "' + esc(q) + '"</div>';
                searchDropdown.classList.add('is-visible');
                return;
            }
            searchDropdown.innerHTML = data.data.map(function (r) {
                var stockLabel = r.local_stock > 0
                    ? '<span class="stock-badge stock-badge--local" style="margin-left:auto;">Stock: ' + r.local_stock + '</span>'
                    : '';
                return '<div class="search-result-item" data-part-id="' + r.id_part + '">' +
                    '<div style="flex:1;">' +
                    '<div class="search-result__oem">' + esc(r.oem_part_number) + '</div>' +
                    '<div class="search-result__name">' + esc(r.name) + '</div>' +
                    (r.vehicle_info ? '<div class="search-result__vehicle">' + esc(r.vehicle_info) + '</div>' : '') +
                    '</div>' +
                    stockLabel +
                    '</div>';
            }).join('');
            searchDropdown.classList.add('is-visible');

            searchDropdown.querySelectorAll('.search-result-item').forEach(function (el) {
                el.addEventListener('click', function () {
                    searchDropdown.classList.remove('is-visible');
                    openPartDetail(parseInt(this.dataset.partId));
                });
            });
        });
    }

    // ─── CART ───
    function addToCart(item, qty) {
        qty = qty || 1;
        var existing = cartItems.find(function (c) { return c.id === item.id; });
        if (existing) {
            existing.quantity += qty;
        } else {
            cartItems.push({
                id: item.id,
                part_number: item.part_number,
                name: item.name,
                brand: item.brand || '',
                price: item.price,
                tax_rate: item.tax_rate || 0.16,
                unit: item.unit || 'PZA',
                stock: item.stock,
                source: item.source || 'local',
                inventory_id: item.inventory_id,
                quantity: qty,
            });
        }
        saveCart();
        renderCart();
        if (!cartSidebar.classList.contains('open')) toggleCart();
    }

    function removeFromCart(index) {
        cartItems.splice(index, 1);
        saveCart();
        renderCart();
    }

    function updateQuantity(index, qty) {
        qty = parseInt(qty);
        if (qty <= 0) { removeFromCart(index); return; }
        cartItems[index].quantity = qty;
        saveCart();
        renderCart();
    }

    function clearCart() {
        cartItems = [];
        saveCart();
        renderCart();
    }

    function saveCart() { localStorage.setItem('pos_cart', JSON.stringify(cartItems)); }

    function renderCart() {
        var total = cartItems.reduce(function (s, c) { return s + c.quantity; }, 0);
        if (cartBadge) {
            cartBadge.textContent = total;
            cartBadge.style.display = total > 0 ? 'flex' : 'none';
        }

        if (!cartItems.length) {
            cartItemsEl.innerHTML = '';
            cartEmptyEl.style.display = 'block';
            if (checkoutBtn) checkoutBtn.disabled = true;
            cartSubtotalEl.textContent = '$0.00';
            cartTaxEl.textContent = '$0.00';
            cartTotalEl.textContent = '$0.00';
            return;
        }

        cartEmptyEl.style.display = 'none';
        if (checkoutBtn) checkoutBtn.disabled = false;

        var subtotal = 0;
        var tax = 0;
        cartItemsEl.innerHTML = cartItems.map(function (c, i) {
            var lineTotal = c.price * c.quantity;
            var lineTax = lineTotal * c.tax_rate;
            subtotal += lineTotal;
            tax += lineTax;
            return '<div class="cart-item">' +
                '<div style="flex:1;">' +
                '<div style="font-weight:600;font-size:0.85rem;color:var(--color-text-primary);">' + esc(c.name) + '</div>' +
                '<div style="font-size:0.75rem;color:var(--color-text-muted);">' + esc(c.part_number) + '</div>' +
                '<div style="margin-top:4px;display:flex;align-items:center;gap:6px;">' +
                '<button data-cart-action="dec" data-idx="' + i + '" style="width:24px;height:24px;border:1px solid var(--color-border);background:var(--color-bg-base);border-radius:var(--radius-sm);cursor:pointer;color:var(--color-text-primary);">-</button>' +
                '<span style="font-weight:600;color:var(--color-text-primary);">' + c.quantity + '</span>' +
                '<button data-cart-action="inc" data-idx="' + i + '" style="width:24px;height:24px;border:1px solid var(--color-border);background:var(--color-bg-base);border-radius:var(--radius-sm);cursor:pointer;color:var(--color-text-primary);">+</button>' +
                '</div></div>' +
                '<div style="text-align:right;">' +
                '<div style="font-weight:600;color:var(--color-text-primary);">$' + fmt(lineTotal) + '</div>' +
                '<button data-cart-action="remove" data-idx="' + i + '" style="font-size:0.75rem;color:var(--color-error,#ef4444);background:none;border:none;cursor:pointer;margin-top:4px;">Quitar</button>' +
                '</div></div>';
        }).join('');

        cartSubtotalEl.textContent = '$' + fmt(subtotal);
        cartTaxEl.textContent = '$' + fmt(tax);
        cartTotalEl.textContent = '$' + fmt(subtotal + tax);

        // Wire cart buttons
        cartItemsEl.querySelectorAll('[data-cart-action]').forEach(function (btn) {
            btn.addEventListener('click', function () {
                var idx = parseInt(this.dataset.idx);
                var action = this.dataset.cartAction;
                if (action === 'dec') updateQuantity(idx, cartItems[idx].quantity - 1);
                else if (action === 'inc') updateQuantity(idx, cartItems[idx].quantity + 1);
                else if (action === 'remove') removeFromCart(idx);
            });
        });
    }

    function toggleCart() {
        var isOpen = cartSidebar.classList.toggle('open');
        cartOverlay.classList.toggle('open', isOpen);
    }

    function goToCheckout() {
        if (!cartItems.length) return;
        localStorage.setItem('pos_cart', JSON.stringify(cartItems));
        window.location.href = '/pos/sale';
    }

    cartFab.addEventListener('click', toggleCart);
    cartCloseBtn.addEventListener('click', toggleCart);
    cartOverlay.addEventListener('click', toggleCart);
    checkoutBtn.addEventListener('click', goToCheckout);

    // ─── OFFLINE FALLBACK ───
    function enterOfflineMode() {
        isOffline = true;
        document.getElementById('offlineBanner').style.display = '';
        document.getElementById('offlineBannerText').innerHTML = '<strong>Modo offline</strong> — Mostrando solo tu inventario local.';
        levelTitle.textContent = 'Inventario local';
        setupLevelFilter(false);
        // TODO: load local inventory via legacy /pos/api/catalog/search endpoint
        showEmpty('Sin conexion al catalogo', 'Verifica tu conexion. El catalogo TecDoc requiere acceso al servidor central.');
    }

    // ─── BARCODE SCANNER ───
    var barcodeBuffer = '';
    var barcodeTimeout = null;

    document.addEventListener('keydown', function (e) {
        // F1 → focus search
        if (e.key === 'F1') { e.preventDefault(); searchInput.focus(); return; }
        // Escape → close panels
        if (e.key === 'Escape') {
            closeDetail();
            if (cartSidebar.classList.contains('open')) toggleCart();
            return;
        }
        // Barcode scanner detection
        if (document.activeElement.tagName === 'INPUT' || document.activeElement.tagName === 'TEXTAREA') return;
        if (e.key === 'Enter' && barcodeBuffer.length >= 4) {
            var code = barcodeBuffer.trim();
            barcodeBuffer = '';
            // Search for the barcode
            searchInput.value = code;
            runSearch(code);
            return;
        }
        if (e.key.length === 1) {
            barcodeBuffer += e.key;
            clearTimeout(barcodeTimeout);
            barcodeTimeout = setTimeout(function () { barcodeBuffer = ''; }, 200);
        }
    });

    // ─── THEME SWITCHER ───
    document.querySelectorAll('[data-theme-switch]').forEach(function (btn) {
        btn.addEventListener('click', function () {
            var theme = this.dataset.themeSwitch;
            document.documentElement.setAttribute('data-theme', theme);
            localStorage.setItem('pos_theme', theme);
            document.querySelectorAll('[data-theme-switch]').forEach(function (b) {
                b.classList.remove('is-active');
                b.setAttribute('aria-pressed', 'false');
            });
            this.classList.add('is-active');
            this.setAttribute('aria-pressed', 'true');
        });
        // Set initial active state
        var current = localStorage.getItem('pos_theme') || 'industrial';
        if (btn.dataset.themeSwitch === current) {
            btn.classList.add('is-active');
            btn.setAttribute('aria-pressed', 'true');
        } else {
            btn.classList.remove('is-active');
            btn.setAttribute('aria-pressed', 'false');
        }
    });

    // ─── EXPOSE GLOBALS (for backward compat) ───
    window.CatalogApp = {
        toggleCart: toggleCart,
        goToCheckout: goToCheckout,
        addToCart: addToCart,
        removeFromCart: removeFromCart,
        updateQty: updateQuantity,
        clearCart: clearCart,
        loadPage: function (p) { loadParts(p); },
    };

    // ─── INIT ───
    renderCart();
    loadBrands();

})();