// /home/Autopartes/pos/static/js/catalog.js
// Catalog UI: browsable inventory with cart, barcode scanner, external lookup
// Aligned with design-system catalog.html IDs and class names.

(function () {
    'use strict';

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

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

    // ─── DOM refs (design-system IDs) ───
    const productGrid   = document.getElementById('productGrid');
    const emptyState     = document.getElementById('emptyState');
    const emptyTitle     = document.getElementById('emptyStateTitle');
    const emptySubtitle  = document.getElementById('emptyStateSubtitle');
    const searchInput    = document.getElementById('inp-part');
    const partSearchBtn  = document.getElementById('partSearchBtn');
    const cartSidebar    = document.getElementById('cartSidebar');
    const cartOverlay    = document.getElementById('cartOverlay');
    const cartItemsEl    = document.getElementById('cartItems');
    const cartEmptyEl    = document.getElementById('cartEmpty');
    const cartSubtotalEl = document.getElementById('cartSubtotal');
    const cartTaxEl      = document.getElementById('cartTax');
    const cartTotalEl    = document.getElementById('cartTotal');
    const cartBadge      = document.getElementById('cartBadge');
    const checkoutBtn    = document.getElementById('checkoutBtn');
    const paginationNav  = document.querySelector('.pagination');

    // ─── State ───
    let currentPage = 1;
    let currentFilters = {};
    let cartItems = JSON.parse(localStorage.getItem('pos_cart') || '[]');
    let barcodeBuffer = '';
    let barcodeTimeout = null;
    let catalogItemsMap = {};  // id -> item for cart lookup

    // ─── API helpers ───
    async function apiFetch(url, opts) {
        try {
            var resp = await fetch(url, Object.assign({ headers: headers }, opts || {}));
            if (resp.status === 401) {
                localStorage.removeItem('pos_token');
                window.location.href = '/pos/login';
                return null;
            }
            return resp.json();
        } catch (e) {
            console.error('API fetch error:', e);
            return null;
        }
    }

    // ─── Catalog loading ───
    async function loadCatalog(page, filters) {
        currentPage = page || 1;
        currentFilters = filters || currentFilters;
        var params = new URLSearchParams({ page: currentPage, per_page: 30 });
        if (currentFilters.q) params.set('q', currentFilters.q);
        if (currentFilters.category) params.set('category', currentFilters.category);
        if (currentFilters.brand) params.set('brand', currentFilters.brand);
        if (currentFilters.vehicle_brand) params.set('vehicle_brand', currentFilters.vehicle_brand);

        var data = await apiFetch(API + '/catalog/search?' + params.toString());
        if (!data) return;

        var items = data.data || [];
        renderGrid(items);
        renderPagination(data.pagination || {});
        updateResultsCount(data.pagination || {});
    }

    function renderGrid(items) {
        // Clear demo/hardcoded cards
        productGrid.innerHTML = '';

        if (!items.length) {
            productGrid.style.display = 'none';
            emptyState.classList.add('is-visible');
            emptyTitle.textContent = 'No se encontraron productos';
            emptySubtitle.textContent = currentFilters.q
                ? 'No hay resultados para "' + currentFilters.q + '". Intenta con otro termino.'
                : 'Intenta con otro termino de busqueda o verifica el numero de parte';
            return;
        }

        emptyState.classList.remove('is-visible');
        productGrid.style.display = '';

        catalogItemsMap = {};
        items.forEach(function (it) { catalogItemsMap[it.id] = it; });

        productGrid.innerHTML = items.map(function (it) {
            var stockClass, stockLabel;
            if (it.stock <= 0) {
                stockClass = 'stock-out';
                stockLabel = 'Agotado';
            } else if (it.low_stock) {
                stockClass = 'stock-low';
                stockLabel = 'Ultimas ' + it.stock;
            } else {
                stockClass = 'stock-ok';
                stockLabel = 'En stock';
            }

            var isOut = it.stock <= 0;
            var imgHtml;
            if (it.image_url) {
                imgHtml = '<img src="' + escHtml(it.image_url) + '" alt="' + escHtml(it.name) + '" style="width:100%;height:100%;object-fit:contain;">';
            } else {
                imgHtml = '<svg width="48" height="48" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1" aria-hidden="true"><rect x="3" y="3" width="18" height="18" rx="2"/><path d="M8 7h8M8 12h8M8 17h5"/></svg>' +
                    '<span class="product-card__image-label" aria-hidden="true">IMG</span>';
            }

            return '<article class="product-card" role="listitem" data-id="' + it.id + '">' +
                '<div class="product-card__image">' +
                imgHtml +
                '<div class="stock-badge ' + stockClass + '" role="status">' + stockLabel + '</div>' +
                '</div>' +
                '<div class="product-card__body">' +
                (it.category_name ? '<div class="product-card__category">' + escHtml(it.category_name) + '</div>' : '') +
                '<div class="product-card__name">' + escHtml(it.name) + '</div>' +
                '<div class="product-card__oem" title="Numero de parte">' + escHtml(it.part_number || '') + '</div>' +
                '<div class="product-card__brand">' +
                '<span>' + escHtml(it.brand || '') + '</span>' +
                '</div>' +
                '</div>' +
                '<div class="product-card__footer">' +
                '<div class="product-card__pricing">' +
                '<div class="product-card__price">$' + fmt(it.price_1) + '</div>' +
                '<div class="product-card__price-unit">MXN / ' + escHtml(it.unit || 'PZA') + '</div>' +
                '</div>' +
                (isOut
                    ? '<button class="btn-add" disabled style="opacity:0.45;cursor:not-allowed;" aria-label="Producto agotado">' +
                      '<svg width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5" aria-hidden="true"><circle cx="12" cy="12" r="10"/><path d="M4.93 4.93l14.14 14.14"/></svg> Agotado</button>'
                    : '<button class="btn-add" onclick="CatalogApp.addToCart(' + it.id + ')" aria-label="Agregar ' + escHtml(it.name) + ' al carrito">' +
                      '<svg width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5" aria-hidden="true"><path d="M12 5v14M5 12h14"/></svg> Agregar</button>'
                ) +
                '</div>' +
                '</article>';
        }).join('');
    }

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

        var html = '';

        // Previous button
        if (pg.page <= 1) {
            html += '<button class="page-item page-item--wide is-disabled" disabled aria-label="Pagina anterior">' +
                '<svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="15,18 9,12 15,6"/></svg> Anterior</button>';
        } else {
            html += '<button class="page-item page-item--wide" onclick="CatalogApp.loadPage(' + (pg.page - 1) + ')" aria-label="Pagina anterior">' +
                '<svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="15,18 9,12 15,6"/></svg> Anterior</button>';
        }

        // Page numbers
        var pages = buildPageNumbers(pg.page, pg.total_pages);
        pages.forEach(function (p) {
            if (p === '...') {
                html += '<span class="page-ellipsis" aria-hidden="true">&hellip;</span>';
            } else if (p === pg.page) {
                html += '<button class="page-item is-active" aria-label="Pagina ' + p + ', actual" aria-current="page">' + p + '</button>';
            } else {
                html += '<button class="page-item" onclick="CatalogApp.loadPage(' + p + ')" aria-label="Ir a pagina ' + p + '">' + p + '</button>';
            }
        });

        // Next button
        if (pg.page >= pg.total_pages) {
            html += '<button class="page-item page-item--wide is-disabled" disabled aria-label="Pagina siguiente">Siguiente ' +
                '<svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="9,18 15,12 9,6"/></svg></button>';
        } else {
            html += '<button class="page-item page-item--wide" onclick="CatalogApp.loadPage(' + (pg.page + 1) + ')" aria-label="Pagina siguiente">Siguiente ' +
                '<svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="9,18 15,12 9,6"/></svg></button>';
        }

        paginationNav.innerHTML = html;
    }

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

    function updateResultsCount(pg) {
        var el = document.querySelector('.results-count');
        if (!el || !pg) return;
        var total = pg.total || 0;
        el.innerHTML = '<strong>' + total.toLocaleString('es-MX') + '</strong> partes encontradas';
    }

    // ─── Barcode scanner ───
    async function lookupBarcode(code) {
        var data = await apiFetch(API + '/catalog/barcode/' + encodeURIComponent(code));
        if (!data || data.error) { alert('Parte no encontrada: ' + code); return; }
        addToCart(data);
    }

    document.addEventListener('keydown', function (e) {
        if (e.key === 'F1') {
            e.preventDefault();
            if (searchInput) searchInput.focus();
            return;
        }
        if (document.activeElement.tagName === 'INPUT' || document.activeElement.tagName === 'TEXTAREA' || document.activeElement.tagName === 'SELECT') return;
        if (e.key === 'Enter' && barcodeBuffer.length >= 4) {
            lookupBarcode(barcodeBuffer.trim());
            barcodeBuffer = '';
            return;
        }
        if (e.key.length === 1) {
            barcodeBuffer += e.key;
            clearTimeout(barcodeTimeout);
            barcodeTimeout = setTimeout(function () { barcodeBuffer = ''; }, 200);
        }
    });

    // ─── Cart ───
    function addToCartById(id) {
        var it = catalogItemsMap[id];
        if (it) addToCart(it);
    }

    function addToCart(item) {
        var existing = cartItems.find(function (c) { return c.id === item.id; });
        if (existing) {
            existing.quantity += 1;
        } else {
            cartItems.push({
                id: item.id, part_number: item.part_number, name: item.name,
                brand: item.brand, price: item.price_1 || item.price, tax_rate: item.tax_rate || 0.16,
                unit: item.unit || 'PZA', stock: item.stock, quantity: 1
            });
        }
        saveCart();
        renderCart();
        // Brief open to show item was added
        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 clearCartFn() {
        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);">' + escHtml(c.name) + '</div>' +
                '<div style="font-size:0.75rem;color:var(--color-text-muted);">' + escHtml(c.part_number) + '</div>' +
                '<div style="margin-top:4px;display:flex;align-items:center;gap:6px;">' +
                '<button onclick="CatalogApp.updateQty(' + i + ',' + (c.quantity - 1) + ')" 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 onclick="CatalogApp.updateQty(' + i + ',' + (c.quantity + 1) + ')" 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 onclick="CatalogApp.removeFromCart(' + 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);
    }

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

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

    // ─── External availability ───
    async function checkExternalAvailability(partNumber) {
        var pn = partNumber || currentFilters.q || '';
        if (!pn) return;
        alert('Buscando "' + pn + '" en bodegas Nexus...');

        var data = await apiFetch(API + '/catalog/external-availability/' + encodeURIComponent(pn));
        if (!data || !data.data || !data.data.length) {
            alert('No se encontraron resultados externos para "' + pn + '"');
            return;
        }
        var msg = data.data.map(function (r) {
            return (r.name || r.part_number || pn) + ' - Stock: ' + (r.stock || 'N/A');
        }).join('\n');
        alert('Resultados externos:\n' + msg);
    }

    // ─── Helpers ───
    function fmt(n) { return (parseFloat(n) || 0).toFixed(2); }
    function escHtml(s) { if (!s) return ''; var d = document.createElement('div'); d.textContent = s; return d.innerHTML; }

    // ─── Search input ───
    var searchTimeout = null;
    if (searchInput) {
        searchInput.addEventListener('input', function () {
            clearTimeout(searchTimeout);
            searchTimeout = setTimeout(function () {
                currentFilters.q = searchInput.value.trim();
                loadCatalog(1, currentFilters);
            }, 300);
        });
        searchInput.addEventListener('keydown', function (e) {
            if (e.key === 'Enter') {
                e.preventDefault();
                clearTimeout(searchTimeout);
                currentFilters.q = searchInput.value.trim();
                loadCatalog(1, currentFilters);
            }
        });
    }

    // ─── Part search button ───
    if (partSearchBtn) {
        partSearchBtn.addEventListener('click', function () {
            if (searchInput) {
                currentFilters.q = searchInput.value.trim();
                loadCatalog(1, currentFilters);
            }
        });
    }

    // ─── Filter chips (dynamic from inventory brands) ───
    async function loadBrandChips() {
        var data = await apiFetch(API + '/catalog/brands');
        if (!data || !data.data) return;
        var container = document.getElementById('brandChips');
        if (!container) return;
        container.innerHTML = '';
        data.data.forEach(function(b) {
            var btn = document.createElement('button');
            btn.className = 'chip';
            btn.setAttribute('data-chip', b.name);
            btn.setAttribute('aria-pressed', 'false');
            btn.textContent = b.name + ' (' + b.count + ')';
            container.appendChild(btn);
        });
        // Re-wire all chip clicks (including the "Todos" chip)
        wireChipClicks();
    }

    function wireChipClicks() {
        document.querySelectorAll('[data-chip]').forEach(function (chip) {
            chip.addEventListener('click', function () {
                var isActive = chip.classList.contains('is-active');
                document.querySelectorAll('[data-chip]').forEach(function (c) {
                    c.classList.remove('is-active');
                    c.setAttribute('aria-pressed', 'false');
                });
                if (!isActive && chip.dataset.chip) {
                    chip.classList.add('is-active');
                    chip.setAttribute('aria-pressed', 'true');
                    currentFilters.brand = chip.dataset.chip;
                    delete currentFilters.chip;
                } else {
                    // "Todos" or deselect
                    document.querySelector('[data-chip=""]').classList.add('is-active');
                    document.querySelector('[data-chip=""]').setAttribute('aria-pressed', 'true');
                    delete currentFilters.brand;
                    delete currentFilters.chip;
                }
                loadCatalog(1, currentFilters);
            });
        });
    }

    loadBrandChips();
    wireChipClicks();

    // ─── Expose globals for inline onclick handlers ───
    window.CatalogApp = {
        toggleCart: toggleCart,
        goToCheckout: goToCheckout,
        addToCart: addToCartById,
        removeFromCart: removeFromCart,
        updateQty: updateQuantity,
        clearCart: clearCartFn,
        loadPage: function (p) { loadCatalog(p); },
        checkExternal: checkExternalAvailability
    };

    // Also keep legacy window._ handlers for backward compat
    window.toggleCart = toggleCart;
    window.goToCheckout = goToCheckout;
    window.checkExternalAvailability = checkExternalAvailability;

    // ─── Init ───
    renderCart();
    loadCatalog(1, {});
})();