/** 상품 그리드·페이지네이션 렌더링 */
import { state, saveSelection } from './state.js';
import { ITEMS_PER_PAGE, STATUS_META, STATUS_COLOR, PRODUCT_CONDITIONS } from './config.js';
import { updateSummary } from './main.js';

// --- 터치 및 드래그 관련 전역 변수 및 핸들러 ---
window.isDragging = false;
let touchStartX = 0;
let touchStartY = 0;

// 터치 기기 여부 확인
const isTouchDevice = 'ontouchstart' in window || navigator.maxTouchPoints > 0;

window.handleTouchStart = function (e) {
    window.isDragging = false;
    touchStartX = e.touches[0].clientX;
    touchStartY = e.touches[0].clientY;
};

window.handleTouchMove = function (e) {
    const touchX = e.touches[0].clientX;
    const touchY = e.touches[0].clientY;

    // 10px 이상 움직이면 드래그(스크롤)로 간주
    if (Math.abs(touchX - touchStartX) > 10 || Math.abs(touchY - touchStartY) > 10) {
        window.isDragging = true;
    }
};

window.handleTouchEnd = function (e) {
    // 필요한 경우 추가 로직 작성 가능 (현재는 isDragging 상태 유지만으로 충분)
};

// 썸네일 호버 핸들러 (PC에서만 동작하도록 수정)
window.handleThumbnailHover = function (e, id) {
    if (isTouchDevice) return; // 모바일에서는 호버 로직 실행 안 함

    const product = state.visibleProducts.find((p) => p.id === id);
    if (!product || !product.images || product.images.length <= 1) return;

    const rect = e.currentTarget.getBoundingClientRect();
    const x = e.clientX - rect.left;
    const sectionWidth = rect.width / product.images.length;
    const index = Math.floor(x / sectionWidth);

    const thumb = document.getElementById(`thumb-${id}`);
    const indicators = document.querySelector(`#indicator-${id}`)?.children;

    if (thumb && product.images[index]) {
        thumb.style.backgroundImage = `url("${product.images[index]}")`;
    }

    if (indicators) {
        Array.from(indicators).forEach((dot, i) => {
            if (i === index) {
                dot.classList.add('bg-white', 'scale-125');
                dot.classList.remove('bg-white/40');
            } else {
                dot.classList.remove('bg-white', 'scale-125');
                dot.classList.add('bg-white/40');
            }
        });
    }
};

window.handleThumbnailLeave = function (id) {
    if (isTouchDevice) return;

    const product = state.visibleProducts.find((p) => p.id === id);
    const thumb = document.getElementById(`thumb-${id}`);
    const indicators = document.querySelector(`#indicator-${id}`)?.children;

    if (thumb && product) {
        thumb.style.backgroundImage = `url("${product.images[0]}")`;
    }

    if (indicators) {
        Array.from(indicators).forEach((dot, i) => {
            if (i === 0) {
                dot.classList.add('bg-white', 'scale-125');
                dot.classList.remove('bg-white/40');
            } else {
                dot.classList.remove('bg-white', 'scale-125');
                dot.classList.add('bg-white/40');
            }
        });
    }
};

// 1. 체크박스 전역 핸들러 등록
window.toggleSelectItem = function (id) {
    if (state.selectedIds.has(id)) {
        state.selectedIds.delete(id);
    } else {
        state.selectedIds.add(id);
    }
    saveSelection();
    renderProducts(state.currentPage);
    updateSummary();
};

export function renderProducts(page = 1) {
    const grid = document.getElementById('product-grid');
    const tableWrapper = document.getElementById('product-table-wrapper');
    const tableBody = document.getElementById('product-table-body');
    const summaryBar = document.getElementById('selection-summary');
    const paginationContainer = document.getElementById('pagination');

    if (!grid || !tableWrapper) return;

    if (state.visibleProducts.length === 0) {
        grid.classList.remove('grid');
        grid.classList.add('hidden');
        tableWrapper.classList.add('hidden');
        const emptyMsg = `
            <div class="col-span-full flex flex-col items-center justify-center py-20 w-full text-center">
                <svg class="w-20 h-20 text-slate-300 dark:text-slate-700 mb-6" viewBox="0 -960 960 960" fill="currentColor">
                    <path d="M138.5-138.5Q80-197 80-280t58.5-141.5Q197-480 280-480t141.5 58.5Q480-363 480-280t-58.5 141.5Q363-80 280-80t-141.5-58.5ZM824-120 568-376q-12-13-25.5-26.5T516-428q38-24 61-64t23-88q0-75-52.5-127.5T420-760q-75 0-127.5 52.5T240-580q0 6 .5 11.5T242-557q-18 2-39.5 8T164-535q-2-11-3-22t-1-23q0-109 75.5-184.5T420-840q109 0 184.5 75.5T680-580q0 43-13.5 81.5T629-428l251 252-56 56Zm-615-61 71-71 70 71 29-28-71-71 71-71-28-28-71 71-71-71-28 28 71 71-71 71 28 28Z"/>
                </svg>
                <h3 class="text-xl font-bold text-slate-900 dark:text-white mb-2">검색 결과가 없습니다</h3>
                <p class="text-slate-500 dark:text-slate-400 text-sm">입력하신 검색어나 선택한 필터를 확인해 주세요.</p>
            </div>`;
        grid.innerHTML = emptyMsg;
        grid.classList.remove('hidden');
        if (paginationContainer) paginationContainer.innerHTML = '';
        return;
    }

    if (state.viewMode === 'grid') {
        grid.classList.remove('hidden');
        grid.classList.add('grid');
        tableWrapper.classList.add('hidden');
        if (summaryBar) {
            summaryBar.classList.remove('flex');
            summaryBar.classList.add('hidden');
        }
    } else {
        grid.classList.remove('grid');
        grid.classList.add('hidden');
        tableWrapper.classList.remove('hidden');
        updateSummary();
    }

    const startIndex = (page - 1) * ITEMS_PER_PAGE;
    const pagedProducts = state.visibleProducts.slice(startIndex, startIndex + ITEMS_PER_PAGE);

    if (state.viewMode === 'grid') {
        grid.innerHTML = '';
        pagedProducts.forEach((product) => {
            const isSold = STATUS_META[product.status]?.soldOut === true;
            const isNonSale = product.status === '미판매';
            const conditionKey = product.specs?.condition;
            const conditionConfig = PRODUCT_CONDITIONS[conditionKey];
            const conditionDisplay = conditionConfig ? conditionConfig.label : conditionKey || '';

            grid.insertAdjacentHTML(
                'beforeend',
                `
                <div class="product-card group flex flex-col gap-4 cursor-pointer"
                     data-id="${product.id}"
                     onclick="if(!window.isDragging) window.openModal('${product.id}')"
                     ontouchstart="window.handleTouchStart(event)"
                     ontouchmove="window.handleTouchMove(event)"
                     ontouchend="window.handleTouchEnd(event)"
                     onmousemove="window.handleThumbnailHover(event, '${product.id}')" 
                     onmouseleave="window.handleThumbnailLeave('${product.id}')">
                    
                    <div class="relative w-full aspect-card bg-slate-200 dark:bg-slate-800 rounded-xl overflow-hidden shadow-sm">
                        <div id="thumb-${product.id}"
                             class="w-full h-full bg-center bg-no-repeat bg-cover absolute inset-0 transition-all duration-500 ${isSold ? 'grayscale opacity-60' : 'group-hover:scale-105'}"
                             style="background-image: none; will-change: background-image, transform;">
                        </div>

                        <div id="thumb-fade-${product.id}"
                             class="w-full h-full bg-center bg-no-repeat bg-cover absolute inset-0 opacity-0 pointer-events-none transition-all duration-500 ${isSold ? 'grayscale' : 'group-hover:scale-105'}"
                             style="background-image: none; will-change: background-image, opacity, transform;">
                        </div>

                        <div class="absolute top-3 left-3 z-10">
                            <span class="px-2 py-1 text-[10px] uppercase tracking-wider font-bold rounded ${STATUS_COLOR[product.status]} backdrop-blur-md border">${product.status}</span>
                        </div>

                        ${
                            !isSold && product.images?.length > 1
                                ? `
                            <div id="indicator-${product.id}" class="absolute bottom-3 left-1/2 -translate-x-1/2 hidden md:flex gap-1.5 opacity-0 group-hover:opacity-100 transition-all duration-300 pointer-events-none z-10">
                                ${product.images
                                    .map(
                                        (_, i) => `
                                    <div class="w-1.5 h-1.5 rounded-full transition-all duration-300 shadow-sm ${i === 0 ? 'bg-white scale-125' : 'bg-white/40'}"></div>
                                `,
                                    )
                                    .join('')}
                            </div>`
                                : ''
                        }
                    </div>

                    <div class="flex flex-col gap-1.5">
                        <div class="flex flex-col justify-between items-start sm:items-baseline gap-1">
                            <h3 class="text-slate-900 dark:text-white text-base font-semibold leading-tight break-keep ${isSold ? 'line-through text-slate-400' : ''}">${product.title}</h3>
                            <p class="text-base font-bold whitespace-nowrap ${isNonSale ? 'text-slate-400 font-medium text-xs uppercase' : 'text-slate-900 dark:text-white'}">
                                ${isNonSale ? 'Not for Sale' : `${product.currency || '₩'}${product.price.toLocaleString()}`}
                            </p>
                        </div>
                        <div class="flex flex-col">
                            ${conditionDisplay ? `<span class="text-[11px] font-medium text-slate-400 mb-0.5">${conditionDisplay}</span>` : ''}
                            <p class="text-slate-500 dark:text-slate-400 text-sm font-normal line-clamp-1 italic">${product.description}</p>
                        </div>
                    </div>
                </div>`,
            );
        });
        setupLazyLoading();
    } else {
        // 테이블 렌더링 로직 (생략 없이 유지)
        tableBody.innerHTML = pagedProducts
            .map((product) => {
                const meta = STATUS_META[product.status];
                const isSold = meta?.soldOut === true;
                const isSelectable = meta?.selectable !== false;
                const conditionKey = product.specs.condition;
                const conditionConfig = PRODUCT_CONDITIONS[conditionKey];
                let conditionDisplay = conditionConfig ? conditionConfig.label : conditionKey || '상세 설명 참고 ℹ️';
                let conditionClass = conditionConfig ? conditionConfig.color : 'text-slate-500';

                return `
                <tr class="hover:bg-slate-50 dark:hover:bg-slate-800/50 transition-colors ${isSold ? 'opacity-50 grayscale cursor-not-allowed' : 'cursor-pointer'}" 
                    onclick="if(event.target.type !== 'checkbox') { 
                        ${isSold ? "alert('판매 완료된 상품입니다.');" : `window.openModal('${product.id}')`} 
                    }">
                    <td class="py-4 px-4 text-center" onclick="event.stopPropagation()">
                        <input type="checkbox" class="product-check rounded border-slate-300 w-4 h-4 ${isSelectable ? 'cursor-pointer text-primary' : 'opacity-20 cursor-not-allowed'}"
                            ${state.selectedIds.has(product.id) ? 'checked' : ''} ${isSelectable ? '' : 'disabled'}
                            onchange="window.toggleSelectItem('${product.id}')">
                    </td>
                    <td class="py-4 px-4 font-semibold ${isSold ? 'line-through text-slate-400' : 'text-slate-900 dark:text-white'}">${product.title}</td>
                    <td class="py-4 px-4 text-xs break-keep ${conditionClass}">${conditionDisplay}</td>
                    <td class="py-4 px-4 text-right font-bold text-slate-900 dark:text-white">₩${product.price.toLocaleString()}</td>
                    <td class="hidden lg:table-cell py-4 px-4 text-center">
                        <span class="px-2 py-0.5 rounded text-[10px] font-bold border ${STATUS_COLOR[product.status]}">${product.status}</span>
                    </td>
                </tr>`;
            })
            .join('');
    }

    const selectAllCheck = document.getElementById('select-all-current');
    if (selectAllCheck) {
        const startIndex = (page - 1) * ITEMS_PER_PAGE;
        const currentSelectableItems = state.visibleProducts.slice(startIndex, startIndex + ITEMS_PER_PAGE).filter((p) => STATUS_META[p.status]?.selectable !== false);
        selectAllCheck.checked = currentSelectableItems.length > 0 && currentSelectableItems.every((p) => state.selectedIds.has(p.id));
    }

    if (typeof renderPagination === 'function') renderPagination();
}

function setupLazyLoading() {
    const observer = new IntersectionObserver(
        (entries) => {
            entries.forEach((entry) => {
                if (entry.isIntersecting) {
                    const card = entry.target;
                    const productId = card.getAttribute('data-id');
                    // state.js 등에서 가져온 데이터 활용
                    const product = state.visibleProducts.find((p) => p.id === productId);
                    const thumb = document.getElementById(`thumb-${productId}`);

                    if (product && thumb) {
                        // 1. 첫 번째 이미지 로드
                        thumb.style.backgroundImage = `url("${product.images[0]}")`;

                        // 2. 나머지 이미지 프리로드 (반짝임 방지)
                        if (!STATUS_META[product.status]?.soldOut && product.images.length > 1) {
                            product.images.slice(1).forEach((url) => {
                                const img = new Image();
                                img.src = url;
                            });
                        }
                    }
                    observer.unobserve(card);
                }
            });
        },
        { threshold: 0.1 },
    );

    document.querySelectorAll('.product-card').forEach((card) => observer.observe(card));
}

export function renderPagination() {
    const container = document.getElementById('pagination');
    if (!container) return;
    const totalPages = Math.ceil(state.visibleProducts.length / ITEMS_PER_PAGE);
    const { currentPage } = state;

    let html = `<button onclick="changePage(${currentPage - 1})" class="size-10 flex items-center justify-center ${currentPage === 1 ? 'invisible' : ''}">
                    <svg viewBox="0 0 24 24" fill="none" stroke="#64748B" stroke-width="3" stroke-linecap="round" stroke-linejoin="round" class="w-5 h-5">
                        <path d="M15 18l-6-6 6-6" />
                    </svg>
                </button>`;
    for (let i = 1; i <= totalPages; i++) {
        html += `<button onclick="changePage(${i})" class="size-10 font-bold rounded-lg ${i === currentPage ? 'bg-primary text-white' : 'text-slate-500'}">${i}</button>`;
    }
    html += `<button onclick="changePage(${currentPage + 1})" class="size-10 flex items-center justify-center ${currentPage === totalPages ? 'invisible' : ''}">
                <svg viewBox="0 0 24 24" fill="none" stroke="#64748B" stroke-width="3" stroke-linecap="round" stroke-linejoin="round" class="w-5 h-5">
                    <path d="M9 18l6-6-6-6" />
                </svg>
            </button>`;
    container.innerHTML = html;
}

export function changePage(page) {
    state.currentPage = page;
    renderProducts(page);
    window.scrollTo({ top: 0, behavior: 'smooth' });
}

/** 모든 필터를 초기 상태로 되돌리는 함수 */
function resetAllFilters() {
    state.searchKeyword = '';
    const searchInput = document.getElementById('search-input');
    if (searchInput) searchInput.value = '';

    state.activeCategories.clear();
    state.activeCategories.add('All');

    // 상태 필터 초기화 (config에서 defaultActive인 것만)
    import('./config.js').then(({ STATUS_FILTERS }) => {
        state.activeStatuses.clear();
        STATUS_FILTERS.filter((f) => f.defaultActive).forEach((f) => state.activeStatuses.add(f.key));

        // UI 전체 갱신
        applyFilters();
        renderStatusChips();
        renderCategoryChips(productsData);
    });
}
