/**
 * 书籍目录页面 - 主要逻辑
 */

class BookCatalogApp {
    constructor() {
        this.books = [];
        this.filteredBooks = [];
        this.statistics = null;
        
        this.init();
    }

    async init() {
        try {
            await this.loadStatistics();
            await this.loadBooks();
            this.setupEventListeners();
        } catch (error) {
            console.error('应用初始化失败:', error);
            this.showToast('应用初始化失败，请刷新页面重试', 'error');
        }
    }

    setupEventListeners() {
        // 搜索功能
        const searchInput = document.getElementById('searchInput');
        const searchBtn = document.getElementById('searchBtn');
        
        searchBtn.addEventListener('click', () => this.performSearch());
        searchInput.addEventListener('input', () => this.performSearch());
        searchInput.addEventListener('keypress', (e) => {
            if (e.key === 'Enter') this.performSearch();
        });
    }

    async loadStatistics() {
        try {
            const response = await fetch('/api/v2/statistics');
            if (!response.ok) {
                throw new Error('获取统计信息失败');
            }
            
            const result = await response.json();
            if (!result.success) {
                throw new Error(result.error || '获取统计信息失败');
            }
            
            this.statistics = result.statistics;
            this.renderStatistics();
        } catch (error) {
            console.error('加载统计信息失败:', error);
            // 统计信息加载失败不影响主要功能，只记录错误
        }
    }

    renderStatistics() {
        if (!this.statistics) return;
        
        document.getElementById('totalBooks').textContent = this.statistics.total_books || 0;
        document.getElementById('totalPages').textContent = this.statistics.total_pages || 0;
        document.getElementById('totalPieces').textContent = this.statistics.total_pieces || 0;
        document.getElementById('totalCatalogs').textContent = this.statistics.total_catalogs || 0;
        
        document.getElementById('statistics').style.display = 'grid';
    }

    async loadBooks() {
        const loading = document.getElementById('loading');
        const booksGrid = document.getElementById('booksGrid');
        const emptyState = document.getElementById('emptyState');
        
        loading.style.display = 'block';
        booksGrid.style.display = 'none';
        emptyState.style.display = 'none';
        
        try {
            const response = await fetch('/api/v2/books');
            if (!response.ok) {
                throw new Error('获取书籍列表失败');
            }
            
            const result = await response.json();
            if (!result.success) {
                throw new Error(result.error || '获取书籍列表失败');
            }
            
            this.books = result.books || [];
            this.filteredBooks = [...this.books];
            
            console.log(`加载了 ${this.books.length} 本书籍`);
            
            if (this.books.length === 0) {
                loading.style.display = 'none';
                emptyState.style.display = 'block';
            } else {
                this.renderBooks();
            }
        } catch (error) {
            console.error('加载书籍列表失败:', error);
            loading.style.display = 'none';
            emptyState.style.display = 'block';
            this.showToast('加载书籍列表失败: ' + error.message, 'error');
        }
    }

    renderBooks() {
        const loading = document.getElementById('loading');
        const booksGrid = document.getElementById('booksGrid');
        const emptyState = document.getElementById('emptyState');
        
        loading.style.display = 'none';
        
        if (this.filteredBooks.length === 0) {
            booksGrid.style.display = 'none';
            emptyState.innerHTML = `
                <div><i class="fas fa-search"></i></div>
                <div>未找到匹配的教材</div>
            `;
            emptyState.style.display = 'block';
            return;
        }
        
        booksGrid.style.display = 'grid';
        emptyState.style.display = 'none';
        
        booksGrid.innerHTML = '';
        
        this.filteredBooks.forEach(book => {
            const bookCard = this.createBookCard(book);
            booksGrid.appendChild(bookCard);
        });
    }

    createBookCard(book) {
        const card = document.createElement('div');
        card.className = 'book-card';
        card.dataset.bookId = book.market_book_id;
        
        // 构建封面URL
        const coverUrl = this.getCoverUrl(book);
        
        // 年级和学期信息
        const gradeInfo = this.getGradeInfo(book.grade_id, book.reel_id);
        
        card.innerHTML = `
            <img class="book-cover" src="${coverUrl}" alt="${book.market_book_name}" 
                 onerror="this.style.display='none'">
            <div class="book-info">
                <div class="book-name" title="${book.market_book_name}">${book.market_book_name}</div>
                <div class="book-meta">
                    <span><i class="fas fa-file-alt"></i> ${book.max_page || 0} 页</span>
                    <span>${gradeInfo}</span>
                </div>
                <div class="book-classify">${book.market_classify_name || '未分类'}</div>
            </div>
        `;
        
        // 点击事件
        card.addEventListener('click', () => {
            this.openBook(book.market_book_id);
        });
        
        return card;
    }

    getCoverUrl(book) {
        if (book.market_book_cover) {
            // 如果有封面路径，使用 data 目录
            return `data/${book.market_book_cover}`;
        }
        
        // 默认封面
        return 'data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iMjAwIiBoZWlnaHQ9IjI4MCIgeG1sbnM9Imh0dHA6Ly93d3cudzMub3JnLzIwMDAvc3ZnIj48cmVjdCB3aWR0aD0iMjAwIiBoZWlnaHQ9IjI4MCIgZmlsbD0iIzY2N2VlYSIvPjx0ZXh0IHg9IjUwJSIgeT0iNTAlIiBmb250LWZhbWlseT0iQXJpYWwiIGZvbnQtc2l6ZT0iMjQiIGZpbGw9IndoaXRlIiB0ZXh0LWFuY2hvcj0ibWlkZGxlIiBkeT0iLjNlbSI+8J+TljwvdGV4dD48L3N2Zz4=';
    }

    getGradeInfo(gradeId, reelId) {
        const grades = {
            40: '一年级',
            41: '二年级',
            42: '三年级',
            43: '四年级',
            44: '五年级',
            45: '六年级'
        };
        
        const reels = {
            1: '上册',
            2: '下册'
        };
        
        const grade = grades[gradeId] || `年级${gradeId}`;
        const reel = reels[reelId] || `学期${reelId}`;
        
        return `${grade}${reel}`;
    }

    performSearch() {
        const keyword = document.getElementById('searchInput').value.trim().toLowerCase();
        
        if (!keyword) {
            this.filteredBooks = [...this.books];
        } else {
            this.filteredBooks = this.books.filter(book => {
                return book.market_book_name.toLowerCase().includes(keyword) ||
                       (book.market_classify_name && book.market_classify_name.toLowerCase().includes(keyword));
            });
        }
        
        this.renderBooks();
    }

    openBook(bookId) {
        // 跳转到阅读页面
        window.location.href = `/reader?book_id=${bookId}`;
    }

    showToast(message, type = 'info') {
        const toast = document.getElementById('toast');
        toast.textContent = message;
        toast.className = `toast ${type} show`;
        
        setTimeout(() => {
            toast.classList.remove('show');
        }, 3000);
    }
}

// 页面加载完成后初始化应用
document.addEventListener('DOMContentLoaded', () => {
    new BookCatalogApp();
});