/**
 * 交互式英语学习应用 - 主要逻辑
 * 支持点读、翻译显示和音频播放功能
 */

class InteractiveLearningApp {
    constructor() {
        this.bookData = null;
        this.currentPageIndex = 0;
        this.currentAudio = null;
        this.isPlaying = false;
        this.showTranslation = false;
        this.showInteractiveAreas = false;
        this.bookmarks = [];
        this.searchResults = [];
        this.debugMode = false; // 调试模式
        this.settings = {
            autoTranslation: false,
            playbackSpeed: 1,
            autoPlayNext: false
        };
        
        this.init();
    }

    async init() {
        try {
            await this.loadBookData();
            this.setupEventListeners();
            this.loadSettings();
            this.loadBookmarks();
            this.renderCurrentPage();
            this.updateUI();
        } 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');
        }
    }

    async loadBookData() {
        try {
            const response = await fetch('./book_10242.json');
            if (!response.ok) {
                throw new Error('数据文件加载失败');
            }
            const jsonData = await response.json();
            
            if (!jsonData.Data) {
                throw new Error('数据格式不正确');
            }
            
            this.bookData = JSON.parse(jsonData.Data);
            console.log('书籍数据加载成功:', this.bookData.length, '页');
        } catch (error) {
            console.error('数据加载失败:', error);
            throw error;
        }
    }

    setupEventListeners() {
        // 页面导航
        document.getElementById('prevBtn').addEventListener('click', () => this.previousPage());
        document.getElementById('nextBtn').addEventListener('click', () => this.nextPage());
        
        // 控制按钮
        document.getElementById('translationToggle').addEventListener('click', () => this.toggleTranslation());
        document.getElementById('interactiveToggle').addEventListener('click', () => this.toggleInteractiveAreas());
        document.getElementById('playAllBtn').addEventListener('click', () => this.playAllPieces());
        document.getElementById('bookmarkBtn').addEventListener('click', () => this.toggleBookmark());
        document.getElementById('searchBtn').addEventListener('click', () => this.showSearch());
        document.getElementById('settingsBtn').addEventListener('click', () => this.showSettings());
        
        // 音频控制
        document.getElementById('playPauseBtn').addEventListener('click', () => this.togglePlayPause());
        document.getElementById('repeatBtn').addEventListener('click', () => this.repeatAudio());
        document.getElementById('audioTimeline').addEventListener('click', (e) => this.seekAudio(e));
        
        // 设置面板
        document.getElementById('closeSettings').addEventListener('click', () => this.hideSettings());
        
        // 搜索面板
        document.getElementById('closeSearch').addEventListener('click', () => this.hideSearch());
        document.getElementById('doSearch').addEventListener('click', () => this.performSearch());
        document.getElementById('searchInput').addEventListener('keypress', (e) => {
            if (e.key === 'Enter') this.performSearch();
        });
        
        // 书签面板
        document.getElementById('closeBookmark').addEventListener('click', () => this.hideBookmarks());
        document.getElementById('autoTranslation').addEventListener('change', (e) => {
            this.settings.autoTranslation = e.target.checked;
            this.saveSettings();
        });
        document.getElementById('playbackSpeed').addEventListener('change', (e) => {
            this.settings.playbackSpeed = parseFloat(e.target.value);
            this.saveSettings();
            if (this.currentAudio) {
                this.currentAudio.playbackRate = this.settings.playbackSpeed;
            }
        });
        document.getElementById('autoPlayNext').addEventListener('change', (e) => {
            this.settings.autoPlayNext = e.target.checked;
            this.saveSettings();
        });
        
        // 键盘快捷键
        document.addEventListener('keydown', (e) => this.handleKeyPress(e));
        
        // 点击设置面板外部关闭
        document.getElementById('settingsPanel').addEventListener('click', (e) => {
            if (e.target.id === 'settingsPanel') {
                this.hideSettings();
            }
        });
        
        // 音频事件监听
        const audio = document.getElementById('audio');
        audio.addEventListener('loadedmetadata', () => this.updateAudioUI());
        audio.addEventListener('timeupdate', () => this.updateAudioProgress());
        audio.addEventListener('ended', () => this.onAudioEnded());
        audio.addEventListener('error', (e) => {
            console.error('音频播放失败:', e);
            this.showToast('音频播放失败', 'error');
        });
    }

    renderCurrentPage() {
        if (!this.bookData || this.currentPageIndex >= this.bookData.length) {
            return;
        }

        const page = this.bookData[this.currentPageIndex];
        const pageContainer = document.getElementById('pageContent');
        const loading = document.getElementById('loading');
        
        // 显示加载状态
        loading.style.display = 'block';
        pageContainer.style.display = 'none';
        
        // 加载页面图片
        const pageImage = document.getElementById('pageImage');
        pageImage.onload = () => {
            loading.style.display = 'none';
            pageContainer.style.display = 'block';
            this.renderTextPieces(page);
        };
        
        pageImage.onerror = () => {
            // 如果原始图片加载失败，尝试加载加密图片
            if (pageImage.src === page.originImgUrl && page.encryptImgUrl) {
                pageImage.src = page.encryptImgUrl;
            } else {
                loading.style.display = 'none';
                this.showToast('页面图片加载失败', 'error');
            }
        };
        
        pageImage.src = page.originImgUrl;
        pageImage.alt = `第${page.pageNumber}页`;
    }

    renderTextPieces(page) {
        const textOverlays = document.getElementById('textOverlays');
        const pageImage = document.getElementById('pageImage');
        
        // 清空现有的文本片段
        textOverlays.innerHTML = '';
        
        // 等待图片完全加载后渲染文本片段
        const renderPieces = () => {
            // 获取图片的实际位置和尺寸
            const imageRect = pageImage.getBoundingClientRect();
            const overlayRect = textOverlays.getBoundingClientRect();
            
            // 计算图片相对于overlay容器的偏移
            const offsetX = imageRect.left - overlayRect.left;
            const offsetY = imageRect.top - overlayRect.top;
            
            // 获取图片的实际显示尺寸
            const imageWidth = imageRect.width;
            const imageHeight = imageRect.height;
            
            console.log('图片信息:', {
                imageWidth,
                imageHeight,
                offsetX,
                offsetY,
                debugMode: this.debugMode
            });
            
            page.pieces.forEach((piece, index) => {
                const textPiece = document.createElement('div');
                textPiece.className = 'text-piece';
                textPiece.dataset.pieceIndex = index;
                
                // 在调试模式下添加特殊样式
                if (this.debugMode) {
                    textPiece.style.border = '2px solid red';
                    textPiece.style.backgroundColor = 'rgba(255, 0, 0, 0.2)';
                }
                
                // 根据坐标信息设置位置和大小（coordinate是相对图片的比例坐标）
                const coord = piece.coordinate;
                const left = offsetX + (coord.x * imageWidth);
                const top = offsetY + (coord.y * imageHeight);
                const width = coord.width * imageWidth;
                const height = coord.height * imageHeight;
                
                textPiece.style.left = `${left}px`;
                textPiece.style.top = `${top}px`;
                textPiece.style.width = `${width}px`;
                textPiece.style.height = `${height}px`;
                
                if (this.debugMode) {
                    console.log(`Piece ${index + 1} (${piece.original}):`, {
                        coord,
                        left,
                        top,
                        width,
                        height
                    });
                }
                
                // 创建文本内容
                const originalText = document.createElement('div');
                originalText.className = 'piece-text';
                originalText.textContent = piece.original;
                
                const translationText = document.createElement('div');
                translationText.className = 'piece-translation';
                translationText.textContent = piece.translation;
                
                textPiece.appendChild(originalText);
                textPiece.appendChild(translationText);
                
                // 点击事件
                textPiece.addEventListener('click', () => this.playPiece(piece, textPiece));
                
                textOverlays.appendChild(textPiece);
            });
            
            // 根据设置显示翻译
            if (this.showTranslation || this.settings.autoTranslation) {
                textOverlays.classList.add('show-translation');
            }
        };
        
        // 如果图片已经加载完成，直接渲染
        if (pageImage.complete && pageImage.naturalHeight !== 0) {
            renderPieces();
        } else {
            // 否则等待图片加载完成
            pageImage.addEventListener('load', renderPieces, { once: true });
        }
        
        // 监听窗口大小变化和图片加载事件
        let resizeTimeout;
        const handleResize = () => {
            clearTimeout(resizeTimeout);
            resizeTimeout = setTimeout(() => {
                if (pageImage.complete && pageImage.naturalHeight !== 0) {
                    console.log('窗口大小变化，重新计算坐标');
                    renderPieces();
                }
            }, 100);
        };
        
        // 移除之前的监听器（如果存在）
        if (pageImage.resizeObserver) {
            pageImage.resizeObserver.disconnect();
        }
        
        // 创建新的监听器
        pageImage.resizeObserver = new ResizeObserver(handleResize);
        pageImage.resizeObserver.observe(pageImage);
        
        // 同时监听窗口大小变化
        window.addEventListener('resize', handleResize);
    }

    async playPiece(piece, element) {
        try {
            // 移除其他片段的激活状态
            document.querySelectorAll('.text-piece').forEach(el => {
                el.classList.remove('active', 'playing');
            });
            
            // 激活当前片段
            element.classList.add('active');
            
            // 显示音频播放器
            const audioPlayer = document.getElementById('audioPlayer');
            audioPlayer.style.display = 'block';
            
            // 更新音频文本显示
            const audioText = document.getElementById('audioText');
            audioText.innerHTML = `
                <div style="font-weight: 600; margin-bottom: 0.5rem;">${piece.original}</div>
                <div style="color: var(--text-secondary); font-size: 0.9rem;">${piece.translation}</div>
            `;
            
            // 加载并播放音频
            const audio = document.getElementById('audio');
            const audioUrl = piece.originSoundUrl || piece.encryptSoundUrl;
            
            if (!audioUrl) {
                this.showToast('该片段没有可用的音频', 'warning');
                return;
            }
            
            // 停止当前播放的音频
            if (this.currentAudio && !this.currentAudio.paused) {
                this.currentAudio.pause();
            }
            
            audio.src = audioUrl;
            audio.playbackRate = this.settings.playbackSpeed;
            this.currentAudio = audio;
            
            // 播放音频
            await audio.play();
            this.isPlaying = true;
            element.classList.add('playing');
            this.updatePlayButton();
            
        } catch (error) {
            console.error('音频播放失败:', error);
            this.showToast('音频播放失败', 'error');
            element.classList.remove('active', 'playing');
        }
    }

    async playAllPieces() {
        const page = this.bookData[this.currentPageIndex];
        if (!page || !page.pieces.length) return;
        
        let currentPieceIndex = 0;
        
        const playNext = async () => {
            if (currentPieceIndex >= page.pieces.length) {
                this.showToast('整页播放完成', 'success');
                return;
            }
            
            const piece = page.pieces[currentPieceIndex];
            const element = document.querySelector(`[data-piece-index="${currentPieceIndex}"]`);
            
            if (element) {
                await this.playPiece(piece, element);
                
                // 等待当前音频播放完成
                const audio = document.getElementById('audio');
                audio.addEventListener('ended', () => {
                    currentPieceIndex++;
                    setTimeout(playNext, 500); // 稍微延迟播放下一个
                }, { once: true });
            } else {
                currentPieceIndex++;
                playNext();
            }
        };
        
        playNext();
    }

    togglePlayPause() {
        const audio = document.getElementById('audio');
        if (!audio.src) return;
        
        if (this.isPlaying) {
            audio.pause();
            this.isPlaying = false;
        } else {
            audio.play().then(() => {
                this.isPlaying = true;
            }).catch(error => {
                console.error('播放失败:', error);
                this.showToast('播放失败', 'error');
            });
        }
        
        this.updatePlayButton();
    }

    repeatAudio() {
        const audio = document.getElementById('audio');
        if (audio.src) {
            audio.currentTime = 0;
            if (!this.isPlaying) {
                this.togglePlayPause();
            }
        }
    }

    seekAudio(event) {
        const audio = document.getElementById('audio');
        if (!audio.src || !audio.duration) return;
        
        const timeline = document.getElementById('audioTimeline');
        const rect = timeline.getBoundingClientRect();
        const percentage = (event.clientX - rect.left) / rect.width;
        const newTime = percentage * audio.duration;
        
        audio.currentTime = newTime;
    }

    updatePlayButton() {
        const playPauseBtn = document.getElementById('playPauseBtn');
        const icon = playPauseBtn.querySelector('i');
        
        if (this.isPlaying) {
            icon.className = 'fas fa-pause';
        } else {
            icon.className = 'fas fa-play';
        }
    }

    updateAudioUI() {
        const audio = document.getElementById('audio');
        const totalTime = document.getElementById('totalTime');
        
        if (audio.duration) {
            totalTime.textContent = this.formatTime(audio.duration);
        }
    }

    updateAudioProgress() {
        const audio = document.getElementById('audio');
        const progressBar = document.getElementById('audioProgressBar');
        const currentTime = document.getElementById('currentTime');
        
        if (audio.duration) {
            const percentage = (audio.currentTime / audio.duration) * 100;
            progressBar.style.width = `${percentage}%`;
            currentTime.textContent = this.formatTime(audio.currentTime);
        }
    }

    onAudioEnded() {
        this.isPlaying = false;
        this.updatePlayButton();
        
        // 移除播放状态
        document.querySelectorAll('.text-piece').forEach(el => {
            el.classList.remove('playing');
        });
        
        // 如果启用自动播放下一个
        if (this.settings.autoPlayNext) {
            // 这里可以实现自动播放下一个片段的逻辑
        }
    }

    toggleTranslation() {
        this.showTranslation = !this.showTranslation;
        const textOverlays = document.getElementById('textOverlays');
        const translationBtn = document.getElementById('translationToggle');
        
        if (this.showTranslation) {
            textOverlays.classList.add('show-translation');
            translationBtn.classList.add('active');
        } else {
            textOverlays.classList.remove('show-translation');
            translationBtn.classList.remove('active');
        }
    }

    toggleInteractiveAreas() {
        this.showInteractiveAreas = !this.showInteractiveAreas;
        const textOverlays = document.getElementById('textOverlays');
        const interactiveBtn = document.getElementById('interactiveToggle');
        
        if (this.showInteractiveAreas) {
            textOverlays.classList.add('show-interactive-areas');
            interactiveBtn.classList.add('active');
            interactiveBtn.querySelector('i').className = 'fas fa-eye-slash';
            interactiveBtn.title = '隐藏交互区域';
        } else {
            textOverlays.classList.remove('show-interactive-areas');
            interactiveBtn.classList.remove('active');
            interactiveBtn.querySelector('i').className = 'fas fa-eye';
            interactiveBtn.title = '显示交互区域';
        }
    }

    previousPage() {
        if (this.currentPageIndex > 0) {
            this.currentPageIndex--;
            this.renderCurrentPage();
            this.updateUI();
            this.stopCurrentAudio();
        }
    }

    nextPage() {
        if (this.currentPageIndex < this.bookData.length - 1) {
            this.currentPageIndex++;
            this.renderCurrentPage();
            this.updateUI();
            this.stopCurrentAudio();
        }
    }

    stopCurrentAudio() {
        if (this.currentAudio && !this.currentAudio.paused) {
            this.currentAudio.pause();
            this.isPlaying = false;
            this.updatePlayButton();
        }
        
        // 隐藏音频播放器
        document.getElementById('audioPlayer').style.display = 'none';
        
        // 移除所有激活状态
        document.querySelectorAll('.text-piece').forEach(el => {
            el.classList.remove('active', 'playing');
        });
    }

    updateUI() {
        // 更新页面信息
        document.getElementById('currentPage').textContent = this.currentPageIndex + 1;
        document.getElementById('totalPages').textContent = this.bookData.length;
        
        // 更新进度条
        const progress = ((this.currentPageIndex + 1) / this.bookData.length) * 100;
        document.getElementById('progressFill').style.width = `${progress}%`;
        
        // 更新导航按钮状态
        document.getElementById('prevBtn').disabled = this.currentPageIndex === 0;
        document.getElementById('nextBtn').disabled = this.currentPageIndex === this.bookData.length - 1;
        
        // 更新书签按钮状态
        this.updateBookmarkButton();
    }

    showSettings() {
        document.getElementById('settingsPanel').style.display = 'flex';
        
        // 同步当前设置到UI
        document.getElementById('autoTranslation').checked = this.settings.autoTranslation;
        document.getElementById('playbackSpeed').value = this.settings.playbackSpeed;
        document.getElementById('autoPlayNext').checked = this.settings.autoPlayNext;
    }

    hideSettings() {
        document.getElementById('settingsPanel').style.display = 'none';
    }

    loadSettings() {
        const saved = localStorage.getItem('learningAppSettings');
        if (saved) {
            try {
                this.settings = { ...this.settings, ...JSON.parse(saved) };
            } catch (error) {
                console.error('设置加载失败:', error);
            }
        }
    }

    saveSettings() {
        localStorage.setItem('learningAppSettings', JSON.stringify(this.settings));
    }

    handleKeyPress(event) {
        // 如果设置面板打开，只处理 Escape 键
        if (document.getElementById('settingsPanel').style.display === 'flex') {
            if (event.key === 'Escape') {
                this.hideSettings();
            }
            return;
        }
        
        switch (event.key) {
            case 'ArrowLeft':
                event.preventDefault();
                this.previousPage();
                break;
            case 'ArrowRight':
                event.preventDefault();
                this.nextPage();
                break;
            case ' ':
                event.preventDefault();
                this.togglePlayPause();
                break;
            case 't':
            case 'T':
                event.preventDefault();
                this.toggleTranslation();
                break;
            case 'i':
            case 'I':
                event.preventDefault();
                this.toggleInteractiveAreas();
                break;
            case 'r':
            case 'R':
                event.preventDefault();
                this.repeatAudio();
                break;
            case 'p':
            case 'P':
                event.preventDefault();
                this.playAllPieces();
                break;
            case 'b':
            case 'B':
                event.preventDefault();
                this.toggleBookmark();
                break;
            case 'f':
            case 'F':
                event.preventDefault();
                this.showSearch();
                break;
            case 'd':
            case 'D':
                if (event.ctrlKey) {
                    event.preventDefault();
                    this.toggleDebugMode();
                }
                break;
        }
    }

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

    formatTime(seconds) {
        const mins = Math.floor(seconds / 60);
        const secs = Math.floor(seconds % 60);
        return `${mins}:${secs.toString().padStart(2, '0')}`;
    }

    // 搜索功能
    showSearch() {
        document.getElementById('searchPanel').style.display = 'flex';
        document.getElementById('searchInput').focus();
    }

    hideSearch() {
        document.getElementById('searchPanel').style.display = 'none';
        document.getElementById('searchInput').value = '';
        this.clearSearchResults();
    }

    performSearch() {
        const query = document.getElementById('searchInput').value.trim();
        if (!query) {
            this.showToast('请输入搜索关键词', 'warning');
            return;
        }

        const results = [];
        const regex = new RegExp(query, 'gi');

        this.bookData.forEach((page, pageIndex) => {
            page.pieces.forEach((piece, pieceIndex) => {
                if (regex.test(piece.original) || regex.test(piece.translation)) {
                    results.push({
                        pageIndex,
                        pieceIndex,
                        page: page.pageNumber,
                        original: piece.original,
                        translation: piece.translation,
                        piece
                    });
                }
            });
        });

        this.searchResults = results;
        this.displaySearchResults(query);
    }

    displaySearchResults(query) {
        const resultsContainer = document.getElementById('searchResults');
        
        if (this.searchResults.length === 0) {
            resultsContainer.innerHTML = '<div class="search-empty">未找到匹配的内容</div>';
            return;
        }

        const regex = new RegExp(`(${query})`, 'gi');
        let html = '';

        this.searchResults.forEach((result, index) => {
            const highlightedOriginal = result.original.replace(regex, '<span class="search-highlight">$1</span>');
            const highlightedTranslation = result.translation.replace(regex, '<span class="search-highlight">$1</span>');

            html += `
                <div class="search-result-item" data-result-index="${index}">
                    <div class="search-result-page">第 ${result.page} 页</div>
                    <div class="search-result-text">${highlightedOriginal}</div>
                    <div class="search-result-translation">${highlightedTranslation}</div>
                </div>
            `;
        });

        resultsContainer.innerHTML = html;

        // 添加点击事件
        resultsContainer.querySelectorAll('.search-result-item').forEach(item => {
            item.addEventListener('click', (e) => {
                const index = parseInt(e.currentTarget.dataset.resultIndex);
                this.goToSearchResult(index);
            });
        });
    }

    goToSearchResult(index) {
        const result = this.searchResults[index];
        if (!result) return;

        this.currentPageIndex = result.pageIndex;
        this.renderCurrentPage();
        this.updateUI();
        this.hideSearch();

        // 稍微延迟后高亮显示并播放对应片段
        setTimeout(() => {
            const element = document.querySelector(`[data-piece-index="${result.pieceIndex}"]`);
            if (element) {
                element.scrollIntoView({ behavior: 'smooth', block: 'center' });
                this.playPiece(result.piece, element);
            }
        }, 500);

        this.showToast(`跳转到第 ${result.page} 页`, 'success');
    }

    clearSearchResults() {
        this.searchResults = [];
        document.getElementById('searchResults').innerHTML = '<div class="search-empty">输入关键词开始搜索</div>';
    }

    // 书签功能
    toggleBookmark() {
        const isBookmarked = this.bookmarks.some(b => b.pageIndex === this.currentPageIndex);
        
        if (isBookmarked) {
            const bookmark = this.bookmarks.find(b => b.pageIndex === this.currentPageIndex);
            this.removeBookmark(bookmark.id);
        } else {
            this.addBookmark();
        }
    }
    
    showBookmarks() {
        document.getElementById('bookmarkPanel').style.display = 'flex';
        this.renderBookmarks();
    }

    hideBookmarks() {
        document.getElementById('bookmarkPanel').style.display = 'none';
    }

    addBookmark() {
        const currentPage = this.bookData[this.currentPageIndex];
        if (!currentPage) return;

        const bookmark = {
            id: Date.now(),
            pageIndex: this.currentPageIndex,
            pageNumber: currentPage.pageNumber,
            title: `第 ${currentPage.pageNumber} 页`,
            timestamp: new Date().toISOString()
        };

        // 检查是否已存在
        const exists = this.bookmarks.some(b => b.pageIndex === this.currentPageIndex);
        if (exists) {
            this.showToast('当前页面已在书签中', 'warning');
            return;
        }

        this.bookmarks.push(bookmark);
        this.saveBookmarks();
        this.updateBookmarkButton();
        this.showToast('书签添加成功', 'success');
    }

    removeBookmark(bookmarkId) {
        this.bookmarks = this.bookmarks.filter(b => b.id !== bookmarkId);
        this.saveBookmarks();
        this.updateBookmarkButton();
        this.renderBookmarks();
        this.showToast('书签删除成功', 'success');
    }

    renderBookmarks() {
        const container = document.getElementById('bookmarkList');
        
        if (this.bookmarks.length === 0) {
            container.innerHTML = '<div class="bookmark-empty">还没有添加任何书签</div>';
            return;
        }

        let html = '';
        this.bookmarks.forEach(bookmark => {
            const date = new Date(bookmark.timestamp);
            const timeString = date.toLocaleDateString() + ' ' + date.toLocaleTimeString([], {hour: '2-digit', minute:'2-digit'});
            
            html += `
                <div class="bookmark-item" data-page-index="${bookmark.pageIndex}">
                    <div class="bookmark-info">
                        <div class="bookmark-page">${bookmark.title}</div>
                        <div class="bookmark-time">${timeString}</div>
                    </div>
                    <div class="bookmark-actions">
                        <button class="bookmark-delete" data-bookmark-id="${bookmark.id}">
                            <i class="fas fa-times"></i>
                        </button>
                    </div>
                </div>
            `;
        });

        container.innerHTML = html;

        // 添加点击事件
        container.querySelectorAll('.bookmark-item').forEach(item => {
            item.addEventListener('click', (e) => {
                if (e.target.closest('.bookmark-delete')) return;
                const pageIndex = parseInt(item.dataset.pageIndex);
                this.goToBookmark(pageIndex);
            });
        });

        container.querySelectorAll('.bookmark-delete').forEach(btn => {
            btn.addEventListener('click', (e) => {
                e.stopPropagation();
                const bookmarkId = parseInt(btn.dataset.bookmarkId);
                this.removeBookmark(bookmarkId);
            });
        });
    }

    goToBookmark(pageIndex) {
        this.currentPageIndex = pageIndex;
        this.renderCurrentPage();
        this.updateUI();
        this.hideBookmarks();
        this.showToast(`跳转到第 ${this.bookData[pageIndex].pageNumber} 页`, 'success');
    }

    updateBookmarkButton() {
        const btn = document.getElementById('bookmarkBtn');
        const isBookmarked = this.bookmarks.some(b => b.pageIndex === this.currentPageIndex);
        
        if (isBookmarked) {
            btn.classList.add('active');
            btn.title = '取消书签';
        } else {
            btn.classList.remove('active');
            btn.title = '添加书签';
        }
    }

    loadBookmarks() {
        const saved = localStorage.getItem('learningAppBookmarks');
        if (saved) {
            try {
                this.bookmarks = JSON.parse(saved);
            } catch (error) {
                console.error('书签加载失败:', error);
                this.bookmarks = [];
            }
        }
    }

    saveBookmarks() {
        localStorage.setItem('learningAppBookmarks', JSON.stringify(this.bookmarks));
    }

    // 调试模式
    toggleDebugMode() {
        this.debugMode = !this.debugMode;
        this.showToast(`调试模式: ${this.debugMode ? '开启' : '关闭'}`, 'info');
        
        // 重新渲染当前页面以应用调试样式
        this.renderCurrentPage();
    }
}

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

// 处理页面可见性变化，暂停音频播放
document.addEventListener('visibilitychange', () => {
    if (document.hidden) {
        const audio = document.getElementById('audio');
        if (audio && !audio.paused) {
            audio.pause();
        }
    }
});