@{
    ViewData["Title"] = "图片压缩工具";
    Layout = "_Layout";
}

<div class="container" style="padding-top: 6rem; padding-bottom: 4rem;">
    <!-- 页面头部 -->
    <div class="text-center mb-8">
        <div class="brand-icon" style="width: 4rem; height: 4rem; margin: 0 auto 1.5rem; font-size: 1.8rem;">
            <i class="fas fa-compress-alt"></i>
        </div>
        <h1 class="hero-title">图片压缩工具</h1>
        <p class="hero-description">快速压缩图片文件，支持JPG、PNG、WebP等格式<br>
        保持高质量的同时大幅减小文件体积，提升网站加载速度</p>
    </div>

    <!-- 工具主体 -->
    <div class="card" style="max-width: 800px; margin: 0 auto;">
        <div class="card-body" style="padding: 2rem;">
            <!-- 上传区域 -->
            <div id="uploadArea" class="upload-area">
                <div class="upload-content">
                    <i class="fas fa-cloud-upload-alt" style="font-size: 3rem; color: var(--primary); margin-bottom: 1rem;"></i>
                    <h3>拖拽图片到此处或点击选择</h3>
                    <p style="color: var(--dark-2); margin-bottom: 1.5rem;">支持 JPG、PNG、WebP、GIF 格式，单文件最大 10MB</p>
                    <button type="button" class="btn btn-primary" onclick="selectFiles()">
                        <i class="fas fa-upload"></i>
                        选择图片
                    </button>
                </div>
                <input type="file" id="fileInput" multiple accept="image/*" style="display: none;" onchange="handleFiles(this.files)">
            </div>

            <!-- 压缩设置 -->
            <div id="settingsPanel" class="settings-panel" style="display: none;">
                <h4 style="margin-bottom: 1rem;">压缩设置</h4>
                <div style="display: grid; grid-template-columns: 1fr 1fr; gap: 1.5rem; margin-bottom: 1.5rem;">
                    <div>
                        <label>压缩质量</label>
                        <div style="display: flex; align-items: center; gap: 1rem;">
                            <input type="range" id="qualitySlider" min="0.1" max="1" step="0.1" value="0.8" 
                                   style="flex: 1;" oninput="updateQualityDisplay(this.value)">
                            <span id="qualityDisplay" style="font-weight: 600; min-width: 50px;">80%</span>
                        </div>
                    </div>
                    <div>
                        <label>输出格式</label>
                        <select id="formatSelect" style="width: 100%; padding: 0.75rem; border: 1px solid var(--light-2); border-radius: var(--border-radius);">
                            <option value="original">保持原格式</option>
                            <option value="jpeg">JPEG</option>
                            <option value="png">PNG</option>
                            <option value="webp">WebP</option>
                        </select>
                    </div>
                </div>
                <button type="button" class="btn btn-primary" onclick="compressAllImages()" id="compressBtn">
                    <i class="fas fa-compress"></i>
                    开始压缩
                </button>
            </div>

            <!-- 文件列表 -->
            <div id="fileList" class="file-list" style="display: none;">
                <h4 style="margin-bottom: 1rem;">图片列表</h4>
                <div id="imageItems"></div>
            </div>

            <!-- 压缩结果 -->
            <div id="resultsPanel" class="results-panel" style="display: none;">
                <h4 style="margin-bottom: 1rem;">压缩完成</h4>
                <div id="compressResults"></div>
                <div style="margin-top: 1.5rem; text-align: center;">
                    <button type="button" class="btn btn-primary" onclick="downloadAll()">
                        <i class="fas fa-download"></i>
                        下载全部
                    </button>
                    <button type="button" class="btn btn-outline" onclick="resetTool()" style="margin-left: 1rem;">
                        <i class="fas fa-redo"></i>
                        重新开始
                    </button>
                </div>
            </div>
        </div>
    </div>

    <!-- 使用说明 -->
    <div class="card mt-8">
        <div class="card-body">
            <h3 style="margin-bottom: 1.5rem; text-align: center;">使用说明</h3>
            <div style="display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 2rem;">
                <div style="text-align: center;">
                    <div style="width: 3rem; height: 3rem; background: linear-gradient(135deg, var(--primary), var(--secondary)); border-radius: 50%; display: flex; align-items: center; justify-content: center; margin: 0 auto 1rem; color: white; font-size: 1.2rem;">1</div>
                    <h4>选择图片</h4>
                    <p style="color: var(--dark-2); font-size: 0.875rem;">支持拖拽上传或点击选择，可同时处理多张图片</p>
                </div>
                <div style="text-align: center;">
                    <div style="width: 3rem; height: 3rem; background: linear-gradient(135deg, var(--primary), var(--secondary)); border-radius: 50%; display: flex; align-items: center; justify-content: center; margin: 0 auto 1rem; color: white; font-size: 1.2rem;">2</div>
                    <h4>调整设置</h4>
                    <p style="color: var(--dark-2); font-size: 0.875rem;">设置压缩质量和输出格式，质量越低文件越小</p>
                </div>
                <div style="text-align: center;">
                    <div style="width: 3rem; height: 3rem; background: linear-gradient(135deg, var(--primary), var(--secondary)); border-radius: 50%; display: flex; align-items: center; justify-content: center; margin: 0 auto 1rem; color: white; font-size: 1.2rem;">3</div>
                    <h4>下载结果</h4>
                    <p style="color: var(--dark-2); font-size: 0.875rem;">压缩完成后可单独下载或批量下载所有图片</p>
                </div>
            </div>
        </div>
    </div>
</div>

<style>
.upload-area {
    border: 2px dashed var(--light-2);
    border-radius: var(--border-radius-lg);
    padding: 3rem 2rem;
    text-align: center;
    background: var(--light-1);
    transition: var(--transition);
    cursor: pointer;
}

.upload-area:hover {
    border-color: var(--primary);
    background: rgba(22, 93, 255, 0.05);
}

.upload-area.dragover {
    border-color: var(--primary);
    background: rgba(22, 93, 255, 0.1);
}

.settings-panel, .file-list, .results-panel {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--light-2);
}

.image-item {
    display: flex;
    align-items: center;
    padding: 1rem;
    border: 1px solid var(--light-2);
    border-radius: var(--border-radius);
    margin-bottom: 1rem;
    background: white;
}

.image-preview {
    width: 60px;
    height: 60px;
    object-fit: cover;
    border-radius: var(--border-radius);
    margin-right: 1rem;
}

.image-info {
    flex: 1;
}

.image-actions {
    display: flex;
    gap: 0.5rem;
}

.progress-bar {
    width: 100%;
    height: 6px;
    background: var(--light-2);
    border-radius: 3px;
    overflow: hidden;
    margin-top: 0.5rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    transition: width 0.3s ease;
    width: 0%;
}

.compression-stats {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 1rem;
    text-align: center;
    padding: 1rem;
    background: var(--light-1);
    border-radius: var(--border-radius);
    margin-bottom: 1rem;
}

.stat-item h5 {
    margin: 0 0 0.25rem;
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--primary);
}

.stat-item p {
    margin: 0;
    font-size: 0.875rem;
    color: var(--dark-2);
}

/* 响应式调整 */
@@media (max-width: 768px) {
    .upload-area {
        padding: 2rem 1rem;
    }
    
    .compression-stats {
        grid-template-columns: 1fr;
        gap: 0.5rem;
    }
}
</style>

<script>
let selectedFiles = [];
let compressedFiles = [];

// 文件选择
function selectFiles() {
    document.getElementById('fileInput').click();
}

// 处理文件选择
function handleFiles(files) {
    if (files.length === 0) return;
    
    selectedFiles = Array.from(files).filter(file => {
        return file.type.startsWith('image/') && file.size <= 10 * 1024 * 1024; // 10MB限制
    });
    
    if (selectedFiles.length === 0) {
        toolHub.showToast('请选择有效的图片文件（小于10MB）', 'error');
        return;
    }
    
    displaySelectedFiles();
    document.getElementById('settingsPanel').style.display = 'block';
    document.getElementById('fileList').style.display = 'block';
}

// 显示选中的文件
function displaySelectedFiles() {
    const container = document.getElementById('imageItems');
    container.innerHTML = '';
    
    selectedFiles.forEach((file, index) => {
        const item = document.createElement('div');
        item.className = 'image-item';
        item.innerHTML = `
            <img class="image-preview" src="${URL.createObjectURL(file)}" alt="${file.name}">
            <div class="image-info">
                <div style="font-weight: 600; margin-bottom: 0.25rem;">${file.name}</div>
                <div style="font-size: 0.875rem; color: var(--dark-2);">
                    ${formatFileSize(file.size)} • ${file.type}
                </div>
                <div class="progress-bar" id="progress-${index}" style="display: none;">
                    <div class="progress-fill" id="progress-fill-${index}"></div>
                </div>
            </div>
            <div class="image-actions">
                <button class="btn btn-outline btn-sm" onclick="removeFile(${index})">
                    <i class="fas fa-times"></i>
                </button>
            </div>
        `;
        container.appendChild(item);
    });
}

// 移除文件
function removeFile(index) {
    selectedFiles.splice(index, 1);
    if (selectedFiles.length === 0) {
        document.getElementById('settingsPanel').style.display = 'none';
        document.getElementById('fileList').style.display = 'none';
    } else {
        displaySelectedFiles();
    }
}

// 更新质量显示
function updateQualityDisplay(value) {
    document.getElementById('qualityDisplay').textContent = Math.round(value * 100) + '%';
}

// 压缩所有图片
async function compressAllImages() {
    const quality = parseFloat(document.getElementById('qualitySlider').value);
    const format = document.getElementById('formatSelect').value;
    
    compressedFiles = [];
    document.getElementById('compressBtn').disabled = true;
    document.getElementById('compressBtn').innerHTML = '<i class="fas fa-spinner fa-spin"></i> 压缩中...';
    
    for (let i = 0; i < selectedFiles.length; i++) {
        const file = selectedFiles[i];
        document.getElementById(`progress-${i}`).style.display = 'block';
        
        try {
            const compressedFile = await compressImage(file, quality, format, (progress) => {
                document.getElementById(`progress-fill-${i}`).style.width = progress + '%';
            });
            compressedFiles.push(compressedFile);
        } catch (error) {
            console.error('压缩失败:', error);
            toolHub.showToast(`压缩 ${file.name} 失败`, 'error');
        }
    }
    
    showResults();
    document.getElementById('compressBtn').disabled = false;
    document.getElementById('compressBtn').innerHTML = '<i class="fas fa-compress"></i> 开始压缩';
}

// 压缩单个图片
function compressImage(file, quality, format, onProgress) {
    return new Promise((resolve, reject) => {
        const canvas = document.createElement('canvas');
        const ctx = canvas.getContext('2d');
        const img = new Image();
        
        img.onload = function() {
            canvas.width = img.width;
            canvas.height = img.height;
            
            ctx.drawImage(img, 0, 0);
            
            const outputFormat = format === 'original' ? file.type : `image/${format}`;
            
            canvas.toBlob((blob) => {
                if (blob) {
                    const compressedFile = new File([blob], 
                        getCompressedFileName(file.name, format), 
                        { type: outputFormat }
                    );
                    onProgress(100);
                    resolve({
                        original: file,
                        compressed: compressedFile,
                        compressionRatio: ((file.size - blob.size) / file.size * 100).toFixed(1)
                    });
                } else {
                    reject(new Error('压缩失败'));
                }
            }, outputFormat, quality);
        };
        
        img.onerror = () => reject(new Error('图片加载失败'));
        img.src = URL.createObjectURL(file);
        
        // 模拟进度
        let progress = 0;
        const progressInterval = setInterval(() => {
            progress += 10;
            if (progress >= 90) {
                clearInterval(progressInterval);
            } else {
                onProgress(progress);
            }
        }, 50);
    });
}

// 获取压缩后的文件名
function getCompressedFileName(originalName, format) {
    if (format === 'original') return originalName;
    
    const nameWithoutExt = originalName.substring(0, originalName.lastIndexOf('.'));
    return `${nameWithoutExt}_compressed.${format === 'jpeg' ? 'jpg' : format}`;
}

// 显示压缩结果
function showResults() {
    const totalOriginalSize = compressedFiles.reduce((sum, item) => sum + item.original.size, 0);
    const totalCompressedSize = compressedFiles.reduce((sum, item) => sum + item.compressed.size, 0);
    const totalSavings = ((totalOriginalSize - totalCompressedSize) / totalOriginalSize * 100).toFixed(1);
    
    document.getElementById('compressResults').innerHTML = `
        <div class="compression-stats">
            <div class="stat-item">
                <h5>${formatFileSize(totalOriginalSize)}</h5>
                <p>原始大小</p>
            </div>
            <div class="stat-item">
                <h5>${formatFileSize(totalCompressedSize)}</h5>
                <p>压缩后大小</p>
            </div>
            <div class="stat-item">
                <h5>${totalSavings}%</h5>
                <p>压缩率</p>
            </div>
        </div>
        ${compressedFiles.map((item, index) => `
            <div class="image-item">
                <img class="image-preview" src="${URL.createObjectURL(item.compressed)}" alt="${item.compressed.name}">
                <div class="image-info">
                    <div style="font-weight: 600; margin-bottom: 0.25rem;">${item.compressed.name}</div>
                    <div style="font-size: 0.875rem; color: var(--dark-2);">
                        ${formatFileSize(item.original.size)} → ${formatFileSize(item.compressed.size)} (节省 ${item.compressionRatio}%)
                    </div>
                </div>
                <div class="image-actions">
                    <button class="btn btn-primary btn-sm" onclick="downloadFile(${index})">
                        <i class="fas fa-download"></i> 下载
                    </button>
                </div>
            </div>
        `).join('')}
    `;
    
    document.getElementById('resultsPanel').style.display = 'block';
}

// 下载单个文件
function downloadFile(index) {
    const item = compressedFiles[index];
    const url = URL.createObjectURL(item.compressed);
    const a = document.createElement('a');
    a.href = url;
    a.download = item.compressed.name;
    a.click();
    URL.revokeObjectURL(url);
}

// 下载所有文件
function downloadAll() {
    compressedFiles.forEach((item, index) => {
        setTimeout(() => downloadFile(index), index * 200);
    });
}

// 重置工具
function resetTool() {
    selectedFiles = [];
    compressedFiles = [];
    document.getElementById('fileInput').value = '';
    document.getElementById('settingsPanel').style.display = 'none';
    document.getElementById('fileList').style.display = 'none';
    document.getElementById('resultsPanel').style.display = 'none';
    document.getElementById('imageItems').innerHTML = '';
    document.getElementById('compressResults').innerHTML = '';
}

// 格式化文件大小
function formatFileSize(bytes) {
    if (bytes === 0) return '0 B';
    const k = 1024;
    const sizes = ['B', 'KB', 'MB', 'GB'];
    const i = Math.floor(Math.log(bytes) / Math.log(k));
    return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
}

// 拖拽上传
document.addEventListener('DOMContentLoaded', function() {
    const uploadArea = document.getElementById('uploadArea');
    
    uploadArea.addEventListener('dragover', function(e) {
        e.preventDefault();
        uploadArea.classList.add('dragover');
    });
    
    uploadArea.addEventListener('dragleave', function(e) {
        e.preventDefault();
        uploadArea.classList.remove('dragover');
    });
    
    uploadArea.addEventListener('drop', function(e) {
        e.preventDefault();
        uploadArea.classList.remove('dragover');
        handleFiles(e.dataTransfer.files);
    });
    
    uploadArea.addEventListener('click', selectFiles);
});
</script>