// 自定义JavaScript函数

// 显示加载动画
function showLoading() {
    const loadingElement = document.getElementById('loading');
    if (loadingElement) {
        loadingElement.style.display = 'block';
    }
}

// 隐藏加载动画
function hideLoading() {
    const loadingElement = document.getElementById('loading');
    if (loadingElement) {
        loadingElement.style.display = 'none';
    }
}

// 显示通知
function showNotification(message, type = 'info') {
    // 创建通知元素
    const alertDiv = document.createElement('div');
    alertDiv.className = `alert alert-${type} alert-dismissible fade show`;
    alertDiv.innerHTML = `
        ${message}
        <button type="button" class="btn-close" data-bs-dismiss="alert"></button>
    `;
    
    // 插入到页面中
    const container = document.querySelector('main') || document.body;
    container.insertBefore(alertDiv, container.firstChild);
    
    // 5秒后自动隐藏
    setTimeout(() => {
        if (alertDiv.parentNode) {
            alertDiv.remove();
        }
    }, 5000);
}

// 格式化日期
function formatDate(dateString) {
    if (!dateString) return '-';
    const date = new Date(dateString);
    return date.toLocaleDateString('zh-CN') + ' ' + date.toLocaleTimeString('zh-CN');
}

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