/**
 * 格式化字节大小
 */
export function formatBytes(bytes: number): string {
    if (bytes === 0) return '0 B';

    const k = 1024;
    const sizes = ['B', 'KB', 'MB', 'GB', 'TB'];
    const i = Math.floor(Math.log(bytes) / Math.log(k));

    return `${parseFloat((bytes / Math.pow(k, i)).toFixed(1))} ${sizes[i]}`;
}

/**
 * 格式化日期
 */
export function formatDate(date: Date): string {
    const now = new Date();
    const diffTime = Math.abs(now.getTime() - date.getTime());
    const diffDays = Math.ceil(diffTime / (1000 * 60 * 60 * 24));

    if (diffDays === 1) {
        return '昨天';
    } else if (diffDays <= 7) {
        return `${diffDays} 天前`;
    } else if (diffDays <= 30) {
        const weeks = Math.floor(diffDays / 7);
        return `${weeks} 周前`;
    } else if (diffDays <= 365) {
        const months = Math.floor(diffDays / 30);
        return `${months} 个月前`;
    } else {
        return date.toLocaleDateString('zh-CN', {
            year: 'numeric',
            month: 'short',
            day: 'numeric',
        });
    }
}

/**
 * 格式化文件类型显示名称
 */
export function getFileTypeName(mimeType?: string): string {
    if (!mimeType) return '未知类型';

    const typeMap: Record<string, string> = {
        'application/vnd.openxmlformats-officedocument.wordprocessingml.document': 'Word 文档',
        'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet': 'Excel 表格',
        'application/vnd.openxmlformats-officedocument.presentationml.presentation': 'PowerPoint 演示文稿',
        'application/pdf': 'PDF 文档',
        'text/plain': '文本文件',
        'image/jpeg': 'JPEG 图片',
        'image/png': 'PNG 图片',
        'image/gif': 'GIF 图片',
        'image/svg+xml': 'SVG 图片',
        'video/mp4': 'MP4 视频',
        'video/avi': 'AVI 视频',
        'audio/mp3': 'MP3 音频',
        'audio/wav': 'WAV 音频',
        'application/zip': 'ZIP 压缩包',
        'application/x-rar-compressed': 'RAR 压缩包',
    };

    if (typeMap[mimeType]) {
        return typeMap[mimeType];
    }

    // 回退到通用类型判断
    if (mimeType.startsWith('image/')) return '图片';
    if (mimeType.startsWith('video/')) return '视频';
    if (mimeType.startsWith('audio/')) return '音频';
    if (mimeType.startsWith('text/')) return '文本';

    return '文件';
}

/**
 * 根据文件扩展名获取MIME类型
 */
export function getMimeTypeFromExtension(filename: string): string {
    const ext = filename.split('.').pop()?.toLowerCase();

    const extMap: Record<string, string> = {
        'pdf': 'application/pdf',
        'doc': 'application/msword',
        'docx': 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
        'xls': 'application/vnd.ms-excel',
        'xlsx': 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
        'ppt': 'application/vnd.ms-powerpoint',
        'pptx': 'application/vnd.openxmlformats-officedocument.presentationml.presentation',
        'txt': 'text/plain',
        'jpg': 'image/jpeg',
        'jpeg': 'image/jpeg',
        'png': 'image/png',
        'gif': 'image/gif',
        'svg': 'image/svg+xml',
        'mp4': 'video/mp4',
        'avi': 'video/avi',
        'mp3': 'audio/mp3',
        'wav': 'audio/wav',
        'zip': 'application/zip',
        'rar': 'application/x-rar-compressed',
    };

    return ext ? extMap[ext] || 'application/octet-stream' : 'application/octet-stream';
}