import { NextRequest, NextResponse } from 'next/server';
import fs from 'fs';
import path from 'path';

interface ArticleMeta {
    id: string;
    category: string;
    title: string;
    excerpt: string;
    author: string;
    date: string;
    readTime: number;
}

export async function GET(request: NextRequest) {
    try {
        const contentDir = path.join(process.cwd(), 'content');
        const articles: ArticleMeta[] = [];

        if (!fs.existsSync(contentDir)) {
            return NextResponse.json(articles);
        }

        const folders = fs.readdirSync(contentDir, { withFileTypes: true })
            .filter(dirent => dirent.isDirectory())
            .map(dirent => dirent.name);

        for (const folder of folders) {
            const articleDir = path.join(contentDir, folder);
            const files = fs.readdirSync(articleDir);
            
            // 优先使用中文内容，如果没有则使用英文
            let contentFile = '';
            if (files.includes('zh.md')) {
                contentFile = 'zh.md';
            } else if (files.includes('en.md')) {
                contentFile = 'en.md';
            } else if (files.includes('zh-tw.md')) {
                contentFile = 'zh-tw.md';
            }

            if (contentFile) {
                const filePath = path.join(articleDir, contentFile);
                const content = fs.readFileSync(filePath, 'utf-8');
                
                // 从 Markdown 内容中提取元数据
                const titleMatch = content.match(/^#\s+(.+)$/m);
                const title = titleMatch ? titleMatch[1] : folder;
                
                // 提取摘要（第一段非标题内容）
                const lines = content.split('\n').filter(line => 
                    line.trim() && !line.startsWith('#') && !line.startsWith('---')
                );
                const excerpt = lines[0] || title;
                
                // 根据文件夹名称推断分类
                let category = 'tech';
                if (folder.includes('ecs') || folder.includes('rds') || folder.includes('oss')) {
                    category = 'product';
                } else if (folder.includes('deployment') || folder.includes('guide') || folder.includes('tutorial')) {
                    category = 'tutorial';
                } else if (folder.includes('market') || folder.includes('trend')) {
                    category = 'industry';
                }
                
                // 估算阅读时间（按行数计算）
                const readTime = Math.ceil(content.split('\n').length / 20);
                
                articles.push({
                    id: folder,
                    category,
                    title,
                    excerpt: excerpt.length > 100 ? excerpt.substring(0, 100) + '...' : excerpt,
                    author: 'CloudPro 技术团队',
                    date: new Date().toISOString().split('T')[0], // 使用当前日期作为默认值
                    readTime: Math.max(1, readTime), // 至少1分钟
                });
            }
        }

        // 按日期排序（最新的在前）
        articles.sort((a, b) => new Date(b.date).getTime() - new Date(a.date).getTime());

        return NextResponse.json(articles);
    } catch (error) {
        console.error('Error reading articles:', error);
        return NextResponse.json([], { status: 500 });
    }
}