import fs from 'fs';
import path from 'path';
import Link from 'next/link';
import { ArticleClient } from './ArticleClient';

interface ArticleData {
    content: string;
    meta: {
        title: string;
        description: string;
        author: string;
        date: string;
        readTime: number;
        category: string;
    };
}

export async function generateStaticParams() {
    // 只基于 content 目录中实际存在的文章生成参数
    const contentDir = path.join(process.cwd(), 'content');
    const slugs: string[] = [];
    
    try {
        if (fs.existsSync(contentDir)) {
            const folders = fs
                .readdirSync(contentDir, { withFileTypes: true })
                .filter((dirent) => dirent.isDirectory())
                .map((dirent) => dirent.name);
            slugs.push(...folders);
        }
    } catch (error) {
        console.warn('generateStaticParams: unable to read content dir', error);
    }
    
    return slugs.map(slug => ({ slug }));
}

async function getArticleData(slug: string): Promise<ArticleData | null> {
    try {
        const contentDir = path.join(process.cwd(), 'content');
        const articleDir = path.join(contentDir, slug);
        
        if (!fs.existsSync(articleDir)) {
            return null;
        }
        
        // 优先读取中文内容
        let contentFile = '';
        let lang = 'zh';
        
        if (fs.existsSync(path.join(articleDir, 'zh.md'))) {
            contentFile = 'zh.md';
            lang = 'zh';
        } else if (fs.existsSync(path.join(articleDir, 'en.md'))) {
            contentFile = 'en.md';
            lang = 'en';
        } else if (fs.existsSync(path.join(articleDir, 'zh-tw.md'))) {
            contentFile = 'zh-tw.md';
            lang = 'zh-tw';
        }
        
        if (!contentFile) {
            return null;
        }
        
        const filePath = path.join(articleDir, contentFile);
        const content = fs.readFileSync(filePath, 'utf-8');
        
        // 从内容中提取元数据
        const titleMatch = content.match(/^#\s+(.+)$/m);
        const title = titleMatch ? titleMatch[1] : slug;
        
        // 提取摘要（第一段非标题内容）
        const lines = content.split('\n').filter((line: string) => 
            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 (slug.includes('ecs') || slug.includes('rds') || slug.includes('oss')) {
            category = 'product';
        } else if (slug.includes('deployment') || slug.includes('guide') || slug.includes('tutorial')) {
            category = 'tutorial';
        } else if (slug.includes('market') || slug.includes('trend')) {
            category = 'industry';
        }
        
        return {
            content,
            meta: {
                title,
                description: excerpt.length > 200 ? excerpt.substring(0, 200) + '...' : excerpt,
                author: 'CloudPro 技术团队',
                date: new Date().toISOString().split('T')[0],
                readTime: Math.ceil(content.split('\n').length / 20),
                category,
            }
        };
    } catch (error) {
        console.error('Error reading article:', error);
        return null;
    }
}

export default async function Page({ params }: { params: { slug: string } }) {
    const articleData = await getArticleData(params.slug);
    
    if (!articleData) {
        return (
            <div className="min-h-screen bg-gradient-to-br from-amber-50 to-yellow-50 flex items-center justify-center">
                <div className="text-center">
                    <h1 className="text-2xl font-bold text-amber-900 mb-4">文章未找到</h1>
                    <Link href="/news" className="text-amber-600 hover:text-amber-700">
                        返回资讯列表
                    </Link>
                </div>
            </div>
        );
    }

    return <ArticleClient slug={params.slug} initialData={articleData} />;
}