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

// 为静态导出生成参数
export async function generateStaticParams() {
    // 返回所有可能的consultation ID
    const consultationIds = ['cloud-migration', 'aws-optimization', 'security-audit'];
    
    return consultationIds.map((id) => ({
        id,
    }));
}

const CACHE_DURATION = process.env.NODE_ENV === 'development' ? 0 : 60; // 开发环境10秒，生产环境60秒

interface CacheStore {
    [key: string]: {
        data: any;
        timestamp: number;
    };
}

let cache: CacheStore = {};

function getCachedData<T>(key: string, fetchFn: () => T): T {
    const now = Date.now();
    const cached = cache[key];

    if (cached && now - cached.timestamp < CACHE_DURATION * 1000) {
        return cached.data;
    }

    const data = fetchFn();
    cache[key] = {
        data,
        timestamp: now,
    };

    return data;
}

const docsDirectory = path.join(process.cwd(), 'data/consultations');

function getConsultationById(id: string, locale: 'zh-CN' | 'zh-TW' | 'en') {
    const fileName = `${id}.${locale}.md`;
    const fullPath = path.join(docsDirectory, fileName);

    if (!fs.existsSync(fullPath)) {
        return null;
    }

    const fileContents = fs.readFileSync(fullPath, 'utf8');
    const { data } = matter(fileContents);

    return {
        id,
        metadata: {
            ...data,
        },
    };
}

export async function GET(
    request: NextRequest,
    { params }: { params: { id: string } }
) {
    const { searchParams } = new URL(request.url);
    const locale = (searchParams.get('locale') as 'zh-CN' | 'zh-TW' | 'en') || 'zh-CN';
    const { id } = params;

    try {
        const cacheKey = `consultation:${id}:${locale}`;
        
        const result = getCachedData(cacheKey, () => {
            const consultation = getConsultationById(id, locale);
            
            if (!consultation) {
                return null;
            }
            
            return {
                consultation,
            };
        });

        if (!result) {
            return NextResponse.json({ error: 'Consultation not found' }, { status: 404 });
        }

        // Set cache control headers
        const response = NextResponse.json(result);
        response.headers.set('Cache-Control', `public, s-maxage=${CACHE_DURATION}, stale-while-revalidate`);
        
        return response;
    } catch (error) {
        console.error('Error fetching consultation:', error);
        return NextResponse.json({ error: 'Failed to fetch consultation' }, { status: 500 });
    }
}