import { NextRequest, NextResponse } from 'next/server';
import { getVisitTrends, TimeGranularity } from '@/lib/analytics';

export async function GET(request: NextRequest) {
  try {
    // 获取请求参数
    const { searchParams } = new URL(request.url);
    const linkId = searchParams.get('linkId');
    const startDate = searchParams.get('startDate') || undefined;
    const endDate = searchParams.get('endDate') || undefined;
    const granularity = searchParams.get('granularity') as TimeGranularity || TimeGranularity.DAY;
    
    // 验证必要参数
    if (!linkId) {
      return NextResponse.json(
        { error: 'Missing required parameter: linkId' },
        { status: 400 }
      );
    }
    
    // 验证粒度参数
    const validGranularities = Object.values(TimeGranularity);
    if (granularity && !validGranularities.includes(granularity)) {
      return NextResponse.json(
        { 
          error: 'Invalid granularity value',
          validValues: validGranularities
        },
        { status: 400 }
      );
    }
    
    // 获取访问趋势数据
    const trendsData = await getVisitTrends(
      linkId,
      startDate || undefined,
      endDate || undefined,
      granularity
    );
    
    // 返回数据
    return NextResponse.json(trendsData);
  } catch (error) {
    console.error('Error in trends API:', error);
    return NextResponse.json(
      { error: 'Failed to fetch trends data' },
      { status: 500 }
    );
  }
}