import { NextResponse } from 'next/server'
import { prisma } from '@/lib/prisma'

// 获取排行榜数据
export async function GET() {
  try {
    // 1. 贡献排行榜（上传素材数量最多）
    // 优化：使用SQL聚合查询，保持与其他排行榜一致
    const contributors = await prisma.$queryRaw<Array<{
      userId: string
      username: string
      materialCount: bigint
    }>>`
      SELECT 
        u.id as "userId",
        u.username,
        COUNT(m.id)::bigint as "materialCount"
      FROM users u
      LEFT JOIN materials m ON u.id = m."userId"
      GROUP BY u.id, u.username
      ORDER BY "materialCount" DESC
      LIMIT 10
    `

    // 2. 下载排行榜（素材被下载次数最多的作者）
    // 优化：使用SQL聚合查询，避免N+1问题
    const downloadRankings = await prisma.$queryRaw<Array<{
      userId: string
      totalDownloads: bigint
      username: string
    }>>`
      SELECT 
        m."userId",
        COALESCE(SUM(m."downloadCount"), 0)::bigint as "totalDownloads",
        u.username
      FROM materials m
      INNER JOIN users u ON m."userId" = u.id
      GROUP BY m."userId", u.username
      ORDER BY "totalDownloads" DESC
      LIMIT 10
    `

    const downloadUsers = downloadRankings.map((item) => ({
      username: item.username || '未知用户',
      count: Number(item.totalDownloads),
    }))

    // 3. 点赞排行榜（素材被点赞次数最多的作者）
    // 优化：使用SQL聚合查询，避免N+1问题
    const likeRankings = await prisma.$queryRaw<Array<{
      userId: string
      totalLikes: bigint
      username: string
    }>>`
      SELECT 
        m."userId",
        COALESCE(SUM(m."likeCount"), 0)::bigint as "totalLikes",
        u.username
      FROM materials m
      INNER JOIN users u ON m."userId" = u.id
      GROUP BY m."userId", u.username
      ORDER BY "totalLikes" DESC
      LIMIT 10
    `

    const likeUsers = likeRankings.map((item) => ({
      username: item.username || '未知用户',
      count: Number(item.totalLikes),
    }))

    return NextResponse.json({
      contributors: contributors.map((user) => ({
        username: user.username || '未知用户',
        count: Number(user.materialCount),
      })),
      downloads: downloadUsers,
      likes: likeUsers,
    })
  } catch (error) {
    console.error('[Rankings] GET error:', error)
    return NextResponse.json(
      { error: '获取排行榜失败' },
      { status: 500 }
    )
  }
}