import { NextRequest, NextResponse } from 'next/server'
import { prisma } from '@/lib/prisma'
import { requireAdmin } from '@/lib/admin-auth'

export async function GET(request: NextRequest) {
  try {
    await requireAdmin(request)

    // 按消费金额倒排的前十用户
    const topUsersBySpending = await prisma.user.findMany({
      where: {
        isAdmin: false,
        orders: {
          some: {}
        }
      },
      select: {
        id: true,
        username: true,
        name: true,
        email: true,
        orders: {
          select: {
            totalAmount: true
          }
        }
      },
      take: 10
    })

    const usersWithSpending = topUsersBySpending.map(user => ({
      id: user.id,
      username: user.username,
      name: user.name || user.username,
      email: user.email,
      totalSpending: user.orders.reduce((sum, order) => sum + order.totalAmount, 0),
      orderCount: user.orders.length
    })).sort((a, b) => b.totalSpending - a.totalSpending)

    // 按销售量倒排序的前十配件
    const topComponentsBySales = await prisma.component.findMany({
      select: {
        id: true,
        name: true,
        brand: true,
        price: true,
        componentType: {
          select: {
            name: true
          }
        },
        orderItems: {
          select: {
            quantity: true
          }
        }
      }
    })

    const componentsWithSales = topComponentsBySales.map(component => ({
      id: component.id,
      name: component.name,
      brand: component.brand,
      price: component.price,
      typeName: component.componentType.name,
      totalSales: component.orderItems.reduce((sum, item) => sum + item.quantity, 0),
      totalRevenue: component.orderItems.reduce((sum, item) => sum + (item.quantity * component.price), 0)
    })).sort((a, b) => b.totalSales - a.totalSales).slice(0, 10)

    // 总体统计
    const totalUsers = await prisma.user.count({ where: { isAdmin: false } })
    const totalOrders = await prisma.order.count()
    const totalComponents = await prisma.component.count()
    const totalRevenue = await prisma.order.aggregate({
      _sum: {
        totalAmount: true
      }
    })

    const recentOrders = await prisma.order.findMany({
      take: 5,
      orderBy: {
        createdAt: 'desc'
      },
      include: {
        user: {
          select: {
            username: true,
            name: true
          }
        },
        orderItems: {
          include: {
            component: {
              select: {
                name: true
              }
            }
          }
        }
      }
    })

    return NextResponse.json({
      overview: {
        totalUsers,
        totalOrders,
        totalComponents,
        totalRevenue: totalRevenue._sum.totalAmount || 0
      },
      topUsers: usersWithSpending,
      topComponents: componentsWithSales,
      recentOrders
    })

  } catch (error: any) {
    console.error('获取统计数据失败:', error)
    return NextResponse.json(
      { message: error.message || '获取统计数据失败' },
      { status: error.message === '权限不足' ? 403 : 500 }
    )
  }
}