import { NextRequest, NextResponse } from 'next/server'
import { auth } from '@/lib/auth'
import { prisma } from '@/lib/prisma'
import { UserStatus, Prisma } from '@prisma/client'

/**
 * GET /api/v1/admin/customers
 * List all customers with optional filters
 */
export async function GET(request: NextRequest) {
  try {
    const session = await auth()

    if (!session || session.user.userType !== 'staff') {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
    }

    const searchParams = request.nextUrl.searchParams
    const status = searchParams.get('status') as UserStatus | null
    const search = searchParams.get('search')
    const page = parseInt(searchParams.get('page') || '1')
    const limit = parseInt(searchParams.get('limit') || '50')

    const where: Prisma.UserWhereInput = {}

    if (status) {
      where.status = status
    }

    if (search) {
      where.OR = [
        { email: { contains: search, mode: 'insensitive' } },
        { name: { contains: search, mode: 'insensitive' } },
        { company: { contains: search, mode: 'insensitive' } },
      ]
    }

    const [customers, total] = await Promise.all([
      prisma.user.findMany({
        where,
        select: {
          id: true,
          email: true,
          name: true,
          company: true,
          status: true,
          createdAt: true,
          subscriptions: {
            select: {
              id: true,
              plan: true,
              tier: true,
              status: true,
            },
            take: 1,
            orderBy: { createdAt: 'desc' },
          },
          _count: {
            select: {
              orders: true,
              subscriptions: true,
            },
          },
        },
        orderBy: { createdAt: 'desc' },
        skip: (page - 1) * limit,
        take: limit,
      }),
      prisma.user.count({ where }),
    ])

    return NextResponse.json({
      customers,
      pagination: {
        page,
        limit,
        total,
        totalPages: Math.ceil(total / limit),
      },
    })
  } catch (error) {
    console.error('Error listing customers:', error)
    return NextResponse.json(
      { error: 'Failed to list customers' },
      { status: 500 }
    )
  }
}