import { NextRequest, NextResponse } from 'next/server'
import { withAdminAuth } from '@/lib/admin-middleware'
import { connectDB } from '@/lib/mongodb'
import { User } from '@/models/user'
import { Transaction } from '@/models/transaction'
import { Billing } from '@/models/billing'
import { DeveloperRequest } from '@/models/developer-request'

export async function GET(request: NextRequest) {
  return withAdminAuth(request, async (req, admin) => {
    try {
      await connectDB()

      // Get current date for time-based queries
      const now = new Date()
      const startOfMonth = new Date(now.getFullYear(), now.getMonth(), 1)
      const startOfWeek = new Date(now.setDate(now.getDate() - now.getDay()))
      const startOfDay = new Date(now.getFullYear(), now.getMonth(), now.getDate())

      // User statistics
      const totalUsers = await User.countDocuments()
      const activeUsers = await User.countDocuments({ lastLogin: { $gte: startOfMonth } })
      const newUsersThisMonth = await User.countDocuments({ createdAt: { $gte: startOfMonth } })
      const verifiedUsers = await User.countDocuments({ isVerified: true })

      // Financial statistics
      const totalRevenue = await Billing.aggregate([
        { $group: { _id: null, total: { $sum: '$amount' } } },
      ])

      const monthlyRevenue = await Billing.aggregate([
        { $match: { created_at: { $gte: startOfMonth } } },
        { $group: { _id: null, total: { $sum: '$amount' } } },
      ])

      const weeklyRevenue = await Billing.aggregate([
        { $match: { created_at: { $gte: startOfWeek } } },
        { $group: { _id: null, total: { $sum: '$amount' } } },
      ])

      // Transaction statistics
      const totalTransactions = await Transaction.countDocuments()
      const monthlyTransactions = await Transaction.countDocuments({
        createdAt: { $gte: startOfMonth },
      })

      // Service statistics
      const totalServices = await Billing.countDocuments()
      const activeServices = await Billing.countDocuments({
        payment_status: 'paid',
        service_status: 1, // 1 = active
      })

      // Developer requests
      const totalDeveloperRequests = await DeveloperRequest.countDocuments()
      const pendingDeveloperRequests = await DeveloperRequest.countDocuments({
        status: 'pending',
      })

      // Recent activity (last 7 days)
      const recentUsers = await User.find({ createdAt: { $gte: startOfWeek } })
        .select('name email siliconId createdAt')
        .sort({ createdAt: -1 })
        .limit(10)

      const recentTransactions = await Transaction.find({ createdAt: { $gte: startOfWeek } })
        .populate('userId', 'name email siliconId')
        .sort({ createdAt: -1 })
        .limit(10)

      // Service breakdown
      const serviceBreakdown = await Billing.aggregate([
        {
          $group: {
            _id: '$service_type',
            count: { $sum: 1 },
            revenue: { $sum: '$amount' },
          },
        },
        { $sort: { count: -1 } },
      ])

      // Monthly growth data (last 6 months)
      const sixMonthsAgo = new Date()
      sixMonthsAgo.setMonth(sixMonthsAgo.getMonth() - 6)

      const monthlyGrowth = await User.aggregate([
        { $match: { createdAt: { $gte: sixMonthsAgo } } },
        {
          $group: {
            _id: {
              year: { $year: '$createdAt' },
              month: { $month: '$createdAt' },
            },
            count: { $sum: 1 },
          },
        },
        { $sort: { '_id.year': 1, '_id.month': 1 } },
      ])

      const revenueGrowth = await Billing.aggregate([
        { $match: { created_at: { $gte: sixMonthsAgo } } },
        {
          $group: {
            _id: {
              year: { $year: '$created_at' },
              month: { $month: '$created_at' },
            },
            revenue: { $sum: '$amount' },
          },
        },
        { $sort: { '_id.year': 1, '_id.month': 1 } },
      ])

      return NextResponse.json({
        users: {
          total: totalUsers,
          active: activeUsers,
          newThisMonth: newUsersThisMonth,
          verified: verifiedUsers,
          verificationRate: totalUsers > 0 ? ((verifiedUsers / totalUsers) * 100).toFixed(1) : 0,
        },
        revenue: {
          total: totalRevenue[0]?.total || 0,
          monthly: monthlyRevenue[0]?.total || 0,
          weekly: weeklyRevenue[0]?.total || 0,
        },
        transactions: {
          total: totalTransactions,
          monthly: monthlyTransactions,
        },
        services: {
          total: totalServices,
          active: activeServices,
          breakdown: serviceBreakdown,
        },
        developerRequests: {
          total: totalDeveloperRequests,
          pending: pendingDeveloperRequests,
        },
        recentActivity: {
          users: recentUsers,
          transactions: recentTransactions,
        },
        growth: {
          users: monthlyGrowth,
          revenue: revenueGrowth,
        },
      })
    } catch (error) {
      console.error('Admin dashboard error:', error)
      return NextResponse.json({ error: 'Failed to fetch dashboard data' }, { status: 500 })
    }
  })
}