import { NextRequest, NextResponse } from 'next/server'
import { UserService } from '@/lib/services/database-service'

const userService = new UserService()

export async function GET(request: NextRequest) {
  try {
    const { searchParams } = new URL(request.url)
    const page = parseInt(searchParams.get('page') || '1')
    const limit = parseInt(searchParams.get('limit') || '10')
    const search = searchParams.get('search') || ''
    const department = searchParams.get('department') || ''
    const role = searchParams.get('role') || ''
    const status = searchParams.get('status') || ''

    // 構建查詢條件
    let whereConditions = ['is_active = TRUE']
    let params: any[] = []

    if (search) {
      whereConditions.push('(name LIKE ? OR email LIKE ?)')
      params.push(`%${search}%`, `%${search}%`)
    }

    if (department && department !== 'all') {
      whereConditions.push('department = ?')
      params.push(department)
    }

    if (role && role !== 'all') {
      whereConditions.push('role = ?')
      params.push(role)
    }

    if (status && status !== 'all') {
      if (status === 'active') {
        whereConditions.push('last_login IS NOT NULL AND last_login >= DATE_SUB(NOW(), INTERVAL 30 DAY)')
      } else if (status === 'inactive') {
        whereConditions.push('last_login IS NULL OR last_login < DATE_SUB(NOW(), INTERVAL 30 DAY)')
      }
    }

    const whereClause = whereConditions.length > 0 ? `WHERE ${whereConditions.join(' AND ')}` : ''

    // 使用 UserService 的方法
    const { users, total } = await userService.findAll({
      search,
      department,
      role,
      status,
      page,
      limit
    })

    const stats = await userService.getUserStats()

    return NextResponse.json({
      success: true,
      data: {
        users,
        pagination: {
          page,
          limit,
          total,
          totalPages: Math.ceil(total / limit)
        },
        stats: {
          totalUsers: stats?.total_users || 0,
          activeUsers: stats?.active_users || 0,
          adminCount: stats?.admin_count || 0,
          developerCount: stats?.developer_count || 0,
          inactiveUsers: stats?.inactive_users || 0,
          newThisMonth: stats?.new_this_month || 0
        }
      }
    })

  } catch (error) {
    console.error('獲取用戶列表錯誤:', error)
    return NextResponse.json(
      { error: '獲取用戶列表時發生錯誤' },
      { status: 500 }
    )
  }
}

export async function POST(request: NextRequest) {
  try {
    const { email, role } = await request.json()

    if (!email || !role) {
      return NextResponse.json(
        { error: '請提供電子郵件和角色' },
        { status: 400 }
      )
    }

    // 檢查郵箱是否已存在
    const existingUser = await userService.findByEmail(email)
    if (existingUser) {
      return NextResponse.json(
        { error: '該電子郵件地址已被使用' },
        { status: 400 }
      )
    }

    // 生成邀請 token
    const { v4: uuidv4 } = require('uuid')
    const invitationToken = uuidv4()

    // 創建邀請記錄（這裡可以存儲到邀請表或臨時表）
    // 暫時返回邀請連結
    const baseUrl = process.env.NEXT_PUBLIC_APP_URL || 'http://localhost:3000'
    const invitationLink = `${baseUrl}/register?token=${invitationToken}&email=${encodeURIComponent(email)}&role=${encodeURIComponent(role)}`

    return NextResponse.json({
      success: true,
      message: '用戶邀請已創建',
      data: {
        invitationLink,
        token: invitationToken,
        email,
        role
      }
    })

  } catch (error) {
    console.error('創建用戶邀請錯誤:', error)
    return NextResponse.json(
      { error: '創建用戶邀請時發生錯誤' },
      { status: 500 }
    )
  }
}