import { NextRequest, NextResponse } from 'next/server'
import { getServerSession } from 'next-auth'
import { authOptions } from '@/lib/auth'
import { prisma } from '@/lib/prisma'
import { buildDepartmentDescendants, isDepartmentWithinScope } from '@/lib/departments'

// 激活/禁用用户
export async function POST(req: NextRequest) {
  try {
    const session = await getServerSession(authOptions)

    if (!session || (session.user as any).role !== 'ADMIN') {
      return NextResponse.json(
        { error: '无权限' },
        { status: 403 }
      )
    }

    const { userId, isActive } = await req.json()

    if (!userId || typeof isActive !== 'boolean') {
      return NextResponse.json(
        { error: '参数错误' },
        { status: 400 }
      )
    }

    // 获取当前登录用户信息
    const currentUser = await prisma.user.findUnique({
      where: { id: (session.user as any).id },
      select: { id: true, managedDepartment: true }
    }) as any

    if (!currentUser) {
      return NextResponse.json(
        { error: '当前用户不存在' },
        { status: 404 }
      )
    }

    // 获取当前用户的完整信息（包括 isSuperAdmin）
    const currentUserFull = await prisma.user.findUnique({
      where: { id: (session.user as any).id },
    }) as any

    let departmentDescendantsMap: Map<string, Set<string>> | undefined
    if (currentUser.managedDepartment && !currentUserFull?.isSuperAdmin) {
      const departments = await prisma.department.findMany({ select: { name: true } })
      departmentDescendantsMap = buildDepartmentDescendants(departments)
    }

    // 获取目标用户信息
    const targetUser = await prisma.user.findUnique({
      where: { id: userId },
      select: { id: true, department: true }
    })

    if (!targetUser) {
      return NextResponse.json(
        { error: '用户不存在' },
        { status: 404 }
      )
    }

    // 获取目标用户的完整信息（包括 isSuperAdmin）
    const targetUserFull = await prisma.user.findUnique({
      where: { id: userId },
    }) as any

    // 不能禁用自己
    if (userId === (session.user as any).id) {
      return NextResponse.json(
        { error: '不能禁用自己' },
        { status: 400 }
      )
    }

    // 权限检查：只有最高权限账号或目标用户所属部门的管理员可以操作
    if (!currentUserFull?.isSuperAdmin) {
      // 如果是部门管理员，只能操作自己管理的部门下的用户
      if (currentUser.managedDepartment) {
        const allowed = isDepartmentWithinScope(
          currentUser.managedDepartment,
          targetUser.department,
          departmentDescendantsMap
        )
        if (!allowed) {
          return NextResponse.json(
            { error: '权限不足：只能操作自己管理的部门树范围内的用户' },
            { status: 403 }
          )
        }
      } else {
        // 没有管理部门的管理员不能操作任何人
        return NextResponse.json(
          { error: '权限不足' },
          { status: 403 }
        )
      }
    }

    // 最高权限账号不能被非最高权限账号操作
    if (targetUserFull?.isSuperAdmin && !currentUserFull?.isSuperAdmin) {
      return NextResponse.json(
        { error: '权限不足：不能操作最高权限账号' },
        { status: 403 }
      )
    }

    // 更新用户激活状态
    await prisma.user.update({
      where: { id: userId },
      data: { isActive },
    })

    return NextResponse.json({
      message: isActive ? '用户已激活' : '用户已禁用',
    })
  } catch (error) {
    console.error('Toggle active error:', error)
    return NextResponse.json(
      { error: '操作失败' },
      { status: 500 }
    )
  }
}