import { NextResponse } from "next/server"
import { getServerSession } from "next-auth"
import { authOptions } from "@/lib/auth"
import { prisma } from "@/lib/prisma"

// 检查是否为管理员
async function checkAdmin(userId: string) {
  const user = await prisma.user.findUnique({
    where: { id: userId },
    select: { isAdmin: true }
  })
  return user?.isAdmin === true
}

// 获取所有用户及其家族统计信息
export async function GET() {
  try {
    const session = await getServerSession(authOptions)
    
    if (!session?.user?.id) {
      return NextResponse.json({ error: "未授权" }, { status: 401 })
    }

    // 检查管理员权限
    const isAdmin = await checkAdmin(session.user.id)
    if (!isAdmin) {
      return NextResponse.json({ error: "无权限访问" }, { status: 403 })
    }

    // 获取所有用户及其拥有的家族树
    const users = await prisma.user.findMany({
      select: {
        id: true,
        email: true,
        name: true,
        avatar: true,
        isAdmin: true,
        isActive: true,
        createdAt: true,
        ownedTrees: {
          select: {
            id: true,
            name: true,
            createdAt: true,
            _count: {
              select: {
                members: true,
              },
            },
            // 获取该家族树的协作者
            collaborators: {
              select: {
                role: true,
                user: {
                  select: {
                    id: true,
                    name: true,
                    email: true,
                  }
                }
              }
            }
          },
        },
        // 获取用户作为协作者参与的家族树
        collaborations: {
          select: {
            role: true,
            tree: {
              select: {
                id: true,
                name: true,
                owner: {
                  select: {
                    id: true,
                    name: true,
                    email: true,
                  }
                }
              }
            }
          }
        }
      },
      orderBy: [
        { isAdmin: 'desc' },  // 管理员排在最前面
        { createdAt: 'desc' },
      ],
    })

    // 格式化数据
    const formattedUsers = users.map((user) => ({
      id: user.id,
      email: user.email,
      name: user.name,
      avatar: user.avatar,
      isAdmin: user.isAdmin,
      isActive: user.isActive,
      createdAt: user.createdAt,
      treeCount: user.ownedTrees.length,
      totalMembers: user.ownedTrees.reduce((sum: number, tree) => sum + tree._count.members, 0),
      trees: user.ownedTrees.map((tree) => ({
        id: tree.id,
        name: tree.name,
        createdAt: tree.createdAt,
        memberCount: tree._count.members,
        // 协作者列表
        collaborators: tree.collaborators.map((c) => ({
          id: c.user.id,
          name: c.user.name,
          email: c.user.email,
          role: c.role,
        })),
      })),
      // 作为协作者参与的家族
      collaboratingTrees: user.collaborations.map((c) => ({
        id: c.tree.id,
        name: c.tree.name,
        role: c.role,
        owner: {
          id: c.tree.owner.id,
          name: c.tree.owner.name,
          email: c.tree.owner.email,
        }
      })),
    }))

    // 统计总数
    const stats = {
      totalUsers: users.length,
      totalTrees: formattedUsers.reduce((sum, user) => sum + user.treeCount, 0),
      totalMembers: formattedUsers.reduce((sum, user) => sum + user.totalMembers, 0),
    }

    return NextResponse.json({ users: formattedUsers, stats })
  } catch (error) {
    console.error("获取用户列表失败:", error)
    return NextResponse.json(
      { error: "获取用户列表失败" },
      { status: 500 }
    )
  }
}