import { NextRequest, NextResponse } from 'next/server';
import { getServerSession } from 'next-auth';
import { authOptions } from '@/lib/auth';
import { prisma } from '@/lib/prisma';
import { isSystemAdmin } from '@/lib/department-permission';

// GET /api/admin/users - 获取用户列表
export async function GET() {
  try {
    const session = await getServerSession(authOptions);
    if (!session || !session.user || !isSystemAdmin((session.user as any).role)) {
      return NextResponse.json({ error: '无权限' }, { status: 403 });
    }
    
    const users = await prisma.user.findMany({
      select: {
        id: true,
        email: true,
        username: true,
        realName: true, // 真实姓名（用于搜索）
        role: true,
        isActive: true, // 保留，向后兼容
        status: true, // 新增：用户状态（阶段一）
        canDownload: true,
        department: true, // 保留，向后兼容
        departmentId: true, // 新增：部门ID（阶段二）
        managedDepartment: true, // 管理员负责的部门
        createdAt: true,
        lastLoginAt: true, // 新增：最后登录时间（阶段一）
        loginCount: true, // 新增：登录次数（阶段一）
        archivedAt: true, // 新增：归档时间（阶段一）
        departmentRef: {  // 新增：部门关联信息（阶段二）
          select: {
            id: true,
            name: true,
          }
        },
        _count: {
          select: {
            materials: {
              where: {
                deletedAt: null,
              } as any,
            },
          },
        },
      },
      orderBy: {
        createdAt: 'desc',
      },
    });

    // 批量查询活跃绑定，附加权威部门路径（避免 N+1）
    // 权威人员数据：UserEmployeeBinding -> PerformanceSurveyEmployeeProfile.departmentPath
    const activeBindings = await prisma.userEmployeeBinding.findMany({
      where: { status: 'ACTIVE' },
      select: {
        userId: true,
        employeeProfile: {
          select: {
            departmentPath: true,
            departmentName: true,
            displayName: true,
            positionLevel: true,
            levelType: true,
            isLeadership: true,
            employmentState: true,
          },
        },
      },
    });
    const bindingMap = new Map(
      activeBindings
        .filter((b) => b.employeeProfile)
        .map((b) => [
          b.userId,
          {
            departmentPath: b.employeeProfile!.departmentPath,
            departmentName: b.employeeProfile!.departmentName,
            displayName: b.employeeProfile!.displayName,
            positionLevel: b.employeeProfile!.positionLevel,
            levelType: b.employeeProfile!.levelType,
            isLeadership: b.employeeProfile!.isLeadership,
            employmentState: b.employeeProfile!.employmentState,
          },
        ]),
    );

    // 附加权威部门字段到每个用户
    const enriched = users.map((u) => {
      const binding = bindingMap.get(u.id);
      return {
        ...u,
        // 权威部门路径（新组织树），如「江苏简尚品牌管理有限公司/运营中心G/运营一部（CZ）」
        employeeDeptPath: binding?.departmentPath ?? null,
        // 权威部门名（最后一段）
        employeeDeptName: binding?.departmentPath ? binding.departmentPath.split('/').pop() ?? null : null,
        employeeDisplayName: binding?.displayName ?? null,
        employeePositionLevel: binding?.positionLevel ?? null,
        employeeLevelType: binding?.levelType ?? null,
        employeeIsLeadership: binding?.isLeadership ?? false,
        employeeEmploymentState: binding?.employmentState ?? null,
        // 是否有权威绑定（无绑定 = 待人工确认）
        hasEmployeeBinding: binding != null,
      };
    });
    
    return NextResponse.json(enriched);
  } catch (error) {
    console.error('Error fetching users:', error);
    return NextResponse.json({ error: '获取用户列表失败' }, { status: 500 });
  }
}

// DELETE /api/admin/users - 归档用户（保留其素材和历史记录）
export async function DELETE(request: NextRequest) {
  try {
    const session = await getServerSession(authOptions);
    if (!session || !session.user || !isSystemAdmin((session.user as any).role)) {
      return NextResponse.json({ error: '无权限' }, { status: 403 });
    }
    
    const { searchParams } = new URL(request.url);
    const id = searchParams.get('id');
    
    if (!id) {
      return NextResponse.json({ error: '缺少用户ID' }, { status: 400 });
    }
    
    // 不能删除自己
    if (id === (session.user as any).id) {
      return NextResponse.json({ error: '不能删除自己' }, { status: 400 });
    }
    
    const existingUser = await prisma.user.findUnique({
      where: { id },
      select: { id: true, status: true },
    });

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

    await prisma.user.update({
      where: { id },
      data: {
        status: 'archived',
        isActive: false,
        archivedAt: new Date(),
        statusChangedAt: new Date(),
        statusChangedBy: (session.user as any).id,
      },
    });
    
    return NextResponse.json({ message: '用户已归档，素材和历史记录已保留' });
  } catch (error) {
    console.error('Error deleting user:', error);
    return NextResponse.json({ error: '归档失败' }, { status: 500 });
  }
}