import { ViewModel } from "../contracts/view-models/ViewModel";
import { AdminUserViewModel } from "./AdminUserViewModel";
import type { AdminUserViewData } from '@/lib/view-data/AdminUserViewData';

/**
 * UserListViewModel
 *
 * View Model for user list with pagination and filtering state.
 */
export class UserListViewModel extends ViewModel {
  users: AdminUserViewModel[];
  total: number;
  page: number;
  limit: number;
  totalPages: number;

  // UI-specific derived fields (primitive outputs only)
  readonly hasUsers: boolean;
  readonly showPagination: boolean;
  readonly startIndex: number;
  readonly endIndex: number;

  constructor(data: {
    users: AdminUserViewData[];
    total: number;
    page: number;
    limit: number;
    totalPages: number;
  }) {
    super();
    this.users = data.users.map(viewData => new AdminUserViewModel(viewData));
    this.total = data.total;
    this.page = data.page;
    this.limit = data.limit;
    this.totalPages = data.totalPages;

    // Derive UI state
    this.hasUsers = this.users.length > 0;
    this.showPagination = this.totalPages > 1;
    this.startIndex = this.users.length > 0 ? (this.page - 1) * this.limit + 1 : 0;
    this.endIndex = this.users.length > 0 ? (this.page - 1) * this.limit + this.users.length : 0;
  }
}