import { RegionBehavior } from '../../RegionBehavior';
import { injectable, inject } from 'tsyringe';
import { IRegionViewRegistry } from '../../IRegionViewRegistry';
import { regionViewRegistryInjectionToken } from '../../injectionTokens';
import { ViewRegisteredEventArgs } from '../../events/ViewRegisteredEventArgs';

/**
 * Behavior for populate the region when a view is registered to it.
 *
 * @export
 * @class TabControlRegionSyncBehavior
 * @extends {RegionBehavior}
 * @implements {IHostAwareRegionBehavior}
 * @wType Microsoft.Practices.Prism.Regions.Behaviors.AutoPopulateRegionBehavior
 */
@injectable()
export class AutoPopulateRegionBehavior extends RegionBehavior {
  /**
   * TabControlRegionSyncBehavior key used to register the behavior in the collection
   *
   * @static
   * @type {string}
   * @memberof TabControlRegionSyncBehavior
   */
  public static readonly BehaviorKey: string = 'AutoPopulate';

  /**
   * Region view registry
   *
   * @type {IRegionViewRegistry}
   * @memberof AutoPopulateRegionBehavior
   */
  #regionViewRegistry: IRegionViewRegistry;

  /**
   *Creates an instance of AutoPopulateRegionBehavior.
   * @param {IRegionViewRegistry} registry
   * @memberof AutoPopulateRegionBehavior
   */
  constructor(
    @inject(regionViewRegistryInjectionToken) registry: IRegionViewRegistry
  ) {
    super();
    this.#regionViewRegistry = registry;
  }

  /**
   *
   * Override this method to perform the logic after the behavior has been attached.
   *
   */
  public OnAttach(): void {
    if (!!this.Region.Name) {
      this.#regionViewRegistry.ContentRegistered.addHandler((s, e) =>
        this.OnViewRegistered(s, e)
      );
    }
  }

  public OnViewRegistered(
    sender: unknown,
    eventArgs: ViewRegisteredEventArgs
  ): void {
    if (eventArgs == null) {
      throw new Error('Argument null exception in parameter eventArgs');
    }
    if (eventArgs.RegionName == this.Region.Name) {
      this.Region.Add(eventArgs.GetView());
    }
  }
}