feat: add rxapIfTruthy directive

export * from './lib/confirm-click';

export * from './lib/method.directive';

export * from './lib/movable-divider.directive';

export * from './lib/if-truthy.directive';

import {

  ChangeDetectorRef,

  Directive,

  Input,

  NgModule,

  OnChanges,

  SimpleChanges,

  TemplateRef,

  ViewContainerRef

} from '@angular/core';

import { Method } from '@rxap/utilities/rxjs';

export interface IfTruthyDirectiveTemplateContext<Data> {

  $implicit: Data;

}

// TODO : mv to rxap package

@Directive({

  selector: '[rxapIfTruthy]'

})

export class IfTruthyDirective<Data, Parameters = any> implements OnChanges {

  /**

   * Asserts the correct type of the context for the template that `NgForOf` will render.

   *

   * The presence of this method is a signal to the Ivy template type-check compiler that the

   * `NgForOf` structural directive renders its template with a specific context type.

   */

  static ngTemplateContextGuard<T>(

    dir: IfTruthyDirective<T>,

    ctx: any

  ): ctx is IfTruthyDirectiveTemplateContext<T> {

    return true;

  }

  @Input('rxapIfTruthy')

  public method!: Method<Data, Parameters>;

  @Input('rxapIfTruthyParameters')

  public parameters!: Parameters;

  @Input('rxapIfTruthyTrackBy')

  public trackBy!: (data: Data) => any;

  private _last?: Data;

  constructor(

    private readonly templateRef: TemplateRef<IfTruthyDirectiveTemplateContext<Data>>,

    private readonly viewContainerRef: ViewContainerRef,

    private readonly cdr: ChangeDetectorRef

  ) {

  }

  public ngOnChanges(changes: SimpleChanges) {

    if (this.method && this.parameters) {

      this.execute();

    }

  }

  protected async execute() {

    const result = await this.method.call(this.parameters);

    if (this.hasChanged(result)) {

      this.viewContainerRef.clear();

      if (result) {

        this.viewContainerRef.createEmbeddedView(this.templateRef, { $implicit: result });

      }

    }

    this.cdr.detectChanges();

  }

  protected hasChanged(current: Data) {

    if (this._last !== undefined) {

      const currentTrackBy = this.trackBy ? this.trackBy(current) : current;

      const lastTrackBy = this.trackBy ? this.trackBy(this._last) : this._last;

      return currentTrackBy !== lastTrackBy;

    }

    return true;

  }

}

@NgModule({

  declarations: [ IfTruthyDirective ],

  exports: [ IfTruthyDirective ]

})

export class IfTruthyDirectiveModule {

}