import { DfBaseComponent } from '@allianz/taly-core/dynamic-form';
import {
  ChangeDetectionStrategy,
  ChangeDetectorRef,
  Component,
  DoCheck,
  input,
  OnInit,
  inject
} from '@angular/core';
import { FormGroupDirective, NgForm, UntypedFormControl } from '@angular/forms';
import { ErrorStateMatcher } from '@allianz/ng-aquila/utils';
import { DfSwitcherConfig, SwitcherLabelPosition, SwitcherSize } from './switcher.model';

@Component({
  selector: 'df-switcher',
  styleUrls: ['./switcher.component.scss'],
  templateUrl: './switcher.component.html',
  standalone: false,
  changeDetection: ChangeDetectionStrategy.OnPush
})
export class DfSwitcherComponent
  extends DfBaseComponent<DfSwitcherConfig>
  implements OnInit, DoCheck
{
  private readonly _parentForm = inject(NgForm, { optional: true });
  private readonly _parentFormGroup = inject(FormGroupDirective, { optional: true });
  private readonly errorStateMatcher = inject(ErrorStateMatcher);
  private readonly cdr = inject(ChangeDetectorRef);

  override control = input<UntypedFormControl>(new UntypedFormControl());
  SwitcherLabelPosition = SwitcherLabelPosition;
  SwitcherSize = SwitcherSize;

  protected errorState = false;

  override ngOnInit() {
    super.ngOnInit();
    this.emitFormControlEventOnValueChanges();
  }

  ngDoCheck(): void {
    if (this.control()) {
      // We follow the Aquila approach with the ErrorStateMatcher here:
      // We need to re-evaluate this on every change detection cycle, because there are some
      // error triggers that we can't subscribe to (e.g. parent form submissions). This means
      // that whatever logic is in here has to be super lean or we risk destroying the performance.
      const newErrorState = this.errorStateMatcher.isErrorState(
        this.control(),
        this._parentFormGroup || this._parentForm
      );

      if (this.errorState !== newErrorState) {
        this.errorState = newErrorState;
        this.cdr.markForCheck();
      }
    }
  }
}