///
/// Copyright 2015-2026 Micro Focus or one of its affiliates.
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
///      http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///

import { FocusOrigin } from '@angular/cdk/a11y';
import {
  ChangeDetectionStrategy,
  ChangeDetectorRef,
  Component,
  EventEmitter,
  forwardRef,
  inject,
  Input,
  Output,
  ViewChild,
} from '@angular/core';
import { ControlValueAccessor, NG_VALUE_ACCESSOR } from '@angular/forms';
import { FocusIndicatorDirective } from '../../directives/accessibility';
import { FocusIndicatorDirective as FocusIndicatorDirective_1 } from '../../directives/accessibility/focus-indicator/focus-indicator.directive';
import { FocusableItemToken } from '../menu';
import { FocusableControl } from '../menu/interfaces/focusable-control.interface';

const TOGGLESWITCH_VALUE_ACCESSOR = {
  provide: NG_VALUE_ACCESSOR,
  useExisting: forwardRef(() => ToggleSwitchComponent),
  multi: true,
};

let uniqueToggleSwitchId = 0;

@Component({
  selector: 'ux-toggleswitch',
  templateUrl: './toggleswitch.component.html',
  providers: [
    TOGGLESWITCH_VALUE_ACCESSOR,
    {
      provide: FocusableItemToken,
      useExisting: ToggleSwitchComponent,
    },
  ],
  changeDetection: ChangeDetectionStrategy.OnPush,
  imports: [FocusIndicatorDirective_1],
})
export class ToggleSwitchComponent implements ControlValueAccessor, FocusableControl {
  private readonly _changeDetector = inject(ChangeDetectorRef);

  /** Provide a default unique id value for the toggle switch */
  _toggleSwitchId: string = `ux-toggleswitch-${++uniqueToggleSwitchId}`;

  /** Specify a unique id for the element. */
  @Input() id: string = this._toggleSwitchId;

  /** Specify a form name for the input element. */
  @Input() name: string | null;

  /** Binding for the state of the switch; `true` for "on" and `false` for "off." */
  @Input() value: boolean = false;

  /** Specify a tabindex. */
  @Input() tabindex: number = 0;

  /** If set to `false` the switch will not be updated when clicking on it, can be used if something else is updating the state of the switch. */
  @Input() clickable: boolean = true;

  /** If this value is set to `true` then the toggle switch will be disabled. */
  @Input() disabled: boolean = false;

  /** Specify an aria label for the input element */
  @Input('aria-label') ariaLabel: string = '';

  /** Specify an aria labelledby property for the input element */
  @Input('aria-labelledby') ariaLabelledby: string = null;

  /** Specified if this is a required input. */
  @Input() required: boolean;

  /** Emits when `value` has been changed. */
  @Output() valueChange: EventEmitter<boolean> = new EventEmitter<boolean>();

  /** Get the focus indicator to set focus */
  @ViewChild(FocusIndicatorDirective)
  _focusIndicator?: FocusIndicatorDirective;

  /** Determine if the underlying input component has been focused with the keyboard */
  _focused: boolean = false;

  /** Used to inform Angular forms that the component has been touched */
  // eslint-disable-next-line @typescript-eslint/no-empty-function
  onTouchedCallback: () => void = () => {};

  /** Used to inform Angular forms that the component value has changed */
  // eslint-disable-next-line @typescript-eslint/no-empty-function
  onChangeCallback: (_: unknown) => void = () => {};

  toggle(): void {
    if (!this.disabled && this.clickable) {
      this.value = !this.value;

      // emit the value
      this.valueChange.emit(this.value);

      // update the value if used within a form control
      this.onChangeCallback(this.value);

      // mark the component as touched
      this.onTouchedCallback();
    }
  }

  writeValue(value: boolean): void {
    this.value = !!value;
    this._changeDetector.markForCheck();
  }

  registerOnChange(fn: () => void): void {
    this.onChangeCallback = fn;
  }

  registerOnTouched(fn: () => void): void {
    this.onTouchedCallback = fn;
  }

  setDisabledState(isDisabled: boolean): void {
    this.disabled = isDisabled;
    this._changeDetector.markForCheck();
  }

  /** Focus the input element */
  focus(origin: FocusOrigin): void {
    this._focusIndicator.focus(origin);
  }

  setInputTabIndex(tabindex: number): void {
    this.tabindex = tabindex;
    this._changeDetector.markForCheck();
  }
}