import {
  Directive,
  ElementRef,
  HostListener,
  Inject,
  Input,
  OnDestroy,
  OnInit,
  Optional,
} from '@angular/core';
import {
  ControlValueAccessor,
  NG_VALUE_ACCESSOR,
} from '@angular/forms';

import Cleave from 'cleave.js';

@Directive({
  selector: 'ion-input[cleave],textarea[cleave],input[cleave]',
})
export class IonCleaveDirective implements OnInit, OnDestroy {

  @Input() set cleave (cleave: any) {

    this._cleave = cleave;

    this.setCleave();

  }

  private _cleave: any;
  private _cleaveInstance: Cleave;
  private _value: string;
  private _valueAccessor: ControlValueAccessor;
  private _writeValue: (value) => void;

  constructor (
    private elementRef: ElementRef,
    @Inject(NG_VALUE_ACCESSOR) @Optional() private valueAccessors: ControlValueAccessor[],
  ) {
  }

  ngOnInit () {

    if (!this.valueAccessors) {

      console.warn('Note: The cleave directive should be used with the ngModel, formControl or formControlName directives.');

      return;

    }

    if (this.valueAccessors.length) {

      this._valueAccessor = this.valueAccessors[0];

      this._writeValue = this._valueAccessor.writeValue;
      this._valueAccessor.writeValue = (value) => {

        if (this._writeValue) {
          this._writeValue.call(this._valueAccessor, value);
        }

        this.setCleave();

      };

    }

  }

  ngOnDestroy () {

    if (this._valueAccessor && this._writeValue) {

      this._valueAccessor.writeValue = this._writeValue;

    }

    if (this._cleaveInstance) {

      this._cleaveInstance.destroy();

    }

  }

  @HostListener('input', ['$event.target.value'])
  onInput (value: string): void {

    this._value = value;

  }

  private setCleave () {

    if (this._cleaveInstance) {

      this._cleaveInstance.destroy();

    }

    const el = this.elementRef.nativeElement;
    this._cleaveInstance = new Cleave(el, {
      ...this._cleave,
      onValueChanged: ({ target }) => {
        if (target.value !== this._value) {

          this.dispatchEvent(el, 'input');

        }
      },
    });

    // hack for model -> view cleave
    setTimeout(() => this.dispatchEvent(el, 'input'), 0);

  }

  private dispatchEvent (el, eventType) {

    const event = document.createEvent('Event');
    event.initEvent(eventType, false, false);
    el.dispatchEvent(event);

  }

}