import { ChangeDetectorRef, Directive, ElementRef, forwardRef, Host, Renderer2 } from '@angular/core';
import {
  AbstractControl, ControlValueAccessor, NG_VALIDATORS, NG_VALUE_ACCESSOR, ValidationErrors,
  Validator
} from '@angular/forms';
import { parseDate } from '../chronos/create/local';
import { formatDate } from '../chronos/format';
import { getLocale } from '../chronos/locale/locales';
import { isAfter, isBefore } from '../chronos/utils/date-compare';
import { isArray, isDateValid } from '../chronos/utils/type-checks';
import { BsDatepickerConfig } from './bs-datepicker.config';
import { BsDaterangepickerDirective } from './bs-daterangepicker.component';
import { BsLocaleService } from './bs-locale.service';

const BS_DATERANGEPICKER_VALUE_ACCESSOR = {
  provide: NG_VALUE_ACCESSOR,
  // tslint:disable-next-line
  useExisting: forwardRef(() => BsDaterangepickerInputDirective),
  multi: true
};


const BS_DATERANGEPICKER_VALIDATOR = {
  provide: NG_VALIDATORS,
  useExisting: forwardRef(() => BsDaterangepickerInputDirective),
  multi: true
};


@Directive({
  selector: `input[bsDaterangepicker]`,
  host: {
    '(change)': 'onChange($event)',
    '(keyup.esc)': 'hide()',
    '(blur)': 'onBlur()'
  },
  providers: [BS_DATERANGEPICKER_VALUE_ACCESSOR, BS_DATERANGEPICKER_VALIDATOR]
})
export class BsDaterangepickerInputDirective
  implements ControlValueAccessor, Validator {
  private _onChange = Function.prototype;
  private _onTouched = Function.prototype;
  private _validatorChange = Function.prototype;
  private _value: Date[];

  constructor(@Host() private _picker: BsDaterangepickerDirective,
              private _localeService: BsLocaleService,
              private _renderer: Renderer2,
              private _elRef: ElementRef,
              private changeDetection: ChangeDetectorRef) {
    // update input value on datepicker value update
    this._picker.bsValueChange.subscribe((value: Date[]) => {
      this._setInputValue(value);
      if (this._value !== value) {
        this._value = value;
        this._onChange(value);
        this._onTouched();
      }
      this.changeDetection.markForCheck();
    });

    // update input value on locale change
    this._localeService.localeChange.subscribe(() => {
      this._setInputValue(this._value);
    });
  }

  _setInputValue(date: Date[]): void {
    let range = '';
    if (date) {
      const start = !date[0] ? ''
        : formatDate(date[0],
          this._picker._config.rangeInputFormat,
          this._localeService.currentLocale
        );
      const end = !date[1] ? ''
        : formatDate(
          date[1],
          this._picker._config.rangeInputFormat,
          this._localeService.currentLocale
        );
      range = (start && end) ? start + this._picker._config.rangeSeparator + end : '';
    }
    this._renderer.setProperty(this._elRef.nativeElement, 'value', range);
  }

  onChange(event: any) {
    this.writeValue(event.target.value);
    this._onChange(this._value);
    this._onTouched();
  }

  validate(c: AbstractControl): ValidationErrors | null {
    const _value: [Date, Date] = c.value;

    if (_value === null || _value === undefined || !isArray(_value)) {
      return null;
    }


    const _isDateValid = isDateValid(_value[0]) && isDateValid(_value[0]);

    if (!_isDateValid) {
      return { bsDate: { invalid: _value } };
    }

    if (this._picker && this._picker.minDate && isBefore(_value[0], this._picker.minDate, 'date')) {
      return { bsDate: { minDate: this._picker.minDate } };
    }

    if (this._picker && this._picker.maxDate && isAfter(_value[1], this._picker.maxDate, 'date')) {
      return { bsDate: { maxDate: this._picker.maxDate } };
    }
  }

  registerOnValidatorChange(fn: () => void): void {
    this._validatorChange = fn;
  }

  writeValue(value: Date[] | string) {
    if (!value) {
      this._value = null;
    } else {
      const _localeKey = this._localeService.currentLocale;
      const _locale = getLocale(_localeKey);
      if (!_locale) {
        throw new Error(
          `Locale "${_localeKey}" is not defined, please add it with "defineLocale(...)"`
        );
      }

      let _input: (string[] | Date[]) = [];
      if (typeof value === 'string') {
        _input = value.split(this._picker._config.rangeSeparator);
      }

      if (Array.isArray(value)) {
        _input = value;
      }


      this._value = (_input as string[])
        .map((_val: string): Date =>
          parseDate(_val, this._picker._config.dateInputFormat, this._localeService.currentLocale))
        .map((date: Date) => (isNaN(date.valueOf()) ? null : date));
    }

    this._picker.bsValue = this._value;
  }

  setDisabledState(isDisabled: boolean): void {
    this._picker.isDisabled = isDisabled;
    if (isDisabled) {
      this._renderer.setAttribute(this._elRef.nativeElement, 'disabled', 'disabled');

      return;
    }
    this._renderer.removeAttribute(this._elRef.nativeElement, 'disabled');
  }

  registerOnChange(fn: (value: any) => any): void {
    this._onChange = fn;
  }

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

  onBlur() {
    this._onTouched();
  }

  hide() {
    this._picker.hide();
  }
}