import {
  ChangeDetectorRef,
  Directive,
  ElementRef,
  forwardRef,
  Host,
  Provider,
  Renderer2
} from '@angular/core';

import {
  AbstractControl,
  ControlValueAccessor,
  NG_VALIDATORS,
  NG_VALUE_ACCESSOR,
  ValidationErrors,
  Validator
} from '@angular/forms';

import {
  parseDate,
  formatDate,
  getLocale,
  isAfter,
  isBefore,
  isArray,
  isDateValid,
  utcAsLocal
} from 'mirra-ui/chronos';

import { pDaterangepickerDirective } from './p-daterangepicker.component';
import { BsLocaleService } from './p-locale.service';

const BS_DATERANGEPICKER_VALUE_ACCESSOR: Provider = {
  provide: NG_VALUE_ACCESSOR,
  /* tslint:disable-next-line: no-use-before-declare */
  useExisting: forwardRef(() => pDaterangepickerInputDirective),
  multi: true
};

const BS_DATERANGEPICKER_VALIDATOR: Provider = {
  provide: NG_VALIDATORS,
  /* tslint:disable-next-line: no-use-before-declare */
  useExisting: forwardRef(() => pDaterangepickerInputDirective),
  multi: true
};


@Directive({
  selector: `input[pDaterangepicker]`,
  host: {
    '(change)': 'onChange($event)',
    '(keyup.esc)': 'hide()',
    '(keydown)': 'onKeydownEvent($event)',
    '(blur)': 'onBlur()'
  },
  providers: [BS_DATERANGEPICKER_VALUE_ACCESSOR, BS_DATERANGEPICKER_VALIDATOR]
})
export class pDaterangepickerInputDirective
  implements ControlValueAccessor, Validator {
  private _onChange = Function.prototype;
  private _onTouched = Function.prototype;
  /* tslint:disable-next-line: no-unused-variable */
  private _validatorChange = Function.prototype;
  private _value: Date[];

  constructor(@Host() private _picker: pDaterangepickerDirective,
              private _localeService: BsLocaleService,
              private _renderer: Renderer2,
              private _elRef: ElementRef,
              private changeDetection: ChangeDetectorRef) {
    // update input value on datepicker value update
    this._picker.pValueChange.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);
    });
  }

  onKeydownEvent(event) {
    if (event.keyCode === 13 || event.code === 'Enter') {
      this.hide();
    }
  }

  _setInputValue(date: Date[]): void {
    let range = '';
    if (date) {
      const start: string = !date[0] ? ''
        : formatDate(date[0],
          this._picker._config.rangeInputFormat,
          this._localeService.currentLocale
        );
      const end: string = !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: Event) {
    /* tslint:disable-next-line: no-any*/
    this.writeValue((event.target as any).value);
    this._onChange(this._value);
    if (this._picker._config.returnFocusToInput) {
      this._renderer.selectRootElement(this._elRef.nativeElement).focus();
    }
    this._onTouched();
  }

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

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

    // @ts-ignore
    _value.sort((a, b) => a - b);

    const _isFirstDateValid = isDateValid(_value[0]);
    const _isSecondDateValid = isDateValid(_value[1]);

    if (!_isFirstDateValid) {
      return { pDate: { invalid: _value[0] } };
    }

    if (!_isSecondDateValid) {
      return { pDate: { invalid: _value[1] } };
    }

    if (this._picker && this._picker.minDate && isBefore(_value[0], this._picker.minDate, 'date')) {
      _value[0] = this._picker.minDate;
      errors.push({ pDate: { minDate: this._picker.minDate } });
    }

    if (this._picker && this._picker.maxDate && isAfter(_value[1], this._picker.maxDate, 'date')) {
      _value[1] = this._picker.maxDate;
      errors.push({ pDate: { maxDate: this._picker.maxDate } });
    }
    if (errors.length > 0) {
      this.writeValue(_value);

      return errors;
    }
  }

  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 => {
            if (this._picker._config.useUtc) {
              return utcAsLocal(
                parseDate(_val, this._picker._config.dateInputFormat, this._localeService.currentLocale)
              );
            }

            return parseDate(_val, this._picker._config.dateInputFormat, this._localeService.currentLocale);
          }
        )
        .map((date: Date) => (isNaN(date.valueOf()) ? null : date));
    }

    this._picker.pValue = 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');
  }

  /* tslint:disable-next-line: no-any*/
  registerOnChange(fn: () => void): void {
    this._onChange = fn;
  }

  /* tslint:disable-next-line: no-any*/
  registerOnTouched(fn: () => void): void {
    this._onTouched = fn;
  }

  onBlur() {
    this._onTouched();
  }

  hide() {
    this._picker.hide();
    this._renderer.selectRootElement(this._elRef.nativeElement).blur();

    if (this._picker._config.returnFocusToInput) {
      this._renderer.selectRootElement(this._elRef.nativeElement).focus();
    }
  }
}