import {ECalendarValue} from '../common/types/calendar-value-enum';
import {
  Component,
  EventEmitter,
  forwardRef,
  HostBinding,
  Input,
  OnChanges,
  OnInit,
  Output,
  SimpleChanges,
  ViewEncapsulation
} from '@angular/core';
import {IMonth} from './month.model';
import {MonthCalendarService} from './month-calendar.service';
import {Moment} from 'moment';
import {IMonthCalendarConfig} from './month-calendar-config';
import {
  ControlValueAccessor,
  FormControl,
  NG_VALIDATORS,
  NG_VALUE_ACCESSOR,
  ValidationErrors,
  Validator
} from '@angular/forms';
import {CalendarValue} from '../common/types/calendar-value';
import {UtilsService} from '../common/services/utils/utils.service';

@Component({
  selector: 'dp-month-calendar',
  template: '<div class="dp-month-calendar-container">   <dp-calendar-nav       [label]="getNavLabel()"       [showLeftNav]="shouldShowLeftNav()"       [showLeftSecondaryNav]="shouldShowLeftSecondaryNav()"       [showRightNav]="shouldShowRightNav()"       [showRightSecondaryNav]="shouldShowRightSecondaryNav()"       [isLabelClickable]="isNavHeaderBtnClickable()"       [theme]="theme"       (onLeftNav)="onLeftNav()"       (onLeftSecondaryNav)="onLeftSecondaryNav()"       (onRightNav)="onRightNav()"       (onRightSecondaryNav)="onRightSecondaryNav()"       (onLabelClick)="toggleCalendar()">   </dp-calendar-nav>    <div class="dp-calendar-wrapper">     <div class="dp-months-row" *ngFor="let monthRow of yearMonths">       <button type="button"               class="dp-calendar-month"               *ngFor="let month of monthRow"               [disabled]="isDisabledMonth(month)"               [ngClass]="getMonthBtnCssClass(month)"               (click)="monthClicked(month)">         {{getMonthBtnText(month)}}       </button>     </div>   </div> </div> ',
  styles: ['dp-month-calendar {  display: inline-block;}dp-month-calendar .dp-month-calendar-container {  background: #FFFFFF;}dp-month-calendar .dp-calendar-wrapper {  border: 1px solid #000000;}dp-month-calendar .dp-calendar-month {  box-sizing: border-box;  width: 52.5px;  height: 52.5px;  cursor: pointer;}dp-month-calendar .dp-calendar-month.dp-selected {  background: #106CC8;  color: #FFFFFF;}dp-month-calendar.dp-material .dp-calendar-weekday {  height: 25px;  width: 30px;  line-height: 25px;  background: #E0E0E0;  border: 1px solid #E0E0E0;}dp-month-calendar.dp-material .dp-calendar-wrapper {  border: 1px solid #E0E0E0;}dp-month-calendar.dp-material .dp-calendar-month {  box-sizing: border-box;  background: #FFFFFF;  border-radius: 50%;  border: none;  outline: none;}dp-month-calendar.dp-material .dp-calendar-month:hover {  background: #E0E0E0;}dp-month-calendar.dp-material .dp-selected {  background: #106CC8;  color: #FFFFFF;}dp-month-calendar.dp-material .dp-selected:hover {  background: #106CC8;}dp-month-calendar.dp-material .dp-current-month {  border: 1px solid #106CC8;}'],
  encapsulation: ViewEncapsulation.None,
  providers: [
    MonthCalendarService,
    {
      provide: NG_VALUE_ACCESSOR,
      useExisting: forwardRef(() => MonthCalendarComponent),
      multi: true
    },
    {
      provide: NG_VALIDATORS,
      useExisting: forwardRef(() => MonthCalendarComponent),
      multi: true
    }
  ]
})
export class MonthCalendarComponent implements OnInit, OnChanges, ControlValueAccessor, Validator {
  @Input() config: IMonthCalendarConfig;
  @Input() displayDate: Moment;
  @Input() minDate: Moment;
  @Input() maxDate: Moment;
  @HostBinding('class') @Input() theme: string;
  @Output() onSelect: EventEmitter<IMonth> = new EventEmitter();
  @Output() onNavHeaderBtnClick: EventEmitter<null> = new EventEmitter();

  isInited: boolean = false;
  componentConfig: IMonthCalendarConfig;
  _selected: Moment[];
  yearMonths: IMonth[][];
  currentDateView: Moment;
  inputValue: CalendarValue;
  inputValueType: ECalendarValue;
  validateFn: (inputVal: CalendarValue) => {[key: string]: any};

  set selected(selected: Moment[]) {
    this._selected = selected;
    this.onChangeCallback(this.processOnChangeCallback(selected));
  }

  get selected(): Moment[] {
    return this._selected;
  }

  constructor(public monthCalendarService: MonthCalendarService,
              public utilsService: UtilsService) {
  }

  ngOnInit() {
    this.isInited = true;
    this.init();
    this.initValidators();
  }

  ngOnChanges(changes: SimpleChanges) {
    if (this.isInited) {
      const {minDate, maxDate} = changes;
      this.init();

      if (minDate || maxDate) {
        this.initValidators();
      }
    }
  }

  init() {
    this.componentConfig = this.monthCalendarService.getConfig(this.config);
    this.selected = this.selected || [];
    this.currentDateView = this.displayDate
      ? this.displayDate
      : this.utilsService
        .getDefaultDisplayDate(this.currentDateView, this.selected, this.componentConfig.allowMultiSelect);
    this.yearMonths = this.monthCalendarService.generateYear(this.currentDateView, this.selected);
    this.inputValueType = this.utilsService.getInputType(this.inputValue, this.componentConfig.allowMultiSelect);
  }

  writeValue(value: CalendarValue): void {
    this.inputValue = value;

    if (value) {
      this.selected = this.utilsService
        .convertToMomentArray(value, this.componentConfig.format, this.componentConfig.allowMultiSelect);
      this.yearMonths = this.monthCalendarService.generateYear(this.currentDateView, this.selected);
      this.inputValueType = this.utilsService.getInputType(this.inputValue, this.componentConfig.allowMultiSelect);
    }
  }

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

  onChangeCallback(_: any) {
  };

  registerOnTouched(fn: any): void {
  }

  validate(formControl: FormControl): ValidationErrors | any {
    if (this.minDate || this.maxDate) {
      return this.validateFn(formControl.value);
    } else {
      return () => null;
    }
  }

  processOnChangeCallback(value: Moment[]): CalendarValue {
    return this.utilsService.convertFromMomentArray(this.componentConfig.format, value, this.inputValueType);
  }

  initValidators() {
    this.validateFn = this.validateFn = this.utilsService.createValidator(
      {minDate: this.minDate, maxDate: this.maxDate}, this.componentConfig.format, 'month');

    this.onChangeCallback(this.processOnChangeCallback(this.selected));
  }

  isDisabledMonth(month: IMonth): boolean {
    return this.monthCalendarService.isMonthDisabled(month, this.componentConfig);
  }

  monthClicked(month: IMonth) {
    this.selected = this.utilsService
      .updateSelected(this.componentConfig.allowMultiSelect, this.selected, month, 'month');
    this.yearMonths = this.monthCalendarService
      .generateYear(this.currentDateView, this.selected);
    this.onSelect.emit(month);
  }

  getNavLabel(): string {
    return this.monthCalendarService.getHeaderLabel(this.componentConfig, this.currentDateView);
  }

  onLeftNav() {
    this.currentDateView = this.currentDateView.subtract(1, 'year');
    this.yearMonths = this.monthCalendarService.generateYear(this.currentDateView, this.selected);
  }

  onLeftSecondaryNav() {
    let navigateBy = this.componentConfig.multipleYearsNavigateBy;
    const isOutsideRange = this.componentConfig.min &&
      this.currentDateView.year() - this.componentConfig.min.year() < navigateBy;
    if (isOutsideRange) {
      navigateBy = this.currentDateView.year() - this.componentConfig.min.year();
    }
    this.currentDateView = this.currentDateView.subtract(navigateBy, 'year');
    this.yearMonths = this.monthCalendarService.generateYear(this.currentDateView, this.selected);
  }

  onRightNav() {
    this.currentDateView.add(1, 'year');
    this.yearMonths = this.monthCalendarService.generateYear(this.currentDateView, this.selected);
  }

  onRightSecondaryNav() {
    let navigateBy = this.componentConfig.multipleYearsNavigateBy;
    const isOutsideRange = this.componentConfig.max &&
      this.componentConfig.max.year() - this.currentDateView.year() < navigateBy;
    if (isOutsideRange) {
      navigateBy = this.componentConfig.max.year() - this.currentDateView.year();
    }
    this.currentDateView.add(navigateBy, 'year');
    this.yearMonths = this.monthCalendarService.generateYear(this.currentDateView, this.selected);
  }

  shouldShowLeftNav(): boolean {
    return this.monthCalendarService.shouldShowLeft(this.componentConfig.min, this.currentDateView);
  }

  shouldShowLeftSecondaryNav(): boolean {
    return this.componentConfig.showMultipleYearsNavigation && this.shouldShowLeftNav();
  }

  shouldShowRightNav(): boolean {
    return this.monthCalendarService.shouldShowRight(this.componentConfig.max, this.currentDateView);
  }

  shouldShowRightSecondaryNav(): boolean {
    return this.componentConfig.showMultipleYearsNavigation && this.shouldShowRightNav();
  }

  isNavHeaderBtnClickable(): boolean {
    return this.componentConfig.isNavHeaderBtnClickable;
  }

  toggleCalendar() {
    this.onNavHeaderBtnClick.emit();
  }

  getMonthBtnText(month: IMonth): string {
    return this.monthCalendarService.getMonthBtnText(this.componentConfig, month.date);
  }

  getMonthBtnCssClass(month: IMonth): {[klass: string]: boolean} {
    const cssClass: {[klass: string]: boolean} = {
      'dp-selected': month.selected,
      'dp-current-month': month.currentMonth
    };
    const customCssClass: string = this.monthCalendarService.getMonthBtnCssClass(this.componentConfig, month.date);
    if (customCssClass) {
      cssClass[customCssClass] = true;
    }

    return cssClass;
  }
}