import {
  Component,
  EventEmitter,
  Input,
  Output,
  ViewChild,
  computed,
  effect,
  signal,
} from '@angular/core';

import { CommonModule } from '@angular/common';
import { FormControl } from '@angular/forms';

import dayjs from 'dayjs';
import jalaliday from 'jalaliday';

import { InputText } from 'primeng/inputtext';
import { Popover } from 'primeng/popover';

import { Maybe } from '@/core';
import { formatJalali } from '@/utils';

import { UikitFieldComponent } from '../uikit-field.component';

import {
  MonthInfo,
  MonthlyWeekDate,
  daysName,
  prepareMonthInfo,
  prepareWeekDayDates,
} from './monthly-calendar.helper.util';

dayjs.extend(jalaliday);

@Component({
  selector: 'app-datepicker',
  standalone: true,
  templateUrl: './datepicker.component.html',
  imports: [CommonModule, Popover, InputText, UikitFieldComponent],
})
export class DatepickerComponent {
  @Input({ required: true })
  control!: FormControl<Maybe<string>>;

  @Input()
  alignment: 'vertical' | 'horizontal' = 'vertical';

  @Input()
  name = 'date';

  @Input()
  label = 'تاریخ';

  @Input()
  closeOnSelect = true;

  /**
   * Gregorian YYYY-MM-DD
   */
  @Input()
  min?: string;

  /**
   * Gregorian YYYY-MM-DD
   */
  @Input()
  max?: string;

  @Input()
  closedDays: number[] = [];

  @Output()
  valueChange = new EventEmitter<string>();

  @Output()
  clickOnDayEvent = new EventEmitter<MonthlyWeekDate>();

  @ViewChild('op')
  op!: Popover;

  readonly daysName = daysName;

  /**
   * Currently displayed month
   */
  private readonly activeDateSignal = signal(dayjs().format('YYYY-MM-DD'));

  monthInfo = computed<MonthInfo>(() => prepareMonthInfo(this.activeDateSignal()));

  weekDaysDates = computed(() => prepareWeekDayDates(this.monthInfo(), this.min, this.max));

  constructor() {
    effect(() => {
      const value = this.value;

      if (value) {
        this.activeDateSignal.set(value);
      }
    });
  }

  ngOnInit(): void {
    if (this.control?.value) {
      this.activeDateSignal.set(this.control.value);
    }

    this.control.valueChanges.subscribe((value) => {
      if (value) {
        this.activeDateSignal.set(value);
      }
    });
  }

  get value(): Maybe<string> {
    return this.control?.value ?? null;
  }

  get valueToShow(): Maybe<string> {
    if (!this.value) {
      return null;
    }

    return formatJalali(this.value);
  }

  get activeDate(): string {
    return this.activeDateSignal();
  }

  set activeDate(date: string) {
    this.activeDateSignal.set(date);
  }

  changeMonth(months: number): void {
    this.activeDateSignal.set(
      dayjs(this.activeDateSignal()).add(months, 'month').format('YYYY-MM-DD')
    );
  }

  selectDate(day: MonthlyWeekDate): void {
    if (day.isDisabled) {
      return;
    }

    this.control.setValue(day.gregorianDate);

    this.control.markAsDirty();
    this.control.markAsTouched();

    this.valueChange.emit(day.gregorianDate);
    this.clickOnDayEvent.emit(day);

    if (this.closeOnSelect) {
      this.op.hide();
    }
  }

  isSelected(day: MonthlyWeekDate): boolean {
    return this.value === day.gregorianDate;
  }

  trackByIndex(index: number): number {
    return index;
  }
}