import { AfterContentInit, Component, HostListener, Input, OnDestroy, OnInit, forwardRef } from '@angular/core';
import { FormBuilder, FormControl, FormGroup, NG_VALIDATORS, NG_VALUE_ACCESSOR } from '@angular/forms';
import { Trial } from '@app/domain/models/subscription.model';
import { BaseComp } from '@app/shared/base/base.component';
import { GC } from '@app/shared/global';
import { DateUtils } from '@app/shared/utils';
import { SelectItem } from 'primeng-lts/api';

const MIN_DAYS = 7;

@Component({
  selector: 'trial',
  templateUrl: './trial.component.html',
  styleUrls: ['./trial.component.css'],
  providers: [
    { provide: NG_VALUE_ACCESSOR, useExisting: forwardRef(() => TrialComponent), multi: true },
    { provide: NG_VALIDATORS, useExisting: forwardRef(() => TrialComponent), multi: true }
  ]
})
export class TrialComponent extends BaseComp implements OnDestroy, OnInit, AfterContentInit {
  @Input() trialDays: number[];
  @Input() trials: Trial;
  @Input() disable: boolean;

  DAYS = GC.DAYS;
  BYDATE = GC.BYDATE;

  dayItems: SelectItem[];
  form: FormGroup;
  toDate: Date;
  error: string;
  calMinDate: Date;
  calMaxDate: Date;
  onChange: any = () => { };
  onTouched: any = () => { };

  constructor(
    private readonly fb: FormBuilder
  ) {
    super();
    const ONE_YEAR = 1;
    this.calMinDate = new Date();
    this.calMinDate.setDate(this.calMinDate.getDate() + MIN_DAYS);
    this.calMinDate.setHours(0, 0, 0);
    this.calMaxDate = new Date();
    this.calMaxDate.setFullYear(this.calMaxDate.getFullYear() + ONE_YEAR);
  }

  get value() {
    return this.form.value;
  }

  set value(val) {
    this.writeValue(val);
    this.onChange(val);
    this.onTouched(val);
  }

  ngOnInit(): void {
    this.form = this.fb.group({
      selected: new FormControl({ value: false, disabled: this.disable }),
      type: new FormControl({ value: '', disabled: this.disable }),
      startDate: [],
      lastEndDate: [],
      lastStartDate: [],
      trialDays: new FormControl({ value: '', disabled: this.disable }),
      byDate: []
    });
    this.dayItems = this.trialDays?.map((day) => ({ label: `${day}`, value: day }));

    this.sub$.add(this.form.valueChanges.subscribe((val) => {
      this.onChange(val);
      this.onTouched(val);
    }));
  }

  ngAfterContentInit() {
    const hasExistingTrial = this.trials?.type && (this.trials.trialDays >= MIN_DAYS || this.trials.byDate);
    if (hasExistingTrial) {
      if (this.trials.type === this.BYDATE && this.trials.byDate) {
        this.toDate = new Date(this.trials.byDate);
        this.form.patchValue({ ...this.trials, selected: true });
      } else if (this.trials.type === this.DAYS && this.trials.trialDays >= MIN_DAYS) {
        this.form.patchValue({ ...this.trials, selected: true });
      } else {
        this.form.patchValue({ ...this.trials });
      }
    }
  }

  writeValue(val): void {
    if (val) {
      this.form.patchValue(val);
    }
  }

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

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

  validate() {
    this.checkAndDisplayErr();
    const isTrial = this.form.value.selected;
    const isInValid = !this.isValidTrialDays() && !this.isValidBydate();
    return isTrial ? isInValid ? { trials: { valid: false } } : null : null;
  }

  isValidTrialDays() {
    return this.form.value.type === this.DAYS && this.form.value.trialDays && !isNaN(this.form.value.trialDays) && this.form.value.trialDays >= MIN_DAYS;
  }

  isValidBydate() {
    return this.form.value.type === this.BYDATE && this.form.value.byDate;
  }

  change() {
    const noPrevTrial = !this.form.value.type;
    if (noPrevTrial) {
      this.form.patchValue({ type: this.DAYS });
    }

    const trialDays = this.form.value.trialDays;
    const notExistItem = this.dayItems?.every((item) => item.value != trialDays);
    if (this.isValidTrialDays() && notExistItem) {
      this.dayItems.push({ label: `${trialDays}`, value: Number(trialDays) });
      this.dayItems.sort((a, b) => a.value - b.value);
      this.appConf.saveTrialDays(this.dayItems?.map((item) => item.value));
    }

    this.form.updateValueAndValidity();
  }

  changeCal() {
    this.form.patchValue({
      ...this.trials,
      type: this.BYDATE,
      byDate: DateUtils.tsToDate(
        DateUtils.endUtcTS(
          DateUtils.dateToTS(this.toDate)))
    });
    this.form.updateValueAndValidity();
  }

  checkAndDisplayErr() {
    this.error = '';
    if (this.form.value.selected && this.form.value.type === this.BYDATE) {
      if (!this.toDate) {
        return this.error = `Please fill in end date MM/DD/YYYY from <the mininum ${MIN_DAYS} days ahead>`;
      }
    } else if (this.form.value.selected && this.form.value.type === this.DAYS) {
      if (!this.form.value.trialDays) {
        return this.error = 'Please fill in the number of end days';
      } else if (isNaN(this.form.value.trialDays) || this.form.value.trialDays < MIN_DAYS) {
        return this.error = `Number of days must be number greater than <the mininum ${MIN_DAYS} days ahead>.`;
      }
    }
    return this.error;
  }

  remove(item) {
    this.dayItems = this.dayItems?.filter((day) => day.label !== item.label);
    this.appConf.saveTrialDays(this.dayItems?.map((item) => item.value));
  }

  @HostListener('document:keydown.enter', ['$event']) onKeydownHandler(e: KeyboardEvent) {
    const target = <HTMLInputElement>e.target;
    if (target.name === this.BYDATE) this.changeCal();
  }

  ngOnDestroy(): void {
    super.ngOnDestroy();
  }
}