///
/// Copyright 2015-2026 Micro Focus or one of its affiliates.
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
///      http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///

import { Injectable } from '@angular/core';
import { Subject } from 'rxjs';
import { compareDays, isDateAfter, isDateBefore } from '../date-time-picker/date-time-picker.utils';

@Injectable()
export class DateRangeService {
  /** Indicate whether we want to show a date range */
  isRange: boolean = false;

  /** Specify the direction of the selection */
  direction: DateRangePicker = DateRangePicker.Start;

  /** Specify the start of the range */
  start: Date;

  /** Specify the end of the range */
  end: Date;

  /** Specify the date we are hovering over */
  hover: Date;

  /** Emit whenever the start date changes */
  onStartChange = new Subject<Date>();

  /** Emit whenever the end date changes */
  onEndChange = new Subject<Date>();

  /** Emit whenever the range has changed */
  onRangeChange = new Subject<void>();

  /** Emit whenever the hover date changes */
  onHoverChange = new Subject<void>();

  /** Emit whenever the range is cleared */
  onClear = new Subject<void>();

  /** Indicate if we should show time */
  showTime: boolean = false;

  /** Defines the aria label for the range start picker */
  startPickerAriaLabel: string = 'Selecting the start date';

  /** Defines the aria label for the range end picker */
  endPickerAriaLabel: string = 'Selecting the end date';

  /** Indicate if we are currently changing the time */
  isChangingTime: boolean = false;

  /** Store the current start time */
  startTime: DateRangeTime = { hours: 0, minutes: 0, seconds: 0 };

  /** Store the current end time */
  endTime: DateRangeTime = { hours: 23, minutes: 59, seconds: 59 };

  setStartDate(date: Date | null): void {
    // if the start date is after the end date the clear the end date
    if (date && this.end && isDateAfter(date, this.end)) {
      this.clear();
    }

    this.start = date;
    this.onStartChange.next(this.start);
    this.onRangeChange.next();
  }

  setEndDate(date: Date | null): void {
    // if the end date is before the start date the clear the start date
    if (date && this.start && isDateBefore(date, this.start)) {
      this.clear();
    }

    this.end = date;
    this.onEndChange.next(this.end);
    this.onRangeChange.next();
  }

  clear(): void {
    this.setStartDate(null);
    this.setEndDate(null);
    this.onClear.next();
  }

  setDateMouseEnter(date: Date | null): void {
    this.hover = date;
    this.onHoverChange.next();
  }

  setDateMouseLeave(date: Date): void {
    if (date && this.hover && compareDays(date, this.hover)) {
      this.setDateMouseEnter(null);
    }
  }
}

export enum DateRangePicker {
  Start = 'start',
  End = 'end',
}

export interface DateRangeTime {
  hours: number;
  minutes: number;
  seconds: number;
}