import {Component} from '@angular/core';
import {NgbDateStruct, NgbCalendar} from '@ng-bootstrap/ng-bootstrap';

const equals = (one: NgbDateStruct, two: NgbDateStruct) =>
  one && two && two.year === one.year && two.month === one.month && two.day === one.day;

const before = (one: NgbDateStruct, two: NgbDateStruct) =>
  !one || !two ? false : one.year === two.year ? one.month === two.month ? one.day === two.day
    ? false : one.day < two.day : one.month < two.month : one.year < two.year;

const after = (one: NgbDateStruct, two: NgbDateStruct) =>
  !one || !two ? false : one.year === two.year ? one.month === two.month ? one.day === two.day
    ? false : one.day > two.day : one.month > two.month : one.year > two.year;

@Component({
  selector: 'ngbd-datepicker-range',
  templateUrl: './datepicker-range.html',
  styles: [`
    .custom-day {
      text-align: center;
      padding: 0.185rem 0.25rem;
      display: inline-block;
      height: 2rem;
      width: 2rem;
    }
    .custom-day.focused {
      background-color: #e6e6e6;
    }
    .custom-day.range, .custom-day:hover {
      background-color: rgb(2, 117, 216);
      color: white;
    }
    .custom-day.faded {
      background-color: rgba(2, 117, 216, 0.5);
    }
  `]
})
export class NgbdDatepickerRange {

  hoveredDate: NgbDateStruct;

  fromDate: NgbDateStruct;
  toDate: NgbDateStruct;

  constructor(calendar: NgbCalendar) {
    this.fromDate = calendar.getToday();
    this.toDate = calendar.getNext(calendar.getToday(), 'd', 10);
  }

  onDateSelection(date: NgbDateStruct) {
    if (!this.fromDate && !this.toDate) {
      this.fromDate = date;
    } else if (this.fromDate && !this.toDate && after(date, this.fromDate)) {
      this.toDate = date;
    } else {
      this.toDate = null;
      this.fromDate = date;
    }
  }

  isHovered = date => this.fromDate && !this.toDate && this.hoveredDate && after(date, this.fromDate) && before(date, this.hoveredDate);
  isInside = date => after(date, this.fromDate) && before(date, this.toDate);
  isFrom = date => equals(date, this.fromDate);
  isTo = date => equals(date, this.toDate);
}