import { Component, EventEmitter, OnInit, Output } from '@angular/core';
import { FormControl } from '@angular/forms';
import { DateUtils } from '../utils';

export interface DateRangeSelection {
  startDate: Date;
  endDate: Date;
}

@Component({
  selector: 'agm-date-range-control',
  templateUrl: './date-range-control.component.html',
  styleUrls: ['./date-range-control.component.scss']
})
export class DateRangeControlComponent implements OnInit {
  @Output() rangeChange = new EventEmitter<DateRangeSelection>();

  readonly maxRangeDays = 90;
  readonly maxDate = DateUtils.startOfDay(new Date());
  readonly minDate = DateUtils.addDays(this.maxDate, -(this.maxRangeDays - 1));

  readonly dateRangeControl = new FormControl([]);

  ngOnInit(): void {
    const defaultRange = this.getCurrentWeekRange();
    this.dateRangeControl.setValue(defaultRange);
    this.emitIfRangeComplete(defaultRange);
  }

  onRangeSelected(range: Date[]): void {
    if (!Array.isArray(range) || range.length < 2 || !range[0] || !range[1]) {
      return;
    }

    const startDate = DateUtils.startOfDay(range[0]);
    const selectedEndDate = DateUtils.startOfDay(range[1]);
    const maxEndDate = DateUtils.addDays(startDate, this.maxRangeDays - 1);
    const endDate = selectedEndDate > maxEndDate ? maxEndDate : selectedEndDate;

    if (endDate.getTime() !== selectedEndDate.getTime()) {
      const clampedRange = [startDate, endDate];
      this.dateRangeControl.setValue(clampedRange, { emitEvent: false });
      this.emitIfRangeComplete(clampedRange);
      return;
    }

    this.emitIfRangeComplete([startDate, endDate]);
  }

  private emitIfRangeComplete(range: Date[]): void {
    if (!Array.isArray(range) || range.length < 2 || !range[0] || !range[1]) {
      return;
    }

    this.rangeChange.emit({
      startDate: DateUtils.startOfDay(range[0]),
      endDate: DateUtils.startOfDay(range[1])
    });
  }

  private getCurrentWeekRange(): Date[] {
    const today = DateUtils.startOfDay(new Date());
    const day = today.getDay(); // 0=Sun, 1=Mon, ..., 6=Sat
    const daysSinceMonday = day === 0 ? 6 : day - 1;
    const monday = DateUtils.addDays(today, -daysSinceMonday);
    const sunday = DateUtils.addDays(monday, 6);
    const endDate = sunday > today ? today : sunday;
    return [monday, endDate];
  }
}