library-ts/browser/date/DateMath.ts

import { DateHelper } from "./DateHelper";

export class DateMath
{
  
  static sort( dates:Date[] )
  {
    dates.sort( DateMath.sortDate );
  }

  static sortDate( a:Date, b:Date )
  {
    return DateMath.isBefore( a, b ) ? -1 : 1;
  }

  static isNowOlderThanMS( d:Date, ms:number )
  {
    let difference = this.getDifferenceMs( DateHelper.now(), d );
    return difference > ms; 
  }

  static isBeforeNow( d:Date )
  {
    return d.getTime() < DateHelper.now().getTime();
  }  

  static isInThePast( d:Date )
  {
    return DateMath.isBeforeNow( d );
  }

  static isExpired( d:Date )
  {
    return DateMath.isInThePast( d );
  }

  static isExpiredMS( dateMS:number, durationMS:number )
  {
    let end = dateMS + durationMS;

    return end <= DateHelper.now().getTime();
  }
 
  static isBefore( a:Date, b:Date )
  {
    return a.getTime() < b.getTime();
  }

  static isBeforeOrEquals( a:Date, b:Date )
  {
    return a.getTime() <= b.getTime();
  }

  static isAfter( a:Date, b:Date )
  {
    return a.getTime() > b.getTime();
  }

  static isAfterNow( d:Date )
  {
    return d.getTime() > DateHelper.now().getTime();
  }

  static isInTheFuture( d:Date )
  {
    return DateMath.isAfterNow( d );
  }

  static getDifferenceMs( a:Date, b:Date )
  {
    return a.getTime() - b.getTime();
  }

  static isAfterOrEquals( a:Date, b:Date )
  {
    return a.getTime() >= b.getTime();
  }

  static addMilliseconds( a:Date, durationMS:number )
  {
    let dateMS = a.getTime();
    let milliseconds = dateMS + durationMS;  

    return new Date( milliseconds );
  }

  static fromNowAddDays( days:number )
  {
    return DateMath.addDays( new Date(), days );
  }

  static fromNowAddHours( hours:number )
  {
    return DateMath.addHours( new Date(), hours );
  }

  static fromNowAddMinutes( minutes:number )
  {
    return DateMath.addMinutes( new Date(), minutes );
  }

  static addSeconds( a:Date, duration:number )
  {
    return this.addMilliseconds( a, duration * 1000 );
  }

  static addMinutes( a:Date, durationMinutes:number )
  {
    return this.addSeconds( a, durationMinutes * 60 );
  }

  static addHours( a:Date, durationHours:number )
  {
    return this.addMinutes( a, durationHours * 60 );
  }

  static addDays( a:Date, durationDays:number )
  {
    return this.addHours( a, durationDays * 24 );
  }

  static nextMonth( date:Date )
  {
    date = new Date( date );

    if ( date.getMonth() == 11 )
    {
      date.setFullYear( date.getFullYear() + 1, 0 );
    }
    else
    {
      date.setMonth( date.getMonth() + 1 );
    }

    return date;    
  }

  static isOnSameDay( a:Date, b:Date )
  {
    if ( a.getFullYear() !== b.getFullYear() )
    {
      return false;
    }

    if ( a.getMonth() !== b.getMonth() )
    {
      return false;
    }

    return a.getDate() === b.getDate();
  }


}