iobroker.valuetrackerovertime/KWInfo.js

Tracks number-changes over timepsans like hours/days/years ...

'use strict';
const DateHelper = require('./dateHelper.js');
class KWInfo {
    /**
     * Generate new KWInfo
     *
     * @param date
     */
    constructor(date) {
        // Get Date Objekt from 2021.12.24
        this.date = date;

        // In JavaScript the Sunday has value 0 as return value of getDay() function.
        // So we have to order them first ascending from Monday to Sunday
        // Monday: ((1+6) % 7) = 0
        // Tuesday ((2+6) % 7) = 1
        // Wednesday: ((3+6) % 7) = 2
        // Thursday: ((4+6) % 7) = 3
        // Friday: ((5+6) % 7) = 4
        // Saturday: ((6+6) % 7) = 5
        // Sunday: ((0+6) % 7) = 6
        // (3 - result) is necessary to get the Thursday of the current week.
        // If we want to have Tuesday it would be (1-result)
        const currentThursday = new Date(date.getTime() + (3 - ((date.getDay() + 6) % 7)) * 86400000);
        this.weekstart = new Date(currentThursday);
        this.weekstart.setDate(currentThursday.getDate() - 3);

        this.weekends = new Date(currentThursday);
        this.weekends.setDate(currentThursday.getDate() + 3);

        // At the beginnig or end of a year the thursday could be in another year.
        this.yearOfThursday = currentThursday.getFullYear();

        // Get first Thursday of the year
        const firstThursday = new Date(
            new Date(this.yearOfThursday, 0, 4).getTime() +
                (3 - ((new Date(this.yearOfThursday, 0, 4).getDay() + 6) % 7)) * 86400000,
        );

        // +1 we start with week number 1
        // +0.5 an easy and dirty way to round result (in combinationen with Math.floor)
        this.weekNumber = Math.floor(1 + 0.5 + (currentThursday.getTime() - firstThursday.getTime()) / 86400000 / 7);
        this.InfoString = `KW_${this.weekNumber} (${DateHelper.GetGermanDate(this.weekstart)} - ${DateHelper.GetGermanDate(this.weekends)})`;
        this.weekNumberString = this.weekNumber.toString().padStart(2, '0');
    }
}
module.exports = KWInfo;