DateIndicator.js

class DateIndicator {
    constructor(settings, parentWatch) {
        this.errorChecking(settings);

        if (typeof settings === 'object' && settings.split) {
            this.split = true;
            this.ones = document.getElementById(settings.split.ones);
            this.tenths = document.getElementById(settings.split.tenths);
        } else {
            this.element = document.getElementById(settings.id || settings);
        }

        this.parent = parentWatch;
        this.date = this.parent.rightNow.date();
        this.retrograde = settings.retrograde || null;
        this.max = this.retrograde ? this.retrograde.max : 180;
        this.invert = settings.invert || false;

        if (!this.parent.testing) this.init();
    }

    errorChecking(settings) {
        if (typeof settings === 'object') {
            if (!settings.id && !settings.split) throw new ReferenceError('The Date Indicator class requires that an ID of the indiciator element be provided.');
            if (settings.id && settings.split) throw new ReferenceError('Choose EITHER a primary or split indicator.');
            if (settings.retrograde && settings.split) throw new ReferenceError('Choose EITHER a retrograde or split indicator.');
            if (settings.split && (!settings.split.ones || !settings.split.tenths)) throw new ReferenceError('When choosing a split date display please provide the IDs for both the ones and tenths discs.');
        } else if (typeof settings !== 'string') {
            throw new ReferenceError('The Date Indicator class expects either a settings object or a string containing the element\'s ID.');
        }
    }

    getRotateValue(type = null) {
        let value = 0;

        this.date = this.parent.rightNow.date();

        if (this.retrograde) {
            let rotateValue = this.max / 31;
            value = (this.date - 1) * rotateValue;
        } else {
            if (this.split) {
                if (type === 'ones') {
                    let ones = this.date % 10;
                    value = ones > 1 ? (ones - 1) * 36 : 36;
                } else {
                    let tenths = Math.floor(this.date / 10);
                    value = tenths * 90;
                }
            } else {
                value = (this.date - 1) * 11.61;
            }
        }

        if (this.invert) value *= -1;

        return value;
    }

    rotateElement() {
        if (this.split) {
            this.ones.style.transform = `rotate(${this.getRotateValue('ones')}deg)`;
            this.tenths.style.transform = `rotate(${this.getRotateValue('tenths')}deg)`;
        } else {
            this.element.style.transform = `rotate(${this.getRotateValue()}deg)`;
        }
    }

    init() {
        this.rotateElement();
    }
}

module.exports = DateIndicator;