/* ==========================================================================
    Helper functions
 ========================================================================== */

/*
 * Simple isset method for this does not exist in javascript
 */
const isset = function(obj)
{
    return typeof obj !== 'undefined' && obj !== null;
};

/*
 * Easing Functions - inspired from http://gizma.com/easing/
 * only considering the t value for the range [0, 1] => [0, 1]
 */
const EasingFunctions = {
    // no easing, no acceleration
    linear: function (t) { return t },
    // accelerating from zero velocity
    easeInQuad: function (t) { return t*t },
    // decelerating to zero velocity
    easeOutQuad: function (t) { return t*(2-t) },
    // acceleration until halfway, then deceleration
    easeInOutQuad: function (t) { return t<.5 ? 2*t*t : -1+(4-2*t)*t },
    // accelerating from zero velocity
    easeInCubic: function (t) { return t*t*t },
    // decelerating to zero velocity
    easeOutCubic: function (t) { return (--t)*t*t+1 },
    // acceleration until halfway, then deceleration
    easeInOutCubic: function (t) { return t<.5 ? 4*t*t*t : (t-1)*(2*t-2)*(2*t-2)+1 },
    // accelerating from zero velocity
    easeInQuart: function (t) { return t*t*t*t },
    // decelerating to zero velocity
    easeOutQuart: function (t) { return 1-(--t)*t*t*t },
    // acceleration until halfway, then deceleration
    easeInOutQuart: function (t) { return t<.5 ? 8*t*t*t*t : 1-8*(--t)*t*t*t },
    // accelerating from zero velocity
    easeInQuint: function (t) { return t*t*t*t*t },
    // decelerating to zero velocity
    easeOutQuint: function (t) { return 1+(--t)*t*t*t*t },
    // acceleration until halfway, then deceleration
    easeInOutQuint: function (t) { return t<.5 ? 16*t*t*t*t*t : 1+16*(--t)*t*t*t*t }
};

/*
 * Vanilla version of the $.getScript
 */
const getScript = function (source, callback) {
    let script = document.createElement('script');
    script.async = 1;

    const scripts = document.getElementsByTagName('script');
    let prior = scripts[scripts.length - 1];

    script.onload = script.onreadystatechange = function( _, isAbort ) {
        if(isAbort || !script.readyState || /loaded|complete/.test(script.readyState) ) {
            script.onload = script.onreadystatechange = null;
            script = undefined;

            if(!isAbort) { if(callback) callback(); }
        }
    };

    script.src = source;
    prior.parentNode.insertBefore(script, prior);
};

/**
 * Returns a function, that, as long as it continues to be invoked, will not
 * be triggered. The function will be called after it stops being called for
 * N milliseconds. If `immediate` is passed, trigger the function on the
 * leading edge, instead of the trailing.
 * @param func
 * @param wait
 * @param immediate
 * @returns {Function}
 */
const debounce = function(func, wait, immediate) {
    let timeout;
    return function () {
        let context = this, args = arguments;
        let later = function () {
            timeout = null;
            if (!immediate) func.apply(context, args);
        };
        let callNow = immediate && !timeout;
        clearTimeout(timeout);
        timeout = setTimeout(later, wait);
        if (callNow) func.apply(context, args);
    };
};


const isInt = function(value) {
    var x;
    if (isNaN(value)) {
        return false;
    }
    x = parseFloat(value);
    return (x | 0) === x;
}