/**
 * IASCallbacks v2.3.1
 * https://infiniteajaxscroll.com
 *
 * This file is part of the Infinite AJAX Scroll package
 *
 * Copyright 2014-2018 Webcreate (Jeroen Fiege)
 */

var IASCallbacks = function (aJquery) {
    this.list = [];
    this.fireStack = [];
    this.isFiring = false;
    this.isDisabled = false;
    this.Deferred = aJquery.Deferred;

    /**
     * Calls all added callbacks
     *
     * @private
     * @param args
     */
    this.fire = function (args) {
        var context = args[0],
            deferred = args[1],
            callbackArguments = args[2];

        this.isFiring = true;

        for (var i = 0, l = this.list.length; i < l; i++) {
            if (this.list[i] != undefined) {
                if (false === this.list[i].fn.apply(context, callbackArguments)) {
                    deferred.reject();

                    break;
                }
            }
        }

        this.isFiring = false;

        deferred.resolve();

        if (this.fireStack.length) {
            this.fire(this.fireStack.shift());
        }
    };

    /**
     * Returns index of the callback in the list in a similar way as
     * the indexOf function.
     *
     * @param callback
     * @param {number} index index to start the search from
     * @returns {number}
     */
    this.inList = function (callback, index) {
        index = index || 0;

        for (var i = index, length = this.list.length; i < length; i++) {
            if (this.list[i].fn === callback || (callback.guid && this.list[i].fn.guid && callback.guid === this.list[i].fn.guid)) {
                return i;
            }
        }

        return -1;
    };

    return this;
};

IASCallbacks.prototype = {
    /**
     * Adds a callback
     *
     * @param callback
     * @returns {IASCallbacks}
     * @param priority
     */
    add: function (callback, priority) {
        var callbackObject = {fn: callback, priority: priority};

        priority = priority || 0;

        for (var i = 0, length = this.list.length; i < length; i++) {
            if (priority > this.list[i].priority) {
                this.list.splice(i, 0, callbackObject);

                return this;
            }
        }

        this.list.push(callbackObject);

        return this;
    },

    /**
     * Removes a callback
     *
     * @param callback
     * @returns {IASCallbacks}
     */
    remove: function (callback) {
        var index = 0;

        while (( index = this.inList(callback, index) ) > -1) {
            this.list.splice(index, 1);
        }

        return this;
    },

    /**
     * Checks if callback is added
     *
     * @param callback
     * @returns {*}
     */
    has: function (callback) {
        return (this.inList(callback) > -1);
    },


    /**
     * Calls callbacks with a context
     *
     * @param context
     * @param args
     * @returns {object|void}
     */
    fireWith: function (context, args) {
        var deferred = this.Deferred();

        if (this.isDisabled) {
            return deferred.reject();
        }

        args = args || [];
        args = [ context, deferred, args.slice ? args.slice() : args ];

        if (this.isFiring) {
            this.fireStack.push(args);
        } else {
            this.fire(args);
        }

        return deferred;
    },

    /**
     * Disable firing of new events
     */
    disable: function () {
        this.isDisabled = true;
    },

    /**
     * Enable firing of new events
     */
    enable: function () {
        this.isDisabled = false;
    }
};