/*
 * blueimp helper JS 1.2.0
 * https://github.com/blueimp/Gallery
 *
 * Copyright 2013, Sebastian Tschan
 * https://blueimp.net
 *
 * Licensed under the MIT license:
 * http://www.opensource.org/licenses/MIT
 */

/* global define, window, document */

(function () {
    'use strict';

    function extend(obj1, obj2) {
        var prop;
        for (prop in obj2) {
            if (obj2.hasOwnProperty(prop)) {
                obj1[prop] = obj2[prop];
            }
        }
        return obj1;
    }

    function Helper(query) {
        if (!this || this.find !== Helper.prototype.find) {
            // Called as function instead of as constructor,
            // so we simply return a new instance:
            return new Helper(query);
        }
        this.length = 0;
        if (query) {
            if (typeof query === 'string') {
                query = this.find(query);
            }
            if (query.nodeType || query === query.window) {
                // Single HTML element
                this.length = 1;
                this[0] = query;
            } else {
                // HTML element collection
                var i = query.length;
                this.length = i;
                while (i) {
                    i -= 1;
                    this[i] = query[i];
                }
            }
        }
    }

    Helper.extend = extend;

    Helper.contains = function (container, element) {
        do {
            element = element.parentNode;
            if (element === container) {
                return true;
            }
        } while (element);
        return false;
    };

    Helper.parseJSON = function (string) {
        return window.JSON && JSON.parse(string);
    };

    extend(Helper.prototype, {

        find: function (query) {
            var container = this[0] || document;
            if (typeof query === 'string') {
                if (container.querySelectorAll) {
                    query = container.querySelectorAll(query);
                } else if (query.charAt(0) === '#') {
                    query = container.getElementById(query.slice(1));
                } else {
                    query = container.getElementsByTagName(query);
                }
            }
            return new Helper(query);
        },

        hasClass: function (className) {
            if (!this[0]) {
                return false;
            }
            return new RegExp('(^|\\s+)' + className +
                '(\\s+|$)').test(this[0].className);
        },

        addClass: function (className) {
            var i = this.length,
                element;
            while (i) {
                i -= 1;
                element = this[i];
                if (!element.className) {
                    element.className = className;
                    return this;
                }
                if (this.hasClass(className)) {
                    return this;
                }
                element.className += ' ' + className;
            }
            return this;
        },

        removeClass: function (className) {
            var regexp = new RegExp('(^|\\s+)' + className + '(\\s+|$)'),
                i = this.length,
                element;
            while (i) {
                i -= 1;
                element = this[i];
                element.className = element.className.replace(regexp, ' ');
            }
            return this;
        },

        on: function (eventName, handler) {
            var eventNames = eventName.split(/\s+/),
                i,
                element;
            while (eventNames.length) {
                eventName = eventNames.shift();
                i = this.length;
                while (i) {
                    i -= 1;
                    element = this[i];
                    if (element.addEventListener) {
                        element.addEventListener(eventName, handler, false);
                    } else if (element.attachEvent) {
                        element.attachEvent('on' + eventName, handler);
                    }
                }
            }
            return this;
        },

        off: function (eventName, handler) {
            var eventNames = eventName.split(/\s+/),
                i,
                element;
            while (eventNames.length) {
                eventName = eventNames.shift();
                i = this.length;
                while (i) {
                    i -= 1;
                    element = this[i];
                    if (element.removeEventListener) {
                        element.removeEventListener(eventName, handler, false);
                    } else if (element.detachEvent) {
                        element.detachEvent('on' + eventName, handler);
                    }
                }
            }
            return this;
        },

        empty: function () {
            var i = this.length,
                element;
            while (i) {
                i -= 1;
                element = this[i];
                while (element.hasChildNodes()) {
                    element.removeChild(element.lastChild);
                }
            }
            return this;
        },

        first: function () {
            return new Helper(this[0]);
        }

    });

    if (typeof define === 'function' && define.amd) {
        define(function () {
            return Helper;
        });
    } else {
        window.blueimp = window.blueimp || {};
        window.blueimp.helper = Helper;
    }
}());