/*

This file is part of Ext JS 4

Copyright (c) 2011 Sencha Inc

Contact:  http://www.sencha.com/contact

GNU General Public License Usage
This file may be used under the terms of the GNU General Public License version 3.0 as published by the Free Software Foundation and appearing in the file LICENSE included in the packaging of this file.  Please review the following information to ensure the GNU General Public License version 3.0 requirements will be met: http://www.gnu.org/copyleft/gpl.html.

If you are unsure which license is appropriate for your use, please contact the sales department at http://www.sencha.com/contact.

*/
/**
 * @class Ext
 * @singleton
 */
(function() {
    var global = this,
        objectPrototype = Object.prototype,
        toString = objectPrototype.toString,
        enumerables = true,
        enumerablesTest = { toString: 1 },
        i;

    if (typeof Ext === 'undefined') {
        global.Ext = {};
    }

    Ext.global = global;

    for (i in enumerablesTest) {
        enumerables = null;
    }

    if (enumerables) {
        enumerables = ['hasOwnProperty', 'valueOf', 'isPrototypeOf', 'propertyIsEnumerable',
                       'toLocaleString', 'toString', 'constructor'];
    }

    /**
     * An array containing extra enumerables for old browsers
     * @property {String[]}
     */
    Ext.enumerables = enumerables;

    /**
     * Copies all the properties of config to the specified object.
     * Note that if recursive merging and cloning without referencing the original objects / arrays is needed, use
     * {@link Ext.Object#merge} instead.
     * @param {Object} object The receiver of the properties
     * @param {Object} config The source of the properties
     * @param {Object} defaults A different object that will also be applied for default values
     * @return {Object} returns obj
     */
    Ext.apply = function(object, config, defaults) {
        if (defaults) {
            Ext.apply(object, defaults);
        }

        if (object && config && typeof config === 'object') {
            var i, j, k;

            for (i in config) {
                object[i] = config[i];
            }

            if (enumerables) {
                for (j = enumerables.length; j--;) {
                    k = enumerables[j];
                    if (config.hasOwnProperty(k)) {
                        object[k] = config[k];
                    }
                }
            }
        }

        return object;
    };

    Ext.buildSettings = Ext.apply({
        baseCSSPrefix: 'x-',
        scopeResetCSS: false
    }, Ext.buildSettings || {});

    Ext.apply(Ext, {
        /**
         * A reusable empty function
         */
        emptyFn: function() {},

        baseCSSPrefix: Ext.buildSettings.baseCSSPrefix,

        /**
         * Copies all the properties of config to object if they don't already exist.
         * @param {Object} object The receiver of the properties
         * @param {Object} config The source of the properties
         * @return {Object} returns obj
         */
        applyIf: function(object, config) {
            var property;

            if (object) {
                for (property in config) {
                    if (object[property] === undefined) {
                        object[property] = config[property];
                    }
                }
            }

            return object;
        },

        /**
         * Iterates either an array or an object. This method delegates to
         * {@link Ext.Array#each Ext.Array.each} if the given value is iterable, and {@link Ext.Object#each Ext.Object.each} otherwise.
         *
         * @param {Object/Array} object The object or array to be iterated.
         * @param {Function} fn The function to be called for each iteration. See and {@link Ext.Array#each Ext.Array.each} and
         * {@link Ext.Object#each Ext.Object.each} for detailed lists of arguments passed to this function depending on the given object
         * type that is being iterated.
         * @param {Object} scope (Optional) The scope (`this` reference) in which the specified function is executed.
         * Defaults to the object being iterated itself.
         * @markdown
         */
        iterate: function(object, fn, scope) {
            if (Ext.isEmpty(object)) {
                return;
            }

            if (scope === undefined) {
                scope = object;
            }

            if (Ext.isIterable(object)) {
                Ext.Array.each.call(Ext.Array, object, fn, scope);
            }
            else {
                Ext.Object.each.call(Ext.Object, object, fn, scope);
            }
        }
    });

    Ext.apply(Ext, {

        /**
         * This method deprecated. Use {@link Ext#define Ext.define} instead.
         * @method
         * @param {Function} superclass
         * @param {Object} overrides
         * @return {Function} The subclass constructor from the <tt>overrides</tt> parameter, or a generated one if not provided.
         * @deprecated 4.0.0 Use {@link Ext#define Ext.define} instead
         */
        extend: function() {
            // inline overrides
            var objectConstructor = objectPrototype.constructor,
                inlineOverrides = function(o) {
                for (var m in o) {
                    if (!o.hasOwnProperty(m)) {
                        continue;
                    }
                    this[m] = o[m];
                }
            };

            return function(subclass, superclass, overrides) {
                // First we check if the user passed in just the superClass with overrides
                if (Ext.isObject(superclass)) {
                    overrides = superclass;
                    superclass = subclass;
                    subclass = overrides.constructor !== objectConstructor ? overrides.constructor : function() {
                        superclass.apply(this, arguments);
                    };
                }

                //<debug>
                if (!superclass) {
                    Ext.Error.raise({
                        sourceClass: 'Ext',
                        sourceMethod: 'extend',
                        msg: 'Attempting to extend from a class which has not been loaded on the page.'
                    });
                }
                //</debug>

                // We create a new temporary class
                var F = function() {},
                    subclassProto, superclassProto = superclass.prototype;

                F.prototype = superclassProto;
                subclassProto = subclass.prototype = new F();
                subclassProto.constructor = subclass;
                subclass.superclass = superclassProto;

                if (superclassProto.constructor === objectConstructor) {
                    superclassProto.constructor = superclass;
                }

                subclass.override = function(overrides) {
                    Ext.override(subclass, overrides);
                };

                subclassProto.override = inlineOverrides;
                subclassProto.proto = subclassProto;

                subclass.override(overrides);
                subclass.extend = function(o) {
                    return Ext.extend(subclass, o);
                };

                return subclass;
            };
        }(),

        /**
         * Proxy to {@link Ext.Base#override}. Please refer {@link Ext.Base#override} for further details.

    Ext.define('My.cool.Class', {
        sayHi: function() {
            alert('Hi!');
        }
    }

    Ext.override(My.cool.Class, {
        sayHi: function() {
            alert('About to say...');

            this.callOverridden();
        }
    });

    var cool = new My.cool.Class();
    cool.sayHi(); // alerts 'About to say...'
                  // alerts 'Hi!'

         * Please note that `this.callOverridden()` only works if the class was previously
         * created with {@link Ext#define)
         *
         * @param {Object} cls The class to override
         * @param {Object} overrides The list of functions to add to origClass. This should be specified as an object literal
         * containing one or more methods.
         * @method override
         * @markdown
         */
        override: function(cls, overrides) {
            if (cls.prototype.$className) {
                return cls.override(overrides);
            }
            else {
                Ext.apply(cls.prototype, overrides);
            }
        }
    });

    // A full set of static methods to do type checking
    Ext.apply(Ext, {

        /**
         * Returns the given value itself if it's not empty, as described in {@link Ext#isEmpty}; returns the default
         * value (second argument) otherwise.
         *
         * @param {Object} value The value to test
         * @param {Object} defaultValue The value to return if the original value is empty
         * @param {Boolean} allowBlank (optional) true to allow zero length strings to qualify as non-empty (defaults to false)
         * @return {Object} value, if non-empty, else defaultValue
         */
        valueFrom: function(value, defaultValue, allowBlank){
            return Ext.isEmpty(value, allowBlank) ? defaultValue : value;
        },

        /**
         * Returns the type of the given variable in string format. List of possible values are:
         *
         * - `undefined`: If the given value is `undefined`
         * - `null`: If the given value is `null`
         * - `string`: If the given value is a string
         * - `number`: If the given value is a number
         * - `boolean`: If the given value is a boolean value
         * - `date`: If the given value is a `Date` object
         * - `function`: If the given value is a function reference
         * - `object`: If the given value is an object
         * - `array`: If the given value is an array
         * - `regexp`: If the given value is a regular expression
         * - `element`: If the given value is a DOM Element
         * - `textnode`: If the given value is a DOM text node and contains something other than whitespace
         * - `whitespace`: If the given value is a DOM text node and contains only whitespace
         *
         * @param {Object} value
         * @return {String}
         * @markdown
         */
        typeOf: function(value) {
            if (value === null) {
                return 'null';
            }

            var type = typeof value;

            if (type === 'undefined' || type === 'string' || type === 'number' || type === 'boolean') {
                return type;
            }

            var typeToString = toString.call(value);

            switch(typeToString) {
                case '[object Array]':
                    return 'array';
                case '[object Date]':
                    return 'date';
                case '[object Boolean]':
                    return 'boolean';
                case '[object Number]':
                    return 'number';
                case '[object RegExp]':
                    return 'regexp';
            }

            if (type === 'function') {
                return 'function';
            }

            if (type === 'object') {
                if (value.nodeType !== undefined) {
                    if (value.nodeType === 3) {
                        return (/\S/).test(value.nodeValue) ? 'textnode' : 'whitespace';
                    }
                    else {
                        return 'element';
                    }
                }

                return 'object';
            }

            //<debug error>
            Ext.Error.raise({
                sourceClass: 'Ext',
                sourceMethod: 'typeOf',
                msg: 'Failed to determine the type of the specified value "' + value + '". This is most likely a bug.'
            });
            //</debug>
        },

        /**
         * Returns true if the passed value is empty, false otherwise. The value is deemed to be empty if it is either:
         *
         * - `null`
         * - `undefined`
         * - a zero-length array
         * - a zero-length string (Unless the `allowEmptyString` parameter is set to `true`)
         *
         * @param {Object} value The value to test
         * @param {Boolean} allowEmptyString (optional) true to allow empty strings (defaults to false)
         * @return {Boolean}
         * @markdown
         */
        isEmpty: function(value, allowEmptyString) {
            return (value === null) || (value === undefined) || (!allowEmptyString ? value === '' : false) || (Ext.isArray(value) && value.length === 0);
        },

        /**
         * Returns true if the passed value is a JavaScript Array, false otherwise.
         *
         * @param {Object} target The target to test
         * @return {Boolean}
         * @method
         */
        isArray: ('isArray' in Array) ? Array.isArray : function(value) {
            return toString.call(value) === '[object Array]';
        },

        /**
         * Returns true if the passed value is a JavaScript Date object, false otherwise.
         * @param {Object} object The object to test
         * @return {Boolean}
         */
        isDate: function(value) {
            return toString.call(value) === '[object Date]';
        },

        /**
         * Returns true if the passed value is a JavaScript Object, false otherwise.
         * @param {Object} value The value to test
         * @return {Boolean}
         * @method
         */
        isObject: (toString.call(null) === '[object Object]') ?
        function(value) {
            // check ownerDocument here as well to exclude DOM nodes
            return value !== null && value !== undefined && toString.call(value) === '[object Object]' && value.ownerDocument === undefined;
        } :
        function(value) {
            return toString.call(value) === '[object Object]';
        },

        /**
         * Returns true if the passed value is a JavaScript 'primitive', a string, number or boolean.
         * @param {Object} value The value to test
         * @return {Boolean}
         */
        isPrimitive: function(value) {
            var type = typeof value;

            return type === 'string' || type === 'number' || type === 'boolean';
        },

        /**
         * Returns true if the passed value is a JavaScript Function, false otherwise.
         * @param {Object} value The value to test
         * @return {Boolean}
         * @method
         */
        isFunction:
        // Safari 3.x and 4.x returns 'function' for typeof <NodeList>, hence we need to fall back to using
        // Object.prorotype.toString (slower)
        (typeof document !== 'undefined' && typeof document.getElementsByTagName('body') === 'function') ? function(value) {
            return toString.call(value) === '[object Function]';
        } : function(value) {
            return typeof value === 'function';
        },

        /**
         * Returns true if the passed value is a number. Returns false for non-finite numbers.
         * @param {Object} value The value to test
         * @return {Boolean}
         */
        isNumber: function(value) {
            return typeof value === 'number' && isFinite(value);
        },

        /**
         * Validates that a value is numeric.
         * @param {Object} value Examples: 1, '1', '2.34'
         * @return {Boolean} True if numeric, false otherwise
         */
        isNumeric: function(value) {
            return !isNaN(parseFloat(value)) && isFinite(value);
        },

        /**
         * Returns true if the passed value is a string.
         * @param {Object} value The value to test
         * @return {Boolean}
         */
        isString: function(value) {
            return typeof value === 'string';
        },

        /**
         * Returns true if the passed value is a boolean.
         *
         * @param {Object} value The value to test
         * @return {Boolean}
         */
        isBoolean: function(value) {
            return typeof value === 'boolean';
        },

        /**
         * Returns true if the passed value is an HTMLElement
         * @param {Object} value The value to test
         * @return {Boolean}
         */
        isElement: function(value) {
            return value ? value.nodeType === 1 : false;
        },

        /**
         * Returns true if the passed value is a TextNode
         * @param {Object} value The value to test
         * @return {Boolean}
         */
        isTextNode: function(value) {
            return value ? value.nodeName === "#text" : false;
        },

        /**
         * Returns true if the passed value is defined.
         * @param {Object} value The value to test
         * @return {Boolean}
         */
        isDefined: function(value) {
            return typeof value !== 'undefined';
        },

        /**
         * Returns true if the passed value is iterable, false otherwise
         * @param {Object} value The value to test
         * @return {Boolean}
         */
        isIterable: function(value) {
            return (value && typeof value !== 'string') ? value.length !== undefined : false;
        }
    });

    Ext.apply(Ext, {

        /**
         * Clone almost any type of variable including array, object, DOM nodes and Date without keeping the old reference
         * @param {Object} item The variable to clone
         * @return {Object} clone
         */
        clone: function(item) {
            if (item === null || item === undefined) {
                return item;
            }

            // DOM nodes
            // TODO proxy this to Ext.Element.clone to handle automatic id attribute changing
            // recursively
            if (item.nodeType && item.cloneNode) {
                return item.cloneNode(true);
            }

            var type = toString.call(item);

            // Date
            if (type === '[object Date]') {
                return new Date(item.getTime());
            }

            var i, j, k, clone, key;

            // Array
            if (type === '[object Array]') {
                i = item.length;

                clone = [];

                while (i--) {
                    clone[i] = Ext.clone(item[i]);
                }
            }
            // Object
            else if (type === '[object Object]' && item.constructor === Object) {
                clone = {};

                for (key in item) {
                    clone[key] = Ext.clone(item[key]);
                }

                if (enumerables) {
                    for (j = enumerables.length; j--;) {
                        k = enumerables[j];
                        clone[k] = item[k];
                    }
                }
            }

            return clone || item;
        },

        /**
         * @private
         * Generate a unique reference of Ext in the global scope, useful for sandboxing
         */
        getUniqueGlobalNamespace: function() {
            var uniqueGlobalNamespace = this.uniqueGlobalNamespace;

            if (uniqueGlobalNamespace === undefined) {
                var i = 0;

                do {
                    uniqueGlobalNamespace = 'ExtBox' + (++i);
                } while (Ext.global[uniqueGlobalNamespace] !== undefined);

                Ext.global[uniqueGlobalNamespace] = Ext;
                this.uniqueGlobalNamespace = uniqueGlobalNamespace;
            }

            return uniqueGlobalNamespace;
        },

        /**
         * @private
         */
        functionFactory: function() {
            var args = Array.prototype.slice.call(arguments);

            if (args.length > 0) {
                args[args.length - 1] = 'var Ext=window.' + this.getUniqueGlobalNamespace() + ';' +
                    args[args.length - 1];
            }

            return Function.prototype.constructor.apply(Function.prototype, args);
        }
    });

    /**
     * Old alias to {@link Ext#typeOf}
     * @deprecated 4.0.0 Use {@link Ext#typeOf} instead
     * @method
     * @alias Ext#typeOf
     */
    Ext.type = Ext.typeOf;

})();

