var INHERIT = require('inherit'),
    extend = require('./tools').extend;

/**
 * @class SVG-as-JS Nodes API.
 */
exports.Nodes = INHERIT(
    /**
     * @lends Nodes.prototype
     */
    {

        /**
         * @constructs
         * @private
         */
        __constructor: function(data) {

            extend(this, data);

        },

        /**
         * Remove item.
         */
        remove: function() {

            delete this;

        },

        /**
         * Determine if item is an element
         * (any, with a specific name or in a names array).
         *
         * @param {String|Array} [param] element name or names arrays
         * @return {Boolean}
         */
        isElem: function(param) {

            if (!param) return !!this.elem;

            if (Array.isArray(param)) return !!this.elem && (param.indexOf(this.elem) > -1);

            return !!this.elem && this.elem === param;

        },

        /**
         * Determine if item is a doctype.
         *
         * @return {Boolean}
         */
        isDoctype: function() {

            return !!this.doctype;

        },

        /**
         * Determine if item is a XML Processing Instruction.
         *
         * @return {Boolean}
         */
        isProcInst: function() {

            return !!this.processinginstruction;

        },

        /**
         * Determine if item is a CDATA block.
         *
         * @return {Boolean}
         */
        isCDATA: function() {

            return !!this.cdata;

        },

        /**
         * Determine if item is a comment node.
         *
         * @return {Boolean}
         */
        isComment: function() {

            return !!this.comment;

        },

        /**
         * Determine if item is a text node.
         *
         * @return {Boolean}
         */
        isText: function() {

            return !!this.text;

        },

        /**
         * Determine if element is empty.
         *
         * @return {Boolean}
         */
        isEmpty: function() {

            return !this.content || !this.content.length;

        },

        /**
         * Iterates over all attributes.
         *
         * @param {Function} callback
         * @return {Boolean} false if the are no any attributes
         */
        eachAttr: function(callback) {

            if (!this.hasAttr()) return false;

            Object.getOwnPropertyNames(this.attrs).forEach(function(name) {
                callback(this.attrs[name]);
            }, this);

        },

        /**
         * Determine if element has an attribute
         * (any, or by name or by name + value).
         *
         * @param {String|Object} [name] attribute name or object
         * @param {String} [val] attribute value (will be toString()'ed)
         * @return {Boolean}
         */
        hasAttr: function(attr, val) {

            if (!this.attrs || !Object.keys(this.attrs).length) return false;

            if (!arguments.length) return !!this.attrs;

            if (typeof attr === 'object') {
                val = attr.value;
                attr = attr.name;
            }

            if (val !== undefined) return !!this.attrs[attr] && this.attrs[attr].value === val.toString();

            return !!this.attrs[attr];

        },

        /**
         * Get a specific attribute from an element
         * (by name or name + value).
         *
         * @param {String} [name] attribute name
         * @param {String} [val] attribute value (will be toString()'ed)
         * @return {Object}
         */
        attr: function(name, val) {

            if (!this.hasAttr() || !arguments.length) return undefined;

            if (val !== undefined) return this.hasAttr(name, val) && this.attrs[name];

            return this.hasAttr(name) && this.attrs[name];

        },

        /**
         * Remove a specific attribute.
         *
         * @param {String|Object} attr attribute name or object
         * @param {String} [val] attribute value
         * @return {Boolean}
         */
        removeAttr: function(attr, val) {

            if (!this.hasAttr(attr)) return false;

            if (!arguments.length) {
                delete this.attrs;
                return true;
            }

            if (typeof attr === 'object') {
                val = attr.value;
                attr = attr.name;
            }

            if (val && this.attrs[attr].value !== val) return false;

            delete this.attrs[attr];

            if (!Object.keys(this.attrs).length) delete this.attrs;

            return true;

        },

        /**
         * Add attribute.
         *
         * @param {Object} attr attribute object
         */
        addAttr: function(attr, val) {

            this.attrs = this.attrs || {};

            this.attrs[attr.name] = attr;

        },

        /**
         * Determine if item's content has an element(s)
         * (any or by name or by names array).
         *
         * @param {String|Array} [name] element name or names array
         * @return {Boolean}
         */
        hasElem: function(name) {

            return this.content.some(function(item) {
                return name ? item.isElem(name) : item.isElem();
            });

        },

        /**
         * Determine if item's content has only elements
         * (any or by name or by names array).
         *
         * @param {String|Array} [name] element name or names array
         * @return {Boolean}
         */
        hasAllElems: function(name) {

            return this.content.every(function(item) {
                return name ? item.isElem(name) : item.isElem();
            });

        }

    }
);