/**
 An **Effect** is a the base class for visual effects that are applied to {{#crossLink "ObjectSet"}}ObjectSets{{/crossLink}}.
 
 ## Overview
 
 <ul>
 <li>Effect is subclassed by {{#crossLink "HighlightEffect"}}{{/crossLink}}, {{#crossLink "IsolateEffect"}}{{/crossLink}} and {{#crossLink "XRayEffect"}}{{/crossLink}}.</li>
 <li>Multiple Effects can share the same {{#crossLink "ObjectSet"}}{{/crossLink}} if required.</li>
 <li>An Effect will provide its own default {{#crossLink "ObjectSet"}}{{/crossLink}} when you don't configure it with one.</li>
 </ul>
 
 @class Effect
 @module BIMSURFER
 @submodule effect
 @constructor
 @param [viewer] {Viewer} Parent {{#crossLink "Viewer"}}{{/crossLink}}.
 @param [cfg] {*} Configs
 @param [cfg.id] {String} Optional ID, unique among all components in the parent viewer, generated automatically when omitted.
 @param [cfg.meta] {String:Object} Optional map of user-defined metadata to attach to this Effect.
 @param [cfg.objectSet] {ObjectSet} The {{#crossLink "ObjectSet"}}{{/crossLink}} to apply this Effect to.
 @extends Component
 */
(function () {
 
    "use strict";
 
    BIMSURFER.Effect = BIMSURFER.Component.extend({
 
        /**
         JavaScript class name for this Component.
 
         @property className
         @type String
         @final
         */
        className: "BIMSURFER.Effect",
 
        _init: function (cfg) {
 
            /**
             * The {{#crossLink "ObjectSet"}}{{/crossLink}} that this Effect applies to.
             *
             * @property objectSet
             * @type ObjectSet
             */
            this.objectSet = cfg.objectSet || new BIMSURFER.ObjectSet(this.viewer);
 
            this._dirty = true;
 
            var self = this;
 
            this._onObjectSetUpdated = this.objectSet.on("updated",
                function () {
                    self._dirty = true;
                });
 
            this.invert = cfg.invert;
 
            this.active = cfg.active !== false;
        },
 
        _props: {
 
            /**
             * Flag which indicates whether this Effect is active or not.
             *
             * Fires an {{#crossLink "Effect/active:event"}}{{/crossLink}} event on change.
             *
             * @property active
             * @type Boolean
             */
            active: {
 
                set: function (value) {
 
                    if (this._active === value) {
                        return;
                    }
 
                    if (value) {
 
                        var self = this;
 
 
                        this._tickSub = this.viewer.on("tick",
                            function () {
 
                                if (self._dirty) {
 
                                    if (self._apply) {
                                        self._apply();
                                    }
 
                                    if (self._applyObject) {
 
                                        // Apply effect to Objects in the Viewer
                                        self.viewer.withClasses(["BIMSURFER.Object"],
                                            function (object) {
                                                self._applyObject.call(self, object);
                                            });
 
                                        self.viewer.withClasses(["BIMSURFER.BoxObject"],
                                            function (object) {
                                                self._applyObject.call(self, object);
                                            });
 
                                    }
 
                                    self._dirty = false;
                                }
                            });
 
                    } else {
 
                        this.viewer.off(this._tickSub);
                    }
 
                    /**
                     * Fired whenever this Effect's {{#crossLink "Effect/active:property"}}{{/crossLink}} property changes.
                     * @event active
                     * @param value The property's new value
                     */
                    this.fire('active', this._active = value);
 
                    this._dirty = true;
                },
 
                get: function () {
                    return this._active;
                }
            },
 
            /**
             * Flag which inverts the {{#crossLink "Object"}}Objects{{/crossLink}} that this Effect applies to.
             *
             * <ul>
             *     <li>When true, this Effect applies to {{#crossLink "Object"}}Objects{{/crossLink}} that are in
             *     the {{#crossLink "Component/viewer:property"}}{{/crossLink}} but **not** in the {{#crossLink "Effect/objectSet:property"}}{{/crossLink}}.</li>
             *
             *     <li>When false, this Effect applies to {{#crossLink "Object"}}Objects{{/crossLink}} that are in
             *     the {{#crossLink "Component/viewer:property"}}{{/crossLink}} and **also** in the {{#crossLink "Effect/objectSet:property"}}{{/crossLink}}.</li>
             * </ul>
             *
             * Fires an {{#crossLink "Effect/invert:event"}}{{/crossLink}} event on change.
             *
             * @property invert
             * @type Boolean
             */
            invert: {
 
                set: function (value) {
 
                    value = !!value;
 
                    if (this._invert === value) {
                        return;
                    }
 
                    this._dirty = false;
 
                    /**
                     * Fired whenever this Effect's {{#crossLink "Effect/invert:property"}}{{/crossLink}} property changes.
                     * @event invert
                     * @param value The property's new value
                     */
                    this.fire('invert', this._invert = value);
                },
 
                get: function () {
                    return this._invert;
                }
            }
        },
 
        _destroy: function () {
 
            this.objectSet.off(this._onObjectSetUpdated);
 
            this.active = false;
        }
 
    });
 
})();