bob-gray/solv

/* istanbul ignore if */
if (typeof define !== "function") {
    var define = require("amdefine")(module);
}

define(function (require) {
    "use strict";

    require("../abstract/base");
    require("../array/shim");
    require("../object/shim");

    var Listeners,
        meta = require("../meta"),
        createClass = require("../class"),
        Listener = require("./listener");

    meta.setRequire(require);

    Listeners = createClass(
        meta({
            "name": "Listeners",
            "extends": "../abstract/base",
            "description": "A catalog of listener instances"
        }),
        init
    );

    Listeners.method(
        meta({
            "name": "add",
            "description": "Creates a listener instance and add it to this listeners catalog",
            "arguments": [{
                "name": "targetId",
                "type": "number"
            }, {
                "name": "eventName",
                "type": "string"
            }, {
                "name": "handler",
                "type": "function"
            }],
            "returns": {
                "type": "object",
                "description": "new listeners key"
            }
        }),
        add
    );

    Listeners.method(
        meta({
            "name": "get",
            "description": "Gets a listener from the catalog",
            "arguments": [{
                "name": "listenerKey",
                "type": "object"
            }],
            "returns": {
                "type": "object|null",
                "description": "listener instance"
            }
        }),
        get
    );

    Listeners.method(
        meta({
            "name": "remove",
            "description": "Removes listener from the catalog by it's key",
            "arguments": [{
                "name": "listenerKey",
                "type": "object"
            }]
        }),
        remove
    );

    Listeners.method(
        meta({
            "name": "remove",
            "description": "Removes listener from the catalog by it's targetId",
            "arguments": [{
                "name": "targetId",
                "type": "number"
            }]
        }),
        removeByTargetId
    );

    Listeners.method(
        meta({
            "name": "remove",
            "description": "Removes listener from the catalog by it's targetId and eventName",
            "arguments": [{
                "name": "targetId",
                "type": "number"
            }, {
                "name": "eventName",
                "type": "string"
            }]
        }),
        removeByTargetAndEventName
    );

    function init (targetId, eventName, handler) {
        this.catalog = {};
    }

    function add (targetId, eventName, handler) {
        var listener = new Listener(targetId, eventName, handler),
            listenerKey = listener.getKey();

        this.catalog[listenerKey.listenerId] = listener;

        return listenerKey;
    }

    function get (listenerKey) {
        var listenerId = listenerKey.listenerId;

        return this.catalog[listenerId] || null;
    }

    function remove (listenerKey) {
        var listenerId = listenerKey.listenerId;

        if (listenerId) {
            this.catalog[listenerId] = null;
        }
    }

    function removeByTargetId (targetId) {
        var listeners = this.invoke(toArray),
            forTarget = this.proxy(isTarget, targetId);

        listeners.filter(forTarget).forEach(removeListener, this);
    }

    function removeByTargetAndEventName (targetId, eventName) {
        var listeners = this.invoke(toArray),
            whereTargetAndEvent = this.proxy(isTargetAndEvent, targetId, eventName);

        listeners.filter(whereTargetAndEvent).forEach(removeListener, this);
    }

    function removeListener (listener) {
        this.invoke(remove, listener.getKey());
    }

    function toArray () {
        return Object.keys(this.catalog).map(toListener, this);
    }

    function toListener (listenerId) {
        return this.catalog[listenerId];
    }

    function isTarget (targetId, listener) {
        return listener && listener.targetId === targetId;
    }

    function isTargetAndEvent (targetId, eventName, listener) {
        return listener && listener.targetId === targetId &&
            listener.eventName === eventName;
    }

    return Listeners;
});