// event-wrapper.js

(function(angular, factory) {
    'use strict';

    if (typeof define === 'function' && define.amd) {
        define([
            'angular'
        ], function(angular) {
            return factory(angular);
        });
    } else {
        return factory(angular);
    }
}(window.angular, function(angular) {
    'use strict';
    angular.module('eventWrapper', [])
        .service('eventWrapper', function() {
            var _listeners = {},
                TYPE_ONE = "one";

            return {
                on: function (eventName, callback) {
                    _listeners[eventName] || (_listeners[eventName] = []);
                    _listeners[eventName].push({
                        action: callback
                    });
                },
                one: function (eventName, callback) {
                    _listeners[eventName] || (_listeners[eventName] = []);
                    _listeners[eventName].push({
                        type: TYPE_ONE,
                        action: callback
                    });
                },
                emit: function (eventName) {
                    var chain = _listeners[eventName],
                        len = chain.length,
                        i, item, action;
                    // 逆序遍历，以免删除数组导致问题
                    for (i = len; item = chain[i]; i--) {
                        action = item.action
                        if (typeof action === 'function') {
                            try {
                                action();
                            } catch (e) {
                                "console" in window && console.error(e);
                            }
                        }
                        if(item.type === TYPE_ONE)
                            chain.splice(i, 1);
                    }
                }
            };
        })
}));