radio/libjs/utils/enum.js

"use strict";

var Class = require("./class");

var Enum = Class.inherit({
    className: "Enum",
    constructor: function(name, additional) {
        if (typeof name !== "string" || name.length === 0) {
            throw new Error("An attempt to register enum with wrong or empty name");
        }
        
        if (storage[name]) {
            throw new Error("An attempt to register enum " + name + " for the second time");
        }
        
        Class.fn.constructor.call(this);
        
        this.name = name;
        
        this.straight = Object.create(null);
        this.reversed = Object.create(null);
        
        this.additional = Object.create(null);
        this._additionals = additional || [];
        
        this._lastId = -1;
        
        storage[name] = this;
    },
    add: function(name, additional, id) {
        if (typeof name !== "string" || name.length === 0) {
            throw new Error("An attempt to add an entry with invalid name to enum " + name);
        }
        
        if (!id) {
            id = this._lastId + 1;
        }
        if (this.straight[id] !== undefined) {
            throw new Error("Id duplication in enum " + this.name + " during an attempt to add entry " + name);
        }
        
        if (this.reversed[name] !== undefined) {
            throw new Error("Name duplication in enum " + this.name + " during an attempt to add entry " + name);
        }
        
        this.straight[name] = id;
        this.reversed[id] = name;
        this.additional[id] = Object.create(null);
        
        for (var i = 0; i < this._additionals.length; ++i) {
            var key = this._additionals[i];
            var aVal = additional[key];
            if (aVal === undefined) {
                throw new Error("An attempt to add an entry " + name + " into enum " + this.name + " without providing additional value " + key);
            }
            this.additional[id][key] = aVal;
        }
        
        this._lastId = id;
    },
    hasAdditional: function(name) {
        return this._additionals.indexOf(name) !== -1;
    }
});

var storage = Object.create(null);
Enum.storage = storage;

module.exports = Enum;