renyard/validity

/**
* @namespace
* @name validity.opts
*/

var validity = (function (validity) {
    "use strict";
    var opts = {},
        options = {},
        backend,
        storage;

    opts.option = function(opt, value) {
        var returnVal;

        if (value !== undefined) {
            //    Set option to value.
            opts._set(opt, value);
        }
        returnVal = opts._get(opt);

        return returnVal;
    };

    /**
    * @method
    * @name _get
    */
    opts._get = function(key) {
        return options[key];
    };

    /**
    * @method
    * @name _set
    */
    opts._set = function(key, value) {
        options[key] = value;
        opts._save();
        return value;
    };

    /**
    * @method
    * @name storage
    */
    opts._init = function() {
        opts._load();
        // Load new options on change.
        chrome.storage.onChanged.addListener(opts._load);
    };

    /**
    * @method
    * @name backend
    */
    opts.backend = function(storageObj) {
        if (storageObj) {
            backend = storageObj;
        }
        else if (backend === undefined) {
            backend = chrome.storage.sync;
        }
        return backend;
    };

    /**
    * @method
    * @name _localCache
    */
    opts._localCache = {
        get: function() {
            options = JSON.parse(window.localStorage.getItem('options')) || {};
            return options;
        },
        set: function() {
            return window.localStorage.setItem('options', JSON.stringify(options));
        }
    };

    /**
    * @method
    * @name _load
    */
    opts._load = function() {
        opts.backend().get('options', function(obj) {
            if (obj.options !== undefined) {
                options = JSON.parse(obj.options);
            }
        });
        return opts._localCache.get();
    };

    /**
    * @method
    * @name _save
    */
    opts._save = function() {
        // Store as a single JSON object, so we can cache in memory.
        opts.backend().set({'options': JSON.stringify(options)});
        return opts._localCache.set();
    };

    opts._init();

    validity.opts = opts;
    return validity;
})(validity || {});