/**
 * Copyright 2017 Adobe
 * All Rights Reserved.
 */
define([
    'jquery',
    'underscore',
    'ko',
    'mageUtils',
    'jquery/jquery-storageapi'
], function ($, _, ko, utils) {
    'use strict';

    /**
     * Set data to localStorage with support check.
     *
     * @param {String} namespace
     * @param {Object} data
     */
    function setLocalStorageItem(namespace, data) {
        try {
            window.localStorage.setItem(namespace, JSON.stringify(data));
        } catch (e) {
            console.warn('localStorage is unavailable - skipping local caching of product data');
            console.error(e);
        }
    }

    return {

        /**
         * Class name
         */
        name: 'IdsStorage',

        /**
         * Initializes class
         *
         * @return Chainable.
         */
        initialize: function () {
            if (!this.data) {
                this.data = ko.observable({});
            }

            this.initCustomerDataReloadListener()
                .initLocalStorage()
                .cachesDataFromLocalStorage()
                .initDataListener();

            return this;
        },

        /**
         * Gets data from local storage by current namespace
         *
         * @return {Object}.
         */
        getDataFromLocalStorage: function () {
            return this.localStorage.get();
        },

        /**
         * Caches data from local storage to local scope
         *
         * @return Chainable.
         */
        cachesDataFromLocalStorage: function () {
            this.data(this.getDataFromLocalStorage());

            return this;
        },

        /**
         * Initialize localStorage
         *
         * @return Chainable.
         */
        initLocalStorage: function () {
            this.localStorage = $.initNamespaceStorage(this.namespace).localStorage;

            return this;
        },

        /**
         * Initializes listener to "data" property
         */
        initDataListener: function () {
            this.data.subscribe(this.internalDataHandler.bind(this));
        },

        /**
         * Initialize listener to customer data reload
         *
         * @return Chainable.
         */
        initCustomerDataReloadListener: function () {
            $(document).on('customer-data-reload', function (event, sections) {
                if ((_.isEmpty(sections) || _.contains(sections, this.namespace)) && ~~this.allowToSendRequest) {
                    this.localStorage.removeAll();
                    this.data();
                }
            }.bind(this));

            return this;
        },

        /**
         * Initializes handler to "data" property update
         */
        internalDataHandler: function (data) {
            setLocalStorageItem(this.namespace, data);
        },

        /**
         * Initializes handler to storage update
         */
        externalDataHandler: function (data) {
            data = data.items ? data.items : data;

            this.set(_.extend(utils.copy(this.data()), data));
        }
    };
});

