/* ===========================================================
 * PageState.js v0.0.1
 * ===========================================================
 * Copyright 2015 Prevu
 * ========================================================== */

(function ($) {

    "use strict"; // jshint ;_;
    /* PageState CLASS DEFINITION
    * ====================== */

    var PageState = function (element, options) {
        this.init(element, options);
    };

    PageState.prototype = {
        constructor: PageState,
        init: function(element, options) {
            var that = this;

            this.options = options;

            this.$container = $(element);

            this.$storage = $.sessionStorage;

            this.$dataset = {};
            
            if (!that.$storage)
                return false;
            if (!that.options.pageKey) {
                throw "Required page key not set. Init page state cannot be performed.";
            }

            var pageState = that.$storage.get(that.options.pageKey);
            if (!pageState)
                return false;
            this.$dataset = pageState;
            
            // gather all controls marked with PageState attribute data-ps-key from the specified controller 
            $.each(this.$container.find("[data-ps-key]"), function(index, obj) {
                // mark control as handled to avoid state restoration after user changed anything. Restoration applicable only once.  
                var objType = $(obj).data('ps-type');
                if (!objType) {
                    switch ($(obj).tagName) {
                    default:
                        $(obj).on("change", function() {
                            plugin.saveData($(obj));
                        });
                        break;
                    }
                } else {
                    switch (objType) {
                    case 'date':
                        break;
                    default:
                        $(obj).on("change", function() {
                            plugin.saveData($(obj));
                        });
                        break;
                    }
                }
            });
            if (typeof this.options.initCallback === 'function') {
                this.options.initCallback(this.$dataset);
            }

            return true;
        },
        setData: function(key, value) {
            if (!this.$dataset) {
                throw "Dataset not set. Save page state cannot be performed.";
            }
            this.$dataset[key] = value;
        },
        saveData: function(control) {
            if (!this.$storage) {
                throw "Storage not set. Save page state cannot be performed.";
            }
            if (!this.options.pageKey) {
                throw "Required page key not set. Save page state cannot be performed.";
            }
            if (!this.$dataset) {
                throw "Dataset not set. Save page state cannot be performed.";
            }
            if (!!control) {
                var objType = $(control).data('ps-type');
                if (!objType) {
                    switch ($(control).tagName) {
                    default:
                        this.$dataset[$(control).data('ps-key')] = $(control).val();
                        break;
                    }
                } else {
                    switch (objType) {
                    case 'date':
                        break;
                    default:
                        this.$dataset[$(control).data('ps-key')] = $(control).val();
                        break;
                    }
                }
            }
            this.$storage.set(this.options.pageKey, JSON.stringify(this.$dataset));
        },
        restoreData: function(container) {
            var plugin = this;
            if (!this.$storage)
                throw "Required storage provider is not set. Restore page state cannot be performed.";
            if (!plugin.options.pageKey)
                throw "Required page key not set. Restore page state cannot be performed.";
            var parent = $(container) || this.$container;
            // gather all controls marked with PageState attribute data-ps-key from the specified controller 
            $.each(parent.find("[data-ps-key]:not([data-ps-restored])"), function (index, obj) {
                //plugin.$restored.push($(this));
                // mark control as handled to avoid state restoration after user changed anything. Restoration applicable only once.  
                $(obj).attr('data-ps-restored', true);
                var propValue = plugin.$dataset[$(obj).data('ps-key')];
                var objType = $(obj).data('ps-type');
                if (!objType) {
                    switch ($(obj).tagName) {
                    default:
                        if (!propValue)
                            return;
                        $(obj).val(propValue);
                        break;
                    }
                } else {
                    switch (objType) {
                    case 'date':
                        break;
                    default:
                        if (!propValue)
                            return;
                        $(obj).val(propValue);
                        break;
                    }
                }
            });
            return true;
        },
        destroy: function() {
            var e = $.Event('destroy');

            this.$container.trigger(e);

            if (e.isDefaultPrevented()) return;

            this.$container
                .off('.pageState')
                .removeData('pageState');

            //this.$container.trigger('destroyed');
        }
    };
    /* PAGESTATE PLUGIN DEFINITION
    * ======================= */

    $.fn.pageState = function (option, args) {
        return this.each(function() {
            var $this = $(this),
                data = $this.data('pageState'),
                options = $.extend({}, $.fn.pageState.defaults, $this.data(), typeof option == 'object' && option);

            if (!data) $this.data('pageState', (data = new PageState(this, options)));
            if (typeof option == 'string')
                data[option].apply(data, [].concat(args));
        });
    };
    $.fn.pageState.defaults = {
        pageKey: null
    };

    $.fn.pageState.Constructor = PageState;
    
}(jQuery));