(function () {

     var identityDecoder = function (src) {
         return src;
     };

     var identityEncoder = function (src) {
         return src;
     };

     var mapDecoder = function (src) {
         var map   = {};
         var lines = src.split(/\n/);

         $.each(lines, function () {
                    var m = this.match(/^(\S+)\s+(\S+)$/);

                    map[ m[1] ] = m[2];
                });

         return map;
     };

     var mapEncoder = function (map) {
         var lines = [];

         $.each(map, function (key) {
                    lines.push(key + " " + this);
                });

         return lines.join("\n");
     };

     var boolDecoder = function (src) {
         return src == "*";
     };

     var boolEncoder = function (bool) {
         return bool ? "*" : "";
     };

     var decoder_of = {
         siteName   : identityDecoder,
         baseURI    : identityDecoder,
         defaultPage: identityDecoder,
         styleSheet : identityDecoder,
         languages  : mapDecoder,
         globalLock : boolDecoder
     };

     var encoder_of = {
         siteName   : identityEncoder,
         baseURI    : identityEncoder,
         defaultPage: identityEncoder,
         styleSheet : identityEncoder,
         languages  : mapEncoder,
         globalLock : boolEncoder
     };

     var cachedConf = null;

    Rakka.getSystemConfig = function () {
        if (cachedConf != null) {
            return cachedConf;
        }

        var conf = {};
        cachedConf = conf;

        $.ajax({
            type   : "GET",
            url    : Rakka.baseURI + "systemConfig",
            async  : false,
            success: function (xml) {
                $(xml).find("value").each(function () {
                    var path    = this.getAttribute("path");
                    var decoder = decoder_of[path];

                    if (decoder == null) {
                        throw new Error("unknown config path: " + path);
                    }
                    else {
                        conf[path] = decoder($(this).text());
                    }
                });
            },
            error  : function (req) {
                throw new Error(req.status + " " + req.statusText);
            }
        });

        return conf;
    };

     Rakka.showConfigPanel = function () {
         var conf  = Rakka.getSystemConfig();
         var $area = Rakka.switchScreen();

         $area.append($.H1({}, "Configuration"));

         var fldSiteName
             = $.INPUT({type: "text", value: conf.siteName});

         var fldBaseURI
             = $.INPUT({type: "text", value: conf.baseURI});

         var fldDefaultPage
             = $.INPUT({type: "text", value: conf.defaultPage});

         var fldStyleSheet
             = $.INPUT({type: "text", value: conf.styleSheet});

         var fldLanguages
             = $.TEXTAREA({value: encoder_of.languages(conf.languages)});

         var chkGlobalLock
             = $.INPUT({type: "checkbox", checked: conf.globalLock});

         var btnSave
             = $.INPUT({type: "button", value: "Save"});

         var btnCancel
             = $.INPUT({type: "button", value: "Cancel"});

         var configPanel
             = $.TABLE({className: "pageEditor"},
                       $.TBODY({},
                               $.TR({},
                                    $.TH({}, "Site name"),
                                    $.TD({}, fldSiteName)
                                   ),
                               $.TR({},
                                    $.TH({}, "Base URI"),
                                    $.TD({}, fldBaseURI)
                                   ),
                               $.TR({},
                                    $.TH({}, "Default page"),
                                    $.TD({}, fldDefaultPage)
                                   ),
                               $.TR({},
                                    $.TH({}, "Style sheet"),
                                    $.TD({}, fldStyleSheet)
                                   ),
                               $.TR({},
                                    $.TH({}, "Languages"),
                                    $.TD({}, fldLanguages)
                                   ),
                               $.TR({},
                                    $.TH({}, "Global lock"),
                                    $.TD({},
                                         $.LABEL({},
                                                 chkGlobalLock,
                                                 "Disallow guest users to edit pages."))
                                   ),
                               $.TR({},
                                    $.TH({}),
                                    $.TD({}, btnSave, btnCancel)
                                   )
                              )
                      );

         $area.append(configPanel);
     };

    $(document).ready(function () {
        $("input.configButton")
            .click(function () {
                       Rakka.showConfigPanel();
                   });
    });

})();