Rakka.editPage = function (baseURI, pageName) {
    var $area = Rakka.switchScreen();

    Rakka.displayWaitingMessage("Loading... please wait.");
    
    // XML 版のページを取得する。
    $.ajax({
        url    : baseURI + pageName + ".xml",
        success: function (pageXml) {
            Rakka.hideWaitingMessage();
            
            var $page       = $(pageXml).find("page");
            var oldRevision = $page.attr("revision");
            var defaultType
                = $page.attr("isBinary") == "yes"          ? "binary"
                : $page.attr("type")     == "text/x-rakka" ? "rakka"
                : $page.attr("type")     == "text/css"     ? "css"
                :                                            "unknown"
                ;
            var source = $page.find("textData").text();
            Rakka.displayPageEditor(baseURI, pageName, oldRevision, defaultType, source);
        },
        error  : function (req) {
            Rakka.hideWaitingMessage();
            
            if (req.status == 404) {
                Rakka.displayPageEditor(baseURI, pageName, null, "rakka", null);
            }
            else {
                $area.text("Error: " + req.status + " " + req.statusText);
            }
        }
    });
};

Rakka.newPage = function (baseURI) {
    Rakka.displayPageEditor(baseURI, "", null, "rakka", null);
};

Rakka.displayPageEditor = function (baseURI, pageName, oldRevision, defaultType, source) {
    var $area = Rakka.switchScreen();
    $area.empty();

    $area.append($.H1({}, pageName == "" ? "Create page" : "Edit page"));

    var fldPageName
        = $.INPUT({type : "text", value: pageName});

    var btnTypeRakka
        = $.INPUT({type   : "radio",
                   name   : "type",
                   checked: (defaultType == "rakka"  ? "checked" : "")});

    var btnTypeCSS
        = $.INPUT({type   : "radio",
                   name   : "type",
                   checked: (defaultType == "css"    ? "checked" : "")});

    var btnTypeBinary
        = $.INPUT({type   : "radio",
                   name   : "type",
                   checked: (defaultType == "binary" ? "checked" : "")});
    

    var fldRakkaSource
        = $.TEXTAREA({}, (defaultType == "rakka" && source != null ? source : ""));

    var fldCSSSource
        = $.TEXTAREA({}, (defaultType == "css"   && source != null ? source : ""));

    var fldUploadFile
        = $.INPUT({type: "file"});

    var trContent
        = $.TR({}, 
               $.TH({}),
               $.TD({})
              );

    var btnPreview
        = $.INPUT({type: "button", value: "Preview page"});
    
    $(btnPreview).click(function () {
        throw new Error("FIXME: not implemented yet");
    });

    var btnSubmit
        = $.INPUT({type: "button", value: "Submit page"});
    
    $(btnSubmit).click(function () {
        if (btnTypeRakka.checked) {
            Rakka.submitTextPage(
                baseURI,
                pageName,
                oldRevision,
                fldPageName.value,
                "text/x-rakka",
                fldRakkaSource.value);
        }
        else if (btnTypeCSS.checked) {
            Rakka.submitTextPage(
                baseURI,
                pageName,
                oldRevision,
                fldPageName.value,
                "text/css",
                fldCSSSource.value);
        }
        else if (btnTypeBinary.checked) {
            Rakka.submitBinaryPage(
                baseURI,
                pageName,
                oldRevision,
                fldPageName.value,
                fldUploadFile.value);
        }
    });

    var btnDelete
        = $.INPUT({type: "button", value: "Delete this page"});
    
    $(btnDelete).click(function () {
        throw new Error("FIXME: not implemented yet");
    });

    var updateTRContent = function () {
        if (btnTypeRakka.checked) {
            $(trContent).find("th").text("Wiki source");
            $(trContent).find("td").empty().append(fldRakkaSource);
        }
        else if (btnTypeCSS.checked) {
            $(trContent).find("th").text("CSS source");
            $(trContent).find("td").empty().append(fldCSSSource);
        }
        else if (btnTypeBinary.checked) {
            $(trContent).find("th").text("File");
            $(trContent).find("td").empty().append(fldUploadFile);
        }
    };
    $(btnTypeRakka ).change(updateTRContent);
    $(btnTypeCSS   ).change(updateTRContent);
    $(btnTypeBinary).change(updateTRContent);
    updateTRContent();

    var pageEditor
        = $.TABLE({className: "pageEditor"},
                  $.TBODY({},
                          $.TR({},
                               $.TH({}, "Page name"),
                               $.TD({}, fldPageName)
                              ),
                          $.TR({},
                               $.TH({}, "Page type"),
                               $.TD({},
                                    $.UL({},
                                         $.LI({},
                                              $.LABEL({},
                                                      btnTypeRakka,
                                                      "Wiki page"
                                                     )
                                             ),
                                         $.LI({},
                                              $.LABEL({},
                                                      btnTypeCSS,
                                                      "Style sheet"
                                                     )
                                             ),
                                         $.LI({},
                                              $.LABEL({},
                                                      btnTypeBinary,
                                                      "Binary file"
                                                     )
                                             )
                                        )
                                   )
                              ),
                          trContent,
                          $.TR({},
                               $.TH({}),
                               $.TD({}, btnPreview, btnSubmit, btnDelete)
                              )
                         )
                 );

    if (oldRevision == null || oldRevision == 0) {
        // 削除不可
        $(btnDelete).hide();
    }

    $area.append(pageEditor);
};

Rakka.submitTextPage = function (baseURI, pageName, oldRevision, givenPageName, mimeType, text) {
    var doc = document.implementation.createDocument(
        "http://cielonegro.org/schema/Rakka/Page/1.0", "page", null);

    var page = doc.documentElement;

    if (oldRevision != null) {
        // ページ書換時
        var updateInfo = doc.createElement("updateInfo");
        updateInfo.setAttribute("oldRevision", oldRevision);

        if (pageName != givenPageName) {
            var move = doc.createElement("move");
            move.setAttribute("from", pageName);
            updateInfo.appendChild(move);
        }

        page.appendChild(updateInfo);
    }

    if (0) {
        // redirection
    }
    else {
        page.setAttribute("type", mimeType);

        var textData = doc.createElement("textData");
        textData.appendChild(
            doc.createTextNode(text));

        page.appendChild(textData);
    }

    Rakka.displayWaitingMessage("Submitting... please wait.");

    var url = baseURI + encodeURI(givenPageName);
    $.ajax({
        type       : "PUT",
        url        : url,
        contentType: "text/xml",
        data       : doc,
        processData: false,
        success    : function () {
            window.location.replace(url);
        },
        error      : function (req) {
            Rakka.hideWaitingMessage();
            
            var $area = Rakka.switchScreen();
            $area.text("Error: " + req.status + " " + req.statusText);
        }
    });
};