# ServerMessagesPresenter.java

    /*
    ** Module   : ServerMessagesPresenter.java
    ** Abstract : ServerMessagesPresenter is a controller that implements business methods to work
    **            with server messages.
    **
    ** Copyright (c) 2017, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- ----------------Description----------------------
    ** 001 SBI 20170601 Created initial version.
    */
    /*
    ** This program is free software: you can redistribute it and/or modify
    ** it under the terms of the GNU Affero General Public License as
    ** published by the Free Software Foundation, either version 3 of the
    ** License, or (at your option) any later version.
    **
    ** This program is distributed in the hope that it will be useful,
    ** but WITHOUT ANY WARRANTY; without even the implied warranty of
    ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    ** GNU Affero General Public License for more details.
    **
    ** You may find a copy of the GNU Affero GPL version 3 at the following
    ** location: https://www.gnu.org/licenses/agpl-3.0.en.html
    **
    ** Additional terms under GNU Affero GPL version 3 section 7:
    **
    **   Under Section 7 of the GNU Affero GPL version 3, the following additional
    **   terms apply to the works covered under the License.  These additional terms
    **   are non-permissive additional terms allowed under Section 7 of the GNU
    **   Affero GPL version 3 and may not be removed by you.
    **
    **   0. Attribution Requirement.
    **
    **     You must preserve all legal notices or author attributions in the covered
    **     work or Appropriate Legal Notices displayed by works containing the covered
    **     work.  You may not remove from the covered work any author or developer
    **     credit already included within the covered work.
    **
    **   1. No License To Use Trademarks.
    **
    **     This license does not grant any license or rights to use the trademarks
    **     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
    **     of Golden Code Development Corporation. You are not authorized to use the
    **     name Golden Code, FWD, or the names of any author or contributor, for
    **     publicity purposes without written authorization.
    **
    **   2. No Misrepresentation of Affiliation.
    **
    **     You may not represent yourself as Golden Code Development Corporation or FWD.
    **
    **     You may not represent yourself for publicity purposes as associated with
    **     Golden Code Development Corporation, FWD, or any author or contributor to
    **     the covered work, without written authorization.
    **
    **   3. No Misrepresentation of Source or Origin.
    **
    **     You may not represent the covered work as solely your work.  All modified
    **     versions of the covered work must be marked in a reasonable way to make it
    **     clear that the modified work is not originating from Golden Code Development
    **     Corporation or FWD.  All modified versions must contain the notices of
    **     attribution required in this license.
    */

    package com.goldencode.p2j.admin.client.application.home.help;

    import java.util.logging.Level;

    import com.goldencode.p2j.admin.client.NameTokens;
    import com.goldencode.p2j.admin.client.application.Alarm;
    import com.goldencode.p2j.admin.client.application.home.BasePresenter;
    import com.goldencode.p2j.admin.client.application.home.HomePresenter;
    import com.goldencode.p2j.admin.client.widget.dialog.ModalDialogs;
    import com.goldencode.p2j.admin.shared.AdminServiceAsync;
    import com.google.gwt.user.client.*;
    import com.google.gwt.user.client.rpc.AsyncCallback;
    import com.google.inject.Inject;
    import com.google.web.bindery.event.shared.EventBus;
    import com.gwtplatform.mvp.client.HasUiHandlers;
    import com.gwtplatform.mvp.client.View;
    import com.gwtplatform.mvp.client.annotations.NameToken;
    import com.gwtplatform.mvp.client.annotations.ProxyStandard;
    import com.gwtplatform.mvp.client.presenter.slots.NestedSlot;
    import com.gwtplatform.mvp.client.proxy.PlaceManager;
    import com.gwtplatform.mvp.client.proxy.ProxyPlace;
    import com.gwtplatform.mvp.shared.proxy.PlaceRequest;

    /**
     * ServerMessagesPresenter is a controller that implements business methods to work with server
     * messages.
     */
    public class ServerMessagesPresenter
    extends BasePresenter<ServerMessagesPresenter.MyView, ServerMessagesPresenter.MyProxy>
    implements ServerMesagesUiHandlers
    {
       /** The attachment point for dependent modal dialogs on this view */
       public static final NestedSlot MODAL_CONTENT = new NestedSlot();

       /**
        * This view interface that must be implemented by the concrete view according to GWTP
        * framework. Defines the exposed business methods.
        */
       public interface MyView
       extends View, HasUiHandlers<ServerMesagesUiHandlers>
       {
          /**
           * Sets the server messages list model.
           *
           * @param    messages
           *           The array of messages
           */
          void setMessages(String[] messages);
       }

       /**
        * Defines the proxy place for GWTP framework. Binds /help/messages url to this presenter.
        */
       @ProxyStandard
       @NameToken(NameTokens.SERVER_MESSAGES)
       public interface MyProxy
       extends ProxyPlace<ServerMessagesPresenter>
       {}

       /** Administration server interface */
       private final AdminServiceAsync adminService;

       /** The common modal dialogs manager */
       private final ModalDialogs modalDialogsManager;

       /** The server alarms manager */
       private final Alarm serverAlarmsManager;

       /**
        * Defines the Server Messages presenter.
        *
        * @param    eventBus
        *           The event bus
        * @param    view
        *           The associated view
        * @param    proxy
        *           The proxy place
        * @param    placeManager
        *           The place manager
        * @param    adminService
        *           The administration service
        * @param    modalDialogsManager
        *           The common modal dialogs manager
        * @param    serverAlarmsManager
        *           The server alarms
        */
       @Inject
       public ServerMessagesPresenter(EventBus eventBus,
                                      MyView view,
                                      MyProxy proxy,
                                      PlaceManager placeManager,
                                      AdminServiceAsync adminService,
                                      ModalDialogs modalDialogsManager,
                                      Alarm serverAlarmsManager)
       {
          super(eventBus, view, proxy, HomePresenter.SLOT_CONTENT, placeManager);
          this.adminService = adminService;
          this.modalDialogsManager = modalDialogsManager;
          this.serverAlarmsManager = serverAlarmsManager;
          getView().setUiHandlers(this);
       }

       /**
        * Loads the data before the associated view will be displayed.
        *
        * @param    request
        *           The current request
        */
       @Override
       public void prepareFromRequest(PlaceRequest request)
       {
          super.prepareFromRequest(request);
          String action = request.getParameter("action", "");
          if ("clear".equals(action))
          {
             clearMessages();
          }
          else
          {
             showMessages();
          }
       }

       /**
        * Retrieves the server messages asynchronously and updates its view accordingly if this action
        * is completed successfully.
        */
       private void showMessages()
       {
          this.serverAlarmsManager.getAllMessages(messages -> {
             if (messages != null)
             {
                getView().setMessages(messages.toArray(new String[messages.size()]));
             }
          }, false);
       }

       /**
        * Requests to clear the server messages and updates its view accordingly if this action is
        * completed.
        */
       private void clearMessages()
       {
          this.adminService.clearMessages(new AsyncCallback<Void>()
          {

             @Override
             public void onSuccess(Void result)
             {
                showMessages();
             }

             @Override
             public void onFailure(Throwable caught)
             {
                logger.log(Level.SEVERE, "Failed to call clearMessages", caught);
                showMessages();
             }
          });
       }

       /**
        * Hides the Server Messages view and displays the invoker view.
        */
       @Override
       public void onBackAction()
       {
          History.back();
       }
    }