/**
    * This file Copyright (c) 2013-2015 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.ui.workbench;
  
  import info.magnolia.event.EventBus;
  import info.magnolia.objectfactory.ComponentProvider;
  import info.magnolia.ui.api.view.View;
  import info.magnolia.ui.imageprovider.definition.ImageProviderDefinition;
  import info.magnolia.ui.vaadin.integration.contentconnector.ContentConnector;
  import info.magnolia.ui.workbench.contenttool.ContentToolDefinition;
  import info.magnolia.ui.workbench.contenttool.ContentToolPresenter;
  import info.magnolia.ui.workbench.contenttool.search.SearchContentToolPresenter;
  import info.magnolia.ui.workbench.definition.ContentPresenterDefinition;
  import info.magnolia.ui.workbench.definition.WorkbenchDefinition;
  import info.magnolia.ui.workbench.event.QueryStatementChangedEvent;
  import info.magnolia.ui.workbench.event.SelectionChangedEvent;
  import info.magnolia.ui.workbench.event.ViewTypeChangedEvent;
  import info.magnolia.ui.workbench.list.ListPresenterDefinition;
  import info.magnolia.ui.workbench.search.SearchPresenter;
  import info.magnolia.ui.workbench.search.SearchPresenterDefinition;
  import info.magnolia.ui.workbench.tree.TreePresenter;
  
  import java.util.ArrayList;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  
  import javax.inject.Inject;
  
  import org.apache.commons.lang3.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * The WorkbenchPresenter is responsible for creating, configuring and updating the workbench view, as well as handling its interaction.
   */
  public class WorkbenchPresenter implements WorkbenchView.Listener {
  
      private static final Logger log = LoggerFactory.getLogger(WorkbenchPresenter.class);
  
      private final WorkbenchView view;
  
      private final ComponentProvider componentProvider;
  
      private final Map<String, ContentPresenter> contentPresenters = new LinkedHashMap<String, ContentPresenter>();
  
      private ContentPresenter activePresenter;
  
      private final WorkbenchStatusBarPresenter statusBarPresenter;
  
      private WorkbenchDefinition workbenchDefinition;
  
      private EventBus eventBus;
  
      protected ContentConnector contentConnector;
  
      @Inject
      public WorkbenchPresenter(WorkbenchView view, ComponentProvider componentProvider, WorkbenchStatusBarPresenter statusBarPresenter, ContentConnector contentConnector) {
          this.view = view;
          this.componentProvider = componentProvider;
          this.statusBarPresenter = statusBarPresenter;
          this.contentConnector = contentConnector;
      }
  
      public WorkbenchView start(WorkbenchDefinition workbenchDefinition, ImageProviderDefinition imageProviderDefinition, EventBus eventBus) {
          this.workbenchDefinition = workbenchDefinition;
         this.eventBus = eventBus;
 
         sanityCheck(workbenchDefinition);
 
         // add content views
         for (final ContentPresenterDefinition presenterDefinition : workbenchDefinition.getContentViews()) {
             ContentPresenter presenter;
             Class<? extends ContentPresenter> presenterClass = presenterDefinition.getImplementationClass();
             if (presenterClass != null) {
                 presenter = componentProvider.newInstance(presenterClass);
                 contentPresenters.put(presenterDefinition.getViewType(), presenter);
                 ContentView contentView = presenter.start(workbenchDefinition, eventBus, presenterDefinition.getViewType(), contentConnector);
 
                 if (presenterDefinition.isActive()) {
                     activePresenter = presenter;
                     List<Object> ids = new ArrayList<Object>(1);
                     Object workbenchRootItemId = resolveWorkbenchRoot();
                     ids.add(workbenchRootItemId);
                     activePresenter.setSelectedItemIds(ids);
                 }
                 view.addContentView(presenterDefinition.getViewType(), contentView, presenterDefinition);
 
                 if (presenter instanceof TreePresenter && workbenchDefinition.isDialogWorkbench()) {
                     ((TreePresenter) presenter).disableDragAndDrop();
                 }
             } else {
                 throw new RuntimeException("The provided view type [" + presenterDefinition.getViewType() + "] is not valid.");
             }
 
         }
 
 
         if (hasViewType(ListPresenterDefinition.VIEW_TYPE) && hasViewType(SearchPresenterDefinition.VIEW_TYPE)) {
             // always include search component in the toolbar search component
             addSearchContentTool();
         }
 
         // add content tools
         final List<ContentToolDefinition> contentTools = this.workbenchDefinition.getContentTools();
         for (ContentToolDefinition entry : contentTools) {
             Class<? extends ContentToolPresenter> presenterClass = entry.getPresenterClass();
             if (presenterClass != null) {
                 ContentToolPresenter contentToolPresenter = componentProvider.newInstance(presenterClass, entry, eventBus, this);
                 View contentToolView = contentToolPresenter.start();
                 view.addContentTool(contentToolView);
             }
         }
 
         // add status bar
         view.setStatusBarView(statusBarPresenter.start(eventBus, activePresenter));
 
         view.setMultiselect(!workbenchDefinition.isDialogWorkbench());
 
         view.setListener(this);
         return view;
     }
 
     public Object resolveWorkbenchRoot() {
         return contentConnector.getDefaultItemId();
     }
 
     protected void sanityCheck(WorkbenchDefinition workbenchDefinition) {
         if (workbenchDefinition == null) {
             throw new IllegalArgumentException("Trying to init a workbench but got null definition.");
         }
     }
 
     protected void addSearchContentTool() {
         SearchContentToolPresenter searchPresenter = componentProvider.newInstance(SearchContentToolPresenter.class, this, eventBus);
         View searchView = searchPresenter.start();
         this.view.addContentTool(searchView);
     }
 
 
     /**
      * Search logic is now implemented in a corresponding tool presenter.
      *
      * @see SearchContentToolPresenter
      */
     @Override
     public void onSearch(final String searchExpression) {
         // deprecated, does nothing
     }
 
     @Override
     public void onViewTypeChanged(final String viewType) {
         setViewType(viewType);
         eventBus.fireEvent(new ViewTypeChangedEvent(viewType));
     }
 
     @Override
     public void onSearchQueryChange(String searchQuery) {
         eventBus.fireEvent(new QueryStatementChangedEvent(searchQuery));
     }
 
     private void setViewType(String viewType) {
         ContentPresenter oldPresenter = activePresenter;
         List<Object> itemIds = oldPresenter == null ? null : oldPresenter.getSelectedItemIds();
 
         activePresenter = contentPresenters.get(viewType);
         activePresenter.refresh();
         view.setViewType(viewType);
 
         statusBarPresenter.setActivePresenter(activePresenter);
 
         // make sure selection is kept when switching views
         if (itemIds != null) {
             select(itemIds);
         }
     }
 
     public List<Object> getSelectedIds() {
         return activePresenter.getSelectedItemIds();
     }
 
     public void expand(Object itemId) {
         activePresenter.expand(itemId);
     }
 
     public void select(Object itemId) {
         List<Object> ids = new ArrayList<Object>(1);
         ids.add(itemId);
         select(ids);
     }
 
     public void select(List<Object> itemIds) {
         final List<Object> selectedIds = filterExistingItems(itemIds);
         // restore selection
         if (selectedIds.isEmpty()) {
             Object workbenchRootItemId = contentConnector.getDefaultItemId();
             if (workbenchRootItemId != null) {
                 selectedIds.add(workbenchRootItemId);
             }
         }
 
         activePresenter.setSelectedItemIds(selectedIds);
         activePresenter.select(selectedIds);
         // Only send event if items are not empty (do exist)
         eventBus.fireEvent(new SelectionChangedEvent(new HashSet<Object>(selectedIds)));
     }
 
     protected List<Object> filterExistingItems(List<Object> itemIds) {
         List<Object> filteredIds = new ArrayList<Object>();
         Iterator<Object> it = itemIds.iterator();
         while (it.hasNext()) {
             Object itemId = it.next();
             if (contentConnector.canHandleItem(itemId) && contentConnector.getItem(itemId) != null) {
                 filteredIds.add(itemId);
             }
         }
         return filteredIds;
     }
 
     public void refresh() {
         activePresenter.refresh();
         statusBarPresenter.refresh();
     }
 
     public String getDefaultViewType() {
         for (ContentPresenterDefinition definition : this.workbenchDefinition.getContentViews()) {
             if (definition.isActive()) {
                 return definition.getViewType();
             }
         }
         return this.workbenchDefinition.getContentViews().get(0).getViewType();
     }
 
     public boolean hasViewType(String viewType) {
         return contentPresenters.containsKey(viewType);
     }
 
     public void resynch(final List<Object> itemIds, final String viewType, final String query) {
         setViewType(viewType);
         select(itemIds);
 
         if (SearchPresenterDefinition.VIEW_TYPE.equals(viewType)) {
             doSearch(query);
             // update search field and focus it
             view.setSearchQuery(query);
         }
     }
 
     public void doSearch(String searchExpression) {
         // firing new search forces search view as new view type
         if (activePresenter != contentPresenters.get(SearchPresenterDefinition.VIEW_TYPE)) {
             setViewType(SearchPresenterDefinition.VIEW_TYPE);
         }
         final SearchPresenter searchPresenter = (SearchPresenter) activePresenter;
         if (StringUtils.isBlank(searchExpression)) {
             searchPresenter.clear();
         } else {
             searchPresenter.search(searchExpression);
         }
     }
 
     // exposed only for extending classes. these methods should not be public!
     protected final ContentPresenter getActivePresenter() {
         return activePresenter;
     }
 
     protected final EventBus getEventBus() {
         return this.eventBus;
     }
 
     protected final WorkbenchDefinition getWorkbenchDefinition() {
         return this.workbenchDefinition;
     }
 }