/**
    * This file Copyright (c) 2012 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.admincentral.tree.view;
  
  import info.magnolia.ui.admincentral.event.ItemEditedEvent;
  import info.magnolia.ui.vaadin.grid.MagnoliaTreeTable;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Set;
  
  import com.vaadin.data.Container;
  import com.vaadin.data.Item;
  import com.vaadin.data.Property;
  import com.vaadin.data.util.AbstractProperty;
  import com.vaadin.event.Action;
  import com.vaadin.event.Action.Handler;
  import com.vaadin.event.FieldEvents;
  import com.vaadin.event.FieldEvents.BlurEvent;
  import com.vaadin.event.FieldEvents.FocusEvent;
  import com.vaadin.event.ItemClickEvent;
  import com.vaadin.event.ShortcutAction;
  import com.vaadin.ui.AbstractTextField;
  import com.vaadin.ui.Component;
  import com.vaadin.ui.DefaultFieldFactory;
  import com.vaadin.ui.Field;
  
  /**
   * The Inplace-editing TreeTable, for editing item properties inplace, on double click or via keyboard shortcuts.
   * Additionally, editable columns are configurable
   */
  public class InplaceEditingTreeTable extends MagnoliaTreeTable implements ItemClickEvent.ItemClickListener, ItemEditedEvent.Notifier {
  
      private Object editingItemId;
  
      private Object editingPropertyId;
  
      private List<Object> editableColumns;
  
      private ColumnGenerator bypassedColumnGenerator;
  
      private final List<ItemEditedEvent.Handler> listeners = new ArrayList<ItemEditedEvent.Handler>();
  
      public InplaceEditingTreeTable() {
          super();
          setEditable(true);
          setTableFieldFactory(new InplaceEditingFieldFactory());
          addListener(asItemClickListener());
          getActionManager().addActionHandler(new EditingKeyboardHandler());
      }
  
      // INPLACE EDITING ENTRY POINTS.
  
      public void setEditableColumns(Object... editablePropertyIds) {
          if (editableColumns != null) {
              this.editableColumns.clear();
          } else {
              editableColumns = new ArrayList<Object>();
          }
          this.editableColumns.addAll(Arrays.asList(editablePropertyIds));
      }
  
      /**
       * Sets the item and property for inplace editing.
       *
      * @param itemId the item id
      * @param propertyId the property id
      */
     public void setEditing(Object itemId, Object propertyId) {
         if (itemId != null && propertyId != null) {
             if ((bypassedColumnGenerator = getColumnGenerator(propertyId)) != null) {
                 removeGeneratedColumn(propertyId);
             }
         } else {
             if (bypassedColumnGenerator != null) {
                 addGeneratedColumn(editingPropertyId, bypassedColumnGenerator);
                 bypassedColumnGenerator = null;
             }
             focus();
         }
 
         this.editingItemId = itemId;
         this.editingPropertyId = propertyId;
         refreshRowCache();
         requestRepaint();
     }
 
     // INPLACE EDITING FIELD FACTORY
 
     /**
      * A factory for creating the inplace editing field in the right cell.
      */
     private class InplaceEditingFieldFactory extends DefaultFieldFactory {
 
         @Override
         public Field createField(Container container, final Object itemId, final Object propertyId, Component uiContext) {
 
             // add TextField only for selected row/column.
             if (editableColumns.contains(propertyId) && itemId.equals(editingItemId) && propertyId.equals(editingPropertyId)) {
 
                 Field field = super.createField(container, itemId, propertyId, uiContext);
 
                 // set TextField Focus listeners
                 if (field instanceof AbstractTextField) {
                     final AbstractTextField tf = (AbstractTextField) field;
                     tf.addListener(new FieldEvents.FocusListener() {
 
                         @Override
                         public void focus(FocusEvent event) {
                             tf.setCursorPosition(tf.toString().length());
                         }
                     });
 
                     tf.addListener(new FieldEvents.BlurListener() {
 
                         @Override
                         public void blur(BlurEvent event) {
                             fireItemEditedEvent(getItemFromField(tf));
                             setEditing(null, null);
                         }
                     });
                     tf.focus();
                 }
 
                 return field;
             }
             return null;
         }
     }
 
     // FIRING ITEM EDITED EVENTS
 
     @Override
     public void addListener(ItemEditedEvent.Handler listener) {
         listeners.add(listener);
     }
 
     @Override
     public void removeListener(ItemEditedEvent.Handler listener) {
         if (listeners.contains(listener)) {
             listeners.remove(listener);
         }
     }
 
     private void fireItemEditedEvent(Item item) {
         if (item != null) {
             ItemEditedEvent event = new ItemEditedEvent(item);
             for (ItemEditedEvent.Handler listener : listeners) {
                 listener.onItemEdited(event);
             }
         }
     }
 
     /**
      * Gets the item whose property is currently being edited in the given field. Since the {{Table}} doesn't keep
      * references to its items, the only way to get it back is to ask the property datasource for its listeners and see
      * if the Item is there.
      *
      * @param source the vaadin {{Field}} where the editing occured
      * @return the vaadin {{Item}} if it could be fetched, null otherwise.
      */
     private Item getItemFromField(Field source) {
         if (source != null) {
             Property property = source.getPropertyDataSource();
             if (property != null && property instanceof AbstractProperty) {
                 Collection<?> listeners = ((AbstractProperty) property).getListeners(Property.ValueChangeEvent.class);
                 Iterator<?> iterator = listeners.iterator();
                 while (iterator.hasNext()) {
                     Object listener = iterator.next();
                     if (listener instanceof Item) {
                         return (Item) listener;
                     }
                 }
             }
         }
         return null;
     }
 
     // DOUBLE CLICK
 
     @Override
     public void itemClick(ItemClickEvent event) {
         if (event.isDoubleClick()) {
             setEditing(event.getItemId(), event.getPropertyId());
         }
     }
 
     private ItemClickEvent.ItemClickListener asItemClickListener() {
         return this;
     }
 
     // KEYBOARD SHORTCUTS
 
     /**
      * The Class EditingKeyboardHandler for keyboard shortcuts with inplace editing.
      */
     private class EditingKeyboardHandler implements Handler {
 
         private final ShortcutAction enter = new ShortcutAction("Enter", ShortcutAction.KeyCode.ENTER, null);
 
         private final ShortcutAction tabNext = new ShortcutAction("Tab", ShortcutAction.KeyCode.TAB, null);
 
         private final ShortcutAction tabPrev = new ShortcutAction("Shift+Tab", ShortcutAction.KeyCode.TAB, new int[]{ShortcutAction.ModifierKey.SHIFT});
 
         private final ShortcutAction escape = new ShortcutAction("Esc", ShortcutAction.KeyCode.ESCAPE, null);
 
         @Override
         public Action[] getActions(Object target, Object sender) {
             return new Action[]{enter, tabNext, tabPrev, escape};
         }
 
         @Override
         public void handleAction(Action action, Object sender, Object target) {
             /*
              * In case of enter the Action needs to be casted back to
              * ShortcutAction because for some reason the object is not same
              * as this.enter object. In that case keycode is used in comparison.
              */
             if (!(action instanceof ShortcutAction)) {
                 return;
             }
             ShortcutAction shortcut = (ShortcutAction) action;
 
             if (target != InplaceEditingTreeTable.this && target instanceof Field) {
                 Field field = (Field) target;
 
                 if (shortcut == enter || shortcut.getKeyCode() == enter.getKeyCode()) {
                     fireItemEditedEvent(getItemFromField(field));
                     setEditing(null, null);
 
                 } else if (action == tabNext) {
                     // Saves first
                     fireItemEditedEvent(getItemFromField(field));
 
                     // Then updates current editingItemId, and asks for next candidate
                     TableCell nextCell = getNextEditableCandidate(editingItemId, editingPropertyId);
                     setEditing(nextCell.getItemId(), nextCell.getPropertyId());
 
                 } else if (action == tabPrev) {
                     // Saves first
                     fireItemEditedEvent(getItemFromField(field));
 
                     // Then updates current editingItemId, and asks for previous candidate
                     TableCell previousCell = getPreviousEditableCandidate(editingItemId, editingPropertyId);
                     setEditing(previousCell.getItemId(), previousCell.getPropertyId());
 
                 } else if (action == escape) {
                     setEditing(null, null);
                 }
             } else if (target == InplaceEditingTreeTable.this) {
                 if (getValue() == null) {
                     return;
                 }
 
                 if (shortcut == enter || shortcut.getKeyCode() == enter.getKeyCode()) {
                     // get first selected itemId, handles multiple selection mode
                     Object firstSelectedId = getValue();
                     if (firstSelectedId instanceof Set && ((Set<?>) firstSelectedId).size() > 0) {
                         firstSelectedId = ((Set<?>) firstSelectedId).iterator().next();
                     }
                     // Edit selected row at first column
                     Object propertyId = getVisibleColumns()[0];
                     if (!editableColumns.contains(propertyId)) {
                         propertyId = getNextEditableCandidate(firstSelectedId, propertyId).getPropertyId();
                     }
                     setEditing(firstSelectedId, propertyId);
                 }
             }
         }
     }
 
     // NEXT/PREVIOUS EDITABLE PROPERTY CANDIDATES
 
     private TableCell getNextEditableCandidate(Object itemId, Object propertyId) {
 
         List<Object> visibleColumns = Arrays.asList(getVisibleColumns());
         Object newItemId = itemId;
         int newColumn = visibleColumns.indexOf(propertyId);
         do {
             if (newColumn == visibleColumns.size() - 1) {
                 newItemId = nextItemId(newItemId);
             }
             newColumn = (newColumn + 1) % visibleColumns.size();
         } while (!editableColumns.contains(visibleColumns.get(newColumn)) && newItemId != null);
 
         return new TableCell(newItemId, visibleColumns.get(newColumn));
     }
 
     private TableCell getPreviousEditableCandidate(Object itemId, Object propertyId) {
 
         List<Object> visibleColumns = Arrays.asList(getVisibleColumns());
         Object newItemId = itemId;
         int newColumn = visibleColumns.indexOf(propertyId);
         do {
             if (newColumn == 0) {
                 newItemId = prevItemId(newItemId);
             }
             newColumn = (newColumn + visibleColumns.size() - 1) % visibleColumns.size();
         } while (!editableColumns.contains(visibleColumns.get(newColumn)) && newItemId != null);
 
         return new TableCell(newItemId, visibleColumns.get(newColumn));
     }
 
     /**
      * The TableCell supporting class.
      */
     private class TableCell {
 
         private final Object itemId;
 
         private final Object propertyId;
 
         public TableCell(Object itemId, Object propertyId) {
             this.itemId = itemId;
             this.propertyId = propertyId;
         }
 
         public Object getItemId() {
             return itemId;
         }
 
         public Object getPropertyId() {
             return propertyId;
         }
     }
 
 }