/*
    *  XNap - A P2P framework and client.
    *
    *  See the file AUTHORS for copyright information.
    *
    *  This program is free software; you can redistribute it and/or modify
    *  it under the terms of the GNU General Public License as published by
    *  the Free Software Foundation.
    *
   *  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 General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *  along with this program; if not, write to the Free Software
   *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  package org.xnap.gui.table;
  
  import java.beans.PropertyChangeEvent;
  import java.beans.PropertyChangeListener;
  import java.util.Arrays;
  import java.util.HashSet;
  
  import javax.swing.event.ChangeEvent;
  import javax.swing.event.ListSelectionEvent;
  import javax.swing.event.TableColumnModelEvent;
  import javax.swing.event.TableColumnModelListener;
  import javax.swing.table.TableColumnModel;
  
  import org.xnap.util.TablePreferencesProvider;
  
  /***
   * Takes care of the table preferences.
   */
  public class TablePreferencesHandler 
      implements PropertyChangeListener, TableHeaderListener
  {
  
      //--- Data field(s) ---
  
      private TablePreferencesProvider prefs;
      private String table;
      private TableColumnModel tcm;
      private ColumnModel model;
  
      //--- Constructor(s) ---
  
      /***
       *
       */
      public TablePreferencesHandler(TablePreferencesProvider prefs, String table, 
  								   ColumnModel model, TableColumnModel tcm)
      {
  		this.prefs = prefs;
  		this.table = table;
  		this.model = model;
  		this.tcm = tcm;
  
  		tcm.addColumnModelListener(new ColumnListener());
  
  		if (model instanceof SortableModel) {
  			((SortableModel)model).setMaintainSortOrder
  				(prefs.getTableMaintainSortOrder(table));
  		}
  		prefs.addTableListener(table, this);
  
  		restore();
      }
  
      //--- Method(s) ---
  
      public TablePreferencesProvider getPreferencesSupport()
      {
  		return prefs;
      }
  
  	public Column getColumnByKey(String key)
  	{
  		for (int i = 0; i < model.getColumnCount(); i++) {
  			if (model.getColumnAt(i).getKey().equals(key)) {
  				return model.getColumnAt(i);
  			}
  		}
  		return null;
  	}
  
      /***
       * Returns the preferences key.
       */
      public String getTable()
      {
  		return table;
      }
  
      public void propertyChange(PropertyChangeEvent e)
      {
 		setVisible(prefs.getTableColumns(table));
 		if (model instanceof SortableModel) {
 			((SortableModel)model).setMaintainSortOrder
 				(prefs.getTableMaintainSortOrder(table));
 		}
     }
 
     /***
      * Restores the table width and sort order.
      */
     public void restore()
     {
 		// add columns and restore order of columns
 		String[] visibleKeysArray = prefs.getTableColumns(table);
 		for (int i = 0; i < visibleKeysArray.length; i++) {
 			Column c = getColumnByKey(visibleKeysArray[i]);
 			if (c != null) {
 				tcm.addColumn(c);
 				c.setVisible(true);
 			}
 		}
 		
 		// make sure at least one column is visible
 		setVisible(visibleKeysArray);
 
 		// restore table widths
 		int[] widths = prefs.getTableColumnWidths(table);
 		for (int i = 0; i < widths.length && i < model.getColumnCount(); i++) {
 			model.getColumnAt(i).setPreferredWidth(widths[i]);
 			model.getColumnAt(i).setWidth(widths[i]);
 		}
 	    
 		// restore sort order
 		int c = prefs.getTableSortedColumn(table);
 		if (c != 0) {
 			int column = Math.abs(c) - 1;
 			if (model instanceof SortableModel 
 				&& column >= 0 && column < model.getColumnCount()) {
 
 				((SortableModel)model).sortByColumn(column, c > 0, false);
 			}
 		}
     }
 
     public void setVisible(String[] visibleKeysArray)
     {
 		HashSet visibleKeys = new HashSet(Arrays.asList(visibleKeysArray));
 
 		boolean visible = false;
 		for (int i = 0; i < model.getColumnCount(); i++) {
 			boolean newStatus 
 				= visibleKeys.contains(model.getColumnAt(i).getKey());
 			visible |= newStatus;
 			Column c = model.getColumnAt(i);
 			if (c.isVisible() != newStatus) {
 				if (newStatus) {
 					tcm.addColumn(c);
 				}
 				else {
 					tcm.removeColumn(c);
 				}
 				c.setVisible(newStatus);
 			}
 		}
 
 		if (!visible && model.getColumnCount() > 0) {
 			// make sure at least one column is visible
 			prefs.setTableColumns
 				(table, new String[] { model.getColumnAt(0).getKey() });
 		}
     }
 
     /***
      * Saves the sorted column.
      *
      * <p>Writes 0, if no column was ever sorted; index + 1, if the
      * column was sorted ascending; -index - 1, if the column was
      * sorted descending ;).
      */
     public void sortedColumnChanged()
     {
 		if (model instanceof SortableModel) {
 			int column = ((SortableModel)model).getSortedColumn();
 			column = (column == -1)
 				? 0
 				: (((SortableModel)model).isSortedAscending()) 
 				? +(column + 1) 
 				: -(column + 1);
 
 			prefs.setTableSortedColumn(table, column);
 		}
     }
 
     /***
      * Saves the width of all columns.
      */
     public void columnWidthChanged()
     {
 		int[] widths = new int[model.getColumnCount()];
 		for (int i = 0; i < widths.length; i++) {
 			widths[i] = model.getColumnAt(i).getWidth();
 		}
 		prefs.setTableColumnWidths(table, widths);
     }
 
     protected class ColumnListener implements TableColumnModelListener 
     {
 
 		public void columnAdded(TableColumnModelEvent event) 
 		{
 		}
 
 		public void columnMarginChanged(ChangeEvent event)
 		{
 		}
 
 		public void columnMoved(TableColumnModelEvent event)
 		{
 			String[] colKeys = new String[tcm.getColumnCount()];
 			for (int i = 0; i < colKeys.length; i++) {
 				colKeys[i] = ((Column)tcm.getColumn(i)).getKey();
 			}
 
 			try {
 				prefs.setTableColumns(table, colKeys);
 			}
 			catch (IllegalArgumentException e) {
 				// FIX: we should restore the correct order here
 			}
 		}
 
 		public void columnRemoved(TableColumnModelEvent event)
 		{
 		}
 
 		public void columnSelectionChanged(ListSelectionEvent event) 
 		{
 		}
 
     }
 
 }