import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.util.List;

import javax.swing.*;
import javax.swing.event.TableModelEvent;
import javax.swing.event.TableModelListener;
import javax.swing.table.*;

import java.lang.reflect.Method;
import java.lang.reflect.InvocationTargetException;

/**
 * TableSorter is a decorator for TableModels; adding sorting
 * functionality to a supplied TableModel. TableSorter does
 * not store or copy the data in its TableModel; instead it maintains
 * a map from the row indexes of the view to the row indexes of the
 * model. As requests are made of the sorter (like getValueAt(row, col))
 * they are passed to the underlying model after the row numbers
 * have been translated via the internal mapping array. This way,
 * the TableSorter appears to hold another copy of the table
 * with the rows in a different order.
 * <p/>
 * TableSorter registers itself as a listener to the underlying model,
 * just as the JTable itself would. Events recieved from the model
 * are examined, sometimes manipulated (typically widened), and then
 * passed on to the TableSorter's listeners (typically the JTable).
 * If a change to the model has invalidated the order of TableSorter's
 * rows, a note of this is made and the sorter will resort the
 * rows the next time a value is requested.
 * <p/>
 * When the tableHeader property is set, either by using the
 * setTableHeader() method or the two argument constructor, the
 * table header may be used as a complete UI for TableSorter.
 * The default renderer of the tableHeader is decorated with a renderer
 * that indicates the sorting status of each column. In addition,
 * a mouse listener is installed with the following behavior:
 * <ul>
 * <li>
 * Mouse-click: Clears the sorting status of all other columns
 * and advances the sorting status of that column through three
 * values: {NOT_SORTED, ASCENDING, DESCENDING} (then back to
 * NOT_SORTED again).
 * <li>
 * SHIFT-mouse-click: Clears the sorting status of all other columns
 * and cycles the sorting status of the column through the same
 * three values, in the opposite order: {NOT_SORTED, DESCENDING, ASCENDING}.
 * <li>
 * CONTROL-mouse-click and CONTROL-SHIFT-mouse-click: as above except
 * that the changes to the column do not cancel the statuses of columns
 * that are already sorting - giving a way to initiate a compound
 * sort.
 * </ul>
 * <p/>
 * This class first appeared in the swing table demos in 1997 (v1.5) and then
 * had a major rewrite in 2004 (v2.0) to make it compatible with Java 1.4.
 * <p/>
 * This rewrite makes the class compile cleanly with Java 1.5 while
 * maintaining backward compatibility with TableSorter v2.0.
 *
 * @author Philip Milne
 * @author Brendon McLean
 * @author Dan van Enckevort
 * @author Parwinder Sekhon
 * @author ouroborus@ouroborus.org
 * @version 2.1 04/29/06
 */

public class TableSorter extends AbstractTableModel {
	protected TableModel tableModel;

	public static final int DESCENDING = -1;
	public static final int NOT_SORTED = 0;
	public static final int ASCENDING = 1;

	private static Directive EMPTY_DIRECTIVE = new Directive(-1, NOT_SORTED);

	public static final Comparator<Object> COMPARABLE_COMPARATOR = new Comparator<Object>() {
		public int compare(Object o1, Object o2) {
			Method m;
			try {
				// See if o1 is capable of comparing itself to o2
				m = o1.getClass().getDeclaredMethod("compareTo",o2.getClass());
			} catch (NoSuchMethodException e) {
				throw new ClassCastException();
			}

			Object retVal;
			try {
				// make the comparison
				retVal = m.invoke(o1,o2);
			} catch (IllegalAccessException e) {
				throw new ClassCastException();
			} catch (InvocationTargetException e) {
				throw new ClassCastException();
			}

			// Comparable.compareTo() is supposed to return int but invoke()
			// returns Object. We can't cast an Object to an int but we can
			// cast it to an Integer and then extract the int from the Integer.
			// But first, make sure it can be done.
			Integer i = new Integer(0);
			if(!i.getClass().isInstance(retVal)) {
				throw new ClassCastException();
			}

			return i.getClass().cast(retVal).intValue();
		}
	};

	public static final Comparator<Object> LEXICAL_COMPARATOR = new Comparator<Object>() {
		public int compare(Object o1, Object o2) {
			return o1.toString().compareTo(o2.toString());
		}
	};

	private Row[] viewToModel;
	private int[] modelToView;

	private JTableHeader tableHeader;
	private MouseListener mouseListener;
	private TableModelListener tableModelListener;
	private Map<Class,Comparator<Object>> columnComparators = new HashMap<Class,Comparator<Object>>();
	private List<Directive> sortingColumns = new ArrayList<Directive>();

	public TableSorter() {
		this.mouseListener = new MouseHandler();
		this.tableModelListener = new TableModelHandler();
	}

	public TableSorter(TableModel tableModel) {
		this();
		setTableModel(tableModel);
	}

	public TableSorter(TableModel tableModel, JTableHeader tableHeader) {
		this();
		setTableHeader(tableHeader);
		setTableModel(tableModel);
	}

	private void clearSortingState() {
		viewToModel = null;
		modelToView = null;
	}

	public TableModel getTableModel() {
		return tableModel;
	}

	public void setTableModel(TableModel tableModel) {
		if (this.tableModel != null) {
			this.tableModel.removeTableModelListener(tableModelListener);
		}

		this.tableModel = tableModel;
		if (this.tableModel != null) {
			this.tableModel.addTableModelListener(tableModelListener);
		}

		clearSortingState();
		fireTableStructureChanged();
	}

	public JTableHeader getTableHeader() {
		return tableHeader;
	}

	public void setTableHeader(JTableHeader tableHeader) {
		if (this.tableHeader != null) {
			this.tableHeader.removeMouseListener(mouseListener);
			TableCellRenderer defaultRenderer = this.tableHeader.getDefaultRenderer();
			if (defaultRenderer instanceof SortableHeaderRenderer) {
				this.tableHeader.setDefaultRenderer(((SortableHeaderRenderer) defaultRenderer).tableCellRenderer);
			}
		}
		this.tableHeader = tableHeader;
		if (this.tableHeader != null) {
			this.tableHeader.addMouseListener(mouseListener);
			this.tableHeader.setDefaultRenderer(
					new SortableHeaderRenderer(this.tableHeader.getDefaultRenderer()));
		}
	}

	public boolean isSorting() {
		return sortingColumns.size() != 0;
	}

	private Directive getDirective(int column) {
		for (int i = 0; i < sortingColumns.size(); i++) {
			Directive directive = sortingColumns.get(i);
			if (directive.column == column) {
				return directive;
			}
		}
		return EMPTY_DIRECTIVE;
	}

	public int getSortingStatus(int column) {
		return getDirective(column).direction;
	}

	private void sortingStatusChanged() {
		clearSortingState();
		fireTableDataChanged();
		if (tableHeader != null) {
			tableHeader.repaint();
		}
	}

	public void setSortingStatus(int column, int status) {
		Directive directive = getDirective(column);
		if (directive != EMPTY_DIRECTIVE) {
			sortingColumns.remove(directive);
		}
		if (status != NOT_SORTED) {
			sortingColumns.add(new Directive(column, status));
		}
		sortingStatusChanged();
	}

	protected Icon getHeaderRendererIcon(int column, int size) {
		Directive directive = getDirective(column);
		if (directive == EMPTY_DIRECTIVE) {
			return null;
		}
		return new Arrow(directive.direction == DESCENDING, size, sortingColumns.indexOf(directive));
	}

	private void cancelSorting() {
		sortingColumns.clear();
		sortingStatusChanged();
	}

	public void setColumnComparator(Class type, Comparator<Object> comparator) {
		if (comparator == null) {
			columnComparators.remove(type);
		} else {
			columnComparators.put(type, comparator);
		}
	}

	protected Comparator<Object> getComparator(int column) {
		Class columnType = tableModel.getColumnClass(column);
		Comparator<Object> comparator = columnComparators.get(columnType);
		if (comparator != null) {
			return comparator;
		}
		if (Comparable.class.isAssignableFrom(columnType)) {
			return COMPARABLE_COMPARATOR;
		}
		return LEXICAL_COMPARATOR;
	}

	private Row[] getViewToModel() {
		if (viewToModel == null) {
			int tableModelRowCount = tableModel.getRowCount();
			viewToModel = new Row[tableModelRowCount];
			for (int row = 0; row < tableModelRowCount; row++) {
				viewToModel[row] = new Row(row);
			}

			if (isSorting()) {
				Arrays.sort(viewToModel);
			}
		}
		return viewToModel;
	}

	public int modelIndex(int viewIndex) {
		return getViewToModel()[viewIndex].modelIndex;
	}

	private int[] getModelToView() {
		if (modelToView == null) {
			int n = getViewToModel().length;
			modelToView = new int[n];
			for (int i = 0; i < n; i++) {
				modelToView[modelIndex(i)] = i;
			}
		}
		return modelToView;
	}

	// TableModel interface methods

	public int getRowCount() {
		return (tableModel == null) ? 0 : tableModel.getRowCount();
	}

	public int getColumnCount() {
		return (tableModel == null) ? 0 : tableModel.getColumnCount();
	}

	public String getColumnName(int column) {
		return tableModel.getColumnName(column);
	}

	public Class getColumnClass(int column) {
		return tableModel.getColumnClass(column);
	}

	public boolean isCellEditable(int row, int column) {
		return tableModel.isCellEditable(modelIndex(row), column);
	}

	public Object getValueAt(int row, int column) {
		return tableModel.getValueAt(modelIndex(row), column);
	}

	public void setValueAt(Object aValue, int row, int column) {
		tableModel.setValueAt(aValue, modelIndex(row), column);
	}

	// Helper classes

	private class Row implements Comparable<Row> {
		private int modelIndex;

		public Row(int index) {
			this.modelIndex = index;
		}

		public int compareTo(Row o) {
			int row1 = modelIndex;
			int row2 = o.modelIndex;

			for (Iterator<Directive> it = sortingColumns.iterator(); it.hasNext();) {
				Directive directive = it.next();
				int column = directive.column;

				Object o1 = tableModel.getValueAt(row1, column);
				Object o2 = tableModel.getValueAt(row2, column);

				int comparison = 0;
				// Define null less than everything, except null.
				if (o1 == null && o2 == null) {
					comparison = 0;
				} else if (o1 == null) {
					comparison = -1;
				} else if (o2 == null) {
					comparison = 1;
				} else {
					comparison = getComparator(column).compare(o1, o2);
				}
				if (comparison != 0) {
					return directive.direction == DESCENDING ? -comparison : comparison;
				}
			}
			return 0;
		}
	}

	private class TableModelHandler implements TableModelListener {
		public void tableChanged(TableModelEvent e) {
			// If we're not sorting by anything, just pass the event along.
			if (!isSorting()) {
				clearSortingState();
				fireTableChanged(e);
				return;
			}

			// If the table structure has changed, cancel the sorting; the
			// sorting columns may have been either moved or deleted from
			// the model.
			if (e.getFirstRow() == TableModelEvent.HEADER_ROW) {
				cancelSorting();
				fireTableChanged(e);
				return;
			}

			// We can map a cell event through to the view without widening
			// when the following conditions apply:
			//
			// a) all the changes are on one row (e.getFirstRow() == e.getLastRow()) and,
			// b) all the changes are in one column (column != TableModelEvent.ALL_COLUMNS) and,
			// c) we are not sorting on that column (getSortingStatus(column) == NOT_SORTED) and,
			// d) a reverse lookup will not trigger a sort (modelToView != null)
			//
			// Note: INSERT and DELETE events fail this test as they have column == ALL_COLUMNS.
			//
			// The last check, for (modelToView != null) is to see if modelToView
			// is already allocated. If we don't do this check; sorting can become
			// a performance bottleneck for applications where cells
			// change rapidly in different parts of the table. If cells
			// change alternately in the sorting column and then outside of
			// it this class can end up re-sorting on alternate cell updates -
			// which can be a performance problem for large tables. The last
			// clause avoids this problem.
			int column = e.getColumn();
			if (e.getFirstRow() == e.getLastRow()
					&& column != TableModelEvent.ALL_COLUMNS
					&& getSortingStatus(column) == NOT_SORTED
					&& modelToView != null) {
				int viewIndex = getModelToView()[e.getFirstRow()];
				fireTableChanged(new TableModelEvent(TableSorter.this,
													 viewIndex, viewIndex,
													 column, e.getType()));
				return;
			}

			// Something has happened to the data that may have invalidated the row order.
			clearSortingState();
			fireTableDataChanged();
			return;
		}
	}

	private class MouseHandler extends MouseAdapter {
		public void mouseClicked(MouseEvent e) {
			JTableHeader h = (JTableHeader) e.getSource();
			TableColumnModel columnModel = h.getColumnModel();
			int viewColumn = columnModel.getColumnIndexAtX(e.getX());
			int column = columnModel.getColumn(viewColumn).getModelIndex();
			if (column != -1) {
				int status = getSortingStatus(column);
				if (!e.isControlDown()) {
					cancelSorting();
				}
				// Cycle the sorting states through {NOT_SORTED, ASCENDING, DESCENDING} or
				// {NOT_SORTED, DESCENDING, ASCENDING} depending on whether shift is pressed.
				status = status + (e.isShiftDown() ? -1 : 1);
				status = (status + 4) % 3 - 1; // signed mod, returning {-1, 0, 1}
				setSortingStatus(column, status);
			}
		}
	}

	private static class Arrow implements Icon {
		private boolean descending;
		private int size;
		private int priority;

		public Arrow(boolean descending, int size, int priority) {
			this.descending = descending;
			this.size = size;
			this.priority = priority;
		}

		public void paintIcon(Component c, Graphics g, int x, int y) {
			Color color = c == null ? Color.GRAY : c.getBackground();
			// In a compound sort, make each succesive triangle 20%
			// smaller than the previous one.
			int dx = (int)(size/2*Math.pow(0.8, priority));
			int dy = descending ? dx : -dx;
			// Align icon (roughly) with font baseline.
			y = y + 5*size/6 + (descending ? -dy : 0);
			int shift = descending ? 1 : -1;
			g.translate(x, y);

			// Right diagonal.
			g.setColor(color.darker());
			g.drawLine(dx / 2, dy, 0, 0);
			g.drawLine(dx / 2, dy + shift, 0, shift);

			// Left diagonal.
			g.setColor(color.brighter());
			g.drawLine(dx / 2, dy, dx, 0);
			g.drawLine(dx / 2, dy + shift, dx, shift);

			// Horizontal line.
			if (descending) {
				g.setColor(color.darker().darker());
			} else {
				g.setColor(color.brighter().brighter());
			}
			g.drawLine(dx, 0, 0, 0);

			g.setColor(color);
			g.translate(-x, -y);
		}

		public int getIconWidth() {
			return size;
		}

		public int getIconHeight() {
			return size;
		}
	}

	private class SortableHeaderRenderer implements TableCellRenderer {
		private TableCellRenderer tableCellRenderer;

		public SortableHeaderRenderer(TableCellRenderer tableCellRenderer) {
			this.tableCellRenderer = tableCellRenderer;
		}

		public Component getTableCellRendererComponent(JTable table,
													   Object value,
													   boolean isSelected,
													   boolean hasFocus,
													   int row,
													   int column) {
			Component c = tableCellRenderer.getTableCellRendererComponent(table,
					value, isSelected, hasFocus, row, column);
			if (c instanceof JLabel) {
				JLabel l = (JLabel) c;
				l.setHorizontalTextPosition(JLabel.LEFT);
				int modelColumn = table.convertColumnIndexToModel(column);
				l.setIcon(getHeaderRendererIcon(modelColumn, l.getFont().getSize()));
			}
			return c;
		}
	}

	private static class Directive {
		private int column;
		private int direction;

		public Directive(int column, int direction) {
			this.column = column;
			this.direction = direction;
		}
	}
}