/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.netbeans.modules.bugtracking.issuetable;

import java.awt.Component;
import java.awt.Font;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;

import java.util.Map;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
import javax.swing.JTable;
import javax.swing.event.TableModelEvent;
import javax.swing.event.TableModelListener;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.JTableHeader;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableColumnModel;
import javax.swing.table.TableModel;
import org.openide.util.ImageUtilities;

/**
 * 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 is a long overdue rewrite of a class of the same name that
 * first appeared in the swing table demos in 1997.
 * 
 * @author Philip Milne
 * @author Brendon McLean 
 * @author Dan van Enckevort
 * @author Parwinder Sekhon
 * @version 2.0 02/27/04
 */

// XXX ujetaken from versioning util
public final 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<Comparable> COMPARABLE_COMAPRATOR = new Comparator<Comparable>() {
        public int compare(Comparable o1, Comparable o2) {
            return o1.compareTo(o2);
        }
    };
    public static final Comparator LEXICAL_COMPARATOR = new Comparator() {
        public int compare(Object o1, Object o2) {
            return o1.toString().compareTo(o2.toString());
        }
    };

    private final Icon ICON_ASCENDING = new ImageIcon(ImageUtilities.loadImage("org/netbeans/modules/openide/explorer/columnsSortedAsc.gif", true)); // NOI18N
    private final Icon ICON_DESCENDING = new ImageIcon(ImageUtilities.loadImage("org/netbeans/modules/openide/explorer/columnsSortedDesc.gif", true)); // NOI18N
    
    private Row[] viewToModel;
    private int[] modelToView;

    private JTableHeader tableHeader;
    private MouseListener mouseListener;
    private TableModelListener tableModelListener;
    // key is either Class or Integer
    private Map<Object, Comparator> columnComparators = new HashMap<Object, Comparator>();
    private List<Directive> sortingColumns = new ArrayList<Directive>();
    private final IssueTable issueTable;

    public TableSorter(TableModel tableModel) {
        this(tableModel, null);
    }

    public TableSorter(TableModel tableModel, IssueTable issueTable) {
        this.mouseListener = new MouseHandler();
        this.tableModelListener = new TableModelHandler();
        this.issueTable = issueTable;
        setTableModel(tableModel);
    }

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

    public TableModel getTableModel() {
        return tableModel;
    }

    public final 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 directive.direction == ASCENDING ? ICON_ASCENDING : ICON_DESCENDING;
    }

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

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

    /**
     * Sets comparator that will be used to compare values in the specified column. Note that the Comparator will obtain
     * row indices (as Integer objects) to compare and NOT actual cell values.
     * 
     * @param column model index of the column to be sorted 
     * @param comparator comparator that will sort the given column
     */ 
    public void setColumnComparator(int column, Comparator comparator) {
        if (comparator == null) {
            columnComparators.remove(Integer.valueOf(column));
        } else {
            columnComparators.put(Integer.valueOf(column), comparator);
        }
    }
    
    protected Comparator getComparator(int column) {
        Class columnType = tableModel.getColumnClass(column);
        Comparator comparator = columnComparators.get(columnType);
        if (comparator != null) {
            return comparator;
        }
        if (Comparable.class.isAssignableFrom(columnType)) {
            return COMPARABLE_COMAPRATOR;
        }
        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();
    }

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

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

    @Override
    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);
    }

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

    // Helper classes
    
    private class Row implements Comparable {
        private int modelIndex;

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

        public int compareTo(Object o) {
            int row1 = modelIndex;
            int row2 = ((Row) 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 {
                    Comparator comparator = columnComparators.get(Integer.valueOf(column));
                    if (comparator != null) {
                        comparison = comparator.compare(Integer.valueOf(row1), Integer.valueOf(row2));
                    } 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();
        }
    }

    private class MouseHandler extends MouseAdapter {
        @Override
        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 += e.isShiftDown() ? -1 : 1;
                status = (status + 4) % 3 - 1; // signed mod, returning {-1, 0, 1}
                setSortingStatus(column, status);
                if(issueTable != null) {
                    issueTable.sortOrderChanged();
                }
            }
        }
    }

    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;
                int modelColumn = table.convertColumnIndexToModel(column);
                Directive directive = getDirective(modelColumn);
                if (directive != EMPTY_DIRECTIVE) {
                    l.setFont(l.getFont().deriveFont(Font.BOLD));
                }
                l.setHorizontalTextPosition(JLabel.LEFT);
                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;
        }
    }
}
