/*******************************************************************************
 * Copyright (c) 2012, 2020 Original authors and others.
 *
 * This program and the accompanying materials are made
 * available under the terms of the Eclipse Public License 2.0
 * which is available at https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     Original authors and others - initial API and implementation
 ******************************************************************************/
package org.eclipse.nebula.widgets.nattable.group.command;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.eclipse.nebula.widgets.nattable.Messages;
import org.eclipse.nebula.widgets.nattable.columnRename.ColumnRenameDialog;
import org.eclipse.nebula.widgets.nattable.command.AbstractLayerCommandHandler;
import org.eclipse.nebula.widgets.nattable.group.ColumnGroupHeaderLayer;
import org.eclipse.nebula.widgets.nattable.group.ColumnGroupModel;
import org.eclipse.nebula.widgets.nattable.group.ColumnGroupModel.ColumnGroup;
import org.eclipse.nebula.widgets.nattable.group.ColumnGroupUtils;
import org.eclipse.nebula.widgets.nattable.group.event.GroupColumnsEvent;
import org.eclipse.nebula.widgets.nattable.group.event.UngroupColumnsEvent;
import org.eclipse.nebula.widgets.nattable.reorder.command.MultiColumnReorderCommand;
import org.eclipse.nebula.widgets.nattable.selection.SelectionLayer;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Display;

public class ColumnGroupsCommandHandler extends
        AbstractLayerCommandHandler<IColumnGroupCommand> {

    private final ColumnGroupModel model;
    private final SelectionLayer selectionLayer;
    private final ColumnGroupHeaderLayer contextLayer;
    private Map<Integer, Integer> columnIndexesToPositionsMap;

    public ColumnGroupsCommandHandler(ColumnGroupModel model, SelectionLayer selectionLayer, ColumnGroupHeaderLayer contextLayer) {
        this.model = model;
        this.selectionLayer = selectionLayer;
        this.contextLayer = contextLayer;
    }

    @Override
    public boolean doCommand(IColumnGroupCommand command) {
        if (command instanceof CreateColumnGroupCommand) {
            if (this.columnIndexesToPositionsMap.size() > 0) {
                handleGroupColumnsCommand(((CreateColumnGroupCommand) command).getColumnGroupName());
                this.columnIndexesToPositionsMap.clear();
                return true;
            }
        } else if (command instanceof OpenCreateColumnGroupDialog) {
            OpenCreateColumnGroupDialog openDialogCommand = (OpenCreateColumnGroupDialog) command;
            loadSelectedColumnsIndexesWithPositions();
            if (this.selectionLayer.getFullySelectedColumnPositions().length > 0
                    && this.columnIndexesToPositionsMap.size() > 0) {
                openDialogCommand.openDialog(this.contextLayer);
            } else {
                openDialogCommand.openErrorBox(Messages.getString("ColumnGroups.selectNonGroupedColumns")); //$NON-NLS-1$
            }
            return true;
        } else if (command instanceof UngroupColumnCommand) {
            handleUngroupCommand();
            return true;
        } else if (command instanceof RemoveColumnGroupCommand) {
            RemoveColumnGroupCommand removeColumnGroupCommand = (RemoveColumnGroupCommand) command;
            int columnIndex = removeColumnGroupCommand.getColumnIndex();
            handleRemoveColumnGroupCommand(columnIndex);
            return true;
        } else if (command instanceof DisplayColumnGroupRenameDialogCommand) {
            return displayColumnGroupRenameDialog((DisplayColumnGroupRenameDialogCommand) command);
        }
        return false;
    }

    private boolean displayColumnGroupRenameDialog(DisplayColumnGroupRenameDialogCommand command) {
        int columnPosition = command.getColumnPosition();

        ColumnRenameDialog dialog = new ColumnRenameDialog(Display.getDefault().getActiveShell(), null, null);
        Rectangle colHeaderBounds = this.contextLayer.getBoundsByPosition(columnPosition, 0);
        Point point = new Point(colHeaderBounds.x, colHeaderBounds.y + colHeaderBounds.height);
        dialog.setLocation(command.toDisplayCoordinates(point));
        dialog.open();

        if (!dialog.isCancelPressed()) {
            int columnIndex = this.contextLayer.getColumnIndexByPosition(columnPosition);
            ColumnGroup columnGroup = this.model.getColumnGroupByIndex(columnIndex);
            columnGroup.setName(dialog.getNewColumnLabel());
        }

        return true;
    }

    @Override
    public Class<IColumnGroupCommand> getCommandClass() {
        return IColumnGroupCommand.class;
    }

    protected void loadSelectedColumnsIndexesWithPositions() {
        this.columnIndexesToPositionsMap = new LinkedHashMap<>();
        int[] fullySelectedColumns = this.selectionLayer.getFullySelectedColumnPositions();

        if (fullySelectedColumns.length > 0) {
            for (int index = 0; index < fullySelectedColumns.length; index++) {
                final int columnPosition = fullySelectedColumns[index];
                int columnIndex = this.selectionLayer.getColumnIndexByPosition(columnPosition);
                if (this.model.isPartOfAGroup(columnIndex)) {
                    this.columnIndexesToPositionsMap.clear();
                    break;
                }
                this.columnIndexesToPositionsMap.put(columnIndex, columnPosition);
            }

        }
    }

    public void handleGroupColumnsCommand(String columnGroupName) {
        try {
            Set<Integer> positions = new HashSet<>();
            List<Integer> selectedPositions = null;

            ColumnGroup group = this.model.getColumnGroupByName(columnGroupName);
            if (group != null) {
                // a group with the same name already exists so we update the
                // existing group as this command handler does not support
                // multiple groups with the same name
                for (Integer pos : group.getMembers()) {
                    positions.add(this.selectionLayer.getColumnPositionByIndex(pos));
                }
                positions.addAll(this.columnIndexesToPositionsMap.values());
                selectedPositions = new ArrayList<>(positions);
            } else {
                selectedPositions = new ArrayList<>(this.columnIndexesToPositionsMap.values());
            }

            Collections.sort(selectedPositions);

            int[] fullySelectedColumns = new int[this.columnIndexesToPositionsMap.size()];
            int count = 0;
            for (Integer columnIndex : this.columnIndexesToPositionsMap.keySet()) {
                fullySelectedColumns[count++] = columnIndex.intValue();
            }
            // we first need to reorder and then process the group creation,
            // otherwise the group reordering will be processed before the
            // column reordering which breaks the rendering
            this.selectionLayer.doCommand(
                    new MultiColumnReorderCommand(this.selectionLayer, selectedPositions, selectedPositions.get(0)));
            this.model.addColumnsIndexesToGroup(columnGroupName, fullySelectedColumns);
            this.selectionLayer.clear();
        } catch (Exception t) {
            // do nothing
        }
        this.contextLayer.fireLayerEvent(new GroupColumnsEvent(this.contextLayer));
    }

    public void handleUngroupCommand() {
        // Grab fully selected column positions
        int[] fullySelectedColumns = this.selectionLayer.getFullySelectedColumnPositions();
        Map<String, Integer> toColumnPositions = new HashMap<>();
        if (fullySelectedColumns.length > 0) {

            // Pick the ones which belong to a group and remove them from the
            // group
            for (int index = 0; index < fullySelectedColumns.length; index++) {
                final int columnPosition = fullySelectedColumns[index];
                int columnIndex = this.selectionLayer.getColumnIndexByPosition(columnPosition);
                if (this.model.isPartOfAGroup(columnIndex)
                        && !this.model.isPartOfAnUnbreakableGroup(columnIndex)) {
                    handleRemovalFromGroup(toColumnPositions, columnIndex);
                }
            }
            // The groups which were affected should be reordered to the start
            // position, this should group all columns together
            Collection<Integer> values = toColumnPositions.values();
            final Iterator<Integer> toColumnPositionsIterator = values.iterator();
            while (toColumnPositionsIterator.hasNext()) {
                Integer toColumnPosition = toColumnPositionsIterator.next();
                this.selectionLayer.doCommand(
                        new ReorderColumnGroupCommand(this.selectionLayer, toColumnPosition, toColumnPosition));
            }
            this.selectionLayer.clear();
        }

        this.contextLayer.fireLayerEvent(new UngroupColumnsEvent(this.contextLayer));
    }

    private void handleRemovalFromGroup(Map<String, Integer> toColumnPositions, int columnIndex) {
        ColumnGroup columnGroup = this.model.getColumnGroupByIndex(columnIndex);

        final String columnGroupName = columnGroup.getName();
        final List<Integer> columnIndexesInGroup = columnGroup.getMembers();
        final int columnGroupSize = columnIndexesInGroup.size();
        if (!toColumnPositions.containsKey(columnGroupName)) {
            for (int colGroupIndex : columnIndexesInGroup) {
                if (ColumnGroupUtils.isFirstVisibleColumnIndexInGroup(colGroupIndex, this.selectionLayer, this.model)) {
                    int toPosition = this.selectionLayer.getColumnPositionByIndex(colGroupIndex);
                    if (colGroupIndex == columnIndex) {
                        if (columnGroupSize == 1) {
                            break;
                        } else {
                            toPosition++;
                        }
                    }
                    toColumnPositions.put(columnGroupName, toPosition);
                    break;
                }
            }
        } else {
            if (columnGroupSize - 1 <= 0) {
                toColumnPositions.remove(columnGroupName);
            }
        }
        columnGroup.removeColumn(columnIndex);
    }

    private void handleRemoveColumnGroupCommand(int columnIndex) {
        ColumnGroup columnGroup = this.model.getColumnGroupByIndex(columnIndex);
        this.model.removeColumnGroup(columnGroup);
    }

}