/*******************************************************************************
 * 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.examples._500_Layers._501_Data;

import java.util.HashMap;
import java.util.Map;

import org.eclipse.nebula.widgets.nattable.NatTable;
import org.eclipse.nebula.widgets.nattable.config.AbstractRegistryConfiguration;
import org.eclipse.nebula.widgets.nattable.config.DefaultNatTableStyleConfiguration;
import org.eclipse.nebula.widgets.nattable.config.IConfigRegistry;
import org.eclipse.nebula.widgets.nattable.config.IEditableRule;
import org.eclipse.nebula.widgets.nattable.data.IDataProvider;
import org.eclipse.nebula.widgets.nattable.data.ISpanningDataProvider;
import org.eclipse.nebula.widgets.nattable.edit.EditConfigAttributes;
import org.eclipse.nebula.widgets.nattable.edit.config.DefaultEditBindings;
import org.eclipse.nebula.widgets.nattable.edit.config.DefaultEditConfiguration;
import org.eclipse.nebula.widgets.nattable.examples.AbstractNatExample;
import org.eclipse.nebula.widgets.nattable.examples.runner.StandaloneNatExampleRunner;
import org.eclipse.nebula.widgets.nattable.grid.GridRegion;
import org.eclipse.nebula.widgets.nattable.layer.SpanningDataLayer;
import org.eclipse.nebula.widgets.nattable.layer.cell.DataCell;
import org.eclipse.nebula.widgets.nattable.selection.SelectionLayer;
import org.eclipse.nebula.widgets.nattable.viewport.ViewportLayer;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;

/**
 * Example to show the usage of SpanningDataLayer. For this a
 * DummySpanningBodyDataProvider is used that spans several blocks. Editing is
 * also enabled to show and verify that editing of spanned cells is possible.
 *
 * @author Dirk Fauth
 *
 */
public class _5014_SpanningDataLayerExample extends AbstractNatExample {

    public static void main(String[] args) throws Exception {
        StandaloneNatExampleRunner.run(new _5014_SpanningDataLayerExample());
    }

    @Override
    public String getDescription() {
        return "This example shows the usage of the SpanningDataLayer. It uses a ISpanningDataProvider "
                + "that spans several periodic blocks. Editing is also enabled to show and verify "
                + "that editing of spanned cells is working correctly.";
    }

    @Override
    public Control createExampleControl(Composite parent) {
        // To make the default edit and selection configurations work correctly,
        // the region label
        // GridRegion.BODY is necessary, which is directly set to the
        // ViewportLayer instance here.
        ViewportLayer layer = new ViewportLayer(new SelectionLayer(
                new SpanningDataLayer(new DummySpanningBodyDataProvider(100,
                        100))));
        layer.setRegionName(GridRegion.BODY);

        NatTable natTable = new NatTable(parent, layer, false);

        natTable.addConfiguration(new DefaultNatTableStyleConfiguration());

        // add configurations to enable editing
        // this is to verify that spanned cells are also editable and update the
        // data model correctly
        // @see Bug 414754
        layer.addConfiguration(new DefaultEditBindings());
        layer.addConfiguration(new DefaultEditConfiguration());
        layer.addConfiguration(new AbstractRegistryConfiguration() {

            @Override
            public void configureRegistry(IConfigRegistry configRegistry) {
                configRegistry.registerConfigAttribute(
                        EditConfigAttributes.CELL_EDITABLE_RULE,
                        IEditableRule.ALWAYS_EDITABLE);
            }

        });

        natTable.configure();

        return natTable;
    }

    class DummySpanningBodyDataProvider implements IDataProvider,
            ISpanningDataProvider {

        private final int columnCount;
        private final int rowCount;

        private Map<Point, Object> values = new HashMap<>();

        private static final int BLOCK_SIZE = 4;
        private static final int CELL_SPAN = 2;

        public DummySpanningBodyDataProvider(int columnCount, int rowCount) {
            this.columnCount = columnCount;
            this.rowCount = rowCount;
        }

        @Override
        public int getColumnCount() {
            return this.columnCount;
        }

        @Override
        public int getRowCount() {
            return this.rowCount;
        }

        @Override
        public Object getDataValue(int columnIndex, int rowIndex) {
            Point point = new Point(columnIndex, rowIndex);
            if (this.values.containsKey(point)) {
                return this.values.get(point);
            } else {
                return "Col: " + (columnIndex + 1) + ", Row: " + (rowIndex + 1); //$NON-NLS-1$ //$NON-NLS-2$
            }
        }

        @Override
        public void setDataValue(int columnIndex, int rowIndex, Object newValue) {
            this.values.put(new Point(columnIndex, rowIndex), newValue);
        }

        @Override
        public DataCell getCellByPosition(int columnPosition, int rowPosition) {
            int columnBlock = columnPosition / BLOCK_SIZE;
            int rowBlock = rowPosition / BLOCK_SIZE;

            boolean isSpanned = isEven(columnBlock + rowBlock)
                    && (columnPosition % BLOCK_SIZE) < CELL_SPAN
                    && (rowPosition % BLOCK_SIZE) < CELL_SPAN;
            int columnSpan = isSpanned ? CELL_SPAN : 1;
            int rowSpan = isSpanned ? CELL_SPAN : 1;

            int cellColumnPosition = columnPosition;
            int cellRowPosition = rowPosition;

            if (isSpanned) {
                cellColumnPosition -= columnPosition % BLOCK_SIZE;
                cellRowPosition -= rowPosition % BLOCK_SIZE;
            }

            return new DataCell(cellColumnPosition, cellRowPosition,
                    columnSpan, rowSpan);
        }

        private boolean isEven(int i) {
            return i % 2 == 0;
        }

    }
}