/*******************************************************************************
 * Copyright (c) 2012 Original authors and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     Original authors and others - initial API and implementation
 ******************************************************************************/
package org.eclipse.nebula.widgets.nattable.extension.builder.util;

import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

import org.eclipse.nebula.widgets.nattable.columnCategories.ColumnCategoriesModel;
import org.eclipse.nebula.widgets.nattable.columnCategories.Node;
import org.eclipse.nebula.widgets.nattable.extension.builder.model.TableColumn;
import org.eclipse.nebula.widgets.nattable.util.ArrayUtil;

public class ColumnCategoriesModelAssembler {

    public static ColumnCategoriesModel setupColumnCategories(
            TableColumn[] columnProps) {

        ColumnCategoriesModel model = new ColumnCategoriesModel();
        Node rootNode = model.addRootCategory("Root");
        Node all = model.addCategory(rootNode, "All");

        Map<String, List<Integer>> columnCategoryToColumnIndexesMap = new LinkedHashMap<String, List<Integer>>();
        List<Integer> indexesNotCategorized = new LinkedList<Integer>();

        for (TableColumn tableColumn : columnProps) {
            indexesNotCategorized.add(tableColumn.index);
        }

        for (int columnIndex = 0; columnIndex < columnProps.length; columnIndex++) {
            String categoryName = columnProps[columnIndex].categoryName;

            // Column if part of a category
            if (categoryName != null) {
                List<Integer> columnCategoryIndexes = columnCategoryToColumnIndexesMap
                        .get(categoryName);

                // Create an entry in the map for the category
                if (columnCategoryIndexes == null) {
                    columnCategoryIndexes = new LinkedList<Integer>();
                    columnCategoryToColumnIndexesMap.put(categoryName,
                            columnCategoryIndexes);
                }
                // Add to map
                columnCategoryIndexes.add(columnIndex);
                indexesNotCategorized.remove(Integer.valueOf(columnIndex));
            }
        }

        // Transfer the map created to the category model
        all.addChildColumnIndexes(ArrayUtil.asIntArray(indexesNotCategorized));

        for (String columnGroupName : columnCategoryToColumnIndexesMap.keySet()) {
            List<Integer> columnIndexes = columnCategoryToColumnIndexesMap
                    .get(columnGroupName);

            int[] intColumnIndexes = new int[columnIndexes.size()];
            int i = 0;
            for (Integer columnIndex : columnIndexes) {
                intColumnIndexes[i] = columnIndex;
                i++;
            }
            Node node = model.addCategory(all, columnGroupName);
            node.addChildColumnIndexes(ArrayUtil.asIntArray(columnIndexes));
        }

        return model;
    }
}