/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2010, Open Source Geospatial Foundation (OSGeo)
 *
 *    This library is free software; you can redistribute it and/or
 *    modify it under the terms of the GNU Lesser General Public
 *    License as published by the Free Software Foundation;
 *    version 2.1 of the License.
 *
 *    This library is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *    Lesser General Public License for more details.
 */

package org.geotools.grid;

import java.util.Map;

import com.vividsolutions.jts.geom.Polygon;

import org.geotools.feature.simple.SimpleFeatureTypeBuilder;

import org.opengis.feature.simple.SimpleFeatureType;
import org.opengis.referencing.crs.CoordinateReferenceSystem;

/**
 * A basic implementation of {@code GridFeatureBuilder} which will create a
 * {@code SimpleFeatureType} having two properties:
 * <ul>
 * <li>element - TYPE Polygon
 * <li>id - TYPE Integer
 * </ul>
 * The attribute names can also be referred to using
 * {@linkplain GridFeatureBuilder#DEFAULT_GEOMETRY_ATTRIBUTE_NAME} and
 * {@linkplain #ID_ATTRIBUTE_NAME}
 * <p>
 * Grid elements will be assigned sequential id values starting with 1.
 *
 * @author mbedward
 * @since 2.7
 *
 *
 * @source $URL$
 * @version $Id$
 */
public final class DefaultGridFeatureBuilder extends GridFeatureBuilder {

    /** Default feature TYPE name: "grid" */
    public static final String DEFAULT_TYPE_NAME = "grid";

    /** Name used for the integer id attribute: "id" */
    public static final String ID_ATTRIBUTE_NAME = "id";
    
    private int id;

    /**
     * Creates the feature TYPE
     *
     * @param typeName name for the feature TYPE; if {@code null} or empty,
     *        {@linkplain #DEFAULT_TYPE_NAME} will be used
     *
     * @param crs coordinate reference system (may be {@code null})
     *
     * @return the feature TYPE
     */
    protected static SimpleFeatureType createType(String typeName, CoordinateReferenceSystem crs) {
        final String finalName;
        if (typeName != null && typeName.trim().length() > 0) {
            finalName = typeName;
        } else {
            finalName = DEFAULT_TYPE_NAME;
        }

        SimpleFeatureTypeBuilder tb = new SimpleFeatureTypeBuilder();
        tb.setName(finalName);
        tb.add(DEFAULT_GEOMETRY_ATTRIBUTE_NAME, Polygon.class, crs);
        tb.add("id", Integer.class);
        return tb.buildFeatureType();
    }

    /**
     * Creates a new instance with a feature TYPE having the default name
     * and a null coordinate reference system.
     *
     * @see #DEFAULT_TYPE_NAME
     */
    public DefaultGridFeatureBuilder() {
        this(DEFAULT_TYPE_NAME, null);
    }

    /**
     * Creates a new instance with a null coordinate reference system.
     *
     * @param typeName name for the feature TYPE; if {@code null} or empty,
     *        {@linkplain #DEFAULT_TYPE_NAME} will be used
     */
    DefaultGridFeatureBuilder(String typeName) {
        this(typeName, null);
    }

    /**
     * Creates a new instance with a feature TYPE having the default name
     * and the supplied coordinate reference system.
     *
     * @param crs coordinate reference system (may be {@code null})
     *
     * @see #DEFAULT_TYPE_NAME
     */
    public DefaultGridFeatureBuilder(CoordinateReferenceSystem crs) {
        this(DEFAULT_TYPE_NAME, crs);
    }

    /**
     * Creates a new instance.
     *
     * @param typeName name for the feature TYPE; if {@code null} or empty,
     *        {@linkplain #DEFAULT_TYPE_NAME} will be used
     *
     * @param crs coordinate reference system (may be {@code null})
     */
    public DefaultGridFeatureBuilder(String typeName, CoordinateReferenceSystem crs) {
        super(createType(typeName, crs));
        id = 0;
    }

    /**
     * Overrides {@linkplain GridFeatureBuilder#setAttributes(GridElement, Map)}
     * to assign a sequential integer id value to each grid element feature
     * as it is constructed.
     *
     * @param el the element from which the new feature is being constructed
     *
     * @param attributes a {@code Map} with the single key "id"
     */
    @Override
    public void setAttributes(GridElement el, Map<String, Object> attributes) {
        attributes.put("id", ++id);
    }

}