/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2005-2008, 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.referencing.factory.epsg;

// J2SE dependencies
import java.util.Iterator;

import org.geotools.factory.Hints;
import org.geotools.referencing.ReferencingFactoryFinder;
import org.geotools.referencing.factory.epsg.oracle.OracleOnlineTestCase;
import org.geotools.referencing.operation.AbstractCoordinateOperation;
import org.geotools.referencing.operation.AuthorityBackedFactory;
import org.geotools.referencing.operation.BufferedCoordinateOperationFactory;
import org.geotools.resources.Classes;
import org.geotools.util.Utilities;
import org.opengis.referencing.FactoryException;
import org.opengis.referencing.IdentifiedObject;
import org.opengis.referencing.crs.CRSAuthorityFactory;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import org.opengis.referencing.operation.ConcatenatedOperation;
import org.opengis.referencing.operation.Conversion;
import org.opengis.referencing.operation.CoordinateOperation;
import org.opengis.referencing.operation.CoordinateOperationFactory;
import org.opengis.referencing.operation.Transformation;


/**
 * Tests the usage of {@link CoordinateOperationFactory} with the help of the
 * EPSG database.
 *
 *
 *
 * @source $URL$
 * @version $Id$
 * @author Martin Desruisseaux (IRD)
 */
public class OperationFactoryOnlineTest extends OracleOnlineTestCase {

    /**
     * Returns the first identifier for the specified object.
     */
    private static String getIdentifier(final IdentifiedObject object) {
        return object.getIdentifiers().iterator().next().getCode();
    }

    /**
     * Tests the creation of an operation from EPSG:4230 to EPSG:4326. They are the same
     * CRS than the one tested in {@link DefaultDataSourceTest#testTransformations}.
     */
    public void testCreate() throws FactoryException {
        final CRSAuthorityFactory       crsFactory;
        final CoordinateOperationFactory opFactory;
              CoordinateReferenceSystem  sourceCRS;
              CoordinateReferenceSystem  targetCRS;
              CoordinateOperation        operation;

        crsFactory = ReferencingFactoryFinder.getCRSAuthorityFactory("EPSG", null);
        opFactory  = ReferencingFactoryFinder.getCoordinateOperationFactory(null);
        sourceCRS  = crsFactory.createCoordinateReferenceSystem("4230");
        targetCRS  = crsFactory.createCoordinateReferenceSystem("4326");
        operation  = opFactory.createOperation(sourceCRS, targetCRS);

        assertSame(sourceCRS, operation.getSourceCRS());
        assertSame(targetCRS, operation.getTargetCRS());
        assertSame(operation, opFactory.createOperation(sourceCRS, targetCRS));
        assertTrue("Expected a buffered factory but got " + opFactory.getClass().getName(),
                opFactory instanceof BufferedCoordinateOperationFactory);
        assertTrue("EPSG authority factory not found.",
                ((BufferedCoordinateOperationFactory) opFactory).getImplementationHints().
                get(Hints.COORDINATE_OPERATION_FACTORY) instanceof AuthorityBackedFactory);
        assertEquals("1612", getIdentifier(operation)); // See comment in DefaultDataSourceTest.
        assertEquals(1.0, AbstractCoordinateOperation.getAccuracy(operation), 1E-6);
        assertTrue(operation instanceof Transformation);
        /*
         * Tests a transformation not backed directly by an authority factory.
         * However, the inverse transform may exist in the authority factory.
         */
        sourceCRS  = crsFactory.createCoordinateReferenceSystem("4326");
        targetCRS  = crsFactory.createCoordinateReferenceSystem("2995");
        operation  = opFactory.createOperation(sourceCRS, targetCRS);
        assertTrue("This test needs an operation not backed by the EPSG factory.",
                   operation.getIdentifiers().isEmpty());
        // Should contains exactly one transformations and an arbitrary number of conversions.
        assertTrue(operation instanceof ConcatenatedOperation);
        int count = 0;
        for (final Iterator it=((ConcatenatedOperation) operation).getOperations().iterator(); it.hasNext();) {
            final CoordinateOperation op = (CoordinateOperation) it.next();
            if (op instanceof Transformation) {
                count++;
            } else {
                assertTrue("Expected Conversion but got " + 
                           Classes.getShortName(AbstractCoordinateOperation.getType(op)) + ". ",
                           (op instanceof Conversion));
            }
        }
        assertEquals("The coordinate operation should contains exactly 1 transformation", 1, count);
        assertTrue(AbstractCoordinateOperation.getAccuracy(operation) <= 25);
    }
}