/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.sis.referencing.crs;

import java.util.Map;
import javax.xml.bind.annotation.XmlType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import org.opengis.referencing.cs.CoordinateSystem;
import org.opengis.referencing.cs.AffineCS;
import org.opengis.referencing.crs.ImageCRS;
import org.opengis.referencing.cs.CartesianCS;
import org.opengis.referencing.datum.ImageDatum;
import org.apache.sis.internal.referencing.WKTKeywords;
import org.apache.sis.internal.metadata.MetadataUtilities;
import org.apache.sis.referencing.cs.AxesConvention;
import org.apache.sis.referencing.AbstractReferenceSystem;
import org.apache.sis.io.wkt.Formatter;

import static org.apache.sis.util.ArgumentChecks.ensureNonNull;


/**
 * A 2-dimensional engineering coordinate reference system applied to locations in images.
 * Image coordinate reference systems are treated as a separate sub-type because a separate
 * user community exists for images with its own terms of reference.
 *
 * <p><b>Used with datum type:</b>
 *   {@linkplain org.apache.sis.referencing.datum.DefaultImageDatum Image}.<br>
 * <b>Used with coordinate system types:</b>
 *   {@linkplain org.apache.sis.referencing.cs.DefaultCartesianCS Cartesian} or
 *   {@linkplain org.apache.sis.referencing.cs.DefaultAffineCS Affine}.
 * </p>
 *
 * <h2>Immutability and thread safety</h2>
 * This class is immutable and thus thread-safe if the property <em>values</em> (not necessarily the map itself),
 * the coordinate system and the datum instances given to the constructor are also immutable. Unless otherwise noted
 * in the javadoc, this condition holds if all components were created using only SIS factories and static constants.
 *
 * @author  Martin Desruisseaux (IRD, Geomatys)
 * @version 0.7
 *
 * @see org.apache.sis.referencing.datum.DefaultImageDatum
 * @see org.apache.sis.referencing.factory.GeodeticAuthorityFactory#createImageCRS(String)
 *
 * @since 0.4
 * @module
 */
@XmlType(name = "ImageCRSType", propOrder = {
    "cartesianCS",
    "affineCS",
    "datum"
})
@XmlRootElement(name = "ImageCRS")
public class DefaultImageCRS extends AbstractCRS implements ImageCRS {
    /**
     * Serial number for inter-operability with different versions.
     */
    private static final long serialVersionUID = 7312452786096397847L;

    /**
     * The datum.
     *
     * <p><b>Consider this field as final!</b>
     * This field is modified only at unmarshalling time by {@link #setDatum(ImageDatum)}</p>
     *
     * @see #getDatum()
     */
    private ImageDatum datum;

    /**
     * Creates a coordinate reference system from the given properties, datum and coordinate system.
     * The properties given in argument follow the same rules than for the
     * {@linkplain AbstractReferenceSystem#AbstractReferenceSystem(Map) super-class constructor}.
     * The following table is a reminder of main (not all) properties:
     *
     * <table class="sis">
     *   <caption>Recognized properties (non exhaustive list)</caption>
     *   <tr>
     *     <th>Property name</th>
     *     <th>Value type</th>
     *     <th>Returned by</th>
     *   </tr>
     *   <tr>
     *     <td>{@value org.opengis.referencing.IdentifiedObject#NAME_KEY}</td>
     *     <td>{@link org.opengis.metadata.Identifier} or {@link String}</td>
     *     <td>{@link #getName()}</td>
     *   </tr>
     *   <tr>
     *     <td>{@value org.opengis.referencing.IdentifiedObject#ALIAS_KEY}</td>
     *     <td>{@link org.opengis.util.GenericName} or {@link CharSequence} (optionally as array)</td>
     *     <td>{@link #getAlias()}</td>
     *   </tr>
     *   <tr>
     *     <td>{@value org.opengis.referencing.IdentifiedObject#IDENTIFIERS_KEY}</td>
     *     <td>{@link org.opengis.metadata.Identifier} (optionally as array)</td>
     *     <td>{@link #getIdentifiers()}</td>
     *   </tr>
     *   <tr>
     *     <td>{@value org.opengis.referencing.IdentifiedObject#REMARKS_KEY}</td>
     *     <td>{@link org.opengis.util.InternationalString} or {@link String}</td>
     *     <td>{@link #getRemarks()}</td>
     *   </tr>
     *   <tr>
     *     <td>{@value org.opengis.referencing.ReferenceSystem#DOMAIN_OF_VALIDITY_KEY}</td>
     *     <td>{@link org.opengis.metadata.extent.Extent}</td>
     *     <td>{@link #getDomainOfValidity()}</td>
     *   </tr>
     *   <tr>
     *     <td>{@value org.opengis.referencing.ReferenceSystem#SCOPE_KEY}</td>
     *     <td>{@link org.opengis.util.InternationalString} or {@link String}</td>
     *     <td>{@link #getScope()}</td>
     *   </tr>
     * </table>
     *
     * @param  properties  the properties to be given to the coordinate reference system.
     * @param  datum       the datum.
     * @param  cs          the coordinate system.
     *
     * @see org.apache.sis.referencing.factory.GeodeticObjectFactory#createImageCRS(Map, ImageDatum, AffineCS)
     */
    public DefaultImageCRS(final Map<String,?> properties,
                           final ImageDatum    datum,
                           final AffineCS      cs)
    {
        super(properties, cs);
        ensureNonNull("datum", datum);
        this.datum = datum;
    }

    /**
     * Constructs a new coordinate reference system with the same values than the specified one.
     * This copy constructor provides a way to convert an arbitrary implementation into a SIS one
     * or a user-defined one (as a subclass), usually in order to leverage some implementation-specific API.
     *
     * <p>This constructor performs a shallow copy, i.e. the properties are not cloned.</p>
     *
     * @param  crs  the coordinate reference system to copy.
     *
     * @see #castOrCopy(ImageCRS)
     */
    protected DefaultImageCRS(final ImageCRS crs) {
        super(crs);
        datum = crs.getDatum();
    }

    /**
     * Returns a SIS coordinate reference system implementation with the same values than the given
     * arbitrary implementation. If the given object is {@code null}, then this method returns {@code null}.
     * Otherwise if the given object is already a SIS implementation, then the given object is returned unchanged.
     * Otherwise a new SIS implementation is created and initialized to the attribute values of the given object.
     *
     * @param  object  the object to get as a SIS implementation, or {@code null} if none.
     * @return a SIS implementation containing the values of the given object (may be the
     *         given object itself), or {@code null} if the argument was null.
     */
    public static DefaultImageCRS castOrCopy(final ImageCRS object) {
        return (object == null) || (object instanceof DefaultImageCRS)
                ? (DefaultImageCRS) object : new DefaultImageCRS(object);
    }

    /**
     * Returns the GeoAPI interface implemented by this class.
     * The SIS implementation returns {@code ImageCRS.class}.
     *
     * <div class="note"><b>Note for implementers:</b>
     * Subclasses usually do not need to override this method since GeoAPI does not define {@code ImageCRS}
     * sub-interface. Overriding possibility is left mostly for implementers who wish to extend GeoAPI with
     * their own set of interfaces.</div>
     *
     * @return {@code ImageCRS.class} or a user-defined sub-interface.
     */
    @Override
    public Class<? extends ImageCRS> getInterface() {
        return ImageCRS.class;
    }

    /**
     * Returns the datum.
     *
     * @return the datum.
     */
    @Override
    @XmlElement(name = "imageDatum", required = true)
    public ImageDatum getDatum() {
        return datum;
    }

    /**
     * Returns the coordinate system.
     *
     * @return the coordinate system.
     */
    @Override
    public AffineCS getCoordinateSystem() {
        return (AffineCS) super.getCoordinateSystem();
    }

    /**
     * {@inheritDoc}
     *
     * @return {@inheritDoc}
     */
    @Override
    public DefaultImageCRS forConvention(final AxesConvention convention) {
        return (DefaultImageCRS) super.forConvention(convention);
    }

    /**
     * Returns a coordinate reference system of the same type than this CRS but with different axes.
     */
    @Override
    final AbstractCRS createSameType(final Map<String,?> properties, final CoordinateSystem cs) {
        return new DefaultImageCRS(properties, datum, (AffineCS) cs);
    }

    /**
     * Formats this CRS as a <cite>Well Known Text</cite> {@code ImageCRS[…]} element.
     *
     * <div class="note"><b>Compatibility note:</b>
     * {@code ImageCRS} are defined in the WKT 2 specification only.</div>
     *
     * @return {@code "ImageCRS"}.
     *
     * @see <a href="http://docs.opengeospatial.org/is/12-063r5/12-063r5.html#79">WKT 2 specification §12</a>
     */
    @Override
    protected String formatTo(final Formatter formatter) {
        super.formatTo(formatter);
        if (formatter.getConvention().majorVersion() == 1) {
            formatter.setInvalidWKT(this, null);
        }
        return WKTKeywords.ImageCRS;
    }


    //////////////////////////////////////////////////////////////////////////////////////////////////
    ////////                                                                                  ////////
    ////////                               XML support with JAXB                              ////////
    ////////                                                                                  ////////
    ////////        The following methods are invoked by JAXB using reflection (even if       ////////
    ////////        they are private) or are helpers for other methods invoked by JAXB.       ////////
    ////////        Those methods can be safely removed if Geographic Markup Language         ////////
    ////////        (GML) support is not needed.                                              ////////
    ////////                                                                                  ////////
    //////////////////////////////////////////////////////////////////////////////////////////////////

    /**
     * Constructs a new object in which every attributes are set to a null value.
     * <strong>This is not a valid object.</strong> This constructor is strictly
     * reserved to JAXB, which will assign values to the fields using reflexion.
     */
    private DefaultImageCRS() {
        /*
         * The datum and the coordinate system are mandatory for SIS working. We do not verify their presence
         * here because the verification would have to be done in an 'afterMarshal(…)' method and throwing an
         * exception in that method causes the whole unmarshalling to fail.  But the SC_CRS adapter does some
         * verifications.
         */
    }

    /**
     * Invoked by JAXB at unmarshalling time.
     *
     * @see #getDatum()
     */
    private void setDatum(final ImageDatum value) {
        if (datum == null) {
            datum = value;
        } else {
            MetadataUtilities.propertyAlreadySet(DefaultImageCRS.class, "setDatum", "imageDatum");
        }
    }

    /**
     * Used by JAXB only (invoked by reflection).
     * Only one of {@code getCartesianCS()} and {@link #getAffineCS()} can return a non-null value.
     *
     * <div class="note"><b>Implementation note:</b>
     * The usual way to handle {@code <xs:choice>} with JAXB is to annotate a single method like below:
     *
     * {@preformat java
     *     &#64;Override
     *     &#64;XmlElements({
     *       &#64;XmlElement(name = "cartesianCS", type = DefaultCartesianCS.class),
     *       &#64;XmlElement(name = "affineCS",    type = DefaultAffineCS.class)
     *     })
     *     public AffineCS getCoordinateSystem() {
     *         return super.getCoordinateSystem();
     *     }
     * }
     *
     * However our attempts to apply this approach worked for {@link DefaultEngineeringCRS} but not for this class:
     * for an unknown reason, the unmarshalled CS object is empty. Maybe this is because the covariant return type
     * ({@code AffineCS} instead than {@code CoordinateSystem} in above code) is causing confusion.</div>
     *
     * @see <a href="http://issues.apache.org/jira/browse/SIS-166">SIS-166</a>
     */
    @XmlElement(name = "cartesianCS") private CartesianCS getCartesianCS() {return getCoordinateSystem(CartesianCS.class);}
    @XmlElement(name = "affineCS")    private AffineCS    getAffineCS()    {return getCoordinateSystem(AffineCS.class);}

    /**
     * Used by JAXB only (invoked by reflection).
     *
     * @see #getCartesianCS()
     */
    private void setCartesianCS(final CartesianCS cs) {setCoordinateSystem("cartesianCS", cs);}
    private void setAffineCS   (final AffineCS    cs) {setCoordinateSystem("affineCS",    cs);}
}