FrameFacade.java

/* Copyright 2002-2021 CS GROUP
 * Licensed to CS GROUP (CS) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * CS 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.orekit.files.ccsds.definitions;

import org.orekit.data.DataContext;
import org.orekit.errors.OrekitException;
import org.orekit.frames.Frame;
import org.orekit.utils.IERSConventions;

/** Facade in front of several frames types in CCSDS messages.
 * @author Luc Maisonobe
 * @since 11.0
 */
public class FrameFacade {

    /** Reference to node in Orekit frames tree. */
    private final Frame frame;

    /** Reference to celestial body centered frame. */
    private final CelestialBodyFrame celestialBodyFrame;

    /** Reference to orbit-relative frame. */
    private final OrbitRelativeFrame orbitRelativeFrame;

    /** Reference to spacecraft body frame. */
    private final SpacecraftBodyFrame spacecraftBodyFrame;

    /** Name of the frame. */
    private final String name;

    /** Simple constructor.
     * <p>
     * At most one of {@code celestialBodyFrame}, {@code orbitRelativeFrame}
     * or {@code spacecraftBodyFrame} may be non null. They may all be null
     * if frame is unknown, in which case only the name will be available.
     * </p>
     * @param frame reference to node in Orekit frames tree (may be null)
     * @param celestialBodyFrame reference to celestial body centered frame (may be null)
     * @param orbitRelativeFrame reference to orbit-relative frame (may be null)
     * @param spacecraftBodyFrame reference to spacecraft body frame (may be null)
     * @param name name of the frame
     */
    public FrameFacade(final Frame frame,
                       final CelestialBodyFrame celestialBodyFrame,
                       final OrbitRelativeFrame orbitRelativeFrame,
                       final SpacecraftBodyFrame spacecraftBodyFrame,
                       final String name) {
        this.frame               = frame;
        this.celestialBodyFrame  = celestialBodyFrame;
        this.orbitRelativeFrame  = orbitRelativeFrame;
        this.spacecraftBodyFrame = spacecraftBodyFrame;
        this.name                = name;
    }

    /**
     * Get the associated frame tree node.
     * @return associated frame tree node, or null if none exists
     */
    public Frame asFrame() {
        return frame;
    }

    /** Get the associated {@link CelestialBodyFrame celestial body frame}.
     * @return associated celestial body frame, or null if frame is
     * associated to a {@link #asOrbitRelativeFrame() orbit},
     * a {@link #asSpacecraftBodyFrame spacecraft} or is not supported
     */
    public CelestialBodyFrame asCelestialBodyFrame() {
        return celestialBodyFrame;
    }

    /** Get the associated {@link OrbitRelativeFrame orbit relative frame}.
     * @return associated orbit relative frame, or null if frame is
     * associated to a {@link #asCelestialBodyFrame() celestial body},
     * a {@link #asSpacecraftBodyFrame spacecraft} or is not supported
     */
    public OrbitRelativeFrame asOrbitRelativeFrame() {
        return orbitRelativeFrame;
    }

    /** Get the associated {@link SpacecraftBodyFrame spacecraft body frame}.
     * @return associated spacecraft body frame, or null if frame is
     * associated to a {@link #asCelestialBodyFrame() celestial body},
     * an {@link #asOrbitRelativeFrame orbit} or is not supported
     */
    public SpacecraftBodyFrame asSpacecraftBodyFrame() {
        return spacecraftBodyFrame;
    }

    /** Get the CCSDS name for the frame.
     * @return CCSDS name
     */
    public String getName() {
        return name;
    }

    /** Map an Orekit frame to a CCSDS frame facade.
     * @param frame a reference frame.
     * @return the CCSDSFrame corresponding to the Orekit frame
     */
    public static FrameFacade map(final Frame frame) {
        final CelestialBodyFrame cbf = CelestialBodyFrame.map(frame);
        return new FrameFacade(frame, cbf, null, null, cbf.name());
    }

    /** Simple constructor.
     * @param name name of the frame
     * @param conventions IERS conventions to use
     * @param simpleEOP if true, tidal effects are ignored when interpolating EOP
     * @param dataContext to use when creating the frame
     * @param allowCelestial if true, {@link CelestialBodyFrame} are allowed
     * @param allowOrbit if true, {@link OrbitRelativeFrame} are allowed
     * @param allowSpacecraft if true, {@link SpacecraftBodyFrame} are allowed
     * @return frame facade corresponding to the CCSDS name
     */
    public static FrameFacade parse(final String name,
                                    final IERSConventions conventions,
                                    final boolean simpleEOP,
                                    final DataContext dataContext,
                                    final boolean allowCelestial,
                                    final boolean allowOrbit,
                                    final boolean allowSpacecraft) {
        try {
            final CelestialBodyFrame cbf = CelestialBodyFrame.parse(name);
            if (allowCelestial) {
                return new FrameFacade(cbf.getFrame(conventions, simpleEOP, dataContext),
                                       cbf, null, null, cbf.name());
            }
        } catch (IllegalArgumentException iaeC) {
            try {
                final OrbitRelativeFrame orf = OrbitRelativeFrame.valueOf(name.replace(' ', '_'));
                if (allowOrbit) {
                    return new FrameFacade(null, null, orf, null, orf.name());
                }
            } catch (IllegalArgumentException iaeO) {
                try {
                    final SpacecraftBodyFrame sbf = SpacecraftBodyFrame.parse(name.replace(' ', '_'));
                    if (allowSpacecraft) {
                        return new FrameFacade(null, null, null, sbf, sbf.toString());
                    }
                } catch (OrekitException | IllegalArgumentException e) {
                    // nothing to do here, use fallback below
                }
            }
        }

        // we don't know any frame with this name, just store the name itself
        return new FrameFacade(null, null, null, null, name);

    }

}