1   /* Copyright 2022-2025 Thales Alenia Space
2    * Licensed to CS GROUP (CS) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * CS licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *   http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.orekit.time;
18  
19  import org.hipparchus.CalculusFieldElement;
20  import org.orekit.errors.OrekitException;
21  import org.orekit.errors.OrekitMessages;
22  import org.orekit.utils.TimeSpanMap;
23  
24  /** Offset clock model aggregating several other clock models.
25   * @author Luc Maisonobe
26   * @since 12.1
27   */
28  public class AggregatedClockModel implements ClockModel {
29  
30      /** Underlying clock models. */
31      private final TimeSpanMap<ClockModel> models;
32  
33      /** Simple constructor.
34       * @param models underlying clock models
35       */
36      public AggregatedClockModel(final TimeSpanMap<ClockModel> models) {
37          this.models = models;
38      }
39  
40      /** Get the underlying models.
41       * @return underlying models
42       */
43      public TimeSpanMap<ClockModel> getModels() {
44          return models;
45      }
46  
47      /** {@inheritDoc} */
48      @Override
49      public AbsoluteDate getValidityStart() {
50          return models.getFirstNonNullSpan().getStart();
51      }
52  
53      /** {@inheritDoc} */
54      @Override
55      public AbsoluteDate getValidityEnd() {
56          return models.getLastNonNullSpan().getEnd();
57      }
58  
59      /** {@inheritDoc} */
60      @Override
61      public ClockOffset getOffset(final AbsoluteDate date) {
62          return getModel(date).getOffset(date);
63      }
64  
65      /** {@inheritDoc} */
66      @Override
67      public <T extends CalculusFieldElement<T>> FieldClockOffset<T> getOffset(final FieldAbsoluteDate<T> date) {
68          return getModel(date.toAbsoluteDate()).getOffset(date);
69      }
70  
71      /** Get the model valid at specified date.
72       * @param date date for which model is requested
73       * @return clock model valid at date
74       */
75      private ClockModel getModel(final AbsoluteDate date) {
76          final ClockModel clockModel = models.get(date);
77          if (clockModel == null) {
78              // this may happen if map is limited or not contiguous
79              // typically for models retrieved from SP3Ephemeris
80              throw new OrekitException(OrekitMessages.NO_DATA_GENERATED, date);
81          }
82          return clockModel;
83      }
84  
85  }