1   /* Copyright 2022-2026 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.clocks;
18  
19  import org.hipparchus.CalculusFieldElement;
20  import org.orekit.errors.OrekitException;
21  import org.orekit.errors.OrekitMessages;
22  import org.orekit.time.AbsoluteDate;
23  import org.orekit.time.FieldAbsoluteDate;
24  import org.orekit.utils.TimeSpanMap;
25  
26  /** Offset clock model aggregating several other clock models.
27   * @author Luc Maisonobe
28   * @since 12.1
29   */
30  public class AggregatedClockModel implements ClockModel {
31  
32      /** Underlying clock models. */
33      private final TimeSpanMap<ClockModel> models;
34  
35      /** Simple constructor.
36       * @param models underlying clock models
37       */
38      public AggregatedClockModel(final TimeSpanMap<ClockModel> models) {
39          this.models = models;
40      }
41  
42      /** Get the underlying models.
43       * @return underlying models
44       */
45      public TimeSpanMap<ClockModel> getModels() {
46          return models;
47      }
48  
49      /** {@inheritDoc} */
50      @Override
51      public AbsoluteDate getValidityStart() {
52          return models.getFirstNonNullSpan().getStart();
53      }
54  
55      /** {@inheritDoc} */
56      @Override
57      public AbsoluteDate getValidityEnd() {
58          return models.getLastNonNullSpan().getEnd();
59      }
60  
61      /** {@inheritDoc} */
62      @Override
63      public ClockOffset getOffset(final AbsoluteDate date) {
64          return getModel(date).getOffset(date);
65      }
66  
67      /** {@inheritDoc} */
68      @Override
69      public <T extends CalculusFieldElement<T>> FieldClockOffset<T> getOffset(final FieldAbsoluteDate<T> date) {
70          return getModel(date.toAbsoluteDate()).getOffset(date);
71      }
72  
73      /** Get the model valid at specified date.
74       * @param date date for which model is requested
75       * @return clock model valid at date
76       */
77      private ClockModel getModel(final AbsoluteDate date) {
78          final ClockModel clockModel = models.get(date);
79          if (clockModel == null) {
80              // this may happen if map is limited or not contiguous
81              // typically for models retrieved from SP3Ephemeris
82              throw new OrekitException(OrekitMessages.NO_DATA_GENERATED, date);
83          }
84          return clockModel;
85      }
86  
87  }