1   /* Copyright 2002-2026 CS GROUP
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  
18  package org.orekit.forces.maneuvers.trigger;
19  
20  import org.hipparchus.CalculusFieldElement;
21  import org.hipparchus.Field;
22  import org.orekit.forces.maneuvers.Maneuver;
23  import org.orekit.propagation.FieldSpacecraftState;
24  import org.orekit.propagation.SpacecraftState;
25  import org.orekit.propagation.events.EventDetector;
26  import org.orekit.propagation.events.EventDetectorsProvider;
27  import org.orekit.propagation.events.FieldEventDetector;
28  import org.orekit.time.AbsoluteDate;
29  import org.orekit.time.FieldAbsoluteDate;
30  import org.orekit.utils.ParameterDriver;
31  import org.orekit.utils.ParameterDriversProvider;
32  
33  import java.util.Collections;
34  import java.util.List;
35  import java.util.stream.Stream;
36  
37  /** Generic interface for the maneuver triggers used in a {@link Maneuver}.
38   * @author Maxime Journot
39   * @since 10.2
40   */
41  public interface ManeuverTriggers extends ParameterDriversProvider, EventDetectorsProvider {
42  
43      /** Initialization method called at propagation start.
44       * <p>
45       * The default implementation does nothing.
46       * </p>
47       * @param initialState initial spacecraft state (at the start of propagation).
48       * @param target date of propagation. Not equal to {@code initialState.getDate()}.
49       */
50      default void init(final SpacecraftState initialState, final AbsoluteDate target) {
51          // nothing by default
52      }
53  
54      /** Initialization method called at propagation start.
55       * <p>
56       * The default implementation does nothing.
57       * </p>
58       * @param initialState initial spacecraft state (at the start of propagation).
59       * @param target date of propagation. Not equal to {@code initialState.getDate()}.
60       * @param <T> type of the elements
61       * @since 11.1
62       */
63      default <T extends CalculusFieldElement<T>> void init(final FieldSpacecraftState<T> initialState, final FieldAbsoluteDate<T> target) {
64          init(initialState.toSpacecraftState(), target.toAbsoluteDate());
65      }
66  
67      /** Find out if the maneuver is firing or not.
68       * @param date current date
69       * @param parameters maneuver triggers parameters
70       * @return true if the maneuver is firing, false otherwise
71       */
72      boolean isFiring(AbsoluteDate date, double[] parameters);
73  
74      /** Find out if the maneuver is firing or not.
75       * @param date current date
76       * @param parameters maneuver triggers parameters
77       * @param <T> type of the field elements
78       * @return true if the maneuver is firing, false otherwise
79       */
80      <T extends CalculusFieldElement<T>> boolean isFiring(FieldAbsoluteDate<T> date, T[] parameters);
81  
82      /** Get the maneuver name.
83       * @return the maneuver name
84       */
85      default String getName() {
86          return "";
87      }
88  
89      /** {@inheritDoc} */
90      @Override
91      default Stream<EventDetector> getEventDetectors() {
92          return getEventDetectors(getParametersDrivers());
93      }
94  
95      /** {@inheritDoc} */
96      @Override
97      default <T extends CalculusFieldElement<T>> Stream<FieldEventDetector<T>> getFieldEventDetectors(final Field<T> field) {
98          return getFieldEventDetectors(field, getParametersDrivers());
99      }
100 
101     /**
102      * {@inheritDoc}
103      * <p>
104      * By default, no drivers is defined.
105      */
106     @Override
107     default List<ParameterDriver> getParametersDrivers() {
108         return Collections.emptyList();
109     }
110 }