1   /* Copyright 2002-2025 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  package org.orekit.time;
18  
19  import org.junit.jupiter.api.Assertions;
20  import org.junit.jupiter.api.BeforeEach;
21  import org.junit.jupiter.api.Test;
22  import org.orekit.Utils;
23  import org.orekit.utils.Constants;
24  
25  public class BDSScaleTest {
26  
27      @Test
28      public void testT0() {
29          TimeScale scale = TimeScalesFactory.getBDT();
30          Assertions.assertEquals("BDT", scale.toString());
31          AbsoluteDate t0 =
32              new AbsoluteDate(new DateComponents(2006, 1, 1), new TimeComponents(0, 0, 13), scale);
33          Assertions.assertEquals(new AbsoluteDate(new DateComponents(2006, 1, 1), new TimeComponents(0, 0, 13),
34                                               TimeScalesFactory.getUTC()),
35                              t0);
36      }
37  
38      @Test
39      public void test2010() {
40          AbsoluteDate tBDT =
41              new AbsoluteDate(new DateComponents(2010, 1, 2), TimeComponents.H00, TimeScalesFactory.getBDT());
42          AbsoluteDate tUTC =
43              new AbsoluteDate(new DateComponents(2010, 1, 1), new TimeComponents(23, 59, 59.0),
44                               TimeScalesFactory.getUTC());
45          Assertions.assertEquals(tUTC, tBDT);
46      }
47  
48      @Test
49      public void testDuringLeap() {
50          final TimeScale utc   = TimeScalesFactory.getUTC();
51          final TimeScale scale = TimeScalesFactory.getBDT();
52          final AbsoluteDate before = new AbsoluteDate(new DateComponents(1983, 6, 30),
53                                                       new TimeComponents(23, 59, 59),
54                                                       utc);
55          final AbsoluteDate during = before.shiftedBy(1.25);
56          Assertions.assertEquals(61, utc.minuteDuration(during));
57          Assertions.assertEquals(1.0, utc.getLeap(during).toDouble(), 1.0e-10);
58          Assertions.assertEquals(60, scale.minuteDuration(during));
59          Assertions.assertEquals(0.0, scale.getLeap(during).toDouble(), 1.0e-10);
60      }
61  
62      @Test
63      public void testConstant() {
64          TimeScale scale = TimeScalesFactory.getBDT();
65          double reference = scale.offsetFromTAI(AbsoluteDate.J2000_EPOCH).toDouble();
66          for (double dt = -10000; dt < 10000; dt += 123.456789) {
67              AbsoluteDate date = AbsoluteDate.J2000_EPOCH.shiftedBy(dt * Constants.JULIAN_DAY);
68              Assertions.assertEquals(reference, scale.offsetFromTAI(date).toDouble(), 1.0e-15);
69          }
70      }
71  
72      @Test
73      public void testAwayFromGPS() {
74          TimeScale bdt = TimeScalesFactory.getBDT();
75          TimeScale gps = TimeScalesFactory.getGPS();
76          for (double dt = -10000; dt < 10000; dt += 123.456789) {
77              AbsoluteDate date = AbsoluteDate.J2000_EPOCH.shiftedBy(7 * Constants.JULIAN_YEAR + dt * Constants.JULIAN_DAY);
78              Assertions.assertEquals(gps.offsetFromTAI(date).toDouble() - 14, bdt.offsetFromTAI(date).toDouble(), 1.0e-15);
79          }
80      }
81  
82      @Test
83      public void testSymmetry() {
84          TimeScale scale = TimeScalesFactory.getBDT();
85          for (double dt = -10000; dt < 10000; dt += 123.456789) {
86              AbsoluteDate date = AbsoluteDate.J2000_EPOCH.shiftedBy(dt * Constants.JULIAN_DAY);
87              double dt1 = scale.offsetFromTAI(date).toDouble();
88              DateTimeComponents components = date.getComponents(scale);
89              double dt2 = scale.offsetToTAI(components.getDate(), components.getTime()).toDouble();
90              Assertions.assertEquals( 0.0, dt1 + dt2, 1.0e-10);
91          }
92      }
93  
94      @BeforeEach
95      public void setUp() {
96          Utils.setDataRoot("regular-data");
97      }
98  
99  }