/* Contributed in the public domain.
    * 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.propagation.events;
  
  import org.hamcrest.CoreMatchers;
  import org.hamcrest.MatcherAssert;
  import org.hipparchus.geometry.euclidean.threed.Vector3D;
  import org.hipparchus.ode.events.Action;
  import org.junit.jupiter.api.Test;
  import org.orekit.frames.FramesFactory;
  import org.orekit.orbits.CartesianOrbit;
  import org.orekit.propagation.SpacecraftState;
  import org.orekit.propagation.events.handlers.EventHandler;
  import org.orekit.propagation.events.handlers.StopOnEvent;
  import org.orekit.time.AbsoluteDate;
  import org.orekit.utils.PVCoordinates;
  
  import java.util.function.ToDoubleFunction;
  
  /**
   * Unit tests for {@link FunctionalDetector}
   *
   * @author Evan Ward
   */
  public class FunctionalDetectorTest {
  
      /**
       * Check {@link FunctionalDetector}.
       */
      @Test
      public void testFunctionalDetector() {
          // setup
          ToDoubleFunction<SpacecraftState> g = SpacecraftState::getMass;
          EventHandler handler = new StopOnEvent();
  
          // action
          FunctionalDetector detector = new FunctionalDetector()
                  .withMaxIter(1)
                  .withThreshold(2)
                  .withMaxCheck(3)
                  .withHandler(handler)
                  .withFunction(g);
  
          // verify
          MatcherAssert.assertThat(detector.getMaxIterationCount(), CoreMatchers.is(1));
          MatcherAssert.assertThat(detector.getThreshold(), CoreMatchers.is(2.0));
          MatcherAssert.assertThat(detector.getMaxCheckInterval().currentInterval(null, true), CoreMatchers.is(3.0));
          MatcherAssert.assertThat(detector.getHandler(), CoreMatchers.is(handler));
          SpacecraftState state = new SpacecraftState(
                  new CartesianOrbit(
                          new PVCoordinates(
                                  new Vector3D(1, 2, 3),
                                  new Vector3D(4, 5, 6)),
                          FramesFactory.getGCRF(),
                          AbsoluteDate.CCSDS_EPOCH,
                          4),
                  5);
          MatcherAssert.assertThat(detector.g(state), CoreMatchers.is(5.0));
          MatcherAssert.assertThat(detector.getHandler().eventOccurred(null, detector, false), CoreMatchers.is(Action.STOP));
          MatcherAssert.assertThat(detector.getFunction(), CoreMatchers.is(g));
      }
  
  }