/* Copyright 2022-2025 Luc Maisonobe
    * 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.analytical.gnss;
  
  import org.hipparchus.CalculusFieldElement;
  import org.hipparchus.analysis.differentiation.FieldGradient;
  import org.hipparchus.util.Binary64;
  import org.hipparchus.util.Binary64Field;
  import org.junit.jupiter.api.Assertions;
  import org.orekit.propagation.analytical.gnss.data.FieldGnssOrbitalElements;
  import org.orekit.propagation.analytical.gnss.data.GNSSOrbitalElements;
  import org.orekit.time.AbsoluteDate;
  import org.orekit.time.FieldAbsoluteDate;
  
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.util.ArrayList;
  import java.util.List;
  
  public class GnssTestUtils {
  
      @SuppressWarnings("unchecked")
      public static <O extends GNSSOrbitalElements<O>>
      void checkFieldConversion(final O message) {
          try {
              // looping over several types to check conversion functions
              FieldGnssOrbitalElements<Binary64, ?> intermediate1 =
                  message.toField(Binary64Field.getInstance());
              FieldGnssOrbitalElements<? extends FieldGradient<?>, ?> intermediate2 =
                  intermediate1.changeField(t -> FieldGradient.constant(6, t));
              final O rebuilt = (O) intermediate2.toNonField();
  
              for (final Method getter : getGetters(message, Integer.TYPE)) {
                  final Method fieldGetter = intermediate2.getClass().getMethod(getter.getName());
                  Assertions.assertEquals(getter.invoke(message), fieldGetter.invoke(intermediate2));
                  Assertions.assertEquals(getter.invoke(message), getter.invoke(rebuilt));
              }
              for (final Method getter : getGetters(message, Double.TYPE)) {
                  final Method fieldGetter = intermediate2.getClass().getMethod(getter.getName());
                  final double f = fieldGetter.getReturnType().equals(Double.TYPE) ?
                                   (Double) fieldGetter.invoke(intermediate2) :
                                   ((CalculusFieldElement<?>) fieldGetter.invoke(intermediate2)).getReal();
                  Assertions.assertEquals((Double) getter.invoke(message), f, 1.0e-15);
                  Assertions.assertEquals((Double) getter.invoke(message), (Double) getter.invoke(rebuilt), 1.0e-15, message.getClass().getName() + "." +getter.getName());
              }
              for (final Method getter : getGetters(message, AbsoluteDate.class)) {
                  final Method               fieldGetter = intermediate2.getClass().getMethod(getter.getName());
                  final AbsoluteDate         date        = (AbsoluteDate) getter.invoke(message);
                  final FieldAbsoluteDate<?> fieldDate   = (FieldAbsoluteDate<?>) fieldGetter.invoke(intermediate2);
                  final AbsoluteDate         rebuiltDate = (AbsoluteDate) getter.invoke(rebuilt);
                  Assertions.assertEquals(0.0, date.durationFrom(fieldDate.toAbsoluteDate()), 1.0e-15);
                  Assertions.assertEquals(0.0, date.durationFrom(rebuiltDate),                1.0e-15);
              }
          } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException nsme) {
              Assertions.fail(nsme.getLocalizedMessage());
          }
      }
  
      private static List<Method> getGetters(final Object o, final Class<?> returnType) {
          final List<Method> getters = new ArrayList<>();
          for (Class<?> cls = o.getClass();
               cls.getName().startsWith("org.orekit") ;
               cls = cls.getSuperclass()) {
              for (final Method method : cls.getDeclaredMethods()) {
                  if (method.getName().startsWith("get") && returnType.equals(method.getReturnType())) {
                      getters.add(method);
                  }
              }
          }
          return getters;
      }
  
  }