/* Copyright 2002-2021 CS GROUP
    * 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.forces.gravity.potential;
  
  import org.orekit.forces.gravity.potential.UnnormalizedSphericalHarmonicsProvider.UnnormalizedSphericalHarmonics;
  import org.orekit.time.AbsoluteDate;
  
  /** Wrapper providing normalized coefficients from un-normalized ones.
   * @author Luc Maisonobe
   * @since 6.0
   */
  class Normalizer implements NormalizedSphericalHarmonicsProvider {
  
      /** Un-normalized provider to which everything is delegated. */
      private final UnnormalizedSphericalHarmonicsProvider unnormalized;
  
      /** Factors for normalization. */
      private final double[][] factors;
  
      /** Simple constructor.
       * @param unnormalized provider to normalize
       */
      Normalizer(final UnnormalizedSphericalHarmonicsProvider unnormalized) {
          this.unnormalized = unnormalized;
          this.factors      = GravityFieldFactory.getUnnormalizationFactors(unnormalized.getMaxDegree(),
                                                                            unnormalized.getMaxOrder());
      }
  
      /** {@inheritDoc} */
      @Override
      public int getMaxDegree() {
          return unnormalized.getMaxDegree();
      }
  
      /** {@inheritDoc} */
      @Override
      public int getMaxOrder() {
          return unnormalized.getMaxOrder();
      }
  
      /** {@inheritDoc} */
      @Override
      public double getMu() {
          return unnormalized.getMu();
      }
  
      /** {@inheritDoc} */
      @Override
      public double getAe() {
          return unnormalized.getAe();
      }
  
      /** {@inheritDoc} */
      @Override
      public AbsoluteDate getReferenceDate() {
          return unnormalized.getReferenceDate();
      }
  
      /** {@inheritDoc} */
      @Override
      public double getOffset(final AbsoluteDate date) {
          return unnormalized.getOffset(date);
      }
  
      /** {@inheritDoc} */
      @Override
      public TideSystem getTideSystem() {
          return unnormalized.getTideSystem();
      }
  
      /** {@inheritDoc} */
      @Override
      public NormalizedSphericalHarmonics onDate(final AbsoluteDate date) {
          final UnnormalizedSphericalHarmonics harmonics = unnormalized.onDate(date);
          return new NormalizedSphericalHarmonics() {
  
              /** {@inheritDoc} */
              @Override
              public AbsoluteDate getDate() {
                  return date;
              }
  
              /** {@inheritDoc} */
              @Override
              public double getNormalizedCnm(final int n, final int m) {
                 return harmonics.getUnnormalizedCnm(n, m) / factors[n][m];
             }
 
             /** {@inheritDoc} */
             @Override
             public double getNormalizedSnm(final int n, final int m) {
                 return harmonics.getUnnormalizedSnm(n, m) / factors[n][m];
             }
 
         };
     }
 
 }