/* Copyright 2002-2025 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.files.rinex.navigation;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import org.orekit.files.rinex.section.Label;
  import org.orekit.files.rinex.section.RinexBaseHeader;
  import org.orekit.files.rinex.utils.RinexFileType;
  import org.orekit.files.rinex.utils.ParsingUtils;
  import org.orekit.gnss.SatelliteSystem;
  import org.orekit.time.TimeScales;
  
  /** Header for Rinex Navigation.
   * @author Luc Maisonobe
   * @since 12.0
   */
  public class RinexNavigationHeader extends RinexBaseHeader {
  
      /** Index of label in header lines. */
      public static final int LABEL_INDEX = 60;
  
      /** Ionospheric corrections. */
      private final List<IonosphericCorrection> ionosphericCorrections;
  
      /** List of time system corrections. */
      private final List<TimeSystemCorrection> timeSystemCorrections;
  
      /** Number of merged files. */
      private int mergedFiles;
  
      /** Simple constructor.
       */
      public RinexNavigationHeader() {
          super(RinexFileType.NAVIGATION);
          this.ionosphericCorrections = new ArrayList<>();
          this.timeSystemCorrections  = new ArrayList<>();
          this.mergedFiles            = -1;
      }
  
      /** {@inheritDoc} */
      @Override
      public SatelliteSystem parseSatelliteSystem(final String line, final SatelliteSystem defaultSatelliteSystem) {
          if (getFormatVersion() < 3.0) {
              // the satellite system is hidden within the entry, with GPS as default
  
              // look if default is overridden somewhere in the entry
              final String entry = line.substring(0, 80).toUpperCase();
              for (final SatelliteSystem satelliteSystem : SatelliteSystem.values()) {
                  if (entry.contains(satelliteSystem.name())) {
                      // we found a satellite system hidden in the middle of the line
                      return satelliteSystem;
                  }
              }
  
              // return default value
              return defaultSatelliteSystem;
  
          } else {
              // the satellite system is in column 40 for 3.X and later
              return SatelliteSystem.parseSatelliteSystem(line.substring(40, 41), defaultSatelliteSystem);
          }
      }
  
      /** {@inheritDoc} */
      @Override
      public void parseProgramRunByDate(final String line, final TimeScales timeScales) {
          parseProgramRunByDate(ParsingUtils.parseString(line, 0, 20),
                                ParsingUtils.parseString(line, 20, 20),
                                ParsingUtils.parseString(line, 40, 20),
                                timeScales);
      }
  
      /**
       * Getter for the ionospheric corrections.
       * @return the ionospheric corrections
       */
      public List<IonosphericCorrection> getIonosphericCorrections() {
          return ionosphericCorrections;
      }
  
      /**
       * Add a ionospheric correction.
       * @param ionosphericCorrection the ionospheric correction type to add
      */
     public void addIonosphericCorrection(final IonosphericCorrection ionosphericCorrection) {
         this.ionosphericCorrections.add(ionosphericCorrection);
     }
 
     /**
      * Getter for the time system corrections contained in the file header.
      * <p>
      * Corrections to transform the system time to UTC or oter time system.
      * </p>
      * @return the list of time system corrections
      */
     public List<TimeSystemCorrection> getTimeSystemCorrections() {
         return timeSystemCorrections;
     }
 
     /**
      * Add a time system correction to the list.
      * @param timeSystemCorrection the element to add
      */
     public void addTimeSystemCorrections(final TimeSystemCorrection timeSystemCorrection) {
         this.timeSystemCorrections.add(timeSystemCorrection);
     }
 
     /**
      * Getter for the number of merged files.
      * @return the number of merged files
      */
     public int getMergedFiles() {
         return mergedFiles;
     }
 
     /**
      * Setter for the number of merged files.
      * @param mergedFiles the number of merged files
      */
     public void setMergedFiles(final int mergedFiles) {
         this.mergedFiles = mergedFiles;
     }
 
     /** {@inheritDoc} */
     @Override
     public void checkType(final String line, final String name) {
         checkType(line, 20, name);
     }
 
     /** {@inheritDoc} */
     @Override
     public int getLabelIndex() {
         return LABEL_INDEX;
     }
 
     /** {@inheritDoc} */
     @Override
     public boolean matchFound(final Label label, final String line) {
         return label.matches(line.substring(getLabelIndex()).trim());
     }
 
 }