/* Copyright 2002-2026 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.observation;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.hipparchus.geometry.euclidean.threed.Vector3D;
  import org.hipparchus.geometry.euclidean.twod.Vector2D;
  import org.orekit.files.rinex.section.Label;
  import org.orekit.files.rinex.section.RinexClockObsBaseHeader;
  import org.orekit.files.rinex.utils.ParsingUtils;
  import org.orekit.files.rinex.utils.RinexFileType;
  import org.orekit.gnss.SatInSystem;
  import org.orekit.gnss.SatelliteSystem;
  import org.orekit.time.AbsoluteDate;
  import org.orekit.time.TimeScales;
  
  /** Container for Rinex observation file header.
   * @since 9.2
   */
  public class RinexObservationHeader extends RinexClockObsBaseHeader {
  
      /** Index of label in header lines. */
      public static final int LABEL_INDEX = 60;
  
      /** Name of the Antenna Marker. */
      private String markerName;
  
      /** Number of Antenna marker. */
      private String markerNumber;
  
      /** Type of Antenna marker. */
      private String markerType;
  
      /** Name of Observer. */
      private String observerName;
  
      /** Name of Agency. */
      private String agencyName;
  
      /** Antenna Number. */
      private String antennaNumber;
  
      /** Antenna Type. */
      private String antennaType;
  
      /** Approximate Marker Position (WGS84). */
      private Vector3D approxPos;
  
      /** Antenna Height. */
      private double antennaHeight;
  
      /** Eccentricities of antenna center. */
      private Vector2D eccentricities;
  
      /** Position of antenna reference point for antenna on vehicle. */
      private Vector3D antRefPoint;
  
      /** Satellite system for average phasecenter position.
       * @since 12.0
       */
      private SatelliteSystem phaseCenterSystem;
  
      /** Observation code of the average phasecenter position w/r to antenna reference point. */
      private String observationCode;
  
      /** Antenna phasecenter.
       * North/East/Up (fixed station) or X/Y/Z in body fixed system (vehicle). */
      private Vector3D antennaPhaseCenter;
  
      /** Antenna B.Sight.
       * Direction of the “vertical” antenna axis towards the GNSS satellites.  */
      private Vector3D antennaBSight;
  
      /** Azimuth of the zero direction of a fixed antenna (degrees, from north). */
      private double antennaAzimuth;
  
      /** Zero direction of antenna. */
      private Vector3D antennaZeroDirection;
  
      /** Current center of mass (X,Y,Z, meters) of vehicle in body fixed coordinate system. */
     private Vector3D centerMass;
 
     /** Unit of the carrier to noise ratio observables Snn (if present) DBHZ: S/N given in dbHz. */
     private String signalStrengthUnit;
 
     /** Observation interval in seconds. */
     private double interval;
 
     /** Time of First observation record. */
     private AbsoluteDate tFirstObs;
 
     /** Time of last observation record. */
     private AbsoluteDate tLastObs;
 
     /** Flag for application of real time-derived receiver clock offset.
      * @since 12.1
      */
     private boolean clockOffsetApplied;
 
     /** List of phase shift correction used to generate phases consistent w/r to cycle shifts. */
     private final List<PhaseShiftCorrection> phaseShiftCorrections;
 
     /** List of scale factor corrections. */
     private final Map<SatelliteSystem, List<ScaleFactorCorrection>> scaleFactorCorrections;
 
     /** List of GLONASS satellite-channel associations.
      * @since 12.0
      */
     private final List<GlonassSatelliteChannel> glonassChannels;
 
     /** Number of satellites.
      * @since 12.0
      */
     private int nbSat;
 
     /** Number of observations per satellite.
      * @since 12.0
      */
     private final Map<SatInSystem, Map<String, Integer>> nbObsPerSat;
 
     /** Code phase bias correction for GLONASS C1C signal.
      * @since 12.0
      */
     private double c1cCodePhaseBias;
 
     /** Code phase bias correction for GLONASS C1P signal.
      * @since 12.0
      */
     private double c1pCodePhaseBias;
 
     /** Code phase bias correction for GLONASS C2C signal.
      * @since 12.0
      */
     private double c2cCodePhaseBias;
 
     /** Code phase bias correction for GLONASS C2P signal.
      * @since 12.0
      */
     private double c2pCodePhaseBias;
 
     /** Simple constructor.
      */
     public RinexObservationHeader() {
         super(RinexFileType.OBSERVATION);
         antennaAzimuth         = Double.NaN;
         antennaHeight          = Double.NaN;
         eccentricities         = Vector2D.ZERO;
         clockOffsetApplied     = false;
         nbSat                  = -1;
         interval               = Double.NaN;
         phaseShiftCorrections  = new ArrayList<>();
         scaleFactorCorrections = new HashMap<>();
         glonassChannels        = new ArrayList<>();
         nbObsPerSat            = new HashMap<>();
         tLastObs               = AbsoluteDate.FUTURE_INFINITY;
         c1cCodePhaseBias       = Double.NaN;
         c1pCodePhaseBias       = Double.NaN;
         c2cCodePhaseBias       = Double.NaN;
         c2pCodePhaseBias       = Double.NaN;
     }
 
     /** {@inheritDoc} */
     @Override
     public SatelliteSystem parseSatelliteSystem(final String line, final SatelliteSystem defaultSatelliteSystem) {
         // for observation files, the satellite system is in column 40, and empty defaults to GPS
         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);
     }
 
     /** Set name of the antenna marker.
      * @param markerName name of the antenna marker
      */
     public void setMarkerName(final String markerName) {
         this.markerName = markerName;
     }
 
     /** Get name of the antenna marker.
      * @return name of the antenna marker
      */
     public String getMarkerName() {
         return markerName;
     }
 
     /** Set number of the antenna marker.
      * @param markerNumber number of the antenna marker
      */
     public void setMarkerNumber(final String markerNumber) {
         this.markerNumber = markerNumber;
     }
 
     /** Get number of the antenna marker.
      * @return number of the antenna marker
      */
     public String getMarkerNumber() {
         return markerNumber;
     }
 
     /** Set name of the observer.
      * @param observerName name of the observer
      */
     public void setObserverName(final String observerName) {
         this.observerName = observerName;
     }
 
     /** Get name of the observer.
      * @return name of the observer
      */
     public String getObserverName() {
         return observerName;
     }
 
     /**
      * Setter for the agency name.
      * @param agencyName the agency name to set
      */
     public void setAgencyName(final String agencyName) {
         this.agencyName = agencyName;
     }
 
     /** Get name of the agency.
      * @return name of the agency
      */
     public String getAgencyName() {
         return agencyName;
     }
 
     /** Set the number of the antenna.
      * @param antennaNumber number of the antenna
      */
     public void setAntennaNumber(final String antennaNumber) {
         this.antennaNumber = antennaNumber;
     }
 
     /** Get the number of the antenna.
      * @return number of the antenna
      */
     public String getAntennaNumber() {
         return antennaNumber;
     }
 
     /** Set the type of the antenna.
      * @param antennaType type of the antenna
      */
     public void setAntennaType(final String antennaType) {
         this.antennaType = antennaType;
     }
 
     /** Get the type of the antenna.
      * @return type of the antenna
      */
     public String getAntennaType() {
         return antennaType;
     }
 
     /** Set the Approximate Marker Position.
      * @param approxPos Approximate Marker Position
      */
     public void setApproxPos(final Vector3D approxPos) {
         this.approxPos = approxPos;
     }
 
     /** Get the Approximate Marker Position.
      * @return Approximate Marker Position
      */
     public Vector3D getApproxPos() {
         return approxPos;
     }
 
     /** Set the antenna height.
      * @param antennaHeight height of the antenna
      */
     public void setAntennaHeight(final double antennaHeight) {
         this.antennaHeight = antennaHeight;
     }
 
     /** Get the antenna height.
      * @return height of the antenna
      */
     public double getAntennaHeight() {
         return antennaHeight;
     }
 
     /** Set the eccentricities of antenna center.
      * @param eccentricities Eccentricities of antenna center
      */
     public void setEccentricities(final Vector2D eccentricities) {
         this.eccentricities = eccentricities;
     }
 
     /** Get the eccentricities of antenna center.
      * @return Eccentricities of antenna center
      */
     public Vector2D getEccentricities() {
         return eccentricities;
     }
 
     /** Set the application flag for realtime-derived receiver clock offset.
      * @param clockOffsetApplied application flag for realtime-derived receiver clock offset
      * @since 12.1
      */
     public void setClockOffsetApplied(final boolean clockOffsetApplied) {
         this.clockOffsetApplied = clockOffsetApplied;
     }
 
     /** Get the application flag for realtime-derived receiver clock offset.
      * @return application flag for realtime-derived receiver clock offset
      * @since 12.1
      */
     public boolean getClockOffsetApplied() {
         return clockOffsetApplied;
     }
 
     /** Set the observation interval in seconds.
      * @param interval Observation interval in seconds
      */
     public void setInterval(final double interval) {
         this.interval = interval;
     }
 
     /** Get the observation interval in seconds.
      * @return Observation interval in seconds
      */
     public double getInterval() {
         return interval;
     }
 
     /** Set the time of First observation record.
      * @param firstObs Time of First observation record
      */
     public void setTFirstObs(final AbsoluteDate firstObs) {
         this.tFirstObs = firstObs;
     }
 
     /** Get the time of First observation record.
      * @return Time of First observation record
      */
     public AbsoluteDate getTFirstObs() {
         return tFirstObs;
     }
 
     /** Set the time of last observation record.
      * @param lastObs Time of last observation record
      */
     public void setTLastObs(final AbsoluteDate lastObs) {
         this.tLastObs = lastObs;
     }
 
     /** Get the time of last observation record.
      * @return Time of last observation record
      */
     public AbsoluteDate getTLastObs() {
         return tLastObs;
     }
 
     /** Set type of the antenna marker.
      * @param markerType type of the antenna marker
      */
     public void setMarkerType(final String markerType) {
         this.markerType = markerType;
     }
 
     /** Get type of the antenna marker.
      * @return type of the antenna marker
      */
     public String getMarkerType() {
         return markerType;
     }
 
     /** Set the position of antenna reference point for antenna on vehicle.
      * @param refPoint Position of antenna reference point for antenna on vehicle
      */
     public void setAntennaReferencePoint(final Vector3D refPoint) {
         this.antRefPoint = refPoint;
     }
 
     /** Get the position of antenna reference point for antenna on vehicle.
      * @return Position of antenna reference point for antenna on vehicle
      */
     public Vector3D getAntennaReferencePoint() {
         return antRefPoint;
     }
 
     /** Set satellite system for average phase center.
      * @param phaseCenterSystem satellite system for average phase center
      * @since 12.0
      */
     public void setPhaseCenterSystem(final SatelliteSystem phaseCenterSystem) {
         this.phaseCenterSystem = phaseCenterSystem;
     }
 
     /** Get satellite system for average phase center.
      * @return satellite system for average phase center
      * @since 12.0
      */
     public SatelliteSystem getPhaseCenterSystem() {
         return phaseCenterSystem;
     }
 
     /** Set the observation code of the average phasecenter position w/r to antenna reference point.
      * @param observationCode Observation code of the average phasecenter position w/r to antenna reference point
      */
     public void setObservationCode(final String observationCode) {
         this.observationCode = observationCode;
     }
 
     /** Get the observation code of the average phasecenter position w/r to antenna reference point.
      * @return Observation code of the average phasecenter position w/r to antenna reference point
      */
     public String getObservationCode() {
         return observationCode;
     }
 
     /** Set the antenna phasecenter.
      * @param antennaPhaseCenter Antenna phasecenter
      */
     public void setAntennaPhaseCenter(final Vector3D antennaPhaseCenter) {
         this.antennaPhaseCenter = antennaPhaseCenter;
     }
 
     /** Get the antenna phasecenter.
      * @return Antenna phasecenter
      */
     public Vector3D getAntennaPhaseCenter() {
         return antennaPhaseCenter;
     }
 
     /** Set the antenna B.Sight.
      * @param antennaBSight Antenna B.Sight
      */
     public void setAntennaBSight(final Vector3D antennaBSight) {
         this.antennaBSight = antennaBSight;
     }
 
     /** Get the antenna B.Sight.
      * @return Antenna B.Sight
      */
     public Vector3D getAntennaBSight() {
         return antennaBSight;
     }
 
     /** Set the azimuth of the zero direction of a fixed antenna.
      * @param antennaAzimuth Azimuth of the zero direction of a fixed antenna
      */
     public void setAntennaAzimuth(final double antennaAzimuth) {
         this.antennaAzimuth = antennaAzimuth;
     }
 
     /** Get the azimuth of the zero direction of a fixed antenna.
      * @return Azimuth of the zero direction of a fixed antenna
      */
     public double getAntennaAzimuth() {
         return antennaAzimuth;
     }
 
     /** Set the zero direction of antenna.
      * @param antennaZeroDirection Zero direction of antenna
      */
     public void setAntennaZeroDirection(final Vector3D antennaZeroDirection) {
         this.antennaZeroDirection = antennaZeroDirection;
     }
 
     /** Get the zero direction of antenna.
      * @return Zero direction of antenna
      */
     public Vector3D getAntennaZeroDirection() {
         return antennaZeroDirection;
     }
 
     /** Set the current center of mass of vehicle in body fixed coordinate system.
      * @param centerMass Current center of mass of vehicle in body fixed coordinate system
      */
     public void setCenterMass(final Vector3D centerMass) {
         this.centerMass = centerMass;
     }
 
     /** Get the current center of mass of vehicle in body fixed coordinate system.
      * @return Current center of mass of vehicle in body fixed coordinate system
      */
     public Vector3D getCenterMass() {
         return centerMass;
     }
 
     /** Set the unit of the carrier to noise ratio observables.
      * @param signalStrengthUnit Unit of the carrier to noise ratio observables
      */
     public void setSignalStrengthUnit(final String signalStrengthUnit) {
         this.signalStrengthUnit = signalStrengthUnit;
     }
 
     /** Get the unit of the carrier to noise ratio observables.
      * @return Unit of the carrier to noise ratio observables
      */
     public String getSignalStrengthUnit() {
         return signalStrengthUnit;
     }
 
     /** Add phase shift correction used to generate phases consistent w/r to cycle shifts.
      * @param phaseShiftCorrection phase shift correction used to generate phases consistent w/r to cycle shifts
      */
     public void addPhaseShiftCorrection(final PhaseShiftCorrection phaseShiftCorrection) {
         phaseShiftCorrections.add(phaseShiftCorrection);
     }
 
     /** Get the list of phase shift correction used to generate phases consistent w/r to cycle shifts.
      * @return List of phase shift correction used to generate phases consistent w/r to cycle shifts
      */
     public List<PhaseShiftCorrection> getPhaseShiftCorrections() {
         return Collections.unmodifiableList(phaseShiftCorrections);
     }
 
     /** Add scale factor correction.
      * @param satelliteSystem system to which this scaling factor applies
      * @param scaleFactorCorrection scale factor correction
      */
     public void addScaleFactorCorrection(final SatelliteSystem satelliteSystem, final ScaleFactorCorrection scaleFactorCorrection) {
         final List<ScaleFactorCorrection> sfc;
         synchronized (scaleFactorCorrections) {
             sfc = scaleFactorCorrections.computeIfAbsent(satelliteSystem, k -> new ArrayList<>());
         }
         sfc.add(scaleFactorCorrection);
     }
 
     /** Get the list of scale factor correction.
      * @param satelliteSystem system to which this scaling factor applies
      * @return List of scale factor correction
      */
     public List<ScaleFactorCorrection> getScaleFactorCorrections(final SatelliteSystem satelliteSystem) {
         final List<ScaleFactorCorrection> sfc = scaleFactorCorrections.get(satelliteSystem);
         return sfc == null ? Collections.emptyList() : Collections.unmodifiableList(sfc);
     }
 
     /** Add GLONASS satellite/channel association.
      * @param glonassChannel GLONASS satellite/channel association
      * @since 12.0
      */
     public void addGlonassChannel(final GlonassSatelliteChannel glonassChannel) {
         glonassChannels.add(glonassChannel);
     }
 
     /** Get the list of GLONASS satellite/channel associations.
      * @return List of GLONASS satellite/channel associations
      * @since 12.0
      */
     public List<GlonassSatelliteChannel> getGlonassChannels() {
         return Collections.unmodifiableList(glonassChannels);
     }
 
     /** Set number of satellites.
      * @param nbSat number of satellites
      * @since 12.0
      */
     public void setNbSat(final int nbSat) {
         this.nbSat = nbSat;
     }
 
     /** Get number of satellites.
      * @return number of satellites
      * @since 12.0
      */
     public int getNbSat() {
         return nbSat;
     }
 
     /** Set number of observations for a satellite.
      * @param sat satellite
      * @param type observation type
      * @param nbObs number of observations of this type for this satellite
      * @since 12.0
      */
     public void setNbObsPerSatellite(final SatInSystem sat, final String type, final int nbObs) {
         final Map<String, Integer> satNbObs;
         synchronized (nbObsPerSat) {
             satNbObs = nbObsPerSat.computeIfAbsent(sat, k -> new HashMap<>());
         }
         satNbObs.put(type, nbObs);
     }
 
     /** Get an unmodifiable view of the map of number of observations per satellites.
      * @return unmodifiable view of the map of number of observations per satellites
      * @since 12.0
      */
     public Map<SatInSystem, Map<String, Integer>> getNbObsPerSat() {
         return Collections.unmodifiableMap(nbObsPerSat);
     }
 
     /** Set the code phase bias correction for GLONASS {@link org.orekit.gnss.PredefinedObservationType#C1C} signal.
      * @param c1cCodePhaseBias code phase bias correction for GLONASS {@link org.orekit.gnss.PredefinedObservationType#C1C} signal
      * @since 12.0
      */
     public void setC1cCodePhaseBias(final double c1cCodePhaseBias) {
         this.c1cCodePhaseBias = c1cCodePhaseBias;
     }
 
     /** Get the code phase bias correction for GLONASS {@link org.orekit.gnss.PredefinedObservationType#C1C} signal.
      * @return code phase bias correction for GLONASS {@link org.orekit.gnss.PredefinedObservationType#C1C} signal
      * @since 12.0
      */
     public double getC1cCodePhaseBias() {
         return c1cCodePhaseBias;
     }
 
     /** Set the code phase bias correction for GLONASS {@link org.orekit.gnss.PredefinedObservationType#C1P} signal.
      * @param c1pCodePhaseBias code phase bias correction for GLONASS {@link org.orekit.gnss.PredefinedObservationType#C1P} signal
      * @since 12.0
      */
     public void setC1pCodePhaseBias(final double c1pCodePhaseBias) {
         this.c1pCodePhaseBias = c1pCodePhaseBias;
     }
 
     /** Get the code phase bias correction for GLONASS {@link org.orekit.gnss.PredefinedObservationType#C1P} signal.
      * @return code phase bias correction for GLONASS {@link org.orekit.gnss.PredefinedObservationType#C1P} signal
      * @since 12.0
      */
     public double getC1pCodePhaseBias() {
         return c1pCodePhaseBias;
     }
 
     /** Set the code phase bias correction for GLONASS {@link org.orekit.gnss.PredefinedObservationType#C2C} signal.
      * @param c2cCodePhaseBias code phase bias correction for GLONASS {@link org.orekit.gnss.PredefinedObservationType#C2C} signal
      * @since 12.0
      */
     public void setC2cCodePhaseBias(final double c2cCodePhaseBias) {
         this.c2cCodePhaseBias = c2cCodePhaseBias;
     }
 
     /** Get the code phase bias correction for GLONASS {@link org.orekit.gnss.PredefinedObservationType#C2C} signal.
      * @return code phase bias correction for GLONASS {@link org.orekit.gnss.PredefinedObservationType#C2C} signal
      * @since 12.0
      */
     public double getC2cCodePhaseBias() {
         return c2cCodePhaseBias;
     }
 
     /** Set the code phase bias correction for GLONASS {@link org.orekit.gnss.PredefinedObservationType#C2P} signal.
      * @param c2pCodePhaseBias code phase bias correction for GLONASS {@link org.orekit.gnss.PredefinedObservationType#C2P} signal
      * @since 12.0
      */
     public void setC2pCodePhaseBias(final double c2pCodePhaseBias) {
         this.c2pCodePhaseBias = c2pCodePhaseBias;
     }
 
     /** Get the code phase bias correction for GLONASS {@link org.orekit.gnss.PredefinedObservationType#C2P} signal.
      * @return code phase bias correction for GLONASS {@link org.orekit.gnss.PredefinedObservationType#C2P} signal
      * @since 12.0
      */
     public double getC2pCodePhaseBias() {
         return c2pCodePhaseBias;
     }
 
     /** {@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) {
         final int max = getLabelIndex();
         return line.length() >= max && label.matches(line.substring(max).trim());
     }
 
 }