/* Copyright 2002-2016 CS Systèmes d'Information
    * Licensed to CS Systèmes d'Information (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.ccsds;
  
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.List;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import org.apache.commons.math3.util.FastMath;
  import org.orekit.errors.OrekitException;
  import org.orekit.errors.OrekitInternalError;
  import org.orekit.errors.OrekitMessages;
  import org.orekit.files.general.OrbitFile;
  import org.orekit.time.AbsoluteDate;
  import org.orekit.time.DateTimeComponents;
  import org.orekit.time.TimeScalesFactory;
  import org.orekit.utils.Constants;
  import org.orekit.utils.IERSConventions;
  
  /** Base class for all CCSDS Orbit Data Message parsers.
   * <p>
   * This base class is immutable, and hence thread safe. When parts
   * must be changed, such as reference date for Mission Elapsed Time or
   * Mission Relative Time time systems, or the gravitational coefficient or
   * the IERS conventions, the various {@code withXxx} methods must be called,
   * which create a new immutable instance with the new parameters. This
   * is a combination of the <a href="">builder design pattern</a> and
   * a <a href="http://en.wikipedia.org/wiki/Fluent_interface">fluent
   * interface</a>.
   * </p>
   * @author Luc Maisonobe
   * @since 6.1
   */
  public abstract class ODMParser {
  
      /** Pattern for international designator. */
      private static final Pattern INTERNATIONAL_DESIGNATOR = Pattern.compile("(\\p{Digit}{4})-(\\p{Digit}{3})(\\p{Upper}{1,3})");
  
      /** Reference date for Mission Elapsed Time or Mission Relative Time time systems. */
      private final AbsoluteDate missionReferenceDate;
  
      /** Gravitational coefficient. */
      private final  double mu;
  
      /** IERS Conventions. */
      private final  IERSConventions conventions;
  
      /** Indicator for simple or accurate EOP interpolation. */
      private final  boolean simpleEOP;
  
      /** Launch Year. */
      private int launchYear;
  
      /** Launch number. */
      private int launchNumber;
  
      /** Piece of launch (from "A" to "ZZZ"). */
      private String launchPiece;
  
      /** Complete constructor.
       * @param missionReferenceDate reference date for Mission Elapsed Time or Mission Relative Time time systems
       * @param mu gravitational coefficient
       * @param conventions IERS Conventions
       * @param simpleEOP if true, tidal effects are ignored when interpolating EOP
       * @param launchYear launch year for TLEs
       * @param launchNumber launch number for TLEs
       * @param launchPiece piece of launch (from "A" to "ZZZ") for TLEs
       */
      protected ODMParser(final AbsoluteDate missionReferenceDate, final double mu,
                          final IERSConventions conventions, final boolean simpleEOP,
                          final int launchYear, final int launchNumber, final String launchPiece) {
          this.missionReferenceDate = missionReferenceDate;
          this.mu                   = mu;
          this.conventions          = conventions;
          this.simpleEOP            = simpleEOP;
          this.launchYear           = launchYear;
          this.launchNumber         = launchNumber;
          this.launchPiece          = launchPiece;
      }
  
      /** Set initial date.
      * @param newMissionReferenceDate mission reference date to use while parsing
      * @return a new instance, with mission reference date replaced
      * @see #getMissionReferenceDate()
      */
     public abstract ODMParser withMissionReferenceDate(final AbsoluteDate newMissionReferenceDate);
 
     /** Get initial date.
      * @return mission reference date to use while parsing
      * @see #withMissionReferenceDate(AbsoluteDate)
      */
     public AbsoluteDate getMissionReferenceDate() {
         return missionReferenceDate;
     }
 
     /** Set gravitational coefficient.
      * @param newMu gravitational coefficient to use while parsing
      * @return a new instance, with gravitational coefficient date replaced
      * @see #getMu()
      */
     public abstract ODMParser withMu(final double newMu);
 
     /** Get gravitational coefficient.
      * @return gravitational coefficient to use while parsing
      * @see #withMu(double)
      */
     public double getMu() {
         return mu;
     }
 
     /** Set IERS conventions.
      * @param newConventions IERS conventions to use while parsing
      * @return a new instance, with IERS conventions replaced
      * @see #getConventions()
      */
     public abstract ODMParser withConventions(final IERSConventions newConventions);
 
     /** Get IERS conventions.
      * @return IERS conventions to use while parsing
      * @see #withConventions(IERSConventions)
      */
     public IERSConventions getConventions() {
         return conventions;
     }
 
     /** Set EOP interpolation method.
      * @param newSimpleEOP if true, tidal effects are ignored when interpolating EOP
      * @return a new instance, with EOP interpolation method replaced
      * @see #isSimpleEOP()
      */
     public abstract ODMParser withSimpleEOP(final boolean newSimpleEOP);
 
     /** Get EOP interpolation method.
      * @return true if tidal effects are ignored when interpolating EOP
      * @see #withSimpleEOP(boolean)
      */
     public boolean isSimpleEOP() {
         return simpleEOP;
     }
 
     /** Set international designator.
      * <p>
      * This method may be used to ensure the launch year number and pieces are
      * correctly set if they are not present in the CCSDS file header in the
      * OBJECT_ID in the form YYYY-NNN-P{PP}. If they are already in the header,
      * they will be parsed automatically regardless of this method being called
      * or not (i.e. header information override information set here).
      * </p>
      * @param newLaunchYear launch year
      * @param newLaunchNumber launch number
      * @param newLaunchPiece piece of launch (from "A" to "ZZZ")
      * @return a new instance, with TLE settings replaced
      */
     public abstract ODMParser withInternationalDesignator(final int newLaunchYear,
                                                           final int newLaunchNumber,
                                                           final String newLaunchPiece);
 
     /** Get the launch year.
      * @return launch year
      */
     public int getLaunchYear() {
         return launchYear;
     }
 
     /** Get the launch number.
      * @return launch number
      */
     public int getLaunchNumber() {
         return launchNumber;
     }
 
     /** Get the piece of launch.
      * @return piece of launch
      */
     public String getLaunchPiece() {
         return launchPiece;
     }
 
     /** Parse a CCSDS Orbit Data Message.
      * @param fileName name of the file containing the message
      * @return parsed orbit
      * @exception OrekitException if orbit message cannot be parsed
      */
     public ODMFile parse(final String fileName)
         throws OrekitException {
 
         InputStream stream = null;
 
         try {
             stream = new FileInputStream(fileName);
             return parse(stream, fileName);
         } catch (FileNotFoundException e) {
             throw new OrekitException(OrekitMessages.UNABLE_TO_FIND_FILE, fileName);
         } finally {
             try {
                 if (stream != null) {
                     stream.close();
                 }
             } catch (IOException e) {
                 // ignore
             }
         }
 
     }
 
     /** Parse a CCSDS Orbit Data Message.
      * @param stream stream containing message
      * @return parsed orbit
      * @exception OrekitException if orbit message cannot be parsed
      */
     public ODMFile parse(final InputStream stream)
         throws OrekitException {
         return parse(stream, "<unknown>");
     }
 
     /** Parse a CCSDS Orbit Data Message.
      * @param stream stream containing message
      * @param fileName name of the file containing the message (for error messages)
      * @return parsed orbit
      * @exception OrekitException if orbit message cannot be parsed
      */
     public abstract ODMFile parse(final InputStream stream, final String fileName)
         throws OrekitException;
 
     /** Parse a comment line.
      * @param keyValue key=value pair containing the comment
      * @param comment placeholder where the current comment line should be added
      * @return true if the line was a comment line and was parsed
      */
     protected boolean parseComment(final KeyValue keyValue, final List<String> comment) {
         if (keyValue.getKeyword() == Keyword.COMMENT) {
             comment.add(keyValue.getValue());
             return true;
         } else {
             return false;
         }
     }
 
     /** Parse an entry from the header.
      * @param keyValue key = value pair
      * @param odmFile instance to update with parsed entry
      * @param comment previous comment lines, will be emptied if used by the keyword
      * @return true if the keyword was a header keyword and has been parsed
      * @exception OrekitException if UTC time scale cannot be retrieved to parse creation date
      */
     protected boolean parseHeaderEntry(final KeyValue keyValue,
                                        final ODMFile odmFile, final List<String> comment)
         throws OrekitException {
         switch (keyValue.getKeyword()) {
 
             case CREATION_DATE:
                 if (!comment.isEmpty()) {
                     odmFile.setHeaderComment(comment);
                     comment.clear();
                 }
                 odmFile.setCreationDate(new AbsoluteDate(keyValue.getValue(), TimeScalesFactory.getUTC()));
                 return true;
 
             case ORIGINATOR:
                 odmFile.setOriginator(keyValue.getValue());
                 return true;
 
             default:
                 return false;
 
         }
 
     }
 
     /** Parse a meta-data key = value entry.
      * @param keyValue key = value pair
      * @param metaData instance to update with parsed entry
      * @param comment previous comment lines, will be emptied if used by the keyword
      * @return true if the keyword was a meta-data keyword and has been parsed
      * @exception OrekitException if center body or frame cannot be retrieved
      */
     protected boolean parseMetaDataEntry(final KeyValue keyValue,
                                          final ODMMetaData metaData, final List<String> comment)
         throws OrekitException {
         switch (keyValue.getKeyword()) {
             case OBJECT_NAME:
                 if (!comment.isEmpty()) {
                     metaData.setComment(comment);
                     comment.clear();
                 }
                 metaData.setObjectName(keyValue.getValue());
                 return true;
 
             case OBJECT_ID: {
                 metaData.setObjectID(keyValue.getValue());
                 final Matcher matcher = INTERNATIONAL_DESIGNATOR.matcher(keyValue.getValue());
                 if (matcher.matches()) {
                     metaData.setLaunchYear(Integer.parseInt(matcher.group(1)));
                     metaData.setLaunchNumber(Integer.parseInt(matcher.group(2)));
                     metaData.setLaunchPiece(matcher.group(3));
                 }
                 return true;
             }
 
             case CENTER_NAME:
                 metaData.setCenterName(keyValue.getValue());
                 final String canonicalValue;
                 if (keyValue.getValue().equals("SOLAR SYSTEM BARYCENTER") || keyValue.getValue().equals("SSB")) {
                     canonicalValue = "SOLAR_SYSTEM_BARYCENTER";
                 } else if (keyValue.getValue().equals("EARTH MOON BARYCENTER") || keyValue.getValue().equals("EARTH-MOON BARYCENTER") ||
                         keyValue.getValue().equals("EARTH BARYCENTER") || keyValue.getValue().equals("EMB")) {
                     canonicalValue = "EARTH_MOON";
                 } else {
                     canonicalValue = keyValue.getValue();
                 }
                 for (final CenterName c : CenterName.values()) {
                     if (c.name().equals(canonicalValue)) {
                         metaData.setHasCreatableBody(true);
                         metaData.setCenterBody(c.getCelestialBody());
                         metaData.getODMFile().setMuCreated(c.getCelestialBody().getGM());
                     }
                 }
                 return true;
 
             case REF_FRAME:
                 metaData.setRefFrame(parseCCSDSFrame(keyValue.getValue()).getFrame(getConventions(), isSimpleEOP()));
                 return true;
 
             case REF_FRAME_EPOCH:
                 metaData.setFrameEpochString(keyValue.getValue());
                 return true;
 
             case TIME_SYSTEM:
                 final OrbitFile.TimeSystem timeSystem = OrbitFile.TimeSystem.valueOf(keyValue.getValue());
                 metaData.setTimeSystem(timeSystem);
                 if (metaData.getFrameEpochString() != null) {
                     metaData.setFrameEpoch(parseDate(metaData.getFrameEpochString(), timeSystem));
                 }
                 return true;
 
             default:
                 return false;
         }
     }
 
     /** Parse a general state data key = value entry.
      * @param keyValue key = value pair
      * @param general instance to update with parsed entry
      * @param comment previous comment lines, will be emptied if used by the keyword
      * @return true if the keyword was a meta-data keyword and has been parsed
      * @exception OrekitException if center body or frame cannot be retrieved
      */
     protected boolean parseGeneralStateDataEntry(final KeyValue keyValue,
                                                  final OGMFile general, final List<String> comment)
         throws OrekitException {
         switch (keyValue.getKeyword()) {
 
             case EPOCH:
                 general.setEpochComment(comment);
                 comment.clear();
                 general.setEpoch(parseDate(keyValue.getValue(), general.getTimeSystem()));
                 return true;
 
             case SEMI_MAJOR_AXIS:
                 general.setKeplerianElementsComment(comment);
                 comment.clear();
                 general.setA(keyValue.getDoubleValue() * 1000);
                 general.setHasKeplerianElements(true);
                 return true;
 
             case ECCENTRICITY:
                 general.setE(keyValue.getDoubleValue());
                 return true;
 
             case INCLINATION:
                 general.setI(FastMath.toRadians(keyValue.getDoubleValue()));
                 return true;
 
             case RA_OF_ASC_NODE:
                 general.setRaan(FastMath.toRadians(keyValue.getDoubleValue()));
                 return true;
 
             case ARG_OF_PERICENTER:
                 general.setPa(FastMath.toRadians(keyValue.getDoubleValue()));
                 return true;
 
             case TRUE_ANOMALY:
                 general.setAnomalyType("TRUE");
                 general.setAnomaly(FastMath.toRadians(keyValue.getDoubleValue()));
                 return true;
 
             case MEAN_ANOMALY:
                 general.setAnomalyType("MEAN");
                 general.setAnomaly(FastMath.toRadians(keyValue.getDoubleValue()));
                 return true;
 
             case GM:
                 general.setMuParsed(keyValue.getDoubleValue() * 1e9);
                 return true;
 
             case MASS:
                 comment.addAll(0, general.getSpacecraftComment());
                 general.setSpacecraftComment(comment);
                 comment.clear();
                 general.setMass(keyValue.getDoubleValue());
                 return true;
 
             case SOLAR_RAD_AREA:
                 comment.addAll(0, general.getSpacecraftComment());
                 general.setSpacecraftComment(comment);
                 comment.clear();
                 general.setSolarRadArea(keyValue.getDoubleValue());
                 return true;
 
             case SOLAR_RAD_COEFF:
                 comment.addAll(0, general.getSpacecraftComment());
                 general.setSpacecraftComment(comment);
                 comment.clear();
                 general.setSolarRadCoeff(keyValue.getDoubleValue());
                 return true;
 
             case DRAG_AREA:
                 comment.addAll(0, general.getSpacecraftComment());
                 general.setSpacecraftComment(comment);
                 comment.clear();
                 general.setDragArea(keyValue.getDoubleValue());
                 return true;
 
             case DRAG_COEFF:
                 comment.addAll(0, general.getSpacecraftComment());
                 general.setSpacecraftComment(comment);
                 comment.clear();
                 general.setDragCoeff(keyValue.getDoubleValue());
                 return true;
 
             case COV_REF_FRAME:
                 general.setCovarianceComment(comment);
                 comment.clear();
                 final CCSDSFrame covFrame = parseCCSDSFrame(keyValue.getValue());
                 if (covFrame.isLof()) {
                     general.setCovRefLofType(covFrame.getLofType());
                 } else {
                     general.setCovRefFrame(covFrame.getFrame(getConventions(), isSimpleEOP()));
                 }
                 return true;
 
             case CX_X:
                 general.createCovarianceMatrix();
                 general.setCovarianceMatrixEntry(0, 0, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CY_X:
                 general.setCovarianceMatrixEntry(0, 1, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CY_Y:
                 general.setCovarianceMatrixEntry(1, 1, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CZ_X:
                 general.setCovarianceMatrixEntry(0, 2, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CZ_Y:
                 general.setCovarianceMatrixEntry(1, 2, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CZ_Z:
                 general.setCovarianceMatrixEntry(2, 2, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CX_DOT_X:
                 general.setCovarianceMatrixEntry(0, 3, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CX_DOT_Y:
                 general.setCovarianceMatrixEntry(1, 3, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CX_DOT_Z:
                 general.setCovarianceMatrixEntry(2, 3, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CX_DOT_X_DOT:
                 general.setCovarianceMatrixEntry(3, 3, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CY_DOT_X:
                 general.setCovarianceMatrixEntry(0, 4, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CY_DOT_Y:
                 general.setCovarianceMatrixEntry(1, 4, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CY_DOT_Z:
                 general.setCovarianceMatrixEntry(2, 4, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CY_DOT_X_DOT:
                 general.setCovarianceMatrixEntry(3, 4, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CY_DOT_Y_DOT:
                 general.setCovarianceMatrixEntry(4, 4, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CZ_DOT_X:
                 general.setCovarianceMatrixEntry(0, 5, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CZ_DOT_Y:
                 general.setCovarianceMatrixEntry(1, 5, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CZ_DOT_Z:
                 general.setCovarianceMatrixEntry(2, 5, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CZ_DOT_X_DOT:
                 general.setCovarianceMatrixEntry(3, 5, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CZ_DOT_Y_DOT:
                 general.setCovarianceMatrixEntry(4, 5, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case CZ_DOT_Z_DOT:
                 general.setCovarianceMatrixEntry(5, 5, keyValue.getDoubleValue() * 1.0e6);
                 return true;
 
             case USER_DEFINED_X:
                 general.setUserDefinedParameters(keyValue.getKey(), keyValue.getValue());
                 return true;
 
             default:
                 return false;
         }
     }
 
     /** Parse a CCSDS frame.
      * @param frameName name of the frame, as the value of a CCSDS key=value line
      * @return CCSDS frame corresponding to the name
      */
     protected CCSDSFrame parseCCSDSFrame(final String frameName) {
         return CCSDSFrame.valueOf(frameName.replaceAll("-", ""));
     }
 
     /** Parse a date.
      * @param date date to parse, as the value of a CCSDS key=value line
      * @param timeSystem time system to use
      * @return parsed date
      * @exception OrekitException if some time scale cannot be retrieved
      */
     protected AbsoluteDate parseDate(final String date, final OrbitFile.TimeSystem timeSystem)
         throws OrekitException {
         switch (timeSystem) {
             case GMST:
                 return new AbsoluteDate(date, TimeScalesFactory.getGMST(conventions, false));
             case GPS:
                 return new AbsoluteDate(date, TimeScalesFactory.getGPS());
             case TAI:
                 return new AbsoluteDate(date, TimeScalesFactory.getTAI());
             case TCB:
                 return new AbsoluteDate(date, TimeScalesFactory.getTCB());
             case TDB:
                 return new AbsoluteDate(date, TimeScalesFactory.getTDB());
             case TCG:
                 return new AbsoluteDate(date, TimeScalesFactory.getTCG());
             case TT:
                 return new AbsoluteDate(date, TimeScalesFactory.getTT());
             case UT1:
                 return new AbsoluteDate(date, TimeScalesFactory.getUT1(conventions, false));
             case UTC:
                 return new AbsoluteDate(date, TimeScalesFactory.getUTC());
             case MET: {
                 final DateTimeComponents clock = DateTimeComponents.parseDateTime(date);
                 final double offset = clock.getDate().getYear() * Constants.JULIAN_YEAR +
                         clock.getDate().getDayOfYear() * Constants.JULIAN_DAY +
                         clock.getTime().getSecondsInUTCDay();
                 return missionReferenceDate.shiftedBy(offset);
             }
             case MRT: {
                 final DateTimeComponents clock = DateTimeComponents.parseDateTime(date);
                 final double offset = clock.getDate().getYear() * Constants.JULIAN_YEAR +
                         clock.getDate().getDayOfYear() * Constants.JULIAN_DAY +
                         clock.getTime().getSecondsInUTCDay();
                 return missionReferenceDate.shiftedBy(offset);
             }
             default:
                 throw new OrekitInternalError(null);
         }
     }
 
 }