/* 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.ccsds.utils.generation;
  
  import java.io.IOException;
  import java.time.ZoneOffset;
  import java.time.ZonedDateTime;
  
  import org.orekit.files.ccsds.definitions.TimeConverter;
  import org.orekit.files.ccsds.ndm.NdmConstituent;
  import org.orekit.files.ccsds.section.Header;
  import org.orekit.files.ccsds.section.HeaderKey;
  import org.orekit.files.ccsds.section.Segment;
  import org.orekit.files.ccsds.section.XmlStructureKey;
  import org.orekit.files.ccsds.utils.ContextBinding;
  import org.orekit.files.ccsds.utils.FileFormat;
  import org.orekit.time.AbsoluteDate;
  import org.orekit.time.DateComponents;
  import org.orekit.time.DateTimeComponents;
  import org.orekit.time.TimeComponents;
  import org.orekit.time.TimeScale;
  
  /**
   * Base class for Navigation Data Message (NDM) files.
   * @param <H> type of the header
   * @param <S> type of the segments
   * @param <F> type of the NDM constituent
   * @author Luc Maisonobe
   * @since 11.0
   */
  public abstract class AbstractMessageWriter<H extends Header, S extends Segment<?, ?>, F extends NdmConstituent<H, S>>
      implements MessageWriter<H, S, F> {
  
      /** Default value for {@link HeaderKey#ORIGINATOR}. */
      public static final String DEFAULT_ORIGINATOR = "OREKIT";
  
      /** Root element for XML files. */
      private final String root;
  
      /** Key for format version. */
      private final String formatVersionKey;
  
      /** Default format version. */
      private final double defaultVersion;
  
      /** Current context binding. */
      private ContextBinding context;
  
      /** Current converter for dates. */
      private TimeConverter timeConverter;
  
      /** Current format version. */
      private double version;
  
      /**
       * Constructor used to create a new NDM writer configured with the necessary parameters
       * to successfully fill in all required fields that aren't part of a standard object.
       * <p>
       * If creation date and originator are not present in header, built-in defaults will be used
       * </p>
       * @param root root element for XML files
       * @param formatVersionKey key for format version
       * @param defaultVersion default format version
       * @param context context binding (may be reset for each segment)
       */
      public AbstractMessageWriter(final String root, final String formatVersionKey,
                                   final double defaultVersion, final ContextBinding context) {
  
          this.root             = root;
          this.defaultVersion   = defaultVersion;
          this.formatVersionKey = formatVersionKey;
          this.version          = defaultVersion;
  
          setContext(context);
  
      }
  
      /** Reset context binding.
       * @param context context binding to use
       */
      public void setContext(final ContextBinding context) {
          this.context       = context;
          this.timeConverter = context.getTimeSystem().getConverter(context);
      }
  
     /** Get the current context.
      * @return current context
      */
     public ContextBinding getContext() {
         return context;
     }
 
     /** Get the current time converter.
      * @return current time converter
      */
     public TimeConverter getTimeConverter() {
         return timeConverter;
     }
 
     /** Get the default format version.
      * @return default format version
      */
     public double getDefaultVersion() {
         return defaultVersion;
     }
 
     /** {@inheritDoc} */
     @Override
     public void writeHeader(final Generator generator, final H header) throws IOException {
 
         final ZonedDateTime zdt = ZonedDateTime.now(ZoneOffset.UTC);
         final TimeScale     utc = context.getDataContext().getTimeScales().getUTC();
         final AbsoluteDate date = new AbsoluteDate(zdt.getYear(), zdt.getMonthValue(), zdt.getDayOfMonth(),
                                                    zdt.getHour(), zdt.getMinute(), zdt.getSecond(),
                                                    utc);
 
         // validate before writing
         if (header != null) {
 
             if (!Double.isNaN(header.getFormatVersion())) {
                 // save format version for validating segments
                 version = header.getFormatVersion();
             }
 
             if (header.getCreationDate() == null) {
                 header.setCreationDate(date);
             }
 
             if (header.getOriginator() == null) {
                 header.setOriginator(DEFAULT_ORIGINATOR);
             }
 
             header.validate(version);
 
         }
 
         generator.startMessage(root, formatVersionKey, version);
 
         if (generator.getFormat() == FileFormat.XML) {
             generator.enterSection(XmlStructureKey.header.name());
         }
 
         if (header != null) {
 
             // comments are optional
             generator.writeComments(header.getComments());
 
             // classification is optional
             generator.writeEntry(HeaderKey.CLASSIFICATION.name(), header.getClassification(), null, false);
 
         }
 
         // creation date is informational only, but mandatory and always in UTC
         final DateTimeComponents creationDate = ((header == null) ? date : header.getCreationDate()).getComponents(utc);
         final DateComponents     dc           = creationDate.getDate();
         final TimeComponents     tc           = creationDate.getTime();
         generator.writeEntry(HeaderKey.CREATION_DATE.name(),
                              generator.dateToString(dc.getYear(), dc.getMonth(), dc.getDay(),
                                                     tc.getHour(), tc.getMinute(), tc.getSecond()),
                              null, true);
 
         // Use built-in default if mandatory originator not present
         generator.writeEntry(HeaderKey.ORIGINATOR.name(),
                              header == null ? DEFAULT_ORIGINATOR : header.getOriginator(),
                              null, true);
 
         if (header != null) {
             generator.writeEntry(HeaderKey.MESSAGE_ID.name(), header.getMessageId(), null, false);
         }
 
         if (generator.getFormat() == FileFormat.XML) {
             generator.exitSection();
         }
 
         // add an empty line for presentation
         generator.newLine();
 
         if (generator.getFormat() == FileFormat.XML) {
             generator.enterSection(XmlStructureKey.body.name());
         }
 
     }
 
     /** {@inheritDoc} */
     @Override
     public void writeSegment(final Generator generator, final S segment) throws IOException {
 
         // validate before writing
         segment.getMetadata().validate(version);
         segment.getData().validate(version);
 
         if (generator.getFormat() == FileFormat.XML) {
             generator.enterSection(XmlStructureKey.segment.name());
         }
         writeSegmentContent(generator, version, segment);
         if (generator.getFormat() == FileFormat.XML) {
             generator.exitSection();
         }
 
     }
 
     /** Write one segment content (without XML wrapping).
      * @param generator generator to use for producing output
      * @param formatVersion format version to use
      * @param segment segment to write
      * @throws IOException if any buffer writing operations fails
      */
     protected abstract void writeSegmentContent(Generator generator, double formatVersion, S segment) throws IOException;
 
     /** {@inheritDoc} */
     @Override
     public void writeFooter(final Generator generator) throws IOException {
         if (generator.getFormat() == FileFormat.XML) {
             generator.exitSection();
         }
         generator.endMessage(root);
     }
 
     /** {@inheritDoc} */
     @Override
     public String getRoot() {
         return root;
     }
 
     /** {@inheritDoc} */
     @Override
     public String getFormatVersionKey() {
         return formatVersionKey;
     }
 
     /** {@inheritDoc} */
     @Override
     public double getVersion() {
         return version;
     }
 
 }