/* Copyright 2002-2024 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.util.List;
  
  import org.hipparchus.util.FastMath;
  import org.orekit.files.ccsds.utils.FileFormat;
  import org.orekit.utils.AccurateFormatter;
  import org.orekit.utils.units.Unit;
  
  /** Generator for Key-Value Notation CCSDS messages.
   * @author Luc Maisonobe
   * @since 11.0
   */
  public class KvnGenerator extends AbstractGenerator {
  
      /** Comment keyword. */
      private static final String COMMENT = "COMMENT";
  
      /** Start suffix for sections. */
      private static final String START = "_START";
  
      /** Stop suffix for sections. */
      private static final String STOP = "_STOP";
  
      /** String format used for all key/value pair lines. **/
      private final String kvFormat;
  
      /** Column number for aligning units. */
      private final int unitsColumn;
  
      /** String format used for all comment lines. **/
      private final String commentFormat;
  
      /** Simple constructor.
       * @param output destination of generated output
       * @param paddingWidth padding width for aligning the '=' sign
       * (not counting the extra blank added before the '=' sign)
       * @param outputName output name for error messages
       * @param maxRelativeOffset maximum offset in seconds to use relative dates
       * (if a date is too far from reference, it will be displayed as calendar elements)
       * @param unitsColumn columns number for aligning units (if negative or zero, units are not output)
       * @see org.orekit.files.ccsds.ndm.tdm.TdmWriter#KVN_PADDING_WIDTH     TdmWriter.KVN_PADDING_WIDTH
       * @see org.orekit.files.ccsds.ndm.adm.aem.AemWriter#KVN_PADDING_WIDTH AemWriter.KVN_PADDING_WIDTH
       * @see org.orekit.files.ccsds.ndm.adm.apm.ApmWriter#KVN_PADDING_WIDTH ApmWriter.KVN_PADDING_WIDTH
       * @see org.orekit.files.ccsds.ndm.odm.opm.OpmWriter#KVN_PADDING_WIDTH OpmWriter.KVN_PADDING_WIDTH
       * @see org.orekit.files.ccsds.ndm.odm.omm.OmmWriter#KVN_PADDING_WIDTH OmmWriter.KVN_PADDING_WIDTH
       * @see org.orekit.files.ccsds.ndm.odm.oem.OemWriter#KVN_PADDING_WIDTH OemWriter.KVN_PADDING_WIDTH
       * @see org.orekit.files.ccsds.ndm.odm.ocm.OcmWriter#KVN_PADDING_WIDTH OcmWriter.KVN_PADDING_WIDTH
       */
      public KvnGenerator(final Appendable output, final int paddingWidth,
                          final String outputName, final double maxRelativeOffset,
                          final int unitsColumn) {
          super(output, outputName, maxRelativeOffset, unitsColumn > 0);
          kvFormat = "%-" + FastMath.max(1, paddingWidth) + "s = %s";
          final StringBuilder builder = new StringBuilder(COMMENT);
          builder.append(' ');
          while (builder.length() < paddingWidth + 3) {
              builder.append(' ');
          }
          builder.append("%s%n");
          this.unitsColumn   = unitsColumn;
          this.commentFormat = builder.toString();
      }
  
      /** {@inheritDoc} */
      @Override
      public FileFormat getFormat() {
          return FileFormat.KVN;
      }
  
      /** {@inheritDoc} */
      @Override
      public void startMessage(final String root, final String messageTypeKey, final double version) throws IOException {
          writeEntry(messageTypeKey, String.format(AccurateFormatter.STANDARDIZED_LOCALE, "%.1f", version), null, true);
      }
  
      /** {@inheritDoc} */
      @Override
      public void endMessage(final String root) {
          // nothing to do
      }
  
     /** {@inheritDoc} */
     @Override
     public void writeComments(final List<String> comments) throws IOException {
         for (final String comment : comments) {
             writeRawData(String.format(AccurateFormatter.STANDARDIZED_LOCALE, commentFormat, comment));
         }
     }
 
     /** {@inheritDoc} */
     @Override
     public void writeEntry(final String key, final String value, final Unit unit, final boolean mandatory) throws IOException {
         if (value == null) {
             complain(key, mandatory);
         } else {
             final String s = String.format(AccurateFormatter.STANDARDIZED_LOCALE, kvFormat, key, value);
             writeRawData(s);
             if (writeUnits(unit)) {
                 for (int column = s.length(); column < unitsColumn; ++column) {
                     writeRawData(' ');
                 }
                 writeRawData('[');
                 writeRawData(siToCcsdsName(unit.getName()));
                 writeRawData(']');
             }
             newLine();
         }
     }
 
     /** {@inheritDoc} */
     @Override
     public void enterSection(final String name) throws IOException {
         writeRawData(name);
         writeRawData(START);
         newLine();
         super.enterSection(name);
     }
 
     /** {@inheritDoc} */
     @Override
     public String exitSection() throws IOException {
         final String name = super.exitSection();
         writeRawData(name);
         writeRawData(STOP);
         newLine();
         return name;
     }
 
 }