text: /*
   *
   *  * ******************************************************************************
   *  * Copyright (C) 2014-2020 Dennis Sheirer
   *  *
   *  * This program is free software: you can redistribute it and/or modify
   *  * it under the terms of the GNU General Public License as published by
   *  * the Free Software Foundation, either version 3 of the License, or
   *  * (at your option) any later version.
   *  *
   *  * This program is distributed in the hope that it will be useful,
   *  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  * GNU General Public License for more details.
   *  *
   *  * You should have received a copy of the GNU General Public License
   *  * along with this program.  If not, see <http://www.gnu.org/licenses/>
   *  * *****************************************************************************
   *
   *
   */
  
  package io.github.dsheirer.module.decode.p25.phase1.message.pdu.ambtc.osp;
  
  import io.github.dsheirer.channel.IChannelDescriptor;
  import io.github.dsheirer.identifier.Identifier;
  import io.github.dsheirer.module.decode.p25.identifier.channel.APCO25Channel;
  import io.github.dsheirer.module.decode.p25.identifier.channel.APCO25ExplicitChannel;
  import io.github.dsheirer.module.decode.p25.identifier.radio.APCO25RadioIdentifier;
  import io.github.dsheirer.module.decode.p25.identifier.talkgroup.APCO25Talkgroup;
  import io.github.dsheirer.module.decode.p25.phase1.message.IFrequencyBandReceiver;
  import io.github.dsheirer.module.decode.p25.phase1.message.pdu.PDUSequence;
  import io.github.dsheirer.module.decode.p25.phase1.message.pdu.ambtc.AMBTCMessage;
  import io.github.dsheirer.module.decode.p25.phase1.message.pdu.block.UnconfirmedDataBlock;
  import io.github.dsheirer.module.decode.p25.reference.DataServiceOptions;
  
  import java.util.ArrayList;
  import java.util.List;
  
  public class AMBTCGroupDataChannelGrant extends AMBTCMessage implements IFrequencyBandReceiver
  {
      private static final int[] HEADER_SERVICE_OPTIONS = {64, 65, 66, 67, 68, 69, 70, 71};
      private static final int[] HEADER_RESERVED = {72, 73, 74, 75, 76, 77, 78, 79};
      private static final int[] BLOCK_0_RESERVED = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15};
      private static final int[] BLOCK_0_DOWNLINK_FREQUENCY_BAND = {16, 17, 18, 19};
      private static final int[] BLOCK_0_DOWNLINK_CHANNEL_NUMBER = {20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31};
      private static final int[] BLOCK_0_UPLINK_FREQUENCY_BAND = {32, 33, 34, 35};
      private static final int[] BLOCK_0_UPLINK_CHANNEL_NUMBER = {36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47};
      private static final int[] BLOCK_0_GROUP_ADDRESS = {48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63};
  
      private DataServiceOptions mDataServiceOptions;
      private APCO25Channel mChannel;
      private Identifier mSourceAddress;
      private Identifier mGroupAddress;
      private List<Identifier> mIdentifiers;
      private List<IChannelDescriptor> mChannels;
  
      public AMBTCGroupDataChannelGrant(PDUSequence PDUSequence, int nac, long timestamp)
      {
          super(PDUSequence, nac, timestamp);
      }
  
      public String toString()
      {
          StringBuilder sb = new StringBuilder();
          sb.append(getMessageStub());
          sb.append(" FM:").append(getSourceAddress());
          sb.append(" TO:").append(getGroupAddress());
          sb.append(" CHAN:").append(getChannel());
          sb.append(" SERVICE OPTIONS:").append(getDataServiceOptions());
          return sb.toString();
      }
  
      public DataServiceOptions getDataServiceOptions()
      {
          if(mDataServiceOptions == null)
          {
              mDataServiceOptions = new DataServiceOptions(getHeader().getMessage().getInt(HEADER_SERVICE_OPTIONS));
          }
  
          return mDataServiceOptions;
      }
  
      public Identifier getSourceAddress()
      {
          if(mSourceAddress == null)
          {
              mSourceAddress = APCO25RadioIdentifier.createFrom(getHeader().getMessage().getInt(HEADER_ADDRESS));
          }
  
          return mSourceAddress;
      }
  
      public Identifier getGroupAddress()
      {
          if(mGroupAddress == null && hasDataBlock(0))
          {
              mGroupAddress = APCO25Talkgroup.create(getDataBlock(0).getMessage().getInt(BLOCK_0_GROUP_ADDRESS));
          }
  
          return mGroupAddress;
      }
  
      public boolean isExtendedChannel()
      {
          return hasDataBlock(0) &&
              (getDataBlock(0).getMessage().getInt(BLOCK_0_DOWNLINK_CHANNEL_NUMBER) !=
                  getDataBlock(0).getMessage().getInt(BLOCK_0_UPLINK_CHANNEL_NUMBER));
      }
  
      public APCO25Channel getChannel()
      {
          if(mChannel == null && hasDataBlock(0))
          {
              UnconfirmedDataBlock block = getDataBlock(0);
  
              if(isExtendedChannel())
              {
                  mChannel = APCO25ExplicitChannel.create(block.getMessage().getInt(BLOCK_0_DOWNLINK_FREQUENCY_BAND),
                      block.getMessage().getInt(BLOCK_0_DOWNLINK_CHANNEL_NUMBER),
                      block.getMessage().getInt(BLOCK_0_UPLINK_FREQUENCY_BAND),
                      block.getMessage().getInt(BLOCK_0_UPLINK_CHANNEL_NUMBER));
              }
              else
              {
                  mChannel = APCO25Channel.create(block.getMessage().getInt(BLOCK_0_DOWNLINK_FREQUENCY_BAND),
                      block.getMessage().getInt(BLOCK_0_DOWNLINK_CHANNEL_NUMBER));
              }
          }
  
          if(mChannel == null)
          {
              mChannel = APCO25Channel.create(-1, 0);
          }
  
          return mChannel;
      }
  
      @Override
      public List<Identifier> getIdentifiers()
      {
          if(mIdentifiers == null)
          {
              mIdentifiers = new ArrayList<>();
              if(getSourceAddress() != null)
              {
                  mIdentifiers.add(getSourceAddress());
              }
              if(getGroupAddress() != null)
              {
                  mIdentifiers.add(getGroupAddress());
              }
          }
  
          return mIdentifiers;
      }
  
      @Override
      public List<IChannelDescriptor> getChannels()
      {
          if(mChannels == null)
          {
              mChannels = new ArrayList<>();
  
              if(getChannel() != null)
              {
                  mChannels.add(getChannel());
              }
          }
  
          return mChannels;
      }
  }
  