package org.metricshub.ipmi.core.coding.payload.sol;
   
   /*-
    * ╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲
    * IPMI Java Client
    * ჻჻჻჻჻჻
    * Copyright 2023 Verax Systems, MetricsHub
    * ჻჻჻჻჻჻
    * This program is free software: you can redistribute it and/or modify
   * it under the terms of the GNU Lesser 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 Lesser Public License for more details.
   *
   * You should have received a copy of the GNU General Lesser Public
   * License along with this program.  If not, see
   * <http://www.gnu.org/licenses/lgpl-3.0.html>.
   * ╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱
   */
  
  import org.metricshub.ipmi.core.coding.payload.IpmiPayload;
  import org.metricshub.ipmi.core.common.MessageComposer;
  import org.metricshub.ipmi.core.common.TypeConverter;
  
  /**
   * Implementation of {@link IpmiPayload} for SOL (Serial over LAN) messages.
   */
  public abstract class SolMessage extends IpmiPayload {
  
  	public static final byte MIN_SEQUENCE_NUMBER = 1;
  	public static final byte MAX_SEQUENCE_NUMBER = 15;
  
  	private static final int PACKET_SEQUENCE_NUMBER_LENGTH = 1;
  	private static final int PACKET_ACK_SEQUENCE_NUMBER_LENGTH = 1;
  	private static final int ACCEPTED_CHARACTERS_LENGTH = 1;
  	private static final int OPERATION_STATUS_LENGTH = 1;
  
  	public static final int PAYLOAD_HEADER_LENGTH = PACKET_SEQUENCE_NUMBER_LENGTH + PACKET_ACK_SEQUENCE_NUMBER_LENGTH
  			+ ACCEPTED_CHARACTERS_LENGTH + OPERATION_STATUS_LENGTH;
  
  	/**
  	 * Sequence number of this packet.
  	 */
  	private final byte sequenceNumber;
  
  	/**
  	 * Sequence number of packet being ACKd/NACKd by this packet.
  	 */
  	private final byte ackNackSequenceNumber;
  
  	/**
  	 * Number of characters being accepted from ACKd/NACKd packet.
  	 */
  	private final byte acceptedCharacterCount;
  
  	/**
  	 * Operation to invoke or status of previously send packet.
  	 */
  	private final byte operationStatus;
  
  	protected SolMessage(byte sequenceNumber, byte ackNackSequenceNumber, byte acceptedCharacterCount,
  			byte operationStatus) {
  		this.sequenceNumber = trimSequenceNumber(sequenceNumber);
  		this.ackNackSequenceNumber = trimSequenceNumber(ackNackSequenceNumber);
  		this.acceptedCharacterCount = acceptedCharacterCount;
  		this.operationStatus = operationStatus;
  	}
  
  	/**
  	 * Trims given sequence number to max allowed value for sequence numbers, applying MAX_SEQUENCE_NUMBER mask on it.
  	 *
  	 * @param number
  	 *        Sequence number before trim
  	 * @return trimmed sequence number
  	 */
  	private byte trimSequenceNumber(byte number) {
  		return TypeConverter.intToByte(number & MAX_SEQUENCE_NUMBER);
  	}
  
  	@Override
  	public byte[] getPayloadData() {
  		return MessageComposer.get(getPayloadLength())
  				.appendField(sequenceNumber)
  				.appendField(ackNackSequenceNumber)
  				.appendField(acceptedCharacterCount)
  				.appendField(operationStatus)
  				.appendField(getData())
  				.getMessage();
  	}
  
  	@Override
  	public int getPayloadLength() {
  		return PAYLOAD_HEADER_LENGTH + getData().length;
  	}
  
 	@Override
 	public byte[] getIpmiCommandData() {
 		return getData();
 	}
 
 	@Override
 	public byte[] getData() {
 		byte[] data = super.getData();
 
 		if (data == null) {
 			return new byte[0];
 		}
 
 		return data;
 	}
 
 	public byte getSequenceNumber() {
 		return sequenceNumber;
 	}
 
 	public byte getAckNackSequenceNumber() {
 		return ackNackSequenceNumber;
 	}
 
 	/**
 	 * @return the number of characters accepted from the packet acknowledged, 0 to 255
 	 */
 	public int getAcceptedCharacterCount() {
 		return TypeConverter.byteToInt(acceptedCharacterCount);
 	}
 
 	/**
 	 * Checks if given message carries some data (or operation/status).
 	 */
 	public boolean isDataCarrier() {
 		return sequenceNumber != 0 || getData().length > 0;
 	}
 
 	/**
 	 * Checks if given {@link SolMessage} is an ACK/NACK for some other message.
 	 */
 	public boolean isAcknowledgeMessage() {
 		return ackNackSequenceNumber != 0;
 	}
 }