/********************************************************************************
 * Copyright (c) 2015-2018 Contributors to the Eclipse Foundation
 *
 * See the NOTICE file(s) distributed with this work for additional
 * information regarding copyright ownership.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 ********************************************************************************/


package org.eclipse.mdm.openatfx.mdf.mdf3;

import java.io.IOException;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.channels.SeekableByteChannel;

/**
 * <p>
 * Header block: General description of the measurement file
 * </p>
 * The HDBLOCK always begins at file position 64. It contains general
 * information about the contents of the measured data file.
 *
 * @author Christian Rechner
 */
class HDBLOCK extends BLOCK {

	public static String BLOCK_ID = "HD";

	// LINK 1 Pointer to the first file group block (DGBLOCK)
	private long lnkFirstFileGroup;

	// LINK 1 Pointer to the measurement file comment text (TXBLOCK) (NIL
	// allowed)
	private long lnkFileCommentTxt;

	// LINK 1 Pointer to program block (PRBLOCK) (NIL allowed)
	private long lnkProgramBlock;

	// UINT16 1 Number of data groups
	private int numberOfDataGroups;

	// CHAR 10 Date at which the recording was started in "DD:MM:YYYY" format
	private String dateStarted;

	// CHAR 8 Time at which the recording was started in "HH:MM:SS" format
	private String timeStarted;

	// CHAR 32 Author’s name
	private String author;

	// CHAR 32 Name of organization or department
	private String department;

	// CHAR 32 Project name
	private String projectName;

	// CHAR 32 Measurement object e. g. the vehicle identification
	private String meaObject;

	// UINT64 1 Time stamp at which recording was started in nanoseconds.
	// Elapsed time since 00:00:00 01.01.1970 (local
	// time) (local time = UTC time + UTC time offset) Note: the local time does
	// not contain a daylight saving time
	// (DST) offset! Valid since version 3.20. Default value: 0 See remark below
	private long timestamp;

	// INT16 1 UTC time offset in hours (= GMT time zone) For example 1 means
	// GMT+1 time zone = Central European Time
	// (CET). The value must be in range [-12, 12], i.e. it can be negative!
	// Valid since version 3.20. Default value: 0
	// (= GMT time)
	private int utcTimeOffsetHours;

	// UINT16 1 Time quality class
	// 0 = local PC reference time (Default)
	// 10 = external time source
	// 16 = external absolute synchronized time
	private int timeQualityClass;

	// CHAR 32 Timer identification (time source), e.g. "Local PC Reference
	// Time" or "GPS Reference Time". Valid since
	// version 3.20. Default value: empty string
	private String timerIdent;

	/**
	 * Constructor.
	 *
	 * @param sbc
	 *            The byte channel pointing to the MDF file.
	 * @param pos
	 *            The position of the block within the MDF file.
	 */
	private HDBLOCK(SeekableByteChannel sbc, long pos) {
		super(sbc, pos);
	}

	public long getLnkFirstFileGroup() {
		return lnkFirstFileGroup;
	}

	private void setLnkFirstFileGroup(long lnkFirstFileGroup) {
		this.lnkFirstFileGroup = lnkFirstFileGroup;
	}

	public long getLnkFileCommentTxt() {
		return lnkFileCommentTxt;
	}

	private void setLnkFileCommentTxt(long lnkFileCommentTxt) {
		this.lnkFileCommentTxt = lnkFileCommentTxt;
	}

	public long getLnkProgramBlock() {
		return lnkProgramBlock;
	}

	private void setLnkProgramBlock(long lnkProgramBlock) {
		this.lnkProgramBlock = lnkProgramBlock;
	}

	public int getNumberOfDataGroups() {
		return numberOfDataGroups;
	}

	private void setNumberOfDataGroups(int numberOfDataGroups) {
		this.numberOfDataGroups = numberOfDataGroups;
	}

	public String getDateStarted() {
		return dateStarted;
	}

	private void setDateStarted(String dateStarted) {
		this.dateStarted = dateStarted;
	}

	public String getTimeStarted() {
		return timeStarted;
	}

	private void setTimeStarted(String timeStarted) {
		this.timeStarted = timeStarted;
	}

	public String getAuthor() {
		return author;
	}

	private void setAuthor(String author) {
		this.author = author;
	}

	public String getDepartment() {
		return department;
	}

	private void setDepartment(String department) {
		this.department = department;
	}

	public String getProjectName() {
		return projectName;
	}

	private void setProjectName(String projectName) {
		this.projectName = projectName;
	}

	public String getMeaObject() {
		return meaObject;
	}

	private void setMeaObject(String meaObject) {
		this.meaObject = meaObject;
	}

	public long getTimestamp() {
		return timestamp;
	}

	private void setTimestamp(long timestamp) {
		this.timestamp = timestamp;
	}

	public int getUtcTimeOffsetHours() {
		return utcTimeOffsetHours;
	}

	private void setUtcTimeOffsetHours(int utcTimeOffsetHours) {
		this.utcTimeOffsetHours = utcTimeOffsetHours;
	}

	public int getTimeQualityClass() {
		return timeQualityClass;
	}

	private void setTimeQualityClass(int timeQualityClass) {
		this.timeQualityClass = timeQualityClass;
	}

	public String getTimerIdent() {
		return timerIdent;
	}

	private void setTimerIdent(String timerIdent) {
		this.timerIdent = timerIdent;
	}

	public DGBLOCK getFirstFileGroup() throws IOException {
		if (lnkFirstFileGroup > 0) {
			return DGBLOCK.read(sbc, lnkFirstFileGroup);
		}
		return null;
	}

	public TXBLOCK getFileCommentTxt() throws IOException {
		if (lnkFileCommentTxt > 0) {
			return TXBLOCK.read(sbc, lnkFileCommentTxt);
		}
		return null;
	}

	public PRBLOCK getProgramBlock() throws IOException {
		if (lnkProgramBlock > 0) {
			return PRBLOCK.read(sbc, lnkProgramBlock);
		}
		return null;
	}

	@Override
	public String toString() {
		return "HDBLOCK [lnkFirstFileGroup=" + lnkFirstFileGroup + ", lnkFileCommentTxt=" + lnkFileCommentTxt
				+ ", lnkProgramBlock=" + lnkProgramBlock + ", numberOfDataGroups=" + numberOfDataGroups
				+ ", dateStarted=" + dateStarted + ", timeStarted=" + timeStarted + ", author=" + author
				+ ", department=" + department + ", projectName=" + projectName + ", meaObject=" + meaObject
				+ ", timestamp=" + timestamp + ", utcTimeOffsetHours=" + utcTimeOffsetHours + ", timeQualityClass="
				+ timeQualityClass + ", timerIdent=" + timerIdent + "]";
	}

	/**
	 * Reads a HDBLOCK from the channel starting at current channel position.
	 *
	 * @param sbc
	 *            The channel to read from.
	 * @return The block data.
	 * @throws IOException
	 *             The exception.
	 */
	public static HDBLOCK read(SeekableByteChannel sbc) throws IOException {
		HDBLOCK block = new HDBLOCK(sbc, 64);

		// read block header
		ByteBuffer bb = ByteBuffer.allocate(4);
		bb.order(ByteOrder.LITTLE_ENDIAN);
		sbc.position(64);
		sbc.read(bb);
		bb.rewind();

		// CHAR 2 Block type identifier
		block.setId(Mdf3Util.readChars(bb, 2));
		if (!block.getId().equals(BLOCK_ID)) {
			throw new IOException("Wrong block type - expected '" + BLOCK_ID + "', found '" + block.getId() + "'");
		}

		// UINT16 1 Block size of this block in bytes
		block.setLength(Mdf3Util.readUInt16(bb));

		// read block header
		bb = ByteBuffer.allocate(block.getLength() - 4);
		bb.order(ByteOrder.LITTLE_ENDIAN);
		sbc.position(68);
		sbc.read(bb);
		bb.rewind();

		// LINK 1 Pointer to the first file group block (DGBLOCK)
		block.setLnkFirstFileGroup(Mdf3Util.readLink(bb));

		// LINK 1 Pointer to the measurement file comment text (TXBLOCK) (NIL
		// allowed)
		block.setLnkFileCommentTxt(Mdf3Util.readLink(bb));

		// LINK 1 Pointer to program block (PRBLOCK) (NIL allowed)
		block.setLnkProgramBlock(Mdf3Util.readLink(bb));

		// UINT16 1 Number of data groups
		block.setNumberOfDataGroups(Mdf3Util.readUInt16(bb));

		// CHAR 10 Date at which the recording was started in "DD:MM:YYYY"
		// format
		block.setDateStarted(Mdf3Util.readChars(bb, 10));

		// CHAR 8 Time at which the recording was started in "HH:MM:SS" format
		block.setTimeStarted(Mdf3Util.readChars(bb, 8));

		// CHAR 32 Author’s name
		block.setAuthor(Mdf3Util.readChars(bb, 32));

		// CHAR 32 Name of organization or department
		block.setDepartment(Mdf3Util.readChars(bb, 32));

		// CHAR 32 Project name
		block.setProjectName(Mdf3Util.readChars(bb, 32));

		// CHAR 32 Measurement object e. g. the vehicle identification
		block.setMeaObject(Mdf3Util.readChars(bb, 32));

		// new fields from MDF version >3.20
		if (block.getLength() > 164) {

			// UINT64 1 Time stamp at which recording was started in nanoseconds
			BigInteger nanoseconds = Mdf3Util.readUInt64(bb);
			block.setTimestamp(nanoseconds.longValue());

			// INT16 1 UTC time offset in hours (= GMT time zone)
			block.setUtcTimeOffsetHours(Mdf3Util.readInt16(bb));

			// UINT16 1 Time quality class
			block.setTimeQualityClass(Mdf3Util.readUInt16(bb));

			// CHAR 32 Timer identification (time source)
			block.setTimerIdent(Mdf3Util.readChars(bb, 32));

		}

		return block;
	}

}