import java.io.File;
import java.io.IOException;

import javax.sound.midi.MidiUnavailableException;
import javax.sound.midi.Sequence;
import javax.sound.midi.MidiEvent;
import javax.sound.midi.MidiMessage;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.ShortMessage;
import javax.sound.midi.Track;
import javax.sound.midi.InvalidMidiDataException;
import javax.sound.midi.Sequencer;

/**	<titleabbrev>CreateSequence</titleabbrev>
	<title>Creating a Sequence</title>

	<formalpara><title>Purpose</title>
	<para>
	Shows how to construct a Sequence object with a Track and MidiEvents
	in memory and save it to a Standard MIDI File (SMF).
	</para></formalpara>

	<formalpara><title>Usage</title>
	<para>
	<cmdsynopsis>
	<command>java CreateSequence</command>
	<arg choice="plain"><replaceable class="parameter">midi_file</replaceable></arg>
	</cmdsynopsis>
	</para>
	</formalpara>

	<formalpara><title>Parameters</title>
	<variablelist>
	<varlistentry>
	<term><option><replaceable class="parameter">midi_file</replaceable></option></term>
	<listitem><para>the name of the file to save to as a Standard Midi File.</para></listitem>
	</varlistentry>
	</variablelist>
	</formalpara>

	<formalpara><title>Bugs, limitations</title>
	<para>None
	</para>
	</formalpara>

	<formalpara><title>Source code</title>
	<para>
	<ulink url="CreateSequence.java.html">CreateSequence.java</ulink>
	</para>
	</formalpara>

*/
public class CreateSequence
{
	/*	This velocity is used for all notes.
	 */
	private static final int	VELOCITY = 100;


	public static void main(String[] args) throws InvalidMidiDataException
	{
		if (args.length != 1)
		{
			printUsageAndExit();
		}
		File outputFile = new File(args[0]);
		Sequence	sequence = null;
		try
		{
			sequence = new Sequence(Sequence.PPQ, 1);
		}
		catch (InvalidMidiDataException e)
		{
			e.printStackTrace();
			System.exit(1);
		}
		/* Track objects cannot be created by invoking their constructor
		   directly. Instead, the Sequence object does the job. So we
		   obtain the Track there. This links the Track to the Sequence
		   automatically.
		*/
		Track	track = sequence.createTrack();

		// first chord: C major
		track.add(createNoteOnEvent(60, 0));
		track.add(createNoteOnEvent(64, 0));
		track.add(createNoteOnEvent(67, 0));
		track.add(createNoteOnEvent(72, 0));
		track.add(createNoteOffEvent(60, 1));
		track.add(createNoteOffEvent(64, 1));
		track.add(createNoteOffEvent(67, 1));
		track.add(createNoteOffEvent(72, 1));

		// second chord: f minor N
		track.add(createNoteOnEvent(53, 1));
		track.add(createNoteOnEvent(65, 1));
		track.add(createNoteOnEvent(68, 1));
		track.add(createNoteOnEvent(73, 1));
		track.add(createNoteOffEvent(63, 2));
		track.add(createNoteOffEvent(65, 2));
		track.add(createNoteOffEvent(68, 2));
		track.add(createNoteOffEvent(73, 2));

		// third chord: C major 6-4
		track.add(createNoteOnEvent(55, 2));
		track.add(createNoteOnEvent(64, 2));
		track.add(createNoteOnEvent(67, 2));
		track.add(createNoteOnEvent(72, 2));
		track.add(createNoteOffEvent(64, 3));
		track.add(createNoteOffEvent(72, 3));

		// forth chord: G major 7
		track.add(createNoteOnEvent(65, 3));
		track.add(createNoteOnEvent(71, 3));
		track.add(createNoteOffEvent(55, 4));
		track.add(createNoteOffEvent(65, 4));
		track.add(createNoteOffEvent(67, 4));
		track.add(createNoteOffEvent(71, 4));

		// fifth chord: C major
		track.add(createNoteOnEvent(48, 4));
		track.add(createNoteOnEvent(64, 4));
		track.add(createNoteOnEvent(67, 4));
		track.add(createNoteOnEvent(72, 4));
		track.add(createNoteOffEvent(48, 8));
		track.add(createNoteOffEvent(64, 8));
		track.add(createNoteOffEvent(67, 8));
		track.add(createNoteOffEvent(72, 8));

		/* Now we just save the Sequence to the file we specified.
		   The '0' (second parameter) means saving as SMF type 0.
		   Since we have only one Track, this is actually the only option
		   (type 1 is for multiple tracks).
		*/
		try {
			Sequencer player = MidiSystem.getSequencer();
			player.open(); //the sequencer was never opened
			player.setSequence(sequence);
			player.setLoopStartPoint(0);
			player.start();
			try {
			    Thread.sleep(3000);
			}
			catch (InterruptedException e) {

			}
			player.close();
		}
		catch (MidiUnavailableException e){
			System.out.println("error1");
		}

		try
		{
			MidiSystem.write(sequence, 0, outputFile);
		}
		catch (IOException e)
		{
			e.printStackTrace();
			System.exit(1);
		}

	}



	private static MidiEvent createNoteOnEvent(int nKey, long lTick)
	{
		return createNoteEvent(ShortMessage.NOTE_ON,
							   nKey,
							   VELOCITY,
							   lTick);
	}


	private static MidiEvent createNoteOffEvent(int nKey, long lTick)
	{
		return createNoteEvent(ShortMessage.NOTE_OFF,
							   nKey,
							   0,
							   lTick);
	}



	private static MidiEvent createNoteEvent(int nCommand,
											 int nKey,
											 int nVelocity,
											 long lTick)
	{
		ShortMessage	message = new ShortMessage();
		try
		{
			message.setMessage(nCommand,
							   0,	// always on channel 1
							   nKey,
							   nVelocity);
		}
		catch (InvalidMidiDataException e)
		{
			e.printStackTrace();
			System.exit(1);
		}
		MidiEvent	event = new MidiEvent(message,
										  lTick);
		return event;
	}



	private static void printUsageAndExit()
	{
			out("usage:");
			out("java CreateSequence <midifile>");
			System.exit(1);
	}


	private static void out(String strMessage)
	{
		System.out.println(strMessage);
	}
}