import java.io.File;

import java.io.PrintWriter;

import java.util.Scanner;

import javax.sound.midi.MidiEvent;

import javax.sound.midi.MidiMessage;

import javax.sound.midi.MidiSystem;

import javax.sound.midi.Sequence;

import javax.sound.midi.ShortMessage;

import javax.sound.midi.Track;

public class MidiReader {

public static final int NOTE_ON = 0x90;

public static final int NOTE_OFF = 0x80;

public static void main(String[] args) throws Exception {

String filename;

Scanner scan = new Scanner(System.in);

PrintWriter writer = null;

Sequence sequence;

long timestamp = 0;

int frequency = 0;

int trackNumber = 0;

double timestampConverter = 1;

int tracks;

int pin[];

int length[];

System.out.println("Creating melody.h...");

if(new File("./arduino/MidiPlayer/melody.h").exists()){

System.out.print("melody.h already exists. Is it okay to overwrite it? (y/n) ");

if(!scan.nextLine().equals("y")){

System.out.println("Quitting...");

System.exit(1);

}

} else {

new File("./arduino/MidiPlayer/").mkdirs();

}

writer = new PrintWriter("./arduino/MidiPlayer/melody.h", "UTF-8");

System.out.println("Created melody.h");

while (true) { //loops until working filename is entered

System.out.print("Enter the name of the MIDI file: ");

filename = scan.nextLine();

try {

sequence = MidiSystem.getSequence(new File("./midi/" + filename)); //creating MIDI sequence

} catch (Exception exception) {

System.out.println("Error reading file " + filename + ": " + exception);

continue;

}

break;

}

timestampConverter = ((sequence.getMicrosecondLength() / 1000.0) / sequence.getTickLength()); //conversion rate for MIDI ticks to milliseconds

tracks = sequence.getTracks().length; //getting tracks

pin = new int[tracks]; //info arrays

length = new int[tracks];

writer.println("#include \"common.h\""); //writing out melody.h file

writer.println();

writer.println("#define TRACKS " + tracks);

writer.println();

for (Track track : sequence.getTracks()) { //looping through tracks (1 track to 1 buzzer)

trackNumber++;

timestamp = 0;

length[trackNumber - 1] = 0;

System.out.print("Which buzzer pin is track " + trackNumber + " on? "); //getting buzzer pin

pin[trackNumber - 1] = scan.nextInt();

writer.println("const uint32_t d" + trackNumber + "[] PROGMEM = {");

for (int i = 0; i < track.size(); i++) { //iterating through notes to get timestamps

MidiEvent event = track.get(i);

MidiMessage message = event.getMessage();

if (message instanceof ShortMessage) { //making sure message is valid message

timestamp = event.getTick();

writer.print(((long)(timestamp*timestampConverter)) + ","); //converting to milliseconds and writing to melody.h

length[trackNumber - 1]++;

}

}

writer.println();

writer.println("};");

writer.println();

writer.println("const uint16_t m" + trackNumber + "[] PROGMEM = {");

for (int i = 0; i < track.size(); i++) { //iterating through notes to get frequencies

MidiEvent event = track.get(i);

MidiMessage message = event.getMessage();

if (message instanceof ShortMessage) { //making sure message is valid message

ShortMessage sm = (ShortMessage) message;

if (sm.getCommand() == NOTE_OFF) { //whether event is the end of note...

frequency = 0;

} else if (sm.getCommand() == NOTE_ON) { //or start of note

frequency = (int) ((Math.pow(2.0, (sm.getData1() - 69.0) / 12.0)) * 440.0); // converts key # to frequency (in Hertz)

}

writer.print(frequency + ","); //writing to melody.h

}

}

writer.println();

writer.println("};");

writer.println();

writer.println();

}

writer.println("Track tracks[] = {"); //writing out array of Track structs

for(int i = 0; i<tracks; i++){

writer.println("{" + pin[i] + ", m" + (i+1) + ", d" + (i+1) + ", " + length[i] + "},");

}

writer.println("};");

scan.close();

writer.close();

System.out.println("Finished writing to melody.h!");

}

}