/*
 * MidiC.java
 * Copyright 2001 Michael Castleman, mlc67@columbia.edu
 *
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

import java.io.*;

/**
 * Converts a MIDI file output by CMidi back into C code.
 */
public class MidiC {
    protected InputStream in;
    protected OutputStream out;

    /** pulses per quarter note */
    protected int ppqn;

    /**
     * Constructs a new MidiC
     * @param in The source MIDI file
     * @param out Where the C code will be written to.
     */
    public MidiC(InputStream in, OutputStream out) {
        this.in = in;
        this.out = out;
    }
    
    /**
     * Actually does the conversion.
     * @exception IOException If a read or write error occurred.
     */
    public void doConversion() throws IOException {
        readHeader();

        ReadTrack mtrk;
        do {
            mtrk = new ReadTrack(in);
        } while (!mtrk.chunkType.equals("MTrk"));

        ReadTrack.Event evt;
        while ((evt = mtrk.readEvent()) != null) {
            if ((evt.status == (byte)(0x80)) || // note off, track 0
                ((evt.status == (byte)(0x90)) && (evt.data[1] == 0))) {
                if (evt.deltaTime >= (ppqn / 2)) // 8th note means NL
                    out.write('\n');
                else if (evt.deltaTime >= (ppqn / 4)) // 16th note means NL
                    out.write(' ');
                out.write(evt.data[0]);
            }
        }
        out.write('\n');
    }

    private void readHeader() throws IOException {
        ReadTrack head = new ReadTrack(in);
        if ((!head.chunkType.equals("MThd")) || (head.data.length != 6))
            throw new RuntimeException("input is not a MIDI file");
        if (head.data[1] != (byte)(0x01))
            throw new RuntimeException("I can only handle format-1 MIDI files");
        if (head.data[4] < 0)
            throw new RuntimeException("I don't yet know how to handle SMTPE-timecoded MIDI files");

        ppqn = (head.data[4] << 8) | (head.data[5]);

        // there's a stupid track which we can ignore here.
        // also ignore any non-MTrk chunk (there shouldn't be any, but you never know)
        ReadTrack stupid;
        do {
            stupid = new ReadTrack(in);
        } while (!stupid.chunkType.equals("MTrk"));
    }

    /**
     * Main routine
     * @param args Command-line arguments. Should be the name of the input
     *             MIDI file and the output C file.
     * @exception IOException if there's a problem reading or writing
     */
    public static void main(String[] args) throws IOException {
        if (args.length != 2) {
            System.out.println("Syntax:");
            System.out.println("\tjava -cp cmidi.jar MidiC infile.mid outfile.c");
            System.out.println("\t\"-\" means use stdin/out");
            System.exit(1);
        }
        InputStream ins = (args[0].equals("-") ? System.in : new FileInputStream(args[0]));
        OutputStream outs = (args[1].equals("-") ? (OutputStream)(System.out) : new FileOutputStream(args[1]));
        MidiC mc = new MidiC(ins, outs);
        mc.doConversion();
        ins.close();
        outs.close();
    }
}