/*
 * CMidi.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 .c file (any text file, really) into a MIDI file.
 * @author Michael Castleman, <a href="mailto:mlc67@columbia.edu">mlc67@columbia.edu</a>
 * @version 0.1
 */
public class CMidi {
    protected InputStream in;
    protected OutputStream out;

    /**
     * Constructs a new CMidi
     * @param in The source file
     * @param out Where the MIDI will be written to.
     */
    public CMidi(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 {
        writeHeader();
        TrackChunk tc = new TrackChunk();
        
        // all controllers off
        tc.addBytes(new byte[] {0, (byte)(0xb0), (byte)(121), 0});

        // bank select 0
        tc.addBytes(new byte[] {0, 0, 0});

        // program change: acoustic guitar
        tc.addBytes(new byte[] {0, (byte)(0xc0), 25});

        // max volume
        tc.addBytes(new byte[] {0, (byte)(0xb0), (byte)(7), (byte)(0x7f)});

        int inByte;
        while ((inByte = in.read()) != -1) {
            tc.writeDataByte((byte)inByte);
        }

        tc.endTrack();
        writeChunk(TrackChunk.TRACK_TYPE, tc.getBytes());
    }

    /**
     * Writes the MIDI header
     */
    protected void writeHeader() throws IOException {
        // 0x0001 - multiple track file
        // 0x0002 - 2 tracks
        // 0x0060 - 96 pulses per quarter note (ppqn)
        byte [] chunk = {0x00, 0x01, 0x00, 0x02, 0x00, 0x60};
        writeChunk("MThd", chunk);

        // stupid track
        TrackChunk tc = new TrackChunk();
        tc.addVarLen(0);
        tc.addByte((byte)0xff);
        tc.addByte((byte)0x51);
        tc.addByte((byte)0x03);
        tc.addByte((byte)0x07);
        tc.addByte((byte)0xa1);
        tc.addByte((byte)0x20);
        tc.addVarLen(0);
        tc.addText("This file was created by CMidi. Run MidiC to get the data back out.");
        tc.endTrack();
        writeChunk(TrackChunk.TRACK_TYPE, tc.getBytes());
    }

    /**
     * Writes a chunk
     * @param type Type of chunk. <b>MUST BE 4 CHARS LONG</b>
     * @param data Chunk data.
     * @exception IllegalArgumentException If <code>type.length() != 4</code>
     */
    protected void writeChunk(String type, byte [] data) throws IllegalArgumentException,IOException {
        if (type.length() != 4)
            throw new IllegalArgumentException("Bad type");

        out.write(type.getBytes());
        int len = data.length;
        out.write((byte)((len & 0xFF00000) >> 24));
        out.write((byte)((len & 0x00FF000) >> 16));
        out.write((byte)((len & 0x000FF00) >> 8));
        out.write((byte)((len & 0x00000FF)));
        out.write(data);
    }

    /**
     * Main routine
     * @param args Command-line arguments. Should be the name of the input
     *             C file and the output MIDI 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 CMidi infile.c outfile.mid");
            System.exit(1);
        }
        FileInputStream ins = new FileInputStream(args[0]);
        FileOutputStream outs = new FileOutputStream(args[1]);
        CMidi cm = new CMidi(ins, outs);
        cm.doConversion();
        ins.close();
        outs.close();
    }
}