//Author: John T. Rine
//05-02-2011
//Edited by Matthew Taft
//05-20-2011
//Broke header and length reading routines into functions, added ability to read the first track into a byte array
//To Be Done: Create a class within Orca_Protocol to store tracks as arrays and make an array of them size of the number of tracks
//Ex:
//class trackArray {
//byte track[];
//}
//trackArray totTracks[len]
//for i=0;i<len;i++ {
//totTracks[i] = new trackArray();

import java.io.*;

public class Orca_Protocol {
	FileInputStream in = null;
	BufferedReader br;
	String fileName;
	StringBuffer strContent;
	long dummy, result;
	int c, count, shift;
	int format, ntrks, division, len;
	byte track[];

	public static void main(String[] args) throws IOException {
		Orca_Protocol test = new Orca_Protocol();
		try {
			System.out.print("Enter filename: ");
			BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
			test.fileName = br.readLine();
			test.in = new FileInputStream(test.fileName);
			test.readHeader(test.in);
			test.len = test.lenRead(test.in);
			test.c = 0;
			test.shift = 0;
			int resultt = 0;
			for (int i = 0; i != 2; i++)
			{
				test.c = test.in.read();
				switch(i)
				{
					case 0:
						test.shift = 8;
						break;
					case 1:
						test.shift = 0;
						break;
				}
				test.format = test.c << test.shift;
				resultt = resultt | test.c;
			}
			String fileType;
			switch(test.format)
			{
				case 0:
					fileType = "single track file format";
					break;
				case 1:
					fileType = "multiple track file format";
					break;
				case 2:
					fileType = "multiple song file format (i.e., a series of type 0 files)"; 
					break;
				default:
					fileType = "Error";

			}
			System.out.println("Midi File Type = " + test.format + " " + "File Type: " + fileType);
			test.c = 0;
			test.shift = 0;
			resultt = 0;
			for (int i = 0; i != 2; i++)
			{
				test.c = test.in.read();
				switch(i)
				{
					case 0:
						test.shift = 8;
						break;
					case 1:
						test.shift = 0;
						break;
				}
				test.ntrks = test.c << test.shift;
				resultt = resultt | test.c;
			}
			System.out.println("Number of track chunks that follow the header chunk  = " + test.ntrks);
			test.c = 0;
			test.shift = 0;
			resultt = 0;
			for (int i = 0; i != 2; i++)
			{
				test.c = test.in.read();
				switch(i)
				{
					case 0:
						test.shift = 8;
						break;
					case 1:
						test.shift = 0;
						break;
				}
				test.division = test.c << test.shift;
				resultt = resultt | test.c;
			}
			test.readHeader(test.in);
			test.len = test.lenRead(test.in);
			test.track = new byte[test.len];
			test.in.read(test.track, 0, test.len);
			System.out.println("Track 1: " + test.track);
			System.out.println("Division  = " + test.division);
			System.out.println("Unit of time for delta timing.");
			System.out.println("If the value is positive, then it represents the units per beat.");
			System.out.println("For example, +96 would mean 96 ticks per beat.");
			System.out.println("If the value is negative, delta times are in SMPTE compatible units."); 
		}
		finally
		{
			if (test.in != null)
			{
				test.in.close();
			}
		}
	}

	void readHeader(FileInputStream in) throws IOException {	
//readHeader() takes an argument of the score file opened and checks to see if the header portion read is a midi header
//or a midi track. This function could be changed to return a state on if the encountered string was MThd, MTrk or neither.
//It should be called immediately upon opening the file, and again after the chunk has been completely read in.
		int c;
		StringBuffer strContent = new StringBuffer();
		int count = 0;
		while (count != 4) {
			c = in.read();
			strContent.append((char)c);
			count++;
		}
		System.out.println(strContent);
		String temp = strContent.toString();
		if(temp.equals("MThd")) 
			System.out.println("Midi Header");
		if(temp.equals("MTrk"))
			System.out.println("Midi Track");
	}

	int lenRead(FileInputStream in) throws IOException {
//This function takes an argument of the score file opened and returns the length of the 
//header. This function should be called immediately after reading the first 4 bytes of the file 
//or any bytes containing the chunk headers.
			this.dummy = 0;
			this.c = 0;
			this.shift = 0;
			this.result = 0;
			for (int i = 0; i != 4; i++)
			{
				this.c = in.read();
				this.dummy = 0;
				this.dummy = (long) this.c;
				switch(i)
				{
					case 0:
						this.shift = 24;
						break;
					case 1:
						this.shift = 16;
						break;
					case 2:
						this.shift = 8;
						break;
					case 3:
						this.shift = 0;
						break;
				}
				this.dummy = this.dummy << this.shift;
				this.result = this.result | this.dummy;
			}
			System.out.println("Header Length = " + this.result);
			return((int)this.result);
	}
}