/*
 * $Id: Awk.java,v 1.9 2006-11-24 15:04:23 bacon Exp $
 */

package ase.awk;

import java.io.*;

public abstract class Awk
{
	// mode for open_source & close_source 
	public static final int SOURCE_READ = 1;
	public static final int SOURCE_WRITE = 2;

	static
	{
		System.load ("c://projects//ase/awk/aseawk.dll");
	}

	private long __awk;

	public Awk () throws Exception
	{
		open ();
	}

	public native void close ();
	public native void parse () throws Exception;
	public native void run () throws Exception;
	private native void open () throws Exception;
	private native int setfilename (long run_id, String name);
	private native int setofilename (long run_id, String name);

	public void setInputConsoleName (Extio extio, String name) //throws Exception
	{
		/* TODO: setconsolename is not safe. for example, it can 
		 * crash the program if run_id is invalid. so this wrapper
		 * needs to do some sanity check. */
		//if (setconsolename (run_id, name) == -1)
		//	throw new Exception ("cannot set the consle name");
		setfilename (extio.getRunId(), name);
	}

	public void setOutputConsoleName (Extio extio, String name)
	{
		// TODO:
		setofilename (extio.getRunId(), name);
	}

	/* abstrace methods */
	protected abstract int open_source (int mode);
	protected abstract int close_source (int mode);
	protected abstract int read_source (char[] buf, int len);
	protected abstract int write_source (char[] buf, int len);

	protected int open_extio (Extio extio)
	{
		int type = extio.getType ();
		if (type == Extio.TYPE_CONSOLE) return open_console (extio);
		if (type == Extio.TYPE_FILE) return open_file (extio);
		if (type == Extio.TYPE_PIPE) return open_pipe (extio);
		//if (type == Extio.TYPE_COPROC) return open_coproc (extio);
		return -1;
	}

	protected int close_extio (Extio extio)
	{
		int type = extio.getType ();
		if (type == Extio.TYPE_CONSOLE) return close_console (extio);
		if (type == Extio.TYPE_FILE) return close_file (extio);
		if (type == Extio.TYPE_PIPE) return close_pipe (extio);
		//if (type == Extio.TYPE_COPROC) return close_coproc (extio);
		return -1;
	}

	protected int read_extio (Extio extio, char[] buf, int len)
	{
		// this check is needed because 0 is used to indicate
		// the end of the stream. java streams can return 0 
		// if the data given is 0 bytes and it didn't reach 
		// the end of the stream. 
		if (len <= 0) return -1;

		int type = extio.getType ();
		if (type == Extio.TYPE_CONSOLE) 
			return read_console (extio, buf, len);
		if (type == Extio.TYPE_FILE) 
			return read_file (extio, buf, len);
		if (type == Extio.TYPE_PIPE)
		 	return read_pipe (extio, buf, len);
		//if (type == Extio.TYPE_COPROC)
		//	return read_coproc (extio, buf, len);
		return -1;
	}

	protected int write_extio (Extio extio, char[] buf, int len)
	{
		if (len <= 0) return -1;

		int type = extio.getType ();
		if (type == Extio.TYPE_CONSOLE) 
			return write_console (extio, buf, len);
		if (type == Extio.TYPE_FILE) 
			return write_file (extio, buf, len);
		if (type == Extio.TYPE_PIPE) 
			return write_pipe (extio, buf, len);
		//if (type == Extio.TYPE_COPROC)
		//	return write_coproc (extio, buf, len);
		return -1;
	}

	protected int flush_extio (Extio extio)
	{
		int type = extio.getType ();
		if (type == Extio.TYPE_CONSOLE) return flush_console (extio);
		if (type == Extio.TYPE_FILE) return flush_file (extio);
		if (type == Extio.TYPE_PIPE) return flush_pipe (extio);
		//if (type == Extio.TYPE_COPROC) return flush_coproc (extio);
		return -1;
	}

	protected int next_extio (Extio extio)
	{
		int type = extio.getType ();
		if (type == Extio.TYPE_CONSOLE) return next_console (extio);
		return -1;
	}

	protected abstract int open_console (Extio extio);
	protected abstract int close_console (Extio extio);
	protected abstract int read_console (Extio extio, char[] buf, int len);
	protected abstract int write_console (Extio extio, char[] buf, int len);
	protected abstract int flush_console (Extio extio);
	protected abstract int next_console (Extio extio);

	protected abstract int open_file (Extio extio);
	protected abstract int close_file (Extio extio);
	protected abstract int read_file (Extio extio, char[] buf, int len);
	protected abstract int write_file (Extio extio, char[] buf, int len); 
	protected abstract int flush_file (Extio extio);

	protected abstract int open_pipe (Extio extio);
	protected abstract int close_pipe (Extio extio);
	protected abstract int read_pipe (Extio extio, char[] buf, int len);
	protected abstract int write_pipe (Extio extio, char[] buf, int len); 
	protected abstract int flush_pipe (Extio extio);
}