package sbst.runtool;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.Writer;
import java.io.OutputStream;

public class SBSTChannel
{
    public static class NullOutputStream extends OutputStream {
        public void write(int b) throws IOException {}
    }

	private PrintWriter output, debug;
	private BufferedReader input;

	public SBSTChannel(Reader input, Writer output, PrintWriter debug)
    {
		this.input = new BufferedReader(input);
		this.output = new PrintWriter(output);
        this.debug = debug;
    }

	public SBSTChannel(Reader inputs, Writer outputs)
	{
        this(inputs, outputs, new PrintWriter(new NullOutputStream()));
	}

	public void token(String string) throws IOException
	{
        debug.println("expecting: " + string);
		String line = input.readLine();
        debug.println("<< " + line);
		if(!string.equals(line))
			throw new IOException("Unexpected: " + line + " expecting: "+ string);
	}

	public File directory() throws IOException
	{
        debug.println("expecting existing directory");
		String line = input.readLine();
        debug.println("<< " + line);
		File file = new File(line);
		if(file.exists() && file.isDirectory())
		{
			return file;
		}
		else 
		{
			throw new IOException("Not a valid directory name: "+ line);
		}
	}

	public int number() throws IOException
	{
        debug.println("expecting number");
		String line = input.readLine();
        debug.println("<< " + line);
		try
		{
			return Integer.parseInt(line);
		}
		catch(NumberFormatException e)
		{
			throw new IOException("Not a valid number: " + line);
		}
	}

	public File directory_jarfile() throws IOException
	{
        debug.println("expecting directory or jar file");
		String line = input.readLine();
        debug.println("<< " + line);
		File file = new File(line);
		if(file.exists())			
		{
			if(file.isDirectory() || (file.isFile() && file.getName().endsWith(".jar")))
			{
				return file;
			}
			else 
			{
				throw new IOException("Not a valid directory/jar file name: "+ line);
			}
		}
		else 
		{
			throw new IOException("File/Directory does not exist: "+ line);
		}
	}

	public String className() throws IOException
	{
        debug.println("expecting fully qualified class name");
		String line = input.readLine();
        debug.println("<< " + line);
		if(line.matches("[a-zA-Z_][a-zA-Z_0-9]*(\\.[a-zA-Z_][a-zA-Z_0-9]*)*"))
		{
			return line;
		}
		else
		{
			throw new IOException("Not a valid class name: " + line);
		}
	}

	public void emit(String string)
	{
        debug.println(">> " + string);
		output.println(string);
		output.flush();
	}

	public void emit(int k)
	{
		emit(""+k);
	}

	public void emit(File file)
	{
		emit(file.getAbsolutePath());
	}

	public String readLine() throws IOException
	{
        String line = input.readLine();
        debug.println("<< " + line);
		return line;
	}

}