/**
 * $Id: $
 * $Date: $
 *
 */

package org.xmlsh.sh.grammar;

import java.io.FilterReader;
import java.io.IOException;
import java.io.Reader;


public class ShellParserReader extends FilterReader {



	private char	mReadAhead = (char)-1;


	// Skip UTF8 BOM if its the first char
	private void skipbom() throws IOException
	{
		int c = super.read();
		if( c != '\ufeff' )
			mReadAhead = (char)c; 

	}
	public ShellParserReader(Reader in, boolean bSkipBOM ) throws IOException {
		super(in);	
		if( bSkipBOM )
			skipbom();

	}

	

    // Start of a new command 
    public void reset() {
        try {
            super.reset();
        } catch (IOException e) {
           
        }
        
    } 
	/*
	 * Opposite of InputStream, Readers require you to override read(byte[] .... ) - this is used as just a helper function.
	 * 
	 * 
	 * @see java.io.FilterReader#read()
	 * 
	 */
	@Override
	public int read() throws IOException {
		if( mReadAhead != (char)-1 ){
			char ret = mReadAhead ;
			mReadAhead = (char)-1;
			return ret;
		}


		int c ;
		while ( ( c = super.read()) != -1 ){

			if( c == '\r')
				continue ;
			if( c == '\\') {
				c = super.read();
				if( c == '\r')
					c = super.read();
				if( c == '\n'){
					// skip \\ \n 
					continue ;
				}
				mReadAhead = (char)c ;
				return '\\';
			}
			else
				break ;
		}
		return c;

	}

	/* 
	 * Reads at *most* one line at a time
	 * Note: THIS is the call into read, unlike InputStream.read()
	 * @see java.io.FilterReader#read(char[], int, int)
	 */
	@Override
	public int read(char[] cbuf, int off, int len) throws IOException {
		int nc = 0;
		int c;


		while( nc < len && (c=read()) != -1 ){
			cbuf[off++] = (char)c;
			nc++;
			if( c == '\n') {
				break ;
			}
		}
		return( nc > 0 ? nc : -1 );

	}


}



//
//
//Copyright (C) 2008-2014    David A. Lee.
//
//The contents of this file are subject to the "Simplified BSD License" (the "License");
//you may not use this file except in compliance with the License. You may obtain a copy of the
//License at http://www.opensource.org/licenses/bsd-license.php 
//
//Software distributed under the License is distributed on an "AS IS" basis,
//WITHOUT WARRANTY OF ANY KIND, either express or implied.
//See the License for the specific language governing rights and limitations under the License.
//
//The Original Code is: all this file.
//
//The Initial Developer of the Original Code is David A. Lee
//
//Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
//Contributor(s): none.
//