/* ============================================================
    * JRobin : Pure java implementation of RRDTool's functionality
    * ============================================================
    *
    * Project Info:  http://www.jrobin.org
    * Project Lead:  Sasa Markovic (saxon@jrobin.org);
    *
    * (C) Copyright 2003-2005, by Sasa Markovic.
    *
   * Developers:    Sasa Markovic (saxon@jrobin.org)
   *
   *
   * This library is free software; you can redistribute it and/or modify it under the terms
   * of the GNU Lesser General Public License as published by the Free Software Foundation;
   * either version 2.1 of the License, or (at your option) any later version.
   *
   * This library 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 Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public License along with this
   * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
   * Boston, MA 02111-1307, USA.
   */
  
  package org.jrobin.cmd;
  
  import org.jrobin.core.RrdException;
  
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.LinkedList;
  import java.util.List;
  
  class RrdCmdScanner {
  	private LinkedList<String> words = new LinkedList<String>();
  	private StringBuffer buff;
  
  	RrdCmdScanner(String command) throws RrdException {
  		String cmd = command.trim();
  		// parse words
  		char activeQuote = 0;
  		for (int i = 0; i < cmd.length(); i++) {
  			char c = cmd.charAt(i);
  			if ((c == '"' || c == '\'') && activeQuote == 0) {
  				// opening double or single quote
  				initWord();
  				activeQuote = c;
  				continue;
  			}
  			if (c == activeQuote) {
  				// closing quote
  				activeQuote = 0;
  				continue;
  			}
  			if (isSeparator(c) && activeQuote == 0) {
  				// separator encountered
  				finishWord();
  				continue;
  			}
  			if (c == '\\' && activeQuote == '"' && i + 1 < cmd.length()) {
  				// check for \" and \\ inside double quotes
  				char c2 = cmd.charAt(i + 1);
  				if (c2 == '\\' || c2 == '"') {
  					appendWord(c2);
  					i++;
  					continue;
  				}
  			}
  			// ordinary character
  			appendWord(c);
  		}
  		if (activeQuote != 0) {
  			throw new RrdException("End of command reached but " + activeQuote + " expected");
  		}
  		finishWord();
  	}
  
  	String getCmdType() {
  		if (words.size() > 0) {
  			return words.get(0);
  		}
  		else {
  			return null;
  		}
  	}
  
  	private void appendWord(char c) {
  		if (buff == null) {
  			buff = new StringBuffer("");
  		}
  		buff.append(c);
  	}
  
  	private void finishWord() {
  		if (buff != null) {
  			words.add(buff.toString());
  			buff = null;
  		}
 	}
 
 	private void initWord() {
 		if (buff == null) {
 			buff = new StringBuffer("");
 		}
 	}
 
 	void dump() {
 		for (String word : words) {
 			System.out.println(word);
 		}
 	}
 
 	String getOptionValue(String shortForm, String longForm, String defaultValue)
 			throws RrdException {
 		String value = null;
 		if (shortForm != null) {
 			value = getOptionValue("-" + shortForm);
 		}
 		if (value == null && longForm != null) {
 			value = getOptionValue("--" + longForm);
 		}
 		if (value == null) {
 			value = defaultValue;
 		}
 		return value;
 	}
 
 	String getOptionValue(String shortForm, String longForm)
 			throws RrdException {
 		return getOptionValue(shortForm, longForm, null);
 	}
 
 	private String getOptionValue(String fullForm) throws RrdException {
 		Iterator<String> iter = words.listIterator();
 		while (iter.hasNext()) {
 			String word = iter.next();
 			if (word.equals(fullForm)) {
 				// full match, the value is in the next word
 				if (iter.hasNext()) {
 					iter.remove();
 					String value = iter.next();
 					iter.remove();
 					return value;
 				}
 				else {
 					throw new RrdException("Value for option " + fullForm + " expected but not found");
 				}
 			}
 			if (word.startsWith(fullForm)) {
 				int pos = fullForm.length();
 				if (word.charAt(pos) == '=') {
 					// skip '=' if present
 					pos++;
 				}
 				iter.remove();
 				return word.substring(pos);
 			}
 		}
 		return null;
 	}
 
 	boolean getBooleanOption(String shortForm, String longForm) {
 		Iterator<String> iter = words.listIterator();
 		while (iter.hasNext()) {
 			String word = iter.next();
 			if ((shortForm != null && word.equals("-" + shortForm)) ||
 					(longForm != null && word.equals("--" + longForm))) {
 				iter.remove();
 				return true;
 			}
 		}
 		return false;
 	}
 
 	String[] getMultipleOptions(String shortForm, String longForm) throws RrdException {
 		List<String> values = new ArrayList<String>();
 		for (; ;) {
 			String value = getOptionValue(shortForm, longForm, null);
 			if (value == null) {
 				break;
 			}
 			values.add(value);
 		}
 		return values.toArray(new String[values.size()]);
 	}
 
 	String[] getRemainingWords() {
 		return words.toArray(new String[words.size()]);
 	}
 
 	boolean isSeparator(char c) {
 		return Character.isWhitespace(c);
 	}
 }