/**********************************************************************
Copyright (c) 2000, 2002 IBM Corp. and others.
All rights reserved. This program and the accompanying materials
are made available under the terms of the Common Public License v1.0
which accompanies this distribution, and is available at
http://www.eclipse.org/legal/cpl-v10.html

Contributors:
    IBM Corporation - Initial implementation
    Klaus Hartlage - www.eclipseproject.de
**********************************************************************/
package net.sourceforge.phpeclipse.phpeditor.php;

import java.util.ArrayList;
import java.util.List;

import net.sourceforge.phpeclipse.phpeditor.util.PHPColorProvider;
import net.sourceforge.phpeclipse.phpeditor.util.PHPWhitespaceDetector;
import net.sourceforge.phpeclipse.phpeditor.util.PHPWordDetector;
import org.eclipse.jface.text.TextAttribute;
import org.eclipse.jface.text.rules.EndOfLineRule;
import org.eclipse.jface.text.rules.ICharacterScanner;
import org.eclipse.jface.text.rules.IRule;
import org.eclipse.jface.text.rules.IToken;
import org.eclipse.jface.text.rules.IWordDetector;
import org.eclipse.jface.text.rules.MultiLineRule;
import org.eclipse.jface.text.rules.RuleBasedScanner;
import org.eclipse.jface.text.rules.SingleLineRule;
import org.eclipse.jface.text.rules.Token;
import org.eclipse.jface.text.rules.WhitespaceRule;
import org.eclipse.jface.text.rules.WordRule;

/**
 * PHP Code Scanner
 */
public class PHPCodeScanner extends RuleBasedScanner {

	

	
  private IToken variable;
  
	private class PHPWordRule extends WordRule {
    private StringBuffer fBuffer= new StringBuffer();

		public PHPWordRule(IWordDetector detector) {
			super(detector, Token.UNDEFINED);
		}

		public PHPWordRule(IWordDetector detector, IToken defaultToken) {
			super(detector, defaultToken);
		}

		public IToken evaluate(ICharacterScanner scanner) {
			int c = scanner.read();
      boolean isVariable = false;
			if (fDetector.isWordStart((char) c)) {
        if (c=='$') {
          isVariable = true;
        }
				if (fColumn == UNDEFINED || (fColumn == scanner.getColumn() - 1)) {

					fBuffer.setLength(0);
					do {
						fBuffer.append((char) c);
						c = scanner.read();
					} while (c != scanner.EOF && fDetector.isWordPart((char) c));
					scanner.unread();

          if (isVariable) {
            return variable;
          }
					IToken token = (IToken) fWords.get(fBuffer.toString());
					if (token != null)
						return token;

					if (fDefaultToken.isUndefined())
						unreadBuffer(scanner);

					return fDefaultToken;
				}
			}

			scanner.unread();
			return Token.UNDEFINED;
		}
	}

	private static String[] fgConstants = { "__LINE__", "__FILE__", "true", "false" };
	private TextAttribute fComment;
	private TextAttribute fKeyword;
	private TextAttribute fType;
	private TextAttribute fString;
	private PHPColorProvider fColorProvider;

	/**
	 * Creates a Java code scanner
	 */
	public PHPCodeScanner(PHPColorProvider provider) {

		IToken keyword = new Token(new TextAttribute(provider.getColor(PHPColorProvider.KEYWORD)));
		IToken type = new Token(new TextAttribute(provider.getColor(PHPColorProvider.TYPE)));
		IToken string = new Token(new TextAttribute(provider.getColor(PHPColorProvider.STRING)));
		IToken comment = new Token(new TextAttribute(provider.getColor(PHPColorProvider.SINGLE_LINE_COMMENT)));
		IToken multi_comment = new Token(new TextAttribute(provider.getColor(PHPColorProvider.MULTI_LINE_COMMENT)));
		IToken other = new Token(new TextAttribute(provider.getColor(PHPColorProvider.DEFAULT)));

    variable = new Token(new TextAttribute(provider.getColor(PHPColorProvider.VARIABLE)));

    
		List rules = new ArrayList();

		// Add rule for single line comments.
		rules.add(new EndOfLineRule("//", comment)); //$NON-NLS-1$
		//    EndOfLineRule endOfLine = new EndOfLineRule("#", comment);
		//    endOfLine.setColumnConstraint(0);
		rules.add(new EndOfLineRule("#", comment));

		// Add rule for strings and character constants.
		rules.add(new MultiLineRule("\"", "\"", string, '\\')); //$NON-NLS-2$ //$NON-NLS-1$
		rules.add(new SingleLineRule("'", "'", string, '\\')); //$NON-NLS-2$ //$NON-NLS-1$

		// rules.add(new SingleLineRule("//", "//", php_comment));
		rules.add(new MultiLineRule("/*", "*/", multi_comment));

		// Add generic whitespace rule.
		rules.add(new WhitespaceRule(new PHPWhitespaceDetector()));

		// Add word rule for keywords, types, and constants.
		PHPWordRule wordRule = new PHPWordRule(new PHPWordDetector(), other);
		for (int i = 0; i < PHPKeywords.PHP_KEYWORS.length; i++)
			wordRule.addWord(PHPKeywords.PHP_KEYWORS[i], keyword);
		for (int i = 0; i < PHPFunctionNames.FUNCTION_NAMES.length; i++)
			wordRule.addWord(PHPFunctionNames.FUNCTION_NAMES[i], type);
		for (int i = 0; i < fgConstants.length; i++)
			wordRule.addWord(fgConstants[i], type);
		rules.add(wordRule);

		IRule[] result = new IRule[rules.size()];
		rules.toArray(result);
		setRules(result);
	}
}