/**********************************************************************
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.IPreferenceConstants;
import net.sourceforge.phpeclipse.PHPeclipsePlugin;
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.preference.IPreferenceStore;
import org.eclipse.jface.preference.PreferenceConverter;
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 implements IPreferenceConstants {

  private static Token variable;
  private static Token keyword;
  private static Token functionName;
  private static Token string;
  private static Token comment;
  private static Token multi_comment;
  private static Token other;

  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", "null", "object", "array" };
  //  private static TextAttribute fSingleLine;
  //  private static TextAttribute fMultiLine;
  //  private static TextAttribute fKeyword;
  //  private static TextAttribute fFunctionName;
  //  private static TextAttribute fString;
  //  private static TextAttribute fVariable;
  private PHPColorProvider fColorProvider;

  /**
   * Creates a PHP code scanner
   */
  public PHPCodeScanner(PHPColorProvider provider) {
        final IPreferenceStore store = PHPeclipsePlugin.getDefault().getPreferenceStore();

    variable = new Token(new TextAttribute(provider.getColor(PreferenceConverter.getColor(store, PHP_VARIABLE))));
    keyword = new Token(new TextAttribute(provider.getColor(PreferenceConverter.getColor(store, PHP_KEYWORD))));
    functionName = new Token(new TextAttribute(provider.getColor(PreferenceConverter.getColor(store, PHP_FUNCTIONNAME))));
    string = new Token(new TextAttribute(provider.getColor(PreferenceConverter.getColor(store, PHP_STRING))));
    comment = new Token(new TextAttribute(provider.getColor(PreferenceConverter.getColor(store, PHP_SINGLELINE_COMMENT))));
    multi_comment = new Token(new TextAttribute(provider.getColor(PreferenceConverter.getColor(store, PHP_MULTILINE_COMMENT))));
    other = new Token(new TextAttribute(provider.getColor(PreferenceConverter.getColor(store, PHP_DEFAULT))));


    List rules = new ArrayList();

    // Add rule for single line comments.
    rules.add(new EndOfLineRule("//", comment)); //$NON-NLS-1$
    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], functionName);
    for (int i = 0; i < fgConstants.length; i++)
      wordRule.addWord(fgConstants[i], functionName);
    rules.add(wordRule);

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

  public void updateToken(PHPColorProvider provider) {
    final IPreferenceStore store = PHPeclipsePlugin.getDefault().getPreferenceStore();

    variable.setData(new TextAttribute(provider.getColor(PreferenceConverter.getColor(store, PHP_VARIABLE))));
    keyword.setData(new TextAttribute(provider.getColor(PreferenceConverter.getColor(store, PHP_KEYWORD))));
    functionName.setData(new TextAttribute(provider.getColor(PreferenceConverter.getColor(store, PHP_FUNCTIONNAME))));
    string.setData(new TextAttribute(provider.getColor(PreferenceConverter.getColor(store, PHP_STRING))));
    comment.setData(new TextAttribute(provider.getColor(PreferenceConverter.getColor(store, PHP_SINGLELINE_COMMENT))));
    multi_comment.setData(new TextAttribute(provider.getColor(PreferenceConverter.getColor(store, PHP_MULTILINE_COMMENT))));
    other.setData(new TextAttribute(provider.getColor(PreferenceConverter.getColor(store, PHP_DEFAULT))));
    
  }
}