/*
 * "The Java Developer's Guide to Eclipse"
 *   by D'Anjou, Fairbrother, Kehn, Kellerman, McCarthy
 * 
 * (C) Copyright International Business Machines Corporation, 2003, 2004. 
 * All Rights Reserved.
 * 
 * Code or samples provided herein are provided without warranty of any kind.
 */
package org.teiid.designer.mapping.ui.choice;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.eclipse.jface.text.TextAttribute;
import org.eclipse.jface.text.rules.EndOfLineRule;
import org.eclipse.jface.text.rules.IRule;
import org.eclipse.jface.text.rules.IToken;
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;
import org.eclipse.swt.SWT;
import org.teiid.designer.ui.common.graphics.ColorManager;
import org.teiid.query.ui.sqleditor.sql.SqlWhiteSpaceDetector;
import org.teiid.query.ui.sqleditor.sql.SqlWordDetector;


/**
 * The SQLCodeScanner is a RuleBaseScanner.This class finds SQL comments and keywords, as the user edits the document. It is
 * "programmed" with a sequence of rules that evaluates and returns the offset and the length of the last found token.
 *
 * @since 8.0
 */
public class CriteriaCodeScanner extends RuleBasedScanner {

    private List rules;
    private ColorManager colorManager;
    private List lstReservedWords;

    // tokens
    IToken keyword;
    IToken datatype; // NO_UCD
    IToken function; // NO_UCD
    IToken string;
    IToken comment;
    IToken other;

    /**
     * Constructor for SQLCodeScanner. The SQLCodeScanner, is a RuleBaseScanner. The code scanner creates tokens for keywords,
     * types, and constants. The token is constructed with a TextAttribute. The TextAttribute is constructed with a color and
     * font. A list of rules with the corresponding token are created. The method ends with setting the scanner�s set of rules
     */
    public CriteriaCodeScanner( ColorManager colorManager,
                                List lstReservedWords ) {

        this.colorManager = colorManager;
        this.lstReservedWords = lstReservedWords;

        createTokens();
        setDefaultReturnToken(other);

        init();
    }

    private void init() {

        rules = new ArrayList();

        createStandardRules();
        createReservedWordRules();

        applyRules();
    }

    private void createStandardRules() {

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

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

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

        // Add word rule for keywords, datatypes, and function names.
        WordRule wordRule = new WordRule(new SqlWordDetector(), other);

        rules.add(wordRule);
    }

    private void createReservedWordRules() {
        WordRule wordRule = new WordRule(new SqlWordDetector(), other);

        Iterator it = lstReservedWords.iterator();

        while (it.hasNext()) {
            String sReservedWord = (String)it.next();
            wordRule.addWord(sReservedWord, keyword);
        }

        rules.add(wordRule);
    }

    private void applyRules() {

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

    public void setReservedWords( List lstReservedWords ) {
        this.lstReservedWords = lstReservedWords;
        init();
    }

    public void createTokens() {

        // --------------------------------------
        // Keyword TextAttributes IToken keyword =

        // --------------------------------------
        keyword = new Token(new TextAttribute(colorManager.getColor(ColorManager.KEYWORD), null, SWT.BOLD));
        // --------------------------------------
        // Datatype TextAttributes IToken datatype =

        // --------------------------------------
        datatype = new Token(new TextAttribute(colorManager.getColor(ColorManager.DATATYPE), null, SWT.BOLD));
        // --------------------------------------
        // Function TextAttributes
        // --------------------------------------
        function = new Token(new TextAttribute(colorManager.getColor(ColorManager.FUNCTION), null, SWT.BOLD));
        // --------------------------------------
        // String TextAttributes
        // --------------------------------------
        string = new Token(new TextAttribute(colorManager.getColor(ColorManager.STRING), null, SWT.NORMAL));
        // --------------------------------------
        // Comment TextAttributes
        // --------------------------------------
        comment = new Token(new TextAttribute(colorManager.getColor(ColorManager.SINGLE_LINE_COMMENT), null, SWT.NORMAL));
        // --------------------------------------
        // Default TextAttributes
        // --------------------------------------
        other = new Token(new TextAttribute(colorManager.getColor(ColorManager.DEFAULT), null, SWT.NORMAL));

    }

}