/**
 * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
 */

package net.sourceforge.pmd.lang.java.rule;

import java.util.regex.Pattern;

import net.sourceforge.pmd.lang.java.ast.ASTLiteral;
import net.sourceforge.pmd.lang.java.rule.regex.RegexHelper;
import net.sourceforge.pmd.lang.rule.properties.StringProperty;

/**
 * This class allow to match a Literal (most likely a String) with a regex
 * pattern. Obviously, there are many applications of it (such as
 * basic.xml/AvoidUsingHardCodedIP).
 *
 * @author Romain PELISSE, belaran@gmail.com
 */
// FUTURE This is not referenced by any RuleSet?
public class GenericLiteralCheckerRule extends AbstractJavaRule {

    private Pattern pattern;

    private static final String PROPERTY_NAME = "regexPattern";

    private static final StringProperty REGEX_PROPERTY = new StringProperty(PROPERTY_NAME, "Regular expression", "",
            1.0f);

    public GenericLiteralCheckerRule() {
        definePropertyDescriptor(REGEX_PROPERTY);
    }

    private void init() {
        if (pattern == null) {
            // Retrieve the regex pattern set by user
            String stringPattern = super.getProperty(REGEX_PROPERTY);
            // Compile the pattern only once
            if (stringPattern != null && stringPattern.length() > 0) {
                pattern = Pattern.compile(stringPattern);
            } else {
                throw new IllegalArgumentException("Must provide a value for the '" + PROPERTY_NAME + "' property.");
            }
        }
    }

    /**
     * This method checks if the Literal matches the pattern. If it does, a
     * violation is logged.
     */
    @Override
    public Object visit(ASTLiteral node, Object data) {
        init();
        String image = node.getImage();
        if (image != null && image.length() > 0 && RegexHelper.isMatch(this.pattern, image)) {
            addViolation(data, node);
        }
        return data;
    }
}