////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2017 the original author or authors.
//
// 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 com.puppycrawl.tools.checkstyle.checks.javadoc;

import com.puppycrawl.tools.checkstyle.api.DetailNode;
import com.puppycrawl.tools.checkstyle.api.JavadocTokenTypes;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
import com.puppycrawl.tools.checkstyle.utils.JavadocUtils;

/**
 * Checks that the at-clause tag is followed by description .
 * Default configuration that will check {@code @param}, {@code @return},
 * {@code @throws}, {@code @deprecated} to:
 * <pre>
 * <module name="NonEmptyAtclauseDescription"/>
 * </pre>
 *
 * @author maxvetrenko
 *
 */
public class NonEmptyAtclauseDescriptionCheck extends AbstractJavadocCheck {

    /**
     * A key is pointing to the warning message text in "messages.properties"
     * file.
     */
    public static final String MSG_KEY = "non.empty.atclause";

    @Override
    public int[] getDefaultJavadocTokens() {
        return new int[] {
            JavadocTokenTypes.PARAM_LITERAL,
            JavadocTokenTypes.RETURN_LITERAL,
            JavadocTokenTypes.THROWS_LITERAL,
            JavadocTokenTypes.DEPRECATED_LITERAL,
        };
    }

    @Override
    public int[] getAcceptableTokens() {
        return new int[] {TokenTypes.BLOCK_COMMENT_BEGIN };
    }

    @Override
    public int[] getRequiredTokens() {
        return getAcceptableTokens();
    }

    @Override
    public void visitJavadocToken(DetailNode ast) {
        if (isEmptyTag(ast.getParent())) {
            log(ast.getLineNumber(), MSG_KEY, ast.getText());
        }
    }

    /**
     * Tests if at-clause tag is empty.
     * @param tagNode at-clause tag.
     * @return true, if at-clause tag is empty.
     */
    private static boolean isEmptyTag(DetailNode tagNode) {
        final DetailNode tagDescription =
                JavadocUtils.findFirstToken(tagNode, JavadocTokenTypes.DESCRIPTION);
        return tagDescription == null;
    }
}