/*
 * Copyright 2013 (c) MuleSoft, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 */
package org.xbib.raml.yagi.framework.phase;

import org.xbib.raml.yagi.framework.grammar.rule.ErrorNodeFactory;
import org.xbib.raml.yagi.framework.grammar.rule.Rule;
import org.xbib.raml.yagi.framework.nodes.ErrorNode;
import org.xbib.raml.yagi.framework.nodes.Node;

public class GrammarPhase implements Phase {

    private final Rule rootRule;

    public GrammarPhase(Rule rootRule) {
        this.rootRule = rootRule;
    }

    @Override
    public Node apply(Node node) {
        if (rootRule.matches(node)) {
            final Node result = rootRule.apply(node);
            node.replaceWith(result);
            return result;
        } else if (node instanceof ErrorNode) {
            // trying not to wrap an existing error so that clients won't have to know whether to strip or not to strip
            return node;
        } else {
            final ErrorNode errorNode = ErrorNodeFactory.createInvalidRootElement(node, rootRule.getDescription());
            node.replaceWith(errorNode);
            return errorNode;
        }
    }

}
