/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 freemarker.core;

import java.io.IOException;

import freemarker.core.IteratorBlock.IterationContext;
import freemarker.template.TemplateException;

/**
 * A #sep element.
 */
class Sep extends TemplateElement {

    public Sep(TemplateElements children) {
        setChildren(children);
    }

    @Override
    TemplateElement[] accept(Environment env) throws TemplateException, IOException {
        final IterationContext iterCtx = env.findClosestEnclosingIterationContext();
        if (iterCtx == null) {
            // The parser should prevent this situation
            throw new _MiscTemplateException(env,
                    getNodeTypeSymbol(), " without iteration in context");
        }
        
        if (iterCtx.hasNext()) {
            return getChildBuffer();
        }
        return null;
    }

    @Override
    boolean isNestedBlockRepeater() {
        return false;
    }

    @Override
    protected String dump(boolean canonical) {
        StringBuilder sb = new StringBuilder();
        if (canonical) sb.append('<');
        sb.append(getNodeTypeSymbol());
        if (canonical) {
            sb.append('>');
            sb.append(getChildrenCanonicalForm());
            sb.append("</");
            sb.append(getNodeTypeSymbol());
            sb.append('>');
        }
        return sb.toString();
    }

    @Override
    String getNodeTypeSymbol() {
        return "#sep";
    }

    @Override
    int getParameterCount() {
        return 0;
    }

    @Override
    Object getParameterValue(int idx) {
        throw new IndexOutOfBoundsException();
    }

    @Override
    ParameterRole getParameterRole(int idx) {
        throw new IndexOutOfBoundsException();
    }

}