/*
 * 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 freemarker.template.SimpleScalar;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateScalarModel;
import freemarker.template.TemplateSequenceModel;

/**
 * Sequence variable implementation that wraps a String[] with relatively low
 * resource utilization. Warning: it does not copy the wrapped array, so do
 * not modify that after the model was made!
 */
public class StringArraySequence implements TemplateSequenceModel {
    private String[] stringArray;
    private TemplateScalarModel[] array;

    /**
     * Warning: Does not copy the argument array!
     */
    public StringArraySequence(String[] stringArray) {
        this.stringArray = stringArray;
    }

    @Override
    public TemplateModel get(int index) {
        if (array == null) {
            array = new TemplateScalarModel[stringArray.length];
        }
        TemplateScalarModel result = array[index];
        if (result == null) {
            result = new SimpleScalar(stringArray[index]);
            array[index] = result;
        }
        return result;
    }

    @Override
    public int size() {
        return stringArray.length;
    }
}