/*
 * 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 org.apache.commons.configuration2.web;

import java.util.Collections;
import java.util.Enumeration;
import java.util.Iterator;

import javax.servlet.Servlet;
import javax.servlet.ServletConfig;

/**
 * A configuration wrapper around a {@link ServletConfig}. This configuration is read only, adding or removing a
 * property will throw an UnsupportedOperationException.
 *
 * @since 1.1
 */
public class ServletConfiguration extends BaseWebConfiguration {

    /** Stores a reference to the wrapped {@code ServletConfig}. */
    protected ServletConfig config;

    /**
     * Creates a ServletConfiguration using the initialization parameter of the specified servlet.
     *
     * @param servlet the servlet
     */
    public ServletConfiguration(final Servlet servlet) {
        this(servlet.getServletConfig());
    }

    /**
     * Creates a ServletConfiguration using the servlet initialization parameters.
     *
     * @param config the servlet configuration
     */
    public ServletConfiguration(final ServletConfig config) {
        this.config = config;
    }

    @Override
    protected Object getPropertyInternal(final String key) {
        return handleDelimiters(config.getInitParameter(key));
    }

    @Override
    protected Iterator<String> getKeysInternal() {
        // According to the documentation of getInitParameterNames() the
        // enumeration is of type String.
        final Enumeration<String> en = config.getInitParameterNames();
        return Collections.list(en).iterator();
    }
}
