/*
 * 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.ext.servlet;

import javax.servlet.GenericServlet;
import javax.servlet.ServletContext;

import freemarker.template.ObjectWrapper;
import freemarker.template.TemplateHashModel;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;

/**
 * TemplateHashModel wrapper for a ServletContext attributes.
 */
public final class ServletContextHashModel implements TemplateHashModel {
    private final GenericServlet servlet;
    private final ServletContext servletctx;
    private final ObjectWrapper wrapper;

    public ServletContextHashModel(
        GenericServlet servlet, ObjectWrapper wrapper) {
        this.servlet = servlet;
        this.servletctx = servlet.getServletContext();
        this.wrapper = wrapper;
    }
    
    /**
     * @deprecated use 
     * {@link #ServletContextHashModel(GenericServlet, ObjectWrapper)} instead.
     */
    @Deprecated
    public ServletContextHashModel(
        ServletContext servletctx, ObjectWrapper wrapper) {
        this.servlet = null;
        this.servletctx = servletctx;
        this.wrapper = wrapper;
    }

    @Override
    public TemplateModel get(String key) throws TemplateModelException {
        return wrapper.wrap(servletctx.getAttribute(key));
    }

    @Override
    public boolean isEmpty() {
        return !servletctx.getAttributeNames().hasMoreElements();
    }
    
    /**
     * Returns the underlying servlet. Can return null if this object was
     * created using the deprecated constructor.
     */
    public GenericServlet getServlet() {
        return servlet;
    }
}