/*
 * 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.tuscany.sca.http.tomcat;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URL;
import java.net.URLConnection;
import java.util.Hashtable;

import javax.naming.NamingException;
import javax.naming.directory.Attributes;
import javax.naming.directory.BasicAttributes;
import javax.naming.directory.DirContext;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;

import org.apache.catalina.servlets.DefaultServlet;
import org.apache.naming.resources.FileDirContext;
import org.apache.naming.resources.ProxyDirContext;
import org.apache.naming.resources.Resource;

/**
 * DefaultServlet implementation for Tomcat.
 *
 * @version $Rev$ $Date$
 */
public class TomcatDefaultServlet extends DefaultServlet {
    private static final long serialVersionUID = -7503581551326796573L;
    
    private String documentRoot;
    private ProxyDirContext proxyDirContext;
    
    public TomcatDefaultServlet(String servletPath, String documentRoot) {
        this.documentRoot = documentRoot;
        
        DirContext dirContext;
        URI uri = URI.create(documentRoot);
        if (!"file".equals(uri.getScheme())) {
            
            dirContext = new FileDirContext() {
                @Override
                public Attributes getAttributes(String name) throws NamingException {
                    return new BasicAttributes();
                }
                
                @Override
                public Object lookup(String name) throws NamingException {
                    
                    try {
                        final URL url = new URL(TomcatDefaultServlet.this.documentRoot + name);
                        return new Resource() {
                            @Override
                            public InputStream streamContent() throws IOException {
                                URLConnection connection = url.openConnection();
                                connection.setUseCaches(false);
                                return connection.getInputStream();
                            }
                        };
                    } catch (MalformedURLException e) {
                        throw new NamingException(e.toString());
                    }
                }
            };
            
        } else {
            dirContext = new FileDirContext();
            ((FileDirContext)dirContext).setDocBase(uri.getPath());
        }
        proxyDirContext = new ProxyDirContext(new Hashtable(), dirContext);
        resources = proxyDirContext;            
    }
    
    @Override
    public void init() throws ServletException {
        super.init();
        resources = proxyDirContext;
    }
    
    @Override
    public void init(ServletConfig servletConfig) throws ServletException {
        super.init(servletConfig);
        resources = proxyDirContext;
    }

    @Override
    protected String getRelativePath(HttpServletRequest request) {
        String path = request.getPathInfo();
        if (path == null || path.length() == 0) {
            path = "/";
        }
        return path;
    }
}