/*
 * 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.xerces.util;

import java.io.InputStream;
import java.io.Reader;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.apache.xerces.xni.XMLResourceIdentifier;
import org.apache.xerces.xni.parser.XMLInputSource;

/**
 * This class represents an input source for an XML resource
 * retrievable over HTTP. In addition to the properties
 * provided by an <code>XMLInputSource</code> an HTTP input
 * source also has HTTP request properties and a preference
 * whether HTTP redirects will be followed. Note that these
 * properties will only be used if reading this input source
 * will induce an HTTP connection.
 * 
 * @author Michael Glavassevich, IBM
 * 
 * @version $Id$
 */
public final class HTTPInputSource extends XMLInputSource {

    //
    // Data
    //
    
    /** Preference for whether HTTP redirects should be followed. **/
    protected boolean fFollowRedirects = true;
    
    /** HTTP request properties. **/
    protected Map fHTTPRequestProperties = new HashMap();
    
    //
    // Constructors
    //
    
    /** 
     * Constructs an input source from just the public and system
     * identifiers, leaving resolution of the entity and opening of
     * the input stream up to the caller.
     *
     * @param publicId     The public identifier, if known.
     * @param systemId     The system identifier. This value should
     *                     always be set, if possible, and can be
     *                     relative or absolute. If the system identifier
     *                     is relative, then the base system identifier
     *                     should be set.
     * @param baseSystemId The base system identifier. This value should
     *                     always be set to the fully expanded URI of the
     *                     base system identifier, if possible.
     */
    public HTTPInputSource(String publicId, String systemId, String baseSystemId) {
        super(publicId, systemId, baseSystemId);
    } // <init>(String,String,String)
    
    /** 
     * Constructs an input source from a XMLResourceIdentifier
     * object, leaving resolution of the entity and opening of
     * the input stream up to the caller.
     *
     * @param resourceIdentifier the XMLResourceIdentifier containing the information
     */
    public HTTPInputSource(XMLResourceIdentifier resourceIdentifier) {
        super(resourceIdentifier);
    } // <init>(XMLResourceIdentifier)
    
    /**
     * Constructs an input source from a byte stream.
     *
     * @param publicId     The public identifier, if known.
     * @param systemId     The system identifier. This value should
     *                     always be set, if possible, and can be
     *                     relative or absolute. If the system identifier
     *                     is relative, then the base system identifier
     *                     should be set.
     * @param baseSystemId The base system identifier. This value should
     *                     always be set to the fully expanded URI of the
     *                     base system identifier, if possible.
     * @param byteStream   The byte stream.
     * @param encoding     The encoding of the byte stream, if known.
     */
    public HTTPInputSource(String publicId, String systemId,
            String baseSystemId, InputStream byteStream, String encoding) {
        super(publicId, systemId, baseSystemId, byteStream, encoding);
    } // <init>(String,String,String,InputStream,String)
    
    /**
     * Constructs an input source from a character stream.
     *
     * @param publicId     The public identifier, if known.
     * @param systemId     The system identifier. This value should
     *                     always be set, if possible, and can be
     *                     relative or absolute. If the system identifier
     *                     is relative, then the base system identifier
     *                     should be set.
     * @param baseSystemId The base system identifier. This value should
     *                     always be set to the fully expanded URI of the
     *                     base system identifier, if possible.
     * @param charStream   The character stream.
     * @param encoding     The original encoding of the byte stream
     *                     used by the reader, if known.
     */
    public HTTPInputSource(String publicId, String systemId,
            String baseSystemId, Reader charStream, String encoding) {
        super(publicId, systemId, baseSystemId, charStream, encoding);
    } // <init>(String,String,String,Reader,String)
    
    //
    // Public methods
    //   
    
    /**
     * Returns the preference whether HTTP redirects should
     * be followed. By default HTTP redirects will be followed.
     */
    public boolean getFollowHTTPRedirects() {
        return fFollowRedirects;
    } // getFollowHTTPRedirects():boolean
    
    
    /**
     * Sets the preference whether HTTP redirects should
     * be followed. By default HTTP redirects will be followed.
     */
    public void setFollowHTTPRedirects(boolean followRedirects) {
        fFollowRedirects = followRedirects;
    } // setFollowHTTPRedirects(boolean)
    
    /**
     * Returns the value of the request property 
     * associated with the given property name.
     * 
     * @param key the name of the request property
     * @return the value of the request property or 
     * <code>null</code> if this property has not
     * been set
     */
    public String getHTTPRequestProperty(String key) {
        return (String) fHTTPRequestProperties.get(key);
    } // getHTTPRequestProperty(String):String
    
    /**
     * Returns an iterator for the request properties this
     * input source contains. Each object returned by the
     * iterator is an instance of <code>java.util.Map.Entry</code>
     * where each key and value are a pair of strings corresponding
     * to the name and value of a request property. 
     * 
     * @return an iterator for the request properties this
     * input source contains
     */
    public Iterator getHTTPRequestProperties() {
        return fHTTPRequestProperties.entrySet().iterator();
    } // getHTTPRequestProperties():Iterator
    
    /**
     * Sets the value of the request property
     * associated with the given property name.
     * 
     * @param key the name of the request property
     * @param value the value of the request property
     */
    public void setHTTPRequestProperty(String key, String value) {
        if (value != null) {
            fHTTPRequestProperties.put(key, value);
        }
        else {
            fHTTPRequestProperties.remove(key);
        }
    } // setHTTPRequestProperty(String,String)
    
} // class HTTPInputSource
