/*
 * 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.axis2.kernel;

import org.apache.axiom.blob.Blobs;
import org.apache.axiom.blob.MemoryBlob;
import org.apache.axiom.blob.MemoryBlobOutputStream;
import org.apache.axiom.om.OMOutputFormat;
import org.apache.axiom.util.activation.BlobDataSource;
import org.apache.axis2.AxisFault;
import org.apache.axis2.context.MessageContext;

import java.io.OutputStream;
import java.net.URL;

import javax.activation.DataSource;

/**
 * <p/>
 * MessageFormatter implementations are used by Axis2 to support serialization
 * of messages to different message formats. (Eg: JSON). Users can register
 * MessageFormatter implementations against a message type using the axis2.xml.
 * Message type for a message can be specified by setting the "messageType"
 * property in the MessageContext. This can also be given as a parameter in the
 * service.xml/axis2.xml for a per service based/engine wide configuration.
 * </p>
 * <p/>
 * <messageFormatters>
 * <messageFormatter contentType="application/soap+xml"
 * class="org.apache.axis2.kernel.http.SOAPMessageFormatter"/>
 * </messageFormatters>
 * </p>
 */
public interface MessageFormatter {
    /**
     * To support deffered writing transports as in http chunking.. Axis2 was
     * doing this for some time..
     * <p/>
     * Preserve flag can be used to preserve the envelope for later use. This is
     * usefull when implementing authentication machnisms like NTLM.
     *
     * @param outputStream
     * @param preserve     :
     *                     do not consume the OM when this is set..
     */
    public void writeTo(MessageContext messageContext, OMOutputFormat format,
                        OutputStream outputStream, boolean preserve) throws AxisFault;

    /**
     * Different message formats can set their own content types
     * Eg: JSONFormatter can set the content type as application/json
     *
     * @param messageContext
     * @param format
     * @param soapAction
     */
    public String getContentType(MessageContext messageContext, OMOutputFormat format,
                                 String soapAction);

    /**
     * Some message formats may want to alter the target url.
     *
     * @return the target URL
     */
    public URL getTargetAddress(MessageContext messageContext, OMOutputFormat format,
                                URL targetURL) throws AxisFault;

    /**
     * @return this only if you want set a transport header for SOAP Action
     */
    public String formatSOAPAction(MessageContext messageContext, OMOutputFormat format,
                                   String soapAction);

    /**
     * Get the formatted message as a {@link DataSource} object.
     * 
     * @param messageContext
     * @param format
     * @param soapAction
     * @return
     * @throws AxisFault
     */
    default DataSource getDataSource(MessageContext messageContext, OMOutputFormat format, String soapAction) throws AxisFault {
        MemoryBlob blob = Blobs.createMemoryBlob();
        MemoryBlobOutputStream out = blob.getOutputStream();
        writeTo(messageContext, format, out, false);
        out.close();
        return new BlobDataSource(blob, getContentType(messageContext, format, soapAction));
    }
}