# SourceResponseFactory.java

    /**
     *  Copyright (c) 2009, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
     *
     *  Licensed 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.synapse.transport.passthru.util;

    import org.apache.axiom.om.OMOutputFormat;
    import org.apache.axis2.context.MessageContext;
    import org.apache.axis2.transport.MessageFormatter;
    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;
    import org.apache.http.protocol.HTTP;
    import org.apache.synapse.transport.nhttp.NhttpConstants;
    import org.apache.synapse.transport.nhttp.util.MessageFormatterDecoratorFactory;
    import org.apache.synapse.transport.nhttp.util.NhttpUtil;
    import org.apache.synapse.transport.passthru.PassThroughConstants;
    import org.apache.synapse.transport.passthru.Pipe;
    import org.apache.synapse.transport.passthru.SourceRequest;
    import org.apache.synapse.transport.passthru.SourceResponse;
    import org.apache.synapse.transport.passthru.config.PassThroughConfiguration;
    import org.apache.synapse.transport.passthru.config.SourceConfiguration;

    import java.util.Collection;
    import java.util.HashMap;
    import java.util.Iterator;
    import java.util.Map;

    public class SourceResponseFactory {
        private static Log log = LogFactory.getLog(SourceResponseFactory.class);

        public static SourceResponse create(MessageContext msgContext,
                                            SourceRequest sourceRequest,
                                            SourceConfiguration sourceConfiguration) {
            // determine the status code to be sent
            int statusCode = PassThroughTransportUtils.determineHttpStatusCode(msgContext);
            SourceResponse sourceResponse;
            String statusLine = PassThroughTransportUtils.determineHttpStatusLine(msgContext);

            if (msgContext.getProperty(PassThroughConstants.ORIGINAL_HTTP_SC) != null &&
                    statusCode == ((Integer) msgContext.getProperty(PassThroughConstants.ORIGINAL_HTTP_SC))) {
                sourceResponse = new SourceResponse(sourceConfiguration, statusCode, statusLine, sourceRequest);
            } else {
                if (msgContext.getProperty(PassThroughConstants.ORIGINAL_HTTP_REASON_PHRASE) != null &&
                        (statusLine.equals(msgContext.getProperty(PassThroughConstants.ORIGINAL_HTTP_REASON_PHRASE)))) {
                    sourceResponse = new SourceResponse(sourceConfiguration, statusCode, sourceRequest);
                } else {
                    sourceResponse = new SourceResponse(sourceConfiguration, statusCode, statusLine, sourceRequest);
                }
            }

            // set any transport headers
            Map transportHeaders = (Map) msgContext.getProperty(MessageContext.TRANSPORT_HEADERS);

            boolean forceContentLength = msgContext.isPropertyTrue(NhttpConstants.FORCE_HTTP_CONTENT_LENGTH);
    	    boolean forceContentLengthCopy = msgContext.isPropertyTrue(PassThroughConstants.COPY_CONTENT_LENGTH_FROM_INCOMING);

    	    if (forceContentLength && forceContentLengthCopy && msgContext.getProperty(PassThroughConstants.ORGINAL_CONTEN_LENGTH) != null
                    && !sourceConfiguration.isPreserveHttpHeader(HTTP.CONTENT_LEN)) {
    	    	 sourceResponse.addHeader(HTTP.CONTENT_LEN, (String)msgContext.getProperty(PassThroughConstants.ORGINAL_CONTEN_LENGTH));
    		}

            // When invoking http HEAD request esb set content length as 0 to response header. Since there is no message
            // body content length cannot be calculated inside synapse. Hence content length of the backend response is
            // set to sourceResponse.
            if (sourceRequest != null && PassThroughConstants.HTTP_HEAD.equalsIgnoreCase(sourceRequest.getRequest().getRequestLine().getMethod()) &&
                msgContext.getProperty(PassThroughConstants.ORGINAL_CONTEN_LENGTH) != null
                    && !sourceConfiguration.isPreserveHttpHeader(PassThroughConstants.ORGINAL_CONTEN_LENGTH)) {
                sourceResponse.addHeader(PassThroughConstants.ORGINAL_CONTEN_LENGTH, (String) msgContext.getProperty
                        (PassThroughConstants.ORGINAL_CONTEN_LENGTH));
            }

            if (transportHeaders != null && msgContext.getProperty(org.apache.axis2.Constants.Configuration.MESSAGE_TYPE) != null) {
                if (msgContext.getProperty(org.apache.axis2.Constants.Configuration.CONTENT_TYPE) != null
                        && msgContext.getProperty(org.apache.axis2.Constants.Configuration.CONTENT_TYPE).toString().contains(PassThroughConstants.CONTENT_TYPE_MULTIPART_RELATED)
                        && !sourceConfiguration.isPreserveHttpHeader(org.apache.axis2.Constants.Configuration.MESSAGE_TYPE)) {
                    transportHeaders.put(org.apache.axis2.Constants.Configuration.MESSAGE_TYPE, PassThroughConstants.CONTENT_TYPE_MULTIPART_RELATED);
                } else {
                    Pipe pipe = (Pipe) msgContext.getProperty(PassThroughConstants.PASS_THROUGH_PIPE);
                    if (pipe != null && !Boolean.TRUE.equals(msgContext.getProperty(PassThroughConstants.MESSAGE_BUILDER_INVOKED))
                            && !sourceConfiguration.isPreserveHttpHeader(HTTP.CONTENT_TYPE)) {
                        transportHeaders.put(HTTP.CONTENT_TYPE, msgContext.getProperty(org.apache.axis2.Constants.Configuration.CONTENT_TYPE));
                    }
                }
            }

            if (transportHeaders != null) {
                addResponseHeader(sourceResponse, transportHeaders);
            }else{
            	  Boolean noEntityBody = (Boolean) msgContext.getProperty(NhttpConstants.NO_ENTITY_BODY);
            	 if (noEntityBody == null || Boolean.FALSE == noEntityBody) {
            		 OMOutputFormat format = NhttpUtil.getOMOutputFormat(msgContext);
            		 transportHeaders = new HashMap();
                	 MessageFormatter messageFormatter =
                         MessageFormatterDecoratorFactory.createMessageFormatterDecorator(msgContext);
                	 if(msgContext.getProperty(org.apache.axis2.Constants.Configuration.MESSAGE_TYPE) == null
                             && !sourceConfiguration.isPreserveHttpHeader(HTTP.CONTENT_TYPE)){
                	    transportHeaders.put(HTTP.CONTENT_TYPE, messageFormatter.getContentType(msgContext, format, msgContext.getSoapAction()));
                	 }
                	 addResponseHeader(sourceResponse, transportHeaders);
                 }

            }

    	// Add excess response header.
    	String excessProp = NhttpConstants.EXCESS_TRANSPORT_HEADERS;
    	Map excessHeaders = (Map) msgContext.getProperty(excessProp);
    	if (excessHeaders != null) {
    		for (Iterator iterator = excessHeaders.keySet().iterator(); iterator.hasNext();) {
    			String key = (String) iterator.next();
    			for (String excessVal : (Collection<String>) excessHeaders.get(key)) {
    				sourceResponse.addHeader(key, (String) excessVal);
    			}
    		}
    	}
            // keep alive
            String noKeepAlive = (String) msgContext.getProperty(PassThroughConstants.NO_KEEPALIVE);
            if ("true".equals(noKeepAlive) || PassThroughConfiguration.getInstance().isKeepAliveDisabled()) {
                sourceResponse.setKeepAlive(false);
            } else {
                // If the payload is delayed for GET/HEAD/DELETE, http-core-nio will start processing request, without
                // waiting for the payload. Therefore the delayed payload will be appended to the next request. To avoid
                // that, disable keep-alive to avoid re-using the existing connection by client for the next request.
                if (sourceRequest != null) {
                    String requestMethod = sourceRequest.getRequest().getRequestLine().getMethod();
                    if (requestMethod != null && isPayloadOptionalMethod(requestMethod.toUpperCase()) &&
                        (sourceRequest.getHeaders().containsKey(HTTP.CONTENT_LEN) ||
                         sourceRequest.getHeaders().containsKey(HTTP.TRANSFER_ENCODING))) {
                        if (log.isDebugEnabled()) {
                            log.debug("Disable keep-alive in the client connection : Content-length/Transfer-encoding" +
                                      " headers present for GET/HEAD/DELETE request");
                        }
                        sourceResponse.setKeepAlive(false);
                    }
                }
            }
            return sourceResponse;
        }

    	private static void addResponseHeader(SourceResponse sourceResponse, Map transportHeaders) {
    	    for (Object entryObj : transportHeaders.entrySet()) {
    	        Map.Entry entry = (Map.Entry) entryObj;
    	        String headerValue = getHeaderValueAsString(entry.getValue());
    	        if (entry.getKey() instanceof String && headerValue != null) {
    	            sourceResponse.addHeader((String) entry.getKey(), headerValue);
    	        }
    	    }
        }

        /**
         * Get the header value as a string.
         * <p>
         * If the header value is a string, return it
         * If the header value is null, return empty string. otherwise the header will get dropped
         * Else return null to drop the header
         * </p>
         *
         * @param value the header value
         * @return the header value as a string
         */
        private static String getHeaderValueAsString(Object value) {

            if (value instanceof String) {
                return (String) value;
            } else if (value == null) {
                return "";
            }
            return null;
        }

        private static boolean isPayloadOptionalMethod(String httpMethod) {
            return (PassThroughConstants.HTTP_GET.equals(httpMethod) ||
                    PassThroughConstants.HTTP_HEAD.equals(httpMethod) ||
                    PassThroughConstants.HTTP_DELETE.equals(httpMethod));
        }

    }