/**
 *  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;

import org.apache.axiom.om.OMAbstractFactory;
import org.apache.axiom.soap.SOAPEnvelope;
import org.apache.axiom.soap.SOAPFactory;
import org.apache.axiom.soap.impl.llom.soap11.SOAP11Factory;
import org.apache.axis2.AxisFault;
import org.apache.axis2.Constants;
import org.apache.axis2.addressing.AddressingConstants;
import org.apache.axis2.builder.BuilderUtil;
import org.apache.axis2.context.MessageContext;
import org.apache.axis2.description.Parameter;
import org.apache.axis2.description.WSDL2Constants;
import org.apache.axis2.engine.AxisEngine;
import org.apache.axis2.util.JavaUtils;
import org.apache.axis2.wsdl.WSDLConstants;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.HttpStatus;
import org.apache.http.nio.NHttpServerConnection;
import org.apache.http.protocol.HTTP;
import org.apache.synapse.commons.CorrelationConstants;
import org.apache.synapse.commons.util.ext.TenantInfoInitiator;
import org.apache.synapse.commons.util.ext.TenantInfoInitiatorProvider;
import org.apache.synapse.transport.customlogsetter.CustomLogSetter;
import org.apache.synapse.transport.http.conn.SynapseDebugInfoHolder;
import org.apache.synapse.transport.nhttp.NhttpConstants;
import org.apache.synapse.transport.passthru.config.PassThroughConfiguration;
import org.apache.synapse.transport.passthru.config.TargetConfiguration;
import org.apache.synapse.transport.passthru.util.RelayUtils;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

public class ClientWorker implements Runnable {
    private Log log = LogFactory.getLog(ClientWorker.class);
    /** the Http connectors configuration context */
    private TargetConfiguration targetConfiguration = null;
    /** the response message context that would be created */
    private org.apache.axis2.context.MessageContext responseMsgCtx = null;
    /** the HttpResponse received */
    private TargetResponse response = null;
    /** weather a body is expected or not */
    private boolean expectEntityBody = true;
    /** the axis2 message context of the request */
    private MessageContext requestMessageContext;

    private Long queuedTime = null;

    private PassThroughConfiguration conf = PassThroughConfiguration.getInstance();

    private WorkerState state;

    public ClientWorker(TargetConfiguration targetConfiguration, MessageContext outMsgCtx, TargetResponse response) {
        this(targetConfiguration, outMsgCtx, response, Collections.emptyList());
    }

    public ClientWorker(TargetConfiguration targetConfiguration, MessageContext outMsgCtx, TargetResponse response,
                        List<String> allowedResponseProperties) {
        this.state = WorkerState.CREATED;
        this.queuedTime = System.currentTimeMillis();
        this.targetConfiguration = targetConfiguration;
        this.response = response;
        this.expectEntityBody = response.isExpectResponseBody();
        this.requestMessageContext = outMsgCtx;
        Map<String,String> headers = response.getHeaders();
        Map excessHeaders = response.getExcessHeaders();

		String oriURL = headers.get(PassThroughConstants.LOCATION);
        if (outMsgCtx.getProperty(PassThroughConstants.PASS_THROUGH_SOURCE_CONNECTION) != null) {
            ((NHttpServerConnection) outMsgCtx.getProperty(PassThroughConstants.PASS_THROUGH_SOURCE_CONNECTION)).
                       getContext().setAttribute(PassThroughConstants.CLIENT_WORKER_INIT_TIME, System.currentTimeMillis());
        }
        // Special casing 301, 302, 303 and 307 scenario in following section. Not sure whether it's the correct fix,
		// but this fix makes it possible to do http --> https redirection.
        if (oriURL != null && ((response.getStatus() != HttpStatus.SC_MOVED_TEMPORARILY) &&
                (response.getStatus() != HttpStatus.SC_MOVED_PERMANENTLY) &&
                (response.getStatus() != HttpStatus.SC_CREATED) &&
		(response.getStatus() != HttpStatus.SC_SEE_OTHER) &&
		(response.getStatus() != HttpStatus.SC_TEMPORARY_REDIRECT) &&
        !targetConfiguration.isPreserveHttpHeader(PassThroughConstants.LOCATION))) {
            URL url;
            String urlContext = null;
            try {
                url = new URL(oriURL);
                urlContext = url.getFile();
            } catch (MalformedURLException e) {
                //Fix ESBJAVA-3461 - In the case when relative path is sent should be handled
                if(log.isDebugEnabled()){
                    log.debug("Relative URL received for Location : " + oriURL, e);
                }
                urlContext = oriURL;
            }

            headers.remove(PassThroughConstants.LOCATION);
            String prfix = (String) outMsgCtx.getProperty(PassThroughConstants.SERVICE_PREFIX);
            if (prfix != null) {
                if(urlContext != null && urlContext.startsWith("/")){
                    //Remove the preceding '/' character
                    urlContext = urlContext.substring(1);
                }
                headers.put(PassThroughConstants.LOCATION, prfix + urlContext);
            }

        }
        try {
            responseMsgCtx = outMsgCtx.getOperationContext().
                getMessageContext(WSDL2Constants.MESSAGE_LABEL_IN);
            // fix for RM to work because of a soapAction and wsaAction conflict
            if (responseMsgCtx != null) {
                responseMsgCtx.setSoapAction("");
            }
        } catch (AxisFault af) {
            log.error("Error getting IN message context from the operation context", af);
            return;
        }

        if (responseMsgCtx == null) {
            if (outMsgCtx.getOperationContext().isComplete()) {
                if (log.isDebugEnabled()) {
                    log.debug("Error getting IN message context from the operation context. " +
                            "Possibly an RM terminate sequence message");
                }
                return;

            }
            responseMsgCtx = new MessageContext();
            responseMsgCtx.setOperationContext(outMsgCtx.getOperationContext());
        }
        responseMsgCtx.setProperty("PRE_LOCATION_HEADER",oriURL);
        // copy the important properties from the original message context
        responseMsgCtx.setProperty(PassThroughConstants.PASS_THROUGH_SOURCE_CONNECTION,
                outMsgCtx.getProperty(PassThroughConstants.PASS_THROUGH_SOURCE_CONNECTION));
        responseMsgCtx.setProperty(PassThroughConstants.PASS_THROUGH_SOURCE_CONFIGURATION,
                outMsgCtx.getProperty(PassThroughConstants.PASS_THROUGH_SOURCE_CONFIGURATION));
        responseMsgCtx.setProperty(AddressingConstants.DISABLE_ADDRESSING_FOR_IN_MESSAGES,
                outMsgCtx.getProperty(AddressingConstants.DISABLE_ADDRESSING_FOR_IN_MESSAGES));
        responseMsgCtx.setProperty(PassThroughConstants.INTERNAL_EXCEPTION_ORIGIN,
                outMsgCtx.getProperty(PassThroughConstants.INTERNAL_EXCEPTION_ORIGIN));

        responseMsgCtx.setServerSide(true);
        responseMsgCtx.setDoingREST(outMsgCtx.isDoingREST());
        responseMsgCtx.setProperty(MessageContext.TRANSPORT_IN, outMsgCtx
                .getProperty(MessageContext.TRANSPORT_IN));
        responseMsgCtx.setTransportIn(outMsgCtx.getTransportIn());
        responseMsgCtx.setTransportOut(outMsgCtx.getTransportOut());

        //setting the responseMsgCtx PassThroughConstants.INVOKED_REST property to the one set inside PassThroughTransportUtils
        responseMsgCtx.setProperty(PassThroughConstants.INVOKED_REST, outMsgCtx.isDoingREST());
        responseMsgCtx.setProperty(PassThroughConstants.ORIGINAL_HTTP_SC, response.getStatus());
        responseMsgCtx.setProperty(PassThroughConstants.ORIGINAL_HTTP_REASON_PHRASE, response.getStatusLine());

        // set any transport headers received
        Set<Map.Entry<String, String>> headerEntries = response.getHeaders().entrySet();
        Map<String, String> headerMap = new TreeMap<String, String>(new Comparator<String>() {
            public int compare(String o1, String o2) {
                return o1.compareToIgnoreCase(o2);
            }
        });

        for (Map.Entry<String, String> headerEntry : headerEntries) {
            if (headerMap.containsKey(headerEntry.getKey()) && !conf.isIgnoreCaseSensitiveHeaders()) {
                excessHeaders.put(headerEntry.getKey(), headerMap.get(headerEntry.getKey()));
            }
            headerMap.put(headerEntry.getKey(), headerEntry.getValue());
        }
        responseMsgCtx.setProperty(MessageContext.TRANSPORT_HEADERS, headerMap);
        responseMsgCtx.setProperty(NhttpConstants.EXCESS_TRANSPORT_HEADERS, excessHeaders);

        if (response.getStatus() == 202) {
            responseMsgCtx.setProperty(AddressingConstants.
                    DISABLE_ADDRESSING_FOR_OUT_MESSAGES, Boolean.TRUE);
            responseMsgCtx.setProperty(PassThroughConstants.MESSAGE_BUILDER_INVOKED, Boolean.FALSE);
            responseMsgCtx.setProperty(NhttpConstants.SC_ACCEPTED, Boolean.TRUE);
        }

        responseMsgCtx.setAxisMessage(outMsgCtx.getOperationContext().getAxisOperation().
                getMessage(WSDLConstants.MESSAGE_LABEL_IN_VALUE));
        responseMsgCtx.setOperationContext(outMsgCtx.getOperationContext());
        responseMsgCtx.setConfigurationContext(outMsgCtx.getConfigurationContext());
        responseMsgCtx.setTo(null);

        responseMsgCtx.setProperty(PassThroughConstants.PASS_THROUGH_PIPE, response.getPipe());
        responseMsgCtx.setProperty(PassThroughConstants.PASS_THROUGH_TARGET_RESPONSE, response);
        responseMsgCtx.setProperty(SynapseDebugInfoHolder.SYNAPSE_WIRE_LOG_HOLDER_PROPERTY, response.getConnection()
                .getContext().getAttribute(SynapseDebugInfoHolder.SYNAPSE_WIRE_LOG_HOLDER_PROPERTY));
        responseMsgCtx.setProperty(PassThroughConstants.PASS_THROUGH_TARGET_CONNECTION,
                response.getConnection());
        responseMsgCtx.setProperty(CorrelationConstants.CORRELATION_ID,
                outMsgCtx.getProperty(CorrelationConstants.CORRELATION_ID));
        for (String property : allowedResponseProperties) {
            responseMsgCtx.setProperty(property, outMsgCtx.getProperty(property));
        }
        responseMsgCtx.setProperty(PassThroughConstants.SYNAPSE_ARTIFACT_TYPE,
                                   outMsgCtx.getProperty(PassThroughConstants.SYNAPSE_ARTIFACT_TYPE));
        response.getConnection().getContext().setAttribute(PassThroughConstants.RESPONSE_MESSAGE_CONTEXT,
                                                           responseMsgCtx);
    }

    private void initTenantInfo() {

        CustomLogSetter.getInstance().clearThreadLocalContent();
        TenantInfoInitiator tenantInfoInitiator = TenantInfoInitiatorProvider.getTenantInfoInitiator();
        if (tenantInfoInitiator != null) {
            //check OUT_TRANSPORT_INFO is instanceOf ServerWorker to avoid possible classCastExceptions
            if (requestMessageContext.getProperty(Constants.OUT_TRANSPORT_INFO) instanceof ServerWorker) {
                ServerWorker serverWorker = (ServerWorker) requestMessageContext.getProperty(Constants.OUT_TRANSPORT_INFO);
                // Request received to Synapse is originated from through the HTTP transport
                SourceRequest sourceRequest = serverWorker.getSourceRequest();
                if (sourceRequest != null) {
                    tenantInfoInitiator.initTenantInfo(sourceRequest.getUri());
                    return;
                }
            }
            tenantInfoInitiator.initTenantInfo();
        }
    }

    public void run() {

        initTenantInfo();
        if (responseMsgCtx == null) {
            cleanup();
            return;
        }
        // Mark the start of the request at the beginning of the worker thread
        setWorkerState(WorkerState.RUNNING);

        String expectedMaxQueueingTime = conf.getExpectedMaxQueueingTime();
        if (queuedTime != null && expectedMaxQueueingTime != null) {
            Long expectedMaxQueueingTimeInMillis = Long.parseLong(expectedMaxQueueingTime);
            Long clientWorkerQueuedTime = System.currentTimeMillis() - queuedTime;
            if (clientWorkerQueuedTime >= expectedMaxQueueingTimeInMillis) {
                log.warn("Client worker thread queued time exceeds the expected max queueing time. Expected max " +
                        "queueing time : " + expectedMaxQueueingTimeInMillis + "ms. Actual queued time : " +
                        clientWorkerQueuedTime + "ms"+ ", CORRELATION_ID : "
                        + requestMessageContext.getProperty(CorrelationConstants.CORRELATION_ID));
            }

        }

        if (responseMsgCtx.getProperty(PassThroughConstants.PASS_THROUGH_SOURCE_CONNECTION) != null) {
            ((NHttpServerConnection) responseMsgCtx.getProperty(PassThroughConstants.PASS_THROUGH_SOURCE_CONNECTION)).
                       getContext().setAttribute(PassThroughConstants.CLIENT_WORKER_START_TIME, System.currentTimeMillis());
        }

        if (response.isForceShutdownConnectionOnComplete() && !conf.isConsumeAndDiscardBySecondaryWorkerPool()
                && conf.isConsumeAndDiscard()) {
            // If an error has happened in the request processing, consumes the data in pipe completely and discard it
            try {
                RelayUtils.discardRequestMessage(requestMessageContext);
            } catch (AxisFault af) {
                log.error("Fault discarding request message", af);
            }
        }
        try {
            if (expectEntityBody) {
            	  String cType = response.getHeader(HTTP.CONTENT_TYPE);
                  if(cType == null){
                  	cType =  response.getHeader(HTTP.CONTENT_TYPE.toLowerCase());
                  }
                String contentType;
                if (cType != null) {
                    // This is the most common case - Most of the time servers send the Content-Type
                    contentType = cType;
                } else {
                    // Server hasn't sent the header - Try to infer the content type
                    contentType = inferContentType();
                }

                responseMsgCtx.setProperty(Constants.Configuration.CONTENT_TYPE, contentType);

                String charSetEnc = BuilderUtil.getCharSetEncoding(contentType);
                if (charSetEnc == null) {
                    charSetEnc = MessageContext.DEFAULT_CHAR_SET_ENCODING;
                }
                if (contentType != null) {
                    responseMsgCtx.setProperty(
                            Constants.Configuration.CHARACTER_SET_ENCODING,
                            contentType.indexOf("charset") > 0 ?
                            charSetEnc : MessageContext.DEFAULT_CHAR_SET_ENCODING);
                    responseMsgCtx.removeProperty(PassThroughConstants.NO_ENTITY_BODY);
                }
                
                responseMsgCtx.setServerSide(false);
                SOAPFactory fac = OMAbstractFactory.getSOAP11Factory();
                SOAPEnvelope envelope = fac.getDefaultEnvelope();
                try {
                    responseMsgCtx.setEnvelope(envelope);
                } catch (AxisFault axisFault) {
                    log.error("Error setting SOAP envelope", axisFault);
                }

                responseMsgCtx.setServerSide(true);
            } else {
                // there is no response entity-body
                responseMsgCtx.setProperty(PassThroughConstants.NO_ENTITY_BODY, Boolean.TRUE);
                responseMsgCtx.setEnvelope(new SOAP11Factory().getDefaultEnvelope());
            }

            // copy the HTTP status code as a message context property with the key HTTP_SC to be
            // used at the sender to set the proper status code when passing the message
            int statusCode = this.response.getStatus();
            responseMsgCtx.setProperty(PassThroughConstants.HTTP_SC, statusCode);
            responseMsgCtx.setProperty(PassThroughConstants.HTTP_SC_DESC, response.getStatusLine());
            if (statusCode >= 400) {
                responseMsgCtx.setProperty(PassThroughConstants.FAULT_MESSAGE,
                        PassThroughConstants.TRUE);
            } /*else if (statusCode == 202 && responseMsgCtx.getOperationContext().isComplete()) {
                // Handle out-only invocation scenario
                responseMsgCtx.setProperty(PassThroughConstants.MESSAGE_BUILDER_INVOKED, Boolean.TRUE);
            }*/
            responseMsgCtx.setProperty(PassThroughConstants.NON_BLOCKING_TRANSPORT, true);

            // process response received
            try {
                AxisEngine.receive(responseMsgCtx);
            } catch (AxisFault af) {
                log.error("Fault processing response message through Axis2", af);
                // This will be reached if an exception is thrown within an Axis2 handler
                String errorMessage = "Fault processing response message through Axis2: " +
                        af.getMessage();
                responseMsgCtx.setProperty(
                        NhttpConstants.SENDING_FAULT, Boolean.TRUE);
                responseMsgCtx.setProperty(
                        NhttpConstants.ERROR_CODE, NhttpConstants.RESPONSE_PROCESSING_FAILURE);
                responseMsgCtx.setProperty(
                        NhttpConstants.ERROR_MESSAGE, errorMessage.split("\n")[0]);
                responseMsgCtx.setProperty(
                        NhttpConstants.ERROR_DETAIL, JavaUtils.stackToString(af));
                responseMsgCtx.setProperty(
                        NhttpConstants.ERROR_EXCEPTION, af);
                responseMsgCtx.getAxisOperation().getMessageReceiver().receive(responseMsgCtx);
            }

        } catch (AxisFault af) {
            log.error("Fault creating response SOAP envelope", af);            
        } finally {
            cleanup();
            setWorkerState(WorkerState.FINISHED);
        }
    }

    private String inferContentType() {
        //Check whether server sent Content-Type in different case
        Map<String,String> headers = response.getHeaders();
        for(String header : headers.keySet()){
            if(HTTP.CONTENT_TYPE.equalsIgnoreCase(header)){
                return headers.get(header);
            }
        }
        String cType = response.getHeader("content-type");
        if (cType != null) {
            return cType;
        }
        cType = response.getHeader("Content-type");
        if (cType != null) {
            return cType;
        }

        // Try to get the content type from the message context
        Object cTypeProperty = responseMsgCtx.getProperty(PassThroughConstants.CONTENT_TYPE);
        if (cTypeProperty != null) {
            return cTypeProperty.toString();
        }
        // Try to get the content type from the axis configuration
        Parameter cTypeParam = targetConfiguration.getConfigurationContext().getAxisConfiguration().getParameter(
                PassThroughConstants.CONTENT_TYPE);
        if (cTypeParam != null) {
            return cTypeParam.getValue().toString();
        }

        // When the response from backend does not have the body(Content-Length is 0 )
        // and Content-Type is not set; ESB should not do any modification to the response and pass-through as it is.
        boolean contentLengthHeaderPresent = false;
        String contentLengthHeader = headers.get(HTTP.CONTENT_LEN);

        if (contentLengthHeader != null) {
            contentLengthHeaderPresent = true;
        } else {
            for (String header : headers.keySet()) {
                if (HTTP.CONTENT_LEN.equalsIgnoreCase(header)) {
                    contentLengthHeader = headers.get(header);
                    contentLengthHeaderPresent = true;
                    break;
                }
            }
        }

        boolean transferEncodingHeaderPresent = headers.containsKey(HTTP.TRANSFER_ENCODING);

        if (!transferEncodingHeaderPresent) {

            for (String header : headers.keySet()) {
                if (HTTP.TRANSFER_ENCODING.equalsIgnoreCase(header)) {
                    transferEncodingHeaderPresent = true;
                    break;
                }
            }
        }

        if ((!contentLengthHeaderPresent && !transferEncodingHeaderPresent)
                || "0".equals(contentLengthHeader)) {
            responseMsgCtx.setProperty(PassThroughConstants.NO_ENTITY_BODY, Boolean.TRUE);
            return null;
        }

        // Unable to determine the content type - Return default value
        return PassThroughConstants.DEFAULT_CONTENT_TYPE;
    }

    private void setWorkerState(WorkerState workerState) {
        this.state = workerState;
    }

    public WorkerState getWorkerState() {
        return this.state;
    }

    /**
     * Perform cleanup of ClientWorker
     */
    private void cleanup() {
        //clean threadLocal variables
        MessageContext.destroyCurrentMessageContext();
        TenantInfoInitiator tenantInfoInitiator = TenantInfoInitiatorProvider.getTenantInfoInitiator();
        if (tenantInfoInitiator != null) {
            tenantInfoInitiator.cleanTenantInfo();
        }
    }
}
