<?xml version="1.0" encoding="utf-8"?> 

<!-- Asynchrnous BPEL process -->

<process name="BusinessTravelProcess" 
         targetNamespace="http://packtpub.com/bpel/travel/" 
         xmlns="http://schemas.xmlsoap.org/ws/2003/03/business-process/"
         xmlns:bpws="http://schemas.xmlsoap.org/ws/2003/03/business-process/"
         xmlns:trv="http://packtpub.com/bpel/travel/"
         xmlns:emp="http://packtpub.com/service/employee/"
         xmlns:aln="http://packtpub.com/service/airline/" >
   
   <partnerLinks>
      <partnerLink name="client" 
                   partnerLinkType="trv:travelLT"
                   myRole="travelService"
                   partnerRole="travelServiceCustomer"/>

      <partnerLink name="employeeTravelStatus" 
                   partnerLinkType="emp:employeeLT"
                   partnerRole="employeeTravelStatusService"/>

      <partnerLink name="AmericanAirlines" 
                   partnerLinkType="aln:flightLT"
                   myRole="airlineCustomer"
                   partnerRole="airlineService"/>
                   
      <partnerLink name="DeltaAirlines" 
                   partnerLinkType="aln:flightLT"
                   myRole="airlineCustomer"
                   partnerRole="airlineService"/>
                   
   </partnerLinks>

   <variables>
      <!-- input for this process -->      
      <variable name="TravelRequest" messageType="trv:TravelRequestMessage"/>
      <!-- input for the Employee Travel Status web service -->
      <variable name="EmployeeTravelStatusRequest" messageType="emp:EmployeeTravelStatusRequestMessage"/>
      <!-- output from the Employee Travel Status web service -->
      <variable name="EmployeeTravelStatusResponse" messageType="emp:EmployeeTravelStatusResponseMessage"/>
      <!-- input for American and Delta web services -->
      <variable name="FlightDetails" messageType="aln:FlightTicketRequestMessage"/>
      <!-- output from American Airlines -->
      <variable name="FlightResponseAA" messageType="aln:TravelResponseMessage"/>
      <!-- output from Delta Airlines -->
      <variable name="FlightResponseDA" messageType="aln:TravelResponseMessage"/>
      <!-- output from BPEL process -->
      <variable name="TravelResponse" messageType="aln:TravelResponseMessage"/>
   </variables>

   <sequence>

      <!-- Receive the initial request for business travel from client -->
      <receive partnerLink="client" 
               portType="trv:TravelApprovalPT" 
               operation="TravelApproval" 
               variable="TravelRequest"
               createInstance="yes" />

      <!-- Prepare the input for the Employee Travel Status Web Service -->
      <assign>
        <copy>
          <from variable="TravelRequest" part="employee"/>
          <to variable="EmployeeTravelStatusRequest" part="employee"/>
        </copy>
      </assign>
      
      <!-- Synchronously invoke the Employee Travel Status Web Service -->
      <invoke partnerLink="employeeTravelStatus" 
              portType="emp:EmployeeTravelStatusPT" 
              operation="EmployeeTravelStatus"
              inputVariable="EmployeeTravelStatusRequest" 
              outputVariable="EmployeeTravelStatusResponse" />

      <!-- Prepare the input for AA and DA -->
      <assign>
        <copy>
          <from variable="TravelRequest" part="flightData"/>
          <to variable="FlightDetails" part="flightData"/>
        </copy>
        <copy>
          <from variable="EmployeeTravelStatusResponse" part="travelClass"/>
          <to variable="FlightDetails" part="travelClass"/>
        </copy>
      </assign>

      <!-- Make a concurrent invocation to AA in DA -->
      <flow>
      
        <sequence>
          <!-- Async invoke of the AA web service and wait for the callback -->
        
          <invoke partnerLink="AmericanAirlines" 
              portType="aln:FlightAvailabilityPT" 
              operation="FlightAvailability"
              inputVariable="FlightDetails" />

          <receive partnerLink="AmericanAirlines" 
              portType="aln:FlightCallbackPT" 
              operation="FlightTicketCallback"
              variable="FlightResponseAA" />

        </sequence>

        <sequence>
          <!-- Async invoke of the DA web service and wait for the callback -->
        
          <invoke partnerLink="DeltaAirlines" 
              portType="aln:FlightAvailabilityPT" 
              operation="FlightAvailability"
              inputVariable="FlightDetails" />

          <receive partnerLink="DeltaAirlines" 
              portType="aln:FlightCallbackPT" 
              operation="FlightTicketCallback"
              variable="FlightResponseDA" />

        </sequence>

      </flow>

      <!-- Select the best offer and construct the TravelResponse -->
      <switch>
              
        <case condition="bpws:getVariableData('FlightResponseAA','confirmationData','/confirmationData/aln:Price') 
                      &lt;= bpws:getVariableData('FlightResponseDA','confirmationData','/confirmationData/aln:Price')">
                    
           <!-- Select American Airlines -->
           <assign>
             <copy>
               <from variable="FlightResponseAA" />
               <to variable="TravelResponse" />
             </copy>
           </assign>
        </case>
                    
        <otherwise>
           <!-- Select Delta Airlines -->
           <assign>
             <copy>
               <from variable="FlightResponseDA" />
               <to variable="TravelResponse" />
             </copy>
           </assign>
        </otherwise>
      </switch>
      
      <!-- Make a callback to the client -->
      <invoke partnerLink="client" 
              portType="trv:ClientCallbackPT" 
              operation="ClientCallback"
              inputVariable="TravelResponse" />
   </sequence>
</process>