package wrapper;

import java.util.*;


final class Invocation implements Runnable, CPAMWrapperCallbacks{
  /**The invocation specific settings of all the parameters, contains client specific 
  or default settings if no invocation specific settings exist.*/
  private ParamValueTable invParams; 
  /**The status of the invocation specific parameter settings. The keys are 
     the names of parameters, values are Integers: <br>
*  2: holds client specific setting (set by SETPARAM or taken from default 
          when invocation was created),not ready for extraction by EXTRACT <br>
*  3: holds invocation specific setting (set by INVOKE) 
         not ready for extraction by EXTRACT <br>
*  4: value has been updated by computational (legacy) code, yet does not 
          contain yet final value, ready for progressive extraction <br>
*  5: value has been finally set by computation (legacy) code, 
          computation for that parameter is complete */
  private Map invParamsStatus; 
  /**Contains the accuracy for all parameters. Is initialised to 0 when 
     invocation is created. Is it right not to distinguish between 
     inputs and outputs?*/ 
  private Map invParamsAccuracy;
  /**Progress of the invocation. 0 signifies both that progress is 
      still 0 or that no invocation progress is available at all for this method.*/
  private float invocationProgress = 0; 
  /**Status of the invocation. The following states are possible:<br>
* 0: results need to be computed, legacy code has not started yet<br>
* 1: results need to be computed, legacy code is computing<br>
* 2: some results are ready to some accuracy, legacy code is computing<br>
* 3: legacy code has aborted with error before all results done<br>
* 4: results are all done, client can extract them, legacy code no more active<br>
* 5: client has terminated invocation, legacy code is still working<br>
* 6: client has terminated invocation, legacy code no more active */
  private int invocationStatus = 0; 
  private String methodname;
  protected Connection parent;
  private final Integer invocationId;

  

  Invocation(ParamValueTable clientParams, String methodname, 
         Connection connection, Integer invocationId) {  
    String key;
    parent = connection;
    invParams = new ParamValueTable(parent.parent.paramType);
    invParams.putAll(clientParams);
    invParamsStatus = Collections.synchronizedMap(new HashMap());
    invParamsAccuracy = Collections.synchronizedMap(new HashMap());
    Set keys = invParams.keySet(); Iterator i = keys.iterator();
    while (i.hasNext()) {
        key = (String)i.next();
        invParamsStatus.put(key, new Integer(2));
        invParamsAccuracy.put(key, new Float(0));
    }
    this.methodname = methodname;
    //ADD: check validity of methodname against repository
    this.invocationId = invocationId;
  }
  
  public Integer getInvocationId() {return invocationId;}
  
  void terminate() {
    if (invocationStatus == 1 | invocationStatus == 2) { 
      invocationStatus = 5;
      //notify the computational code that it could abort this invocation
      //as Java does GC we do not take any special action in either case, the
      // connection object will be around as long as the computational code
      // has a reference to it and the callbacks will work, though the client
      // cannot get the resulsts anymore because officially this invocation
      // will be gone
      if (parent.parent.abortExecution(this, methodname)) invocationStatus = 6;
    }
    else if (invocationStatus == 0 | invocationStatus == 3 | 
        invocationStatus == 4) invocationStatus = 6;
    else if (invocationStatus == 5 | invocationStatus == 6) throw 
         new InvalidInvocationIdException("This invocation has been terminated and does not exist anymore.");
    else throw new InvalidInvocationIdException("Invalid status, program bug. Please contact....");
    parent.invocationTerminated(invocationId);
  }
  
  InvocationStatus status() {
    InvocationStatus invstat = new InvocationStatus(invocationId);
    parent.parent.updateExecutionStatus(this, methodname);
    if (invocationStatus <= 1) invstat.status = "NOT_DONE";
    else if (invocationStatus == 2) invstat.status = "PARTIAL";
    else if (invocationStatus == 3) invstat.status = "ERROR";
    else if (invocationStatus == 4) invstat.status = "DONE";
    else if (invocationStatus == 5 | invocationStatus == 6) throw 
           new InvalidInvocationIdException("This invocation has been terminated and does not exist anymore.");
    else throw new InvalidInvocationIdException("Invalid status, program bug. Please contact....");
    invstat.progress= invocationProgress;
    return invstat;
  }   
 
  void initParam(String name, Object value){
    invParams.set (name, value);
    invParamsStatus.put(name, new Integer(3));
  }

  public void updateParam(String name, Object value, boolean resultIsFinal,
            float accuracy){
    invParams.set (name, value);
    if (resultIsFinal) {
      invParamsStatus.put (name, new Integer(5));
      invParamsAccuracy.put(name, new Float(accuracy));
    }
    else {
      invParamsStatus.put (name, new Integer(4));
      invParamsAccuracy.put(name, new Float(accuracy));
      invocationStatus = 2;
    }
  }

  public Object getParam(String name) { //can raise a ParameterNameException
    return invParams.get(name); 
  }

  ResultStatus getParamStatus(String name) { 
    //can raise a MethodNameException
    int intstatus;
    parent.parent.updateResult(name, this, methodname);
    ResultStatus rstatus = new ResultStatus(name, invocationId);
    intstatus = ((Integer)invParamsStatus.get(name)).intValue();
    if (intstatus == 5) rstatus.status = new String("DONE");
    else if (intstatus == 4) rstatus.status = new String ("PARTIAL");
    else rstatus.status = new String ("NOT_DONE");
    rstatus.accuracy = ((Float) invParamsAccuracy.get(name)).floatValue();
    return rstatus;
  }

  public boolean containsParam(String name) {
    //ADD: also check with repository
    return invParams.containsName(name); 
  }

  public void updateInvocationProgress(float progress) { 
    invocationProgress = progress;
  }

  void startExecution() {
    //has to be started asynchronously
    new Thread(this).start();
  } 

  public void run() {  
  //call legacy code
    invocationStatus = 1;
    boolean success = parent.parent.dispatchInvocation(this, methodname); 
    if (invocationStatus == 5)  invocationStatus = 6;
    else if (success) { 
      //ADD: test if all results of the invocation according to repository
      // have status final 
      invocationStatus = 4; 
      invocationProgress = 100;
    }   
    else invocationStatus = 3;
  }

}