// Mark III - interrogate camera for exposure limits
// verify exposure time stability

import java.lang.Math; 


double EvaluateImageTiming(Float etime, Float[] deviations)
{

   // measure average shutter time
   // calculate the standard deviation & mean
   long nPts = 0;
   double mean_ = 0;
   double M2 = 0;
   double delta;
   long value;
   Long boxValue = new Long(0);
   String valueList = new String("");
   mmc.setExposure( etime);
   for( int titter =0; titter<12; ++ titter){
      value = System.currentTimeMillis();
      mmc.snapImage();
      value = System.currentTimeMillis() - value;
      boxValue = value;
      if( 0 < valueList.length())
         valueList += ", ";
      valueList += boxValue.toString();
      // one-pass algorithm for mean and std from Welford / Knuth
      ++nPts;
      delta = value - mean_;
      mean_ = mean_ + delta/nPts;
      M2 = M2 + delta*(value - mean_); // #This expression uses the new value of mean_
      img = mmc.getImage();
      gui.displayImage(img);
   }

   double variance = M2/(nPts - 1);
   double meanScaling = 1.;
   // autobox only the final results !!  
   Float standardDeviation = new Float(java.lang.Math.pow(variance,0.5));
   
   Double theMean = new Double(mean_);
   print(etime.toString() + " durations: {" + valueList+ "}  <snap time>: " + theMean.toString()+
      "  std: " + standardDeviation.toString() );

   deviations[0] = (Float)standardDeviation;

   return mean_;

};



int warnings = 0;
int errors = 0;
String theCamera = new String(mmc.getCameraDevice());
Double minExposure = new Double(0.);
Double maxExposure = new Double(3600000.);
if (mmc.hasProperty(theCamera,"Exposure")){
   if( mmc.hasPropertyLimits(theCamera,"Exposure") ){
      minExposure = mmc.getPropertyLowerLimit(theCamera,"Exposure");
      maxExposure = mmc.getPropertyUpperLimit(theCamera,"Exposure");
   }
};

print ("current camera is " + theCamera + " current exposure range is [" + minExposure.toString() +"," + maxExposure.toString() + "]" );


for( int ite = 0; ite <2;  ++ite){
   mmc.setAutoShutter((1==ite));
   Float [] stdevs0 = new Float[1];
   Float [] stdevs1 = new Float[1];
   Float [] stdevs2 = new Float[1];

   print("running with autoshutter " + (1==ite?"on":"off" ));
   Double st1 = new Double(0);
   Double st2 = new Double(0);

   mmc.setExposure(minExposure);
   exptime = mmc.getExposure();
   // measure the shortest snap time on this equipment



   mmc.snapImage();
   ro0 = System.currentTimeMillis();
   mmc.getImage();
   ro0 = System.currentTimeMillis() - ro0;
   // always include the minimum exposure time!
   Boolean ranMinExposureTime = false;
   Double loopexptime = new Double(0);
   for( loopexptime = 0; loopexptime < 1000; loopexptime*=10) {
      exptime = loopexptime;
      if( maxExposure < exptime)
         break;

      if(ranMinExposureTime && exptime < minExposure)
      {
          continue;
      }

      ranMinExposureTime =(exptime < minExposure);
      exptime = java.lang.Math.max(exptime,minExposure);
         

     EvaluateImageTiming(exptime, stdevs0);
     if( 0 == loopexptime)
        loopexptime = 0.01;
     }
};

print("test completed");
print("total warnings "); print(warnings);
print("total errors "); print(errors);