/*!
\file
\brief Application Estimator

The general task of estimation is defined on the following scheme:
\dot
digraph estimation{
	node [shape=box];
	{rank="same"; "Data Source"; "Bayesian Model"}
	"Data Source" -> "Bayesian Model" [label="data"];
	"Bayesian Model" -> "Result Logger" [label="estimated\n statistics"]; 
	"Data Source" -> "Result Logger" [label="Simulated\n data"];
}
\enddot

Here, 
\li Data Source is an object (class DS) providing sequential data, \f$ [d_1, d_2, \ldots d_t] \f$.
\li Bayesian Model is an object (class BM) performing Bayesian filtering,
\li Result Logger is an object (class logger) dedicated to storing important data from the experiment.

\section  cmd Command-line usage
Execute command:
\code
$> estimator config_file.cfg
\endcode

Full description of the experiment is in the file config_file.cfg which is expected to have the following structure:
\code
system = {type = "DS_offspring", ...};      // definition of a data source
estimator = {type = "BM_offspring", ...};   // definition of an estimator
logger = {type = "logger_type",...};        // definition of a logger
experiment = {ndat = 11000; };              // definition of number of data records
\endcode

The above description must be specialized to specific classes. See, \subpage arx_ui how to do it for estimation of an ARX model.

\section ex Matlab usage
Execute command:
\code
>> estimator('config_file.cfg');
\endcode
when using loggers storing results on hard drives, and
\code
>> Res=estimator('config_file.cfg');
\endcode
when using logger of the type \c "mex_logger". The results will be stored in structure \c M.

 */

#include "estim/arx.h"
#include "stat/emix.h"
#include "base/datasources.h"
#include "base/loggers.h"

//#include "mex_datasource.h"

using namespace bdm;

#ifdef MEX
#include <itpp/itmex.h>
#include "mex/mex_BM.h"
#include "mex/mex_logger.h"
#include "mex/mex_datasource.h"

void mexFunction ( int n_output, mxArray *output[], int n_input, const mxArray *input[] ) {
	// Check the number of inputs and output arguments
	if(n_input<2) mexErrMsgTxt("Usage:\n"  
		"result=estimator(system, estimators, experiment, logger)\n"
		"  system     = struct('class','datasource',...);  % Estimated system\n"
		"  estimators = {struct('class','estimator',...),  % Estimators\n"
		"                struct('class','estimator',...),...} \n"
		"  === optional ==="
		"  experiment = struct('ndat',10);                 % number of data in experiment, full length of finite datasources, 10 otherwise \n"
		"  logger     = struct('class','mexlogger');       % How to store results, default=mexlog, i.e. matlab structure\n\n"
		"see documentation of classes datasource, BM, and mexlogger and their offsprings in BDM.");
	
	RV::clear_all();
	//CONFIG 
	UImxArray Cfg;
	try{
	Cfg.addGroup(input[0],"system");
	Cfg.addList(input[1],"estimators");
	if (n_input>2){
		Cfg.addGroup(input[2],"experiment");
	}
	if (n_input>3){
		Cfg.addGroup(input[3],"logger");
	}/*else{
		// define logger as mexlog
		Setting &S=Cfg.getRoot();
		S.add("logger",Setting::TypeGroup);
		S["logger"].add("class",Setting::TypeString);
		S["logger"]["class"]="mexlog";
		S["logger"].add("maxlen",Setting::TypeInt);
		int maxlen;
		S["experiment"].lookupValue("ndat",maxlen);
		S["logger"]["maxlen"]=maxlen;
	}*/
	} catch(SettingException e){it_error("error: "+string(e.getPath()));}

	//DBG
	Cfg.writeFile("estimator.cfg");

#else
int main ( int argc, char* argv[] ) {
	const char *fname;
	if ( argc>1 ) {
		fname = argv[1];
	} else {
		fname="estimator.cfg";
	}
	UIFile Cfg ( fname );
#endif
	
	shared_ptr<DS> Ds = UI::build<DS>( Cfg, "system" );
	Array<shared_ptr<BM> > Es;	UI::get(Es,Cfg, "estimators" );
	long Ndat=10;
	if (Cfg.exists("experiment")) {
		if (Cfg.lookupValue ( "experiment.ndat",Ndat )) {
			bdm_assert(Ndat<=Ds->max_length(), "Data source has less data then required");
		};
	} else {
		if (Ds->max_length() < inf) {
			Ndat=Ds->max_length();
		};// else Ndat=10;
	}
	shared_ptr<logger> L = UI::build<logger>( Cfg, "logger",UI::optional);
	if (!L) {
		#ifdef MEX
		//mex logger has only from_setting constructor - we  have to fill it...
		L=new mexlog(Ndat);
		#else
		L=new memlog(Ndat, "estimator_logger.it");
		#endif
	}
	
	Ds->log_add ( *L );
	string Ename;
	Setting &S=Cfg;
	for (int i=0; i<Es.length(); i++){
		try{
			UI::get(Ename, S["estimators"][i], "name");
		} catch (UIException e){
			Ename="Est"+num2str(i);
		}
		
		Es(i)->log_add(*L,Ename); // estimate
	}
		L->init();

	vec dt=zeros ( Ds->_drv()._dsize() );   //data variable
	Array<datalink*> Dls(Es.length()); 
	for (int i=0; i<Es.length(); i++){
		Dls(i)=new datalink( Es(i)->_drv(),Ds->_drv() ); //datalink between a datasource and estimator
	}
	
	for ( int tK=0;tK<Ndat;tK++ ) {
		Ds->getdata ( dt );					// read data
		Ds->logit ( *L );
		
		for (int i=0; i<Es.length(); i++){
			Es(i)->bayes ( Dls(i)->pushdown ( dt ) );		// update estimates
			Es(i)->logit (*L);
		}
		L->step();
		Ds->step();							// simulator step
	}

	L->finalize();
	// ------------------ End of routine -----------------------------

#ifdef MEX
	mexlog* mL=dynamic_cast<mexlog*>(L.get());

	if (mL) { // user wants output!!
		if ( n_output<1 ) mexErrMsgTxt ( "Wrong number of output variables!" );
		output[0] = mL->toCell();
	}
#endif
}