#!/usr/bin/env perl

if($#ARGV < 0){&Usage();exit;}

$classname = $ARGV[0];
print "\n";
print "Generating files for factory $classname ";

$USE_TAG = 0;
if($#ARGV >= 1){
	$tag = $ARGV[1];
	$USE_TAG = 1;
	$tag_suffix = "_${tag}";
	print "with tag $tag ";
}
print "....\n";

if(!$USE_TAG){
	$hfile = $fname = "${classname}.h";
	open(FILE,">$hfile");
	&PrintFileHeader();
	&PrintDataClass();
	close(FILE);
	print " - $hfile\n";
}

$dhfile = $fname = "${classname}_factory${tag_suffix}.h";
open(FILE,">$dhfile");
&PrintFileHeader();
&PrintFactoryClass();
close(FILE);
print " - $dhfile\n";

$ccfile = $fname = "${classname}_factory${tag_suffix}.cc";
open(FILE,">$ccfile");
&PrintFileHeader();
&PrintFactoryMethods();
close(FILE);
print " - $ccfile\n";

print "\n";
if($USE_TAG){
print "The file $dhfile";
}else{
print "The files $hfile and $dhfile";
}
print " should be placed in the \n";
print "src/libraries/include directory. The $ccfile should be \n";
print "placed in the appropriate subdirectory in /src/libraries.\n";
print "\n";

###############
# PrintFileHeader
###############
sub PrintFileHeader()
{
	# print a few lines at the very top of the file
	$uname = `uname -nprs`;
	chomp($uname);
	print FILE "// \$Id\$\n";
	print FILE "//\n";
	print FILE "//    File: $fname\n";
	print FILE "// Created: ".`date`;
	print FILE "// Creator: ".$ENV{"USER"}." (on $uname)\n";
	print FILE "//\n";
}

###############
# PrintDataClass
###############
sub PrintDataClass()
{
	# perl doesn't respect scope unless explicitly told to. Hence,
	# all variables (like FILE and $classname) are global.

	$content = "
\#ifndef _${classname}_
\#define _${classname}_

\#include <JANA/JObject.h>
\#include <JANA/JFactory.h>

class ${classname}:public jana::JObject{
	public:
		JOBJECT_PUBLIC(${classname});
		
};

\#endif // _${classname}_

";
	print FILE $content;
	
}

###############
# PrintFactoryClass
###############
sub PrintFactoryClass()
{
	$content = "
\#ifndef _${classname}_factory${tag_suffix}_
\#define _${classname}_factory${tag_suffix}_

\#include <JANA/JFactory.h>
\#include \"${classname}.h\"

class ${classname}_factory${tag_suffix}:public jana::JFactory<${classname}>{
	public:
		${classname}_factory${tag_suffix}(){};
		~${classname}_factory${tag_suffix}(){};
";

	if($USE_TAG){
		$content .= "		const char* Tag(void){return \"$tag\";}";
	}

	$content .=	"

	private:
		jerror_t init(void);						///< Called once at program start.
		jerror_t brun(jana::JEventLoop *eventLoop, int runnumber);	///< Called everytime a new run number is detected.
		jerror_t evnt(jana::JEventLoop *eventLoop, int eventnumber);	///< Called every event.
		jerror_t erun(void);						///< Called everytime run number changes, provided brun has been called.
		jerror_t fini(void);						///< Called after last event of last event source has been processed.
};

\#endif // _${classname}_factory${tag_suffix}_

";
	print FILE $content;
	
}

###############
# PrintDataMethods
###############
sub PrintFactoryMethods()
{
	$content = "

\#include <iostream>
\#include <iomanip>
using namespace std;

\#include \"${classname}_factory${tag_suffix}.h\"
using namespace jana;

//------------------
// init
//------------------
jerror_t ${classname}_factory${tag_suffix}::init(void)
{
	return NOERROR;
}

//------------------
// brun
//------------------
jerror_t ${classname}_factory${tag_suffix}::brun(jana::JEventLoop *eventLoop, int runnumber)
{
	return NOERROR;
}

//------------------
// evnt
//------------------
jerror_t ${classname}_factory${tag_suffix}::evnt(JEventLoop *loop, int eventnumber)
{

	// Code to generate factory data goes here. Add it like:
	//
	// ${classname} *my${classname} = new ${classname};
	// my${classname}->x = x;
	// my${classname}->y = y;
	// ...
	// _data.push_back(my${classname});
	//
	// Note that the objects you create here will be deleted later
	// by the system and the _data vector will be cleared automatically.

	return NOERROR;
}

//------------------
// erun
//------------------
jerror_t ${classname}_factory${tag_suffix}::erun(void)
{
	return NOERROR;
}

//------------------
// fini
//------------------
jerror_t ${classname}_factory${tag_suffix}::fini(void)
{
	return NOERROR;
}

";
	print FILE $content;
	
}

###############
# Usage
###############
sub Usage()
{
	print "\n";
	print "Usage:\n\t mkfactory factory [tag]\n";
	print "\n";
	print "Generate the C++ source and header files to implement a new\n";
	print "data factory for the Hall-D analysis framework. The files will\n";
	print "define two classes. The first is has the name specified on\n";
	print "the command line and will be the class which actually holds\n";
	print "the data. The second is the factory class which is created from\n";
	print "a template and based on the first class.\n";
	print "\n";
	print "If the \"tag\" parameter is given, the factory is created\n";
	print "to provide data of the given type with the specified tag.\n";
	print "By default, factories have an empty tag. Giving a factory a\n";
	print "tag allows it to produce data based on the same class as another\n";
	print "factory produces. The two factories are distinguished by\n";
	print "their tags. If a tag is provided, it is assumed that the\n";
	print "data class already exists so only the factory's header\n";
	print "(and source) file is generated.\n";
	print "\n";
}