#!/usr/bin/env perl

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

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

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

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


print "\n";
print "Create an instance of the DFactoryGenerator_${classname}${tag_suffix} \n";
print "class and use it in a JANA application by registering it\n";
print "with the DApplication object with something like:\n";
print "\n";
print "  app->AddFactoryGenerator(new DFactoryGenerator_${classname}${tag_suffix});\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";
}

###############
# PrintHeaderContent
###############
sub PrintHeaderContent()
{
	$content = "
\#ifndef _DFactoryGenerator_${classname}_
\#define _DFactoryGenerator_${classname}_

\#include <JANA/jerror.h>
\#include <JANA/JFactoryGenerator.h>

\#include \"${classname}_factory${tag_suffix}.h\"

class DFactoryGenerator_${classname}${tag_suffix}: public jana::JFactoryGenerator{
	public:
		DFactoryGenerator_${classname}${tag_suffix}(){}
		virtual ~DFactoryGenerator_${classname}${tag_suffix}(){}
		virtual const char* className(void){return static_className();}
		static const char* static_className(void){return \"DFactoryGenerator_${classname}${tag_suffix}\";}
		
		jerror_t GenerateFactories(jana::JEventLoop *loop){
			loop->AddFactory(new ${classname}_factory${tag_suffix}());
			return NOERROR;
		}

};

\#endif // _DFactoryGenerator_${classname}_

";
	print FILE $content;
	
}

###############
# Usage
###############
sub Usage()
{
	print "\n";
	print "Usage:\n\t mkfactory_generator factory [tag]\n";
	print "\n";
	print "Generate the C++ source and header files to implement a new\n";
	print "generator for an existing data factory. The file will\n";
	print "define one class whose code is contained completely in the\n";
	print "header file. The name will be based on the name specified on\n";
	print "the command line.\n";
	print "\n";
	print "If the \"tag\" parameter is given, the class is created\n";
	print "with a name that includes it in the standard scheme.\n";
	print "\n";
}