""" Simulator Logging
	embed Simlog().instance().msg( "subject", "content" ) in your application
	set Simlog().instance().watch(["subject"]) for all message subjects and only those subjects are logged
"""

import types;
import fnmatch;
import string;
import sys;

class Simlog:
	"Logging with subject filtering"
	myInstance= None;
	def __init__( self ):
		self.subjectSet= [];
		self.all= 0;
	def instance( self ):
		"The single instance of this class"
		if( Simlog.myInstance == None ):
			Simlog.myInstance= self;
		return Simlog.myInstance;
	def summary( self ):
		"summary log - only selected subjects will print"
		self.all= 0;
		return self;
	def detail( self ):
		"detail log - all subjects will print"
		self.all= 1;
		return self;
	def watch( self, subject ):
		"set a watch on a specific subject or list of subjects"
		if( type(subject) == types.StringType ): self.subjectSet.append( subject );
		else: self.subjectSet= subject;
		return self;
	def msg( self, subject, *payload ):
		"if watch set on this subject, print the payload"
		if( len(self.subjectSet) == 0 ):
			m= 0;
		else:
			m= reduce( lambda x,y:x or y, 
				map( lambda pat,sub=subject:fnmatch.fnmatch(sub,pat), self.subjectSet ) );
		if( m or self.all ): 
			print subject, string.join(payload,"; ");
			sys.stdout.flush();
			
def theLog():
	"Utility function to return the singleton instance of the log"
	return Simlog().instance();
	
def test():
	Simlog().instance().watch( [ "bet.anycraps", "sim.*" ] );
	Simlog().instance().msg( "hack", "skip this" );
	Simlog().instance().msg( "bet.pass", "skip this" );
	Simlog().instance().msg( "bet.anycraps", "any craps bet" );
	Simlog().instance().msg( "sim.round", "start of round" );
	Simlog().instance().msg( "sim.end", "end of simulation" );

if( __name__ == "__main__" ):
	test();