#!/usr/bin/python

class Caretaker:
	
	def __init__(self):
		self.objects=dict() # Create empty objects pool
		# Add registers to pool
		for reg in ["MAR","MDR", "PC", "MBR", "SP","LV","CPP","TOS","OPC","H"]:
			self.objects[reg]=0
		self.objects["RAM"]=None
	
	def __getitem__(self,key):
		if key=="MBRU": # If we ask for unsigned
			return(abs(self.objects["MBR"]))
		elif key== "MBR":
			if (self.objects[key]>>7)==1: # If it a negative number (2 complement)
				return(-((self.objects[key]-1)^0xFF)) # transforme bin negative number to python negative number
			else:
				return(self.objects[key])
		return(self.objects[key])

	def __setitem__(self,key,value):# TODO: Do special treatment for MBR (allow only 2^8 value)
									# TODO: Force data to be at most 32 bits longs (Mic-1 architecture constraint)
		self.objects[key]=value
		
	def items(self):
		return(self.objects.items())