Chapter7a

import sys
import re

#NEED TO INITIALIZE STACK POSITION

def cleanLine(line):	#returns line without spaces or comments
	string = ''
	for i in line:
		if i == '/' or i == '\n':	#advance if encounter comment or new line
			break
		if i != ' ':	#remove whitespace
			string = string + i
	return string

def push(num):
	pushStr = 	('D=A\n' +
				'@SP\n' +
				'A=M\n' +
				'M=D\n' +
				'D=A+1\n' +
				'@SP\n' +
				'M=D')
	return '@' + str(num) + '\n' + pushStr

#print(push(5))

def urOp(opType):
	if opType == 'neg':
		oper = '-'
	elif opType == 'not':
		oper = '!'
	opStr = ('@SP\n' +
			'A=M-1\n' +
			'M=')
	opStr = opStr + oper + 'M'
	return opStr

opCnt = 0

def binOp(opType):
	global opCnt
	arithOps = ['add', 'sub', 'and', 'or']
	opStr0 = 	('@SP\n' +
				'A=M-1\n' +
				'D=M\n' +
				'A=A-1\n')
	if opType in arithOps:
		opStr1 = 'MD=' + binOpHash(opType) + '\n'
	else:
		opStr1 = compOps(opType)
	opStr2 =	('(OPS' + str(opCnt) + ')\n'
				'D=A+1\n' +
				'@SP\n' +
				'M=D')
	opStr = opStr0 + opStr1 + opStr2
	opCnt += 1
	return(opStr)
	
def binOpHash(opType):
	opsHash = {
				'add': 'M+D',
				'sub': 'M-D',
				'and': 'M&D',
				'or': 'M|D',
				'eq': 'JEQ',
				'gt': 'JGT',
				'lt': 'JLT'
			}
	return opsHash[opType]

def compOps(opType):
	compStr =   ('D=M-D\n' +
				'@TRUE' + str(opCnt) + '\n' +
				'D;' + binOpHash(opType) + '\n' +
				'@0\n' +
				'D=A\n' +
				'(JMP' + str(opCnt) + ')\n' +
				'@SP\n' +
				'A=M-1\n' +
				'A=A-1\n' +
				'M=D\n' +
				'@OPS' + str(opCnt) + '\n'
				'0;JMP\n' +
				'(TRUE' + str(opCnt) + ')\n' +
				'@-1\n' +
				'D=A\n' +
				'@JMP' + str(opCnt) + '\n'
				'0;JMP\n')
	return compStr
	
#print(binOp('lt'))

fileName = sys.argv[1]

lineList = []
with open(str(fileName), 'r') as f:
	for line in f:
		string = cleanLine(line)
		if string:
			lineList.append(string)

newLines = []
for i in lineList:
	pushPtrn = re.compile('(push|pop)([a-z]+)([0-9]+)')
	pushMatch = pushPtrn.match(i)
	
	binPtrn = re.compile('(add|sub|eq|gt|lt|and|or)')
	binMatch = binPtrn.match(i)
	
	urPtrn = re.compile('(neg|not)')
	urMatch = urPtrn.match(i)
	
	if pushMatch:
		nLine = push(pushMatch.group(3))
	elif binMatch:
		nLine = binOp(binMatch.group(1))
	elif urMatch:
		nLine = urOp(urMatch.group(1))
	
	newLines.append(nLine)
	
for i in newLines:
	print(i)