import re
import sys

REGISTERS=["%rip","%rbp","%rsp","","%rax","%rdi","%r8","%r9"]
OPTIONS = """register_node/.style={rectangle, draw=black!30,
			 fill=black!5, very thick, minimum size=0.5, minimum width=20mm},
			 text_node/.style={}"""

class Emulator:

	def __init__ (self, source_text):
		self.registers = {}
		for reg_name in REGISTERS:
			self.registers[reg_name] = 0
		self.stack = [0,1,2,3,4,5,6,7]
		self.code = []
		self.codep = []
		self.linesExec = []
		self.labels = {}
		self.changes = {}
		self.status = {}
		self.text = ""
		self.x_coord = 0
		self.last_sp = 0
		self.max_stack_size = 0
		index = 0
		for line in iter(source_text.splitlines()):
			index = self.processSourceLine(line, index)

	def getReg (self, reg_name):
		return self.registers[reg_name]

	def setRegs (self, reg_dict):
		for reg_name, reg_val in reg_dict.iteritems():
			self.registers[reg_name] = reg_val

	def getVal (self, valText):
		if valText[0] == "$":
			return int(valText[1:])
		elif valText[0] == "%":
			return self.getReg(valText)
		else:
			raise "NOT A VALUE! UGHGUIHGUE!"

	def compareVal (self, valT1, valT2):
		val1 = self.getVal(valT2)
		val2 = self.getVal(valT1)
		self.status = {"g":val1>val2}

	def writeRegs (self, line_nr=None):
		self.text += self.draw((self.x_coord+1)*2.5-0.5, line_nr)
		self.text += "\n"
		self.x_coord += 1

	def changedRegisters (self, *args):
		for reg, val in args:
			self.changes[reg] = val

	def iterate (self):
		old_rip = self.registers['%rip']
		self.last_sp = self.registers['%rsp']
		#self.linesExec.append(old_rip)
		if self.registers['%rip'] >= len(self.code):
			return False
		instruct = self.code[self.registers['%rip']]
		opcode = instruct[0]
		self.changes = {}
		#print(opcode, instruct)
		if opcode == "push" or opcode == "pushq":
			self.registers['%rsp'] = self.registers['%rsp'] + 1
			self.stack[self.registers['%rsp']] = self.getReg(instruct[1])
			self.changedRegisters(('%rsp',"change"),("m"+str(self.registers['%rsp']),"insert"))
			self.max_stack_size = max(self.registers['%rsp'], self.max_stack_size)
		elif opcode == "popq":
			self.registers[instruct[1]] = self.stack[self.registers['%rsp']]
			self.registers['%rsp'] = self.registers['%rsp'] - 1
			self.changedRegisters(('%rsp',"change"),("m"+str(self.registers['%rsp']+1),"remove"))
		elif opcode == "movq" or opcode == "mov":
			self.changedRegisters((instruct[2],"change"))
			self.registers[instruct[2]] = self.getVal(instruct[1])
		elif opcode == "cmpq":
			self.compareVal(instruct[1],instruct[2])
		elif opcode == "addq":
			self.changedRegisters((instruct[2],"change"))
			self.registers[instruct[2]] = self.getVal(instruct[2]) + self.getVal(instruct[1])
		elif opcode == "subq":
			self.changedRegisters((instruct[2],"change"))
			self.registers[instruct[2]] = self.getVal(instruct[2]) - self.getVal(instruct[1])
		elif opcode == "jg":
			if self.status["g"]:
				self.registers['%rip'] = self.labels[instruct[1]]
		elif opcode == "jmp":
			self.registers['%rip'] = self.labels[instruct[1]]

		elif opcode == "call":
			self.registers['%rsp'] = self.registers['%rsp'] + 1
			self.stack[self.registers['%rsp']] = self.registers['%rip']+1
			self.registers['%rip'] = self.labels[instruct[1]]
			self.changedRegisters(('%rsp',"change"),("m"+str(self.registers['%rsp']),"insert"))
			self.max_stack_size = max(self.registers['%rsp'], self.max_stack_size)
		elif opcode == "leave":
			self.registers["%rsp"] = self.registers["%rbp"]
			self.registers["%rbp"] = self.stack[self.registers['%rsp']]
			self.registers['%rsp'] = self.registers['%rsp'] - 1
			self.changedRegisters(('%rbp',"change"))
			self.changedRegisters(('%rsp',"change"),("m"+str(self.registers['%rsp']+1),"remove"))
		elif opcode == "ret":
			self.registers['%rip'] = self.stack[self.registers['%rsp']]
			self.registers['%rsp'] = self.registers['%rsp'] - 1
			self.changedRegisters(('%rsp',"change"),("m"+str(self.registers['%rsp']+1),"remove"))

		if self.registers['%rip'] == old_rip:
			self.registers['%rip'] += 1
		else:
			self.changedRegisters(('%rip',"change"))

		self.writeRegs(old_rip)

	def processSourceLine(self, line_text, index):
		tokens = re.findall(r'[\w%:$#]+', line_text)
		if len(tokens) <= 0:
			return index
		if tokens[0][-1] == ':':
			self.labels[tokens[0][:-1]] = index
			tokens = tokens[1:]
		for i in range(len(tokens)):
			if tokens[i][0] == "#":
				tokens = tokens[:i]
				break
		self.code.append(tokens)
		self.codep.append(line_text)
		return index + 1

	REG_STATUS_TO_COLOR = {"insert":"green","change":"yellow","remove":"red"}

	def getRegColor (self, reg_name):
		if reg_name in self.changes:
			return self.REG_STATUS_TO_COLOR[self.changes[reg_name]]
		else:
			return "black"

	def getLineSignature (self, line_nr):
		return [ "\\"+token if token[0]=="$" or token[0]=="%" else token for token in self.code[line_nr] ]

	def draw (self, x, line_nr=None):
		x = str(x)
		text = ""
		pos = 0
		for reg_name in REGISTERS:
			reg_dect = "register_node, fill=" + self.getRegColor(reg_name)+"!10"
			if reg_name != "":
				text += "\t\\node["+reg_dect+"]("+reg_name[1:]+") at ("+x+", "+str(pos)+"){"+str(self.registers[reg_name])+"};\n"
			pos -= 0.5

		pos -= 1
		base_sp = max(self.last_sp,self.registers['%rsp'])
		if self.last_sp - 1 == self.registers['%rsp']:
			pos += 0.5
		for index in range(base_sp, -1,-1):
			mem_name = "m"+str(index)
			reg_dect = "register_node, fill=" + self.getRegColor(mem_name)+"!10"
			text += "\t\\node["+reg_dect+"]("+mem_name+") at ("+x+", "+str(pos)+"){"+str(self.stack[index])+"};\n"
			pos -= 0.5

		if line_nr != None:
			pos = 2
			signature = self.getLineSignature(line_nr)
			try:
				for i in range(3):
					text += "\t\\node[text_node]() at ("+str(float(x)-1.25)+", "+str(pos)+"){"+signature[i]+"};\n"
					pos -= 0.5
			except:
				pass
		#for line_nr in self.linesExec:
		#	text += "\t\\node[text_node]() at ("+x+", "+str(pos)+"){"+self.codep[line_nr]+"};\n"
		self.linesExec = []

		return text

	def drawNames (self, x, stack_size=8):
		x = str(x)
		text = ""
		pos = 0
		for reg_name in REGISTERS:
			text += "\t\\node[text_node]("+reg_name[1:]+") at ("+x+", "+str(pos)+"){"+reg_name[1:]+"};\n"
			pos -= 0.5

		text += "\t\\node[text_node]() at ("+x+", "+str(pos-0.5)+"){TOS+1};\n"
		text += "\t\\node[text_node]() at ("+x+", "+str(pos-1)+"){TOS};\n"
		pos -= 1.5
		for index in range(1,stack_size+1):
			mem_name = "m"+str(index)
			text += "\t\\node[text_node]() at ("+x+", "+str(pos)+"){TOS-"+str(index)+"};\n"
			pos -= 0.5

		return text

fib_prog = """
fib:    push %rbp       # push previous base pointer
		movq %rsp,%rbp  # setup new base pointer
if:     cmpq $1, %rdi  # if (a-1) > 0: goto long
		jg long
quick:  movq %rdi, %rax
		jmp return
long:   pushq %rdi      # Push a onto the stack
		subq $1, %rdi
		call fib        # Call fib(a-1)
		pushq %rax      # Push fib(a-1) onto the stack
		subq $1, %rdi
		call fib        # Call fib(a-2)
		popq %rdi        # pop fib(a-1) into rdi
		addq %rdi, %rax  # rax = fib(a-1)+fib(a-2)
		popq %rdi        # Garentee that a lies in rdi.
return: leave           # Clean up (stack pointers?)
		ret             # return m (rax)
"""

fib_iter_prog = """
fib:    push %rbp       # push previous base pointer
        movq %rsp,%rbp  # setup new base pointer

if:     cmpq $1,   %rdi # if (a-1) > 0: goto loops
        jg loops

quick:  movq %rdi, %rax
        jmp return

loops:	movq %rdi, %r8   # i (r8) = a
		movq $1,   %rdi	 # minus_one (rdi) = 1
		movq $0,   %rax	 # minus_two (rax) = 0

loopb:	movq %rdi, %9  # r = minus_one
		addq %rax,  %rdi  # minus_one += minus_two
		movq %9, %rax   # minus_two = r
		subq $1,   %r8   # i--
		cmpq $0,   %r8   # if a > 0
		jg loopb

return:	leave           # Clean up
        ret             # return m (rax)
"""

if __name__ == "__main__":
	try:
		a = int(sys.argv[1])
	except:
		a = 2
	new_em = Emulator(fib_iter_prog)
	new_em.stack = ["junk...","calling eip"]
	for i in range(100):
		new_em.stack.append(0)
	new_em.setRegs({'%rip':0,'%rbp':'old bp','%rsp':1,'%rdi':a})
	print("Running for fib("+str(a)+")")
	new_em.writeRegs()
	while True:
		if new_em.iterate() == False:
			break
	new_em.text += new_em.drawNames(0, new_em.max_stack_size)
	print("fib("+str(a)+") = "+str(new_em.registers["%rax"]))
	with open("tikz.tex","w") as f:
		f.write("\\documentclass{standalone}\n\n\usepackage{tikz}\\begin{document}\n")
		f.write("\\begin{tikzpicture}["+OPTIONS+"]\n")
		f.write(new_em.text)
		f.write("\\end{tikzpicture}\n\\end{document}")