from generators.generator import Generator
from ground_ast import *
from error import traceback

class X86_64Generator(Generator):
	def __init__(self, ast, code, output_path):
		super().__init__(ast, code, output_path)
		self.stack_size = 0

	def init(self):
		self.lines.append("global _start\n\n")
		self.lines.append("_start:\n\t")

		# generate code
		self.generate()
		self.write()

	def push(self, reg: str):
		self.lines.append("push " + reg + "\n\t")
		self.stack_size += 1

	def pop(self, reg: str):
		self.lines.append("pop " + reg + "\n\t")
		self.stack_size -= 1

	def get_variable(self, var_name: str, reg: str):
		self.push(
			f"QWORD [rsp + {(self.stack_size - self.variables.get(var_name)["stack_loc"] - 1) * 8}]"
		)
		self.pop(reg)

	def generate_InstructionNode(self, node: InstructionNode):
		if node.instruction == "end":
			if len(node.arguments) == 0: # example: "end"
				traceback(self.code, "TypeError", "end expects atleast 1 argument.")
			elif len(node.arguments) > 1: # example: "end 1 1"
				traceback(self.code, "TypeError", "end expects only 1 argument.")
			if not type(node.arguments[0]) in [NumberNode, VarRefNode]: # example: "end true"
				traceback(self.code, "TypeError", f"end expects an integer, not {type(node.arguments[0])}")

			self.lines.append("mov rax, 60\n\t")
			if isinstance(node.arguments[0], NumberNode):
				self.lines.append("mov rdi, " + str(node.arguments[0].value) + "\n\t")
			elif isinstance(node.arguments[0], VarRefNode):
				self.get_variable(node.arguments[0].var_name, "rdi")
				#self.lines.append("mov rdi, " + str(self.get_variable(node.arguments[0].var_name)) + "\n\t")
			self.lines.append("syscall\n\t")

		elif node.instruction == "set":
			if len(node.arguments) < 2: # example: "set" or "set &hi"
				traceback(self.code, "TypeError", "set expects atleast 2 arguments.")
			elif len(node.arguments) > 2: # example: "set &hi 0 123"
				traceback(self.code, "TypeError", "set expects only 2 arguments.")
			if not isinstance(node.arguments[0], VarPointerNode):
				traceback(self.code, "TypeError", f"the first argument of set should be a variable pointer, not \"{type(node.arguments[0])}\"")
			if type(node.arguments[1]) not in [NumberNode]:
				traceback(self.code, "TypeError", f"variables can't be of type \"{type(node.arguments[1])}\"")

			self.variables[node.arguments[0].var_name] = {"stack_loc": self.stack_size}
			if type(node.arguments[1]) == NumberNode:
				self.lines.append(f"mov rax, {node.arguments[1].value}\n\t")
				self.push("rax")

		else:
			self.lines.append("; FUCK\n\t")
			#raise NotImplementedError(f"A generate method hasn't been made for the \"{node.instruction}\" instruction.")