from System.CodeDom import *
from System.CodeDom.Compiler import CodeDomProvider, CodeGeneratorOptions
from System.IO import StringWriter
import System.String, System.Int16

from Decoder import Decoder

class Decompiler(object):
	ARITH_ADD = CodeBinaryOperatorType.Add
	ARITH_SUB = CodeBinaryOperatorType.Subtract
	ARITH_MUL = CodeBinaryOperatorType.Multiply
	ARITH_DIV = CodeBinaryOperatorType.Divide
	ARITH_XOR = '^'
	ARITH_LSL = '<<'
	ARITH_LSR = '>>'
	
	def compileExpr(expr):
		provider = CodeDomProvider.CreateProvider('CSharp')
		options = CodeGeneratorOptions()
		options.BracingStyle = 'Block'
		writer = StringWriter()
		provider.GenerateCodeFromExpression(expr, writer, options)
		ret = writer.ToString()
		writer.Close()
		return ret
	
	def arith(op, A, B):
		if isinstance(op, CodeBinaryOperatorType):
			return CodeBinaryOperatorExpression(
				A,
				op,
				B
			)
		else:
			return CodeSnippetExpression(
					'%s %s %s' % (
						compileExpr(A),
						oper,
						compileExpr(B)
					)
				)

	add = lambda A, B: Arith(ARITH_ADD, A, B)
	sub = lambda A, B: Arith(ARITH_SUB, A, B)
	mul = lambda A, B: Arith(ARITH_MUL, A, B)
	div = lambda A, B: Arith(ARITH_DIV, A, B)
	xor = lambda A, B: Arith(ARITH_XOR, A, B)
	lsl = lambda A, B: Arith(ARITH_LSL, A, B)
	lsr = lambda A, B: Arith(ARITH_LSR, A, B)
	
	move = CodeAssignStatement
	
	def branch(L, C=None, cond=None, hintTaken=False):
		pass
	
	def comp(op, A, B):
		pass
	
	V = 1
	
	def formE(code, off, pre):
		pass
	
	forms = {
		'E' : formE,
		'G' : formG,
	}
	sizes = {
		'v' : V,
	}
	
	def form(formstr):
		outform = []
		for opc in formstr.split(','):
			major, minor = opc[0], opc[1]
			outform.append((forms[major], sizes[minor]))
		return outform
	
	opcodes = {
		0x33 : (form('Gv,Ev'), lambda D, S: move(D, xor(D, S)), False),
	}
	
	def decompile(self, code):
		method = CodeMemberMethod()
		method.Name = 'Decompiled'
		method.ReturnType = CodeTypeReference(System.String)
		method.Attributes = MemberAttributes.Public
		
		end = False
		while not end:
			stmt, end = self.decode(code)
			method.Statements.Add(stmt)