import clr
clr.AddReferenceByPartialName('System')
from System.CodeDom import *
from System.CodeDom.Compiler import CodeDomProvider, CodeGeneratorOptions
from System.IO import StringWriter
import System.String

from Decoder import Decoder

import struct

def Opcode(OPCD, XO=0, branch=False):
	def sub(func):
		func.opcode = OPCD | (XO << 6)
		func.branch = branch
		return func
	return sub

class Decompiler(object):
	def __init__(self):
		self.endian = '>'
		self.decoder = Decoder()
		
		self.handlers = {}
		for name in dir(self):
			attr = getattr(self, name)
			
			if hasattr(attr, 'opcode'):
				self.handlers[attr.opcode] = attr, attr.branch
		
	def decompile(self, addr, memory):
		method = CodeMemberMethod()
		method.Name = 'Decompiled'
		method.ReturnType = CodeTypeReference(System.String)
		method.Attributes = MemberAttributes.Public
		
		end = False
		while not end:
			try:
				inst, = struct.unpack(self.endian + 'L', memory[addr:addr+4])
			except (IndexError, struct.error):
				break
			stmts, end = self.handle(addr, inst)
			for stmt in stmts:
				method.Statements.Add(stmt)
			addr += 4
		
		provider = CodeDomProvider.CreateProvider('CSharp')
		options = CodeGeneratorOptions()
		options.BracingStyle = 'Block'
		writer = StringWriter()
		provider.GenerateCodeFromMember(method, writer, options)
		print writer.ToString()
		writer.Close()
	
	def handle(self, addr, inst):
		dec = self.decoder.decode(inst)
		
		if dec[0] in self.handlers:
			handler, branch = self.handlers[dec[0]]
			return handler(addr, *dec), branch
		else:
			raise DecompilerError('No handler for %r', dec)
	
	@Opcode(14)
	def addi(self, addr, OPCD, D, A, SIMM):
		yield CodeCommentStatement('addi r%i, r%i, 0x%04x' % (D, A, SIMM))

if __name__=='__main__':
	decompiler = Decompiler()
	decompiler.decompile(0, '\xde\xad\x39\x0e')