import inspect
from byteplay import Code, opmap

LOAD_FAST = opmap['LOAD_FAST']
STORE_FAST = opmap['STORE_FAST']
LOAD_NAME = opmap['LOAD_NAME']
STORE_NAME = opmap['STORE_NAME']
LOAD_DEREF = opmap['LOAD_DEREF']
STORE_DEREF = opmap['STORE_DEREF']

def AnonymousCodeBlock(function):
    argSpec = inspect.getargspec(function)
    if [i for x in argSpec if x is not None for i in x]:
        raise TypeError("Function '%s' takes arguments" % function.func_name)
    
    code = Code.from_code(function.func_code)
    newBytecode = []
    for opcode, arg in code.code:
        if opcode in (LOAD_FAST, LOAD_DEREF):
            opcode = LOAD_NAME
        elif opcode in (STORE_FAST, STORE_DEREF):
            opcode = STORE_NAME
        newBytecode.append((opcode, arg))
    code.code = newBytecode
    code.newlocals = False
    code.freevars = ()
    return code.to_code()


def thunk():
    print "In thunk"
    print x
    x = 45

def getThunk():
    x = 1
    z = 3
    def innerThunk():
        print 'In inner thunk'
        print x
        x = 7
        print z
    return innerThunk

def main():
    x = 20
    z = 10

    codeObject = AnonymousCodeBlock(thunk)
    exec codeObject
    print x

    print
    exec AnonymousCodeBlock(getThunk())
    print x


if __name__ == '__main__':
    main()
    x = 5
    z = 6
    print
    print 'in local'
    exec AnonymousCodeBlock(getThunk())
    print x