# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.


"""
Test cases for twisted.protocols.stateful
"""

from twisted.trial.unittest import TestCase
from twisted.protocols.test import test_basic
from twisted.protocols.stateful import StatefulProtocol

from struct import pack, unpack, calcsize


class MyInt32StringReceiver(StatefulProtocol):
"""
A stateful Int32StringReceiver.
"""
MAX_LENGTH = 99999
structFormat = "!I"
prefixLength = calcsize(structFormat)

def getInitialState(self):
return self._getHeader, 4

def lengthLimitExceeded(self, length):
self.transport.loseConnection()

def _getHeader(self, msg):
length, = unpack("!i", msg)
if length > self.MAX_LENGTH:
self.lengthLimitExceeded(length)
return
return self._getString, length

def _getString(self, msg):
self.stringReceived(msg)
return self._getHeader, 4

def stringReceived(self, msg):
"""
Override this.
"""
raise NotImplementedError

def sendString(self, data):
"""
Send an int32-prefixed string to the other end of the connection.
"""
self.transport.write(pack(self.structFormat, len(data)) + data)


class TestInt32(MyInt32StringReceiver):
def connectionMade(self):
self.received = []

def stringReceived(self, s):
self.received.append(s)

MAX_LENGTH = 50
closed = 0

def connectionLost(self, reason):
self.closed = 1


class Int32TestCase(TestCase, test_basic.IntNTestCaseMixin):
protocol = TestInt32
strings = ["a", "b" * 16]
illegalStrings = ["\x10\x00\x00\x00aaaaaa"]
partialStrings = ["\x00\x00\x00", "hello there", ""]

def test_bigReceive(self):
r = self.getProtocol()
big = ""
for s in self.strings * 4:
big += pack("!i", len(s)) + s
r.dataReceived(big)
self.assertEqual(r.received, self.strings * 4)