Ayuto's code with RecipientFilter cast removed

# =============================================================================
# >> IMPORTS
# =============================================================================
# Source.Python
from engines.server import engine_server
from filters.recipients import RecipientFilter

from bitbuffers import BitBufferWrite
from bitbuffers import BitBufferRead

import memory

from memory import Convention
from memory import DataType
from memory.hooks import PreHook
from memory.hooks import PostHook


# =============================================================================
# >> GLOBAL VARIABLES
# =============================================================================
engine_server_ptr = memory.get_object_pointer(engine_server)

# CVEngineServer::UserMessageBegin(IRecipientFilter *, int)
UserMessageBegin = engine_server_ptr.make_virtual_function(
    43,
    Convention.THISCALL,
    [DataType.POINTER, DataType.POINTER, DataType.INT],
    DataType.POINTER
)

# CVEngineServer::MessageEnd(void)
MessageEnd = engine_server_ptr.make_virtual_function(
    44,
    Convention.THISCALL,
    [DataType.POINTER],
    DataType.VOID
)

user_message_data = None


# =============================================================================
# >> HOOKS
# =============================================================================
@PostHook(UserMessageBegin)
def post_user_message_begin(args, return_value):
    global user_message_data
    user_message_data = (args[2],
                         memory.make_object(BitBufferWrite, return_value))

@PreHook(MessageEnd)
def pre_message_end(args):
    # This happens when we initialize our hooks, while a user message is
    # currently being created
    if user_message_data is None:
        return

    message_index, buffer = user_message_data
    on_user_message_created(message_index, BitBufferRead(buffer), buffer)


# =============================================================================
# >> TEST
# =============================================================================
from messages import get_message_index

saytext2_index = get_message_index('SayText2')

def on_user_message_created(message_index, buffer_read, buffer_write):
    if message_index != saytext2_index:
        return

    index = buffer_read.read_byte()
    chat = buffer_read.read_byte()
    message = buffer_read.read_string()
    param1 = buffer_read.read_string()

    param2_bits = buffer_read.num_bits_read
    param2 = buffer_read.read_string()

    param3 = buffer_read.read_string()
    param4 = buffer_read.read_string()

    print(index, chat, message, param1, param2, param3, param4)

    # Seek to the param2 bit. At that bit the actual message is stored, which
    # we want to modify.
    buffer_write.seek_to_bit(param2_bits)

    new_message = 'Hello world!'
    buffer_write.write_string(new_message)

    if len(new_message) != len(param2):
        # We need to rewrite the buffer, because the user message might be
        # corrupt now :(
        buffer_write.write_string(param3)
        buffer_write.write_string(param4)