dwc_network_server_emulator/gamespy/gs_query.py

"""DWC Network Server Emulator

    Copyright (C) 2014 polaris-
    Copyright (C) 2014 ToadKing
    Copyright (C) 2014 AdmiralCurtiss
    Copyright (C) 2016 Sepalani

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as
    published by the Free Software Foundation, either version 3 of the
    License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""


def parse_gamespy_message(message):
    """Parse a GameSpy message."""
    stack = []
    messages = {}
    msg = message

    while len(msg) > 0 and msg[0] == '\\' and "\\final\\" in msg:
        # Find the command
        # Don't search for more commands if there isn't a \final\, save the
        # left over for the next packet
        found_command = False
        while len(msg) > 0 and msg[0] == '\\':
            keyEnd = msg[1:].index('\\') + 1
            key = msg[1:keyEnd]
            msg = msg[keyEnd + 1:]

            if key == "final":
                break

            if '\\' in msg:
                if msg[0] == '\\':
                    value = ""
                else:
                    valueEnd = msg[1:].index('\\')
                    value = msg[:valueEnd + 1]
                    msg = msg[valueEnd + 1:]
            else:
                value = msg

            if not found_command:
                messages['__cmd__'] = key
                messages['__cmd_val__'] = value
                found_command = True

            messages[key] = value

        stack.append(messages)
        messages = {}

    # Return msg so we can prepend any leftover commands to the next packet.
    return stack, msg


def create_gamespy_message_from_dict(messages):
    """Generate a list based on the input dictionary.

    The main command must also be stored in __cmd__ for it to put the
    parameter at the beginning.
    """
    cmd = messages.get("__cmd__", "")
    cmd_val = messages.get("__cmd_val__", "")

    l = [("__cmd__", cmd), ("__cmd_val__", cmd_val)]
    l.extend([
        (key, value)
        for key, value in messages.items()
        if key not in (cmd, "__cmd__", "__cmd_val__")
    ])

    return l


def create_gamespy_message_from_list(messages):
    """Generate a string based on the input list."""
    cmd = ""
    cmd_val = ""

    query = ""
    for message in messages:
        if len(message) == 1:
            query += str(message[0])
        elif message[0] == "__cmd__":
            cmd = str(message[1]).strip('\\')
        elif message[0] == "__cmd_val__":
            cmd_val = str(message[1]).strip('\\')
        else:
            query += "\\%s\\%s" % (str(message[0]).strip('\\'),
                                   str(message[1]).strip('\\'))

    if cmd:
        # Prepend the main command if one was found.
        query = "\\%s\\%s%s" % (cmd, cmd_val, query)

    return query


def create_gamespy_message(messages, id=None):
    """Create a message based on a dictionary (or list) of parameters."""
    if isinstance(messages, dict):
        messages = create_gamespy_message_from_dict(messages)

    # Check for an id if the id needs to be updated.
    if id is not None:
        for i, message in enumerate(messages):
            # If it already exists in the list then update it
            if message[0] == "id":
                messages[i] = ("id", str(id))
                break
        else:
            # Otherwise, add it in the list
            messages.append(("id", str(id)))

    query = create_gamespy_message_from_list(messages)
    query += "\\final\\"

    return query