import struct
import fnmatch
from steam.enums import EResult, EUniverse
from steam.enums.emsg import EMsg
from steam.protobufs import steammessages_base_pb2
from steam.protobufs import steammessages_clientserver_pb2
from steam.protobufs import steammessages_clientserver_2_pb2


class MsgHdr:
    _size = struct.calcsize("<Iqq")

    def __init__(self, data=None):
        if data:
            self.load(data)
        else:
            self.msg = EMsg.Invalid
            self.targetJobID = -1
            self.sourceJobID = -1

    def serialize(self):
        return struct.pack("<Iqq",
                           self.msg,
                           self.targetJobID,
                           self.sourceJobID,
                           )

    def load(self, data):
        (msg,
         self.targetJobID,
         self.sourceJobID,
         ) = struct.unpack_from("<Iqq", data)

        self.msg = EMsg(msg)


class ExtendedMsgHdr:
    _size = struct.calcsize("<IBHqqBqi")

    def __init__(self, data=None):
        if data:
            self.load(data)
        else:
            self.msg = EMsg.Invalid
            self.headerSize = 36
            self.headerVersion = 2
            self.targetJobID = -1
            self.sourceJobID = -1
            self.headerCanary = 239
            self.steamID = -1
            self.sessionID = -1

    def serialize(self):
        return struct.pack("<IBHqqBqi",
                           self.msg,
                           self.headerSize,
                           self.headerVersion,
                           self.targetJobID,
                           self.sourceJobID,
                           self.headerCanary,
                           self.steamID,
                           self.sessionID,
                           )

    def load(self, data):
        (msg,
         self.headerSize,
         self.headerVersion,
         self.targetJobID,
         self.sourceJobID,
         self.headerCanary,
         self.steamID,
         self.sessionID,
         ) = struct.unpack_from("<IBHqqBqi", data)

        self.msg = EMsg(msg)

        if self.headerSize != 36 or self.headerVersion != 2:
            raise RuntimeError("Failed to parse header")


protobuf_mask = 0x80000000


def is_proto(emsg):
    return (int(emsg) & protobuf_mask) > 0


def set_proto_bit(emsg):
    return int(emsg) | protobuf_mask


def clear_proto_bit(emsg):
    return int(emsg) & ~protobuf_mask


class MsgHdrProtoBuf:
    _size = struct.calcsize("<II")

    def __init__(self, data=None):
        self.proto = steammessages_base_pb2.CMsgProtoBufHeader()

        if data:
            self.load(data)
        else:
            self.msg = EMsg.Invalid

    def serialize(self):
        proto_data = self.proto.SerializeToString()
        return struct.pack("<II", set_proto_bit(self.msg), len(proto_data)) + proto_data

    def load(self, data):
        msg, proto_length = struct.unpack_from("<II", data)

        self.msg = EMsg(clear_proto_bit(msg))
        size = MsgHdrProtoBuf._size
        self._fullsize = size + proto_length
        self.proto.ParseFromString(data[size:self._fullsize])


class Msg:
    def __init__(self, msg, data=None, extended=False):
        self.extended = extended
        self.header = ExtendedMsgHdr(data) if extended else MsgHdr(data)
        self.msg = msg

        if data:
            data = data[self.header._size:]

        if msg == EMsg.ChannelEncryptRequest:
            self.header.msg = EMsg.ChannelEncryptRequest
            self.body = ChannelEncryptRequest(data)
        elif msg == EMsg.ChannelEncryptResponse:
            self.header.msg = EMsg.ChannelEncryptResponse
            self.body = ChannelEncryptResponse(data)
        elif msg == EMsg.ChannelEncryptResult:
            self.header.msg = EMsg.ChannelEncryptResult
            self.body = ChannelEncryptResult(data)
        else:
            self.body = None

    def serialize(self):
        return self.header.serialize() + self.body.serialize()

    def __str__(self):
        return ''


cmsg_lookup = None
cmsg_lookup2 = None


def get_cmsg(emsg):
    global cmsg_lookup, cmsg_lookup2

    if emsg == EMsg.Multi:
        return steammessages_base_pb2.CMsgMulti

    emsg = "cmsg" + str(emsg).lower()

    if not cmsg_lookup:
        cmsg_list = steammessages_clientserver_pb2.__dict__
        cmsg_list = fnmatch.filter(cmsg_list, 'CMsg*')
        cmsg_lookup = dict(zip(map(lambda x: x.lower(), cmsg_list), cmsg_list))

    name = cmsg_lookup.get(emsg, None)
    if name:
        return getattr(steammessages_clientserver_pb2, name)

    if not cmsg_lookup2:
        cmsg_list = steammessages_clientserver_2_pb2.__dict__
        cmsg_list = fnmatch.filter(cmsg_list, 'CMsg*')
        cmsg_lookup2 = dict(zip(map(lambda x: x.lower(), cmsg_list), cmsg_list))

    name = cmsg_lookup2.get(emsg, None)
    if name:
        return getattr(steammessages_clientserver_2_pb2, name)

    return None


class MsgProto:
    def __init__(self, msg, data=None):
        self._header = MsgHdrProtoBuf(data)
        self._header.msg = msg

        self.msg = msg
        self.header = self._header.proto
        self.body = get_cmsg(msg)()

        if data:
            data = data[self._header._fullsize:]
            self.body.ParseFromString(data)

    def serialize(self):
        return self._header.serialize() + self.body.SerializeToString()

    def __str__(self):
        return '\n'.join(['MsgProto',
                          '-' * 20,
                          str(self.header),
                          '-' * 20,
                          str(self.body),
                          ])


class ChannelEncryptRequest:
    def __init__(self, data=None):
        if data:
            self.load(data)
        else:
            self.protocolVersion = 1
            self.universe = EUniverse.Invalid

    def serialize(self):
        return struct.pack("<II", self.protocolVersion, self.universe)

    def load(self, data):
        (self.protocolVersion,
         universe,
         ) = struct.unpack_from("<II", data)

        self.universe = EUniverse(universe)


class ChannelEncryptResponse:
    def __init__(self, data=None):
        if data:
            self.load(data)
        else:
            self.protocolVersion = 1
            self.keySize = 128
            self.key = ''
            self.crc = 0

    def serialize(self):
        return struct.pack("<II128sII",
                           self.protocolVersion,
                           self.keySize,
                           self.key,
                           self.crc,
                           0
                           )

    def load(self, data):
        (self.protocolVersion,
         self.keySize,
         self.key,
         self.crc,
         _,
         ) = struct.unpack_from("<II128sII", data)


class ChannelEncryptResult:
    def __init__(self, data=None):
        if data:
            self.load(data)
        else:
            self.result

    def serialize(self):
        return struct.pack("<I", self.result)

    def load(self, data):
        (result,) = struct.unpack_from("<I", data)
        self.result = EResult(result)