"""Defines an Error Message."""

# System imports
from enum import Enum

from pyof.v0x01.common.header import Header, Type
from pyof.v0x01.foundation import exceptions
from pyof.v0x01.foundation.base import GenericMessage
from pyof.v0x01.foundation.basic_types import ConstantTypeList, UBInt16

# Third-party imports


__all__ = ('ErrorMsg', 'ErrorType', 'BadActionCode', 'BadRequestCode',
           'FlowModFailedCode', 'HelloFailedCode', 'PortModFailedCode',
           'QueueOpFailedCode')

# Enums


class ErrorType(Enum):
    """Values for ’type’ in ofp_error_message.

    These values are immutable: they will not change in future versions of the
    protocol (although new values may be added).
    """

    #: Hello protocol failed
    OFPET_HELLO_FAILED = 0,
    #: Request was not understood
    OFPET_BAD_REQUEST = 1,
    #: Error in action description
    OFPET_BAD_ACTION = 2,
    #: Problem in modifying Flow entry
    OFPET_FLOW_MOD_FAILED = 3,
    #: Problem in modifying Port entry
    OFPET_PORT_MOD_FAILED = 4,
    #: Problem in modifying Queue entry
    OFPET_QUEUE_OP_FAILED = 5


class HelloFailedCode(Enum):
    """Error_msg 'code' values for OFPET_HELLO_FAILED.

    'data' contains an ASCII text string that may give failure details.
    """

    #: No compatible version
    OFPHFC_INCOMPATIBLE = 0,
    #: Permissions error
    OFPHFC_EPERM = 1


class BadRequestCode(Enum):
    """Error_msg 'code' values for OFPET_BAD_REQUEST.

    'data' contains at least the first 64 bytes of the failed request.
    """

    #: ofp_header.version not supported.
    OFPBRC_BAD_VERSION = 0
    #: ofp_header.type not supported.
    OFPBRC_BAD_TYPE = 1
    #: ofp_stats_request.type not supported.
    OFPBRC_BAD_STAT = 2
    #: Vendor not supported (in ofp_vendor_header or ofp_stats_request or
    #: ofp_stats_reply).
    OFPBRC_BAD_VENDOR = 3
    #: Vendor subtype not supported.
    OFPBRC_BAD_SUBTYPE = 4
    #: Permissions error.
    OFPBRC_EPERM = 5
    #: Wrong request length for type.
    OFPBRC_BAD_LEN = 6
    #: Specified buffer has already been used.
    OFPBRC_BUFFER_EMPTY = 7
    #: Specified buffer does not exist.
    OFPBRC_BUFFER_UNKNOWN = 8


class BadActionCode(Enum):
    """Error_msg 'code' values for OFPET_BAD_ACTION.

    'data' contains at least the first 64 bytes of the failed request.
    """

    #: Unknown action type
    OFPBAC_BAD_TYPE = 0,
    #: Length problem in actions
    OFPBAC_BAD_LEN = 1,
    #: Unknown vendor id specified
    OFPBAC_BAD_VENDOR = 2,
    #: Unknown action type for vendor id
    OFPBAC_BAD_VENDOR_TYPE = 3,
    #: Problem validating output action
    OFPBAC_BAD_OUT_PORT = 4,
    #: Bad action argument
    OFPBAC_BAD_ARGUMENT = 5,
    #: Permissions error
    OFPBAC_EPERM = 6,
    #: Can’t handle this many actions
    OFPBAC_TOO_MANY = 7,
    #: Problem validating output queue
    OFPBAC_BAD_QUEUE = 8


class FlowModFailedCode(Enum):
    """Error_msg 'code' values for OFPET_FLOW_MOD_FAILED.

    'data' contains at least the first 64 bytes of the failed request.
    """

    #: Flow not added because of full tables
    OFPFMFC_ALL_TABLES_FULL = 0
    #: Attempted to add overlapping flow with CHECK_OVERLAP flag set
    OFPFMFC_OVERLAP = 1
    #: Permissions error
    OFPFMFC_EPERM = 2
    #: Flow not added because of non-zero idle/hard timeout
    OFPFMFC_BAD_EMERG_TIMEOUT = 3
    #: Unknown command
    OFPFMFC_BAD_COMMAND = 4
    #: Unsupported action list - cannot process in the order specified
    OFPFMFC_UNSUPPORTED = 5


class PortModFailedCode(Enum):
    """Error_msg 'code' values for OFPET_PORT_MOD_FAILED.

    'data' contains at least the first 64 bytes of the failed request.
    """

    #: Specified port does not exist
    OFPPMFC_BAD_PORT = 0,
    #: Specified hardware address is wrong
    OFPPMFC_BAD_HW_ADDR = 1


class QueueOpFailedCode(Enum):
    """Error msg 'code' values for OFPET_QUEUE_OP_FAILED.

    'data' contains at least the first 64 bytes of the failed request.
    """

    #: Invalid port (or port does not exist)
    OFPQOFC_BAD_PORT = 0,
    #: Queue does not exist
    OFPQOFC_BAD_QUEUE = 1,
    #: Permissions error
    OFPQOFC_EPERM = 2


# Classes

class ErrorMsg(GenericMessage):
    """OpenFlow Error Message.

    This message does not contain a body in addition to the OpenFlow Header.
    """

    #: :class:`~.header.Header`: OpenFlow Header
    header = Header(message_type=Type.OFPT_ERROR)
    error_type = UBInt16(enum_ref=ErrorType)
    code = UBInt16()
    data = ConstantTypeList()

    def __init__(self, xid=None, error_type=None, code=None, data=None):
        """Assign parameters to object attributes.

        Args:
            xid (int): To be included in the message header.
            error_type (ErrorType): Error type.
            code (Enum): Error code.
            data: Its content is specified in the error code documentation.
        """
        super().__init__(xid)
        self.error_type = error_type
        self.code = code
        self.data = [] if data is None else data

    def unpack(self, buff, offset=0):
        """Unpack binary data into python object."""
        raise exceptions.MethodNotImplemented("'Unpack' method not "
                                              "implemented on ErrorMsg class")