# Source code for pamqp.base

    """
    Base classes for the representation of frames and data structures.

    """
    import logging
    import struct
    import typing

    from pamqp import common, decode, encode

    LOGGER = logging.getLogger(__name__)

    class _AMQData:
        """Base class for AMQ methods and properties for encoding and decoding"""
        __annotations__: typing.Dict = {}
        __slots__: typing.List = []
        name = '_AMQData'

        def __contains__(self, item: str) -> bool:
            """Return if the item is in the attribute list"""
            return item in self.__slots__

        def __getitem__(self, item: str) -> common.FieldValue:
            """Return an attribute as if it were a dict

            :param item: The key to use to retrieve the value
            :rtype: :const:`pamqp.common.FieldValue`
            :raises: KeyError

            """
            return getattr(self, item)

        def __iter__(self) \
                -> typing.Generator[typing.Tuple[str, common.FieldValue],
                                    None, None]:
            """Iterate the attributes and values as key, value pairs

            :rtype: (:class:`str`, :const:`pamqp.common.FieldValue`)

            """
            for attribute in self.__slots__:
                yield attribute, getattr(self, attribute)

        def __len__(self) -> int:
            """Return the length of the attribute list"""
            return len(self.__slots__)

        def __repr__(self) -> str:
            """Return the representation of the frame object"""
            return '<{} object at {}>'.format(self.name, hex(id(self)))

        @classmethod
        def amqp_type(cls, attr: str) -> str:
            """Return the AMQP data type for an attribute

            :param attr: The attribute name

            """
            return getattr(cls, '_' + attr)

        @classmethod
        def attributes(cls) -> list:
            """Return the list of attributes"""
            return cls.__slots__

    class Frame(_AMQData):
        """Base Class for AMQ Methods for encoding and decoding"""
        frame_id = 0
        index = 0
        synchronous = False
        valid_responses: typing.List = []

        def marshal(self) -> bytes:
            """Dynamically encode the frame by taking the list of attributes and
            encode them item by item getting the value form the object attribute
            and the data type from the class attribute.

            """
            self.validate()
            byte, offset, output, processing_bitset = -1, 0, [], False
            for argument in self.__slots__:
                data_type = self.amqp_type(argument)
                if not processing_bitset and data_type == 'bit':
                    byte, offset, processing_bitset = 0, 0, True
                data_value = getattr(self, argument, 0)
                if processing_bitset:
                    if data_type != 'bit':
                        processing_bitset = False
                        output.append(encode.octet(byte))
                    else:
                        byte = encode.bit(data_value, byte, offset)
                        offset += 1
                        if offset == 8:  # pragma: nocover
                            output.append(encode.octet(byte))
                            processing_bitset = False
                        continue  # pragma: nocover
                output.append(encode.by_type(data_value, data_type))
            if processing_bitset:
                output.append(encode.octet(byte))
            return b''.join(output)

        def unmarshal(self, data: bytes) -> None:
            """Dynamically decode the frame data applying the values to the method
            object by iterating through the attributes in order and decoding them.

            :param data: The raw AMQP frame data

            """
            offset, processing_bitset = 0, False
            for argument in self.__slots__:
                data_type = self.amqp_type(argument)
                if offset == 7 and processing_bitset:  # pragma: nocover
                    data = data[1:]
                    offset = 0
                if processing_bitset and data_type != 'bit':
                    offset = 0
                    processing_bitset = False
                    data = data[1:]
                consumed, value = decode.by_type(data, data_type, offset)
                if data_type == 'bit':
                    offset += 1
                    processing_bitset = True
                    consumed = 0
                setattr(self, argument, value)
                if consumed:
                    data = data[consumed:]

        def validate(self) -> None:
            """Validate the frame data ensuring all domains or attributes adhere
            to the protocol specification.

            :raises: ValueError

            """

    class BasicProperties(_AMQData):
        """Provide a base object that marshals and unmarshals the Basic.Properties
        object values.

        """
        flags: typing.Dict[str, int] = {}
        name = 'BasicProperties'

        def __eq__(self, other: object) -> bool:
            if not isinstance(other, BasicProperties):
                raise NotImplementedError
            return all(
                getattr(self, k, None) == getattr(other, k, None)
                for k in self.__slots__)

        def encode_property(self, name: str, value: common.FieldValue) -> bytes:
            """Encode a single property value

            :param name: The name of the property to encode
            :param value: The property to encode
            :type value: :const:`pamqp.common.FieldValue`
            :raises: TypeError

            """
            return encode.by_type(value, self.amqp_type(name))

        def marshal(self) -> bytes:
            """Take the Basic.Properties data structure and marshal it into the
            data structure needed for the ContentHeader.

            """
            flags = 0
            parts = []
            for property_name in self.__slots__:
                property_value = getattr(self, property_name)
                if property_value is not None and property_value != '':
                    flags = flags | self.flags[property_name]
                    parts.append(
                        self.encode_property(property_name, property_value))
            flag_pieces = []
            while True:
                remainder = flags >> 16
                partial_flags = flags & 0xFFFE
                if remainder != 0:  # pragma: nocover
                    partial_flags |= 1
                flag_pieces.append(struct.pack('>H', partial_flags))
                flags = remainder
                if not flags:  # pragma: nocover
                    break
            return b''.join(flag_pieces + parts)

        def unmarshal(self, flags: int, data: bytes) -> None:
            """Dynamically decode the frame data applying the values to the method
            object by iterating through the attributes in order and decoding them.

            """
            for property_name in self.__slots__:
                if flags & self.flags[property_name]:
                    data_type = getattr(self.__class__, '_' + property_name)
                    consumed, value = decode.by_type(data, data_type)
                    setattr(self, property_name, value)
                    data = data[consumed:]

        def validate(self) -> None:
            """Validate the frame data ensuring all domains or attributes adhere
            to the protocol specification.

            :raises: ValueError

            """
            if self.cluster_id != '':
                raise ValueError('cluster_id must be empty')
            if self.delivery_mode is not None and self.delivery_mode not in [1, 2]:
                raise ValueError('Invalid delivery_mode value: {}'.format(
                    self.delivery_mode))