# Copyright (C) Nov 2020 Mellanox Technologies Ltd. All rights reserved.
#
# This software is available to you under a choice of one of two
# licenses.  You may choose to be licensed under the terms of the GNU
# General Public License (GPL) Version 2, available from the file
# COPYING in the main directory of this source tree, or the
# OpenIB.org BSD license below:
#
#     Redistribution and use in source and binary forms, with or
#     without modification, are permitted provided that the following
#     conditions are met:
#
#      - Redistributions of source code must retain the above
#        copyright notice, this list of conditions and the following
#        disclaimer.
#
#      - Redistributions in binary form must reproduce the above
#        copyright notice, this list of conditions and the following
#        disclaimer in the documentation and/or other materials
#        provided with the distribution.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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# --

import binascii
import re

from .loader import PacketLoader
from ..constants import PacketType
from ..packet import RawPacket

__all__ = ['RawPacketLoader', 'RawHexPacketLoader']


class RawPacketLoader(PacketLoader):
    """A concrete class that represents packet loader for raw data packets."""
    __product_type__ = PacketType.RAW.value

    def read_packets_file(self):
        """Reads and return the content of the input file.

        :return: The content of the input file.
        :rtype: bytes
        """
        with open(self.path, 'rb') as f:
            return f.read().rstrip()

    def get_packets_buffers(self):
        """Returns list of packets buffers from the input file.

        :return: list of packets buffers.
        :rtype: List[bytes]
        """
        buffer = self.read_packets_file()
        return [buffer]

    def __iter__(self):
        for buffer in self.get_packets_buffers():
            yield RawPacket(buffer)


class RawHexPacketLoader(RawPacketLoader):
    """A concrete class that represents packet loader for hexadecimal

    packets."""
    __product_type__ = PacketType.HEX.value

    @classmethod
    def hex_to_bin(cls, buffer):
        """Return the binary data represented by hexadecimal buffer string.

        :param bytes buffer: An hexadecimal buffer string.
        :return: Binary data.
        :rtype: bytes
        """
        try:
            buffer = re.sub(rb'\s+', b'', buffer)
            return binascii.a2b_hex(buffer)
        except binascii.Error as err:
            error_format = 'invalid packet buffer: {}, error: {}'
            raise ValueError(error_format.format(buffer, str(err).lower()))

    def get_packets_buffers(self):
        """Returns list of packets buffers from the input file.

        :return: list of packets buffers.
        :rtype: List[bytes]
        """
        buffers = self.read_packets_file().splitlines()
        return [self.hex_to_bin(buffer) for buffer in buffers]