###########################################################################
#
# Copyright (c) 2019-2021 Diality Inc. - All Rights Reserved.
#
# THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
# WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
#
# @file    conversions.py
#
# @author  (last)      Sean Nash
# @date    (last)      12-Nov-2021
# @author  (original)  Peter Lucia
# @date    (original)  02-Apr-2020
#
############################################################################
import struct
from typing import List, Union


def byte_to_bytearray(val: int) -> bytes:
    """
    Converts a byte value into a byte array (little endian)

    @param val: (int) integer to convert to byte array
    @return: byte array
    """
    if type(val) != int:
        raise ValueError("Expected integer but received {0} with type {1}".format(val, type(val)))
    return struct.pack("<b", val)


def short_to_bytearray(val: int) -> bytes:
    """
    Converts a short integer (2 bytes) value into a byte array (little endian)

    @param val: (int) integer to convert to byte array
    @return: byte array
    """
    if type(val) != int:
        raise ValueError("Expected integer but received {0} with type {1}".format(val, type(val)))
    return struct.pack("<h", val)


def unsigned_short_to_bytearray(val: int) -> bytes:
    """
    Converts an unsigned short integer (2 bytes) value into a byte array (little endian)

    @param val: (int) integer to convert to byte array
    @return: byte array
    """
    if type(val) != int or val < 0:
        raise ValueError("Expected unsigned integer but received {0} with type {1}".format(val, type(val)))
    return struct.pack("<H", val)


def integer_to_bytearray(val: Union[int, bool]) -> bytes:
    """
    Converts an integer value into a byte array (little endian)

    @param val: integer to convert to byte array, bool is accepted
    @return: byte array
    """
    if type(val) != bool and type(val) != int:
        raise ValueError("Expected integer but received {0} with type {1}".format(val, type(val)))
    return struct.pack("<i", val)


def unsigned_to_bytearray(val: int) -> bytes:
    """
    Converts an integer value into a byte array (little endian)

    @param val: (int) integer to convert to byte array
    @return: byte array
    """
    if type(val) != int or val < 0:
        raise ValueError("Expected unsigned integer but received {0} with type {1}".format(val, type(val)))
    return struct.pack("<I", val)


def float_to_bytearray(val: Union[float, int]) -> bytes:
    """
    Converts a float value into a byte array (little endian)

    @param val:  float to convert to byte array, int is accepted
    @return:: byte array
    """
    if type(val) != float and type(val) != int:
        raise ValueError("Expected float but received {0} with type {1}".format(val, type(val)))
    return struct.pack('<f', val)


def integer_to_bit_array(val: int, num_bits: int = 8) -> List[int]:
    """
    Converts an integer to a bit array. For direct conversion to binary please use bin(val),
    as this function has a separate purpose
    @param val: (int) the number to convert
    @param num_bits: (int) the number of bits needed
    @return: (List[int]) The number represented in binary form as a list of 1's and 0's
    """
    if type(val) != int:
        raise ValueError("Expected integer but received {0} with type {1}".format(val, type(val)))
    return [(val >> bit) & 1 for bit in range(num_bits - 1, -1, -1)]