"""
"""

# Created on 2015.08.19
#
# Author: Giovanni Cannata
#
# Copyright 2015 - 2018 Giovanni Cannata
#
# This file is part of ldap3.
#
# ldap3 is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# ldap3 is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with ldap3 in the COPYING and COPYING.LESSER files.
# If not, see <http://www.gnu.org/licenses/>.

from pyasn1 import __version__ as pyasn1_version
from pyasn1.codec.ber import decoder  # for usage in other modules
from pyasn1.codec.ber.encoder import Encoder # for monkeypatching of boolean value
from ..core.results import RESULT_CODES
from ..utils.conv import to_unicode
from ..protocol.convert import referrals_to_list

CLASSES = {(False, False): 0,  # Universal
           (False, True): 1,  # Application
           (True, False): 2,  # Context
           (True, True): 3}  # Private


# Monkeypatching of pyasn1 for encoding Boolean with the value 0xFF for TRUE
# THIS IS NOT PART OF THE FAST BER DECODER
if pyasn1_version == 'xxx0.2.3':
    from pyasn1.codec.ber.encoder import tagMap, BooleanEncoder, encode
    from pyasn1.type.univ import Boolean
    from pyasn1.compat.octets import ints2octs
    class BooleanCEREncoder(BooleanEncoder):
        _true = ints2octs((255,))

    tagMap[Boolean.tagSet] = BooleanCEREncoder()
else:
    from pyasn1.codec.ber.encoder import tagMap, typeMap, AbstractItemEncoder
    from pyasn1.type.univ import Boolean
    from copy import deepcopy

    class LDAPBooleanEncoder(AbstractItemEncoder):
        supportIndefLenMode = False
        if pyasn1_version <= '0.2.3':
            from pyasn1.compat.octets import ints2octs
            _true = ints2octs((255,))
            _false = ints2octs((0,))
            def encodeValue(self, encodeFun, value, defMode, maxChunkSize):
                return value and self._true or self._false, 0
        elif pyasn1_version <= '0.3.1':
            def encodeValue(self, encodeFun, value, defMode, maxChunkSize):
                return value and (255,) or (0,), False, False
        elif pyasn1_version <= '0.3.4':
            def encodeValue(self, encodeFun, value, defMode, maxChunkSize, ifNotEmpty=False):
                return value and (255,) or (0,), False, False
        elif pyasn1_version <= '0.3.7':
            def encodeValue(self, value, encodeFun, **options):
                return value and (255,) or (0,), False, False
        else:
            def encodeValue(self, value, asn1Spec, encodeFun, **options):
                return value and (255,) or (0,), False, False

    customTagMap = deepcopy(tagMap)
    customTypeMap = deepcopy(typeMap)
    customTagMap[Boolean.tagSet] = LDAPBooleanEncoder()
    customTypeMap[Boolean.typeId] = LDAPBooleanEncoder()

    encode = Encoder(customTagMap, customTypeMap)
# end of monkey patching

# a fast BER decoder for LDAP responses only
def compute_ber_size(data):
    """
    Compute size according to BER definite length rules
    Returns size of value and value offset
    """

    if data[1] <= 127:  # BER definite length - short form. Highest bit of byte 1 is 0, message length is in the last 7 bits - Value can be up to 127 bytes long
        return data[1], 2
    else:  # BER definite length - long form. Highest bit of byte 1 is 1, last 7 bits counts the number of following octets containing the value length
        bytes_length = data[1] - 128
        value_length = 0
        cont = bytes_length
        for byte in data[2: 2 + bytes_length]:
            cont -= 1
            value_length += byte * (256 ** cont)
        return value_length, bytes_length + 2


def decode_message_fast(message):
    ber_len, ber_value_offset = compute_ber_size(get_bytes(message[:10]))  # get start of sequence, at maximum 3 bytes for length
    decoded = decode_sequence(message, ber_value_offset, ber_len + ber_value_offset, LDAP_MESSAGE_CONTEXT)
    return {
        'messageID': decoded[0][3],
        'protocolOp': decoded[1][2],
        'payload': decoded[1][3],
        'controls': decoded[2][3] if len(decoded) == 3 else None
    }


def decode_sequence(message, start, stop, context_decoders=None):
    decoded = []
    while start < stop:
        octet = get_byte(message[start])
        ber_class = CLASSES[(bool(octet & 0b10000000), bool(octet & 0b01000000))]
        ber_constructed = bool(octet & 0b00100000)
        ber_type = octet & 0b00011111
        ber_decoder = DECODERS[(ber_class, octet & 0b00011111)] if ber_class < 2 else None
        ber_len, ber_value_offset = compute_ber_size(get_bytes(message[start: start + 10]))
        start += ber_value_offset
        if ber_decoder:
            value = ber_decoder(message, start, start + ber_len, context_decoders)  # call value decode function
        else:
            # try:
            value = context_decoders[ber_type](message, start, start + ber_len)  # call value decode function for context class
            # except KeyError:
            #     if ber_type == 3:  # Referral in result
            #         value = decode_sequence(message, start, start + ber_len)
            #     else:
            #         raise  # re-raise, should never happen
        decoded.append((ber_class, ber_constructed, ber_type, value))
        start += ber_len

    return decoded


def decode_integer(message, start, stop, context_decoders=None):
    first = message[start]
    value = -1 if get_byte(first) & 0x80 else 0
    for octet in message[start: stop]:
        value = value << 8 | get_byte(octet)

    return value


def decode_octet_string(message, start, stop, context_decoders=None):
    return message[start: stop]


def decode_boolean(message, start, stop, context_decoders=None):
    return False if message[start: stop] == 0 else True


def decode_bind_response(message, start, stop, context_decoders=None):
    return decode_sequence(message, start, stop, BIND_RESPONSE_CONTEXT)


def decode_extended_response(message, start, stop, context_decoders=None):
    return decode_sequence(message, start, stop, EXTENDED_RESPONSE_CONTEXT)


def decode_intermediate_response(message, start, stop, context_decoders=None):
    return decode_sequence(message, start, stop, INTERMEDIATE_RESPONSE_CONTEXT)


def decode_controls(message, start, stop, context_decoders=None):
    return decode_sequence(message, start, stop, CONTROLS_CONTEXT)


def ldap_result_to_dict_fast(response):
    response_dict = dict()
    response_dict['result'] = int(response[0][3])  # resultCode
    response_dict['description'] = RESULT_CODES[response_dict['result']]
    response_dict['dn'] = to_unicode(response[1][3], from_server=True)  # matchedDN
    response_dict['message'] = to_unicode(response[2][3], from_server=True)  # diagnosticMessage
    if len(response) == 4:
        response_dict['referrals'] = referrals_to_list([to_unicode(referral[3], from_server=True) for referral in response[3][3]])  # referrals
    else:
        response_dict['referrals'] = None

    return response_dict


######

if str is not bytes:  # Python 3
    def get_byte(x):
        return x

    def get_bytes(x):
        return x
else:  # Python 2
    def get_byte(x):
        return ord(x)

    def get_bytes(x):
        return bytearray(x)

DECODERS = {
    # Universal
    (0, 1): decode_boolean,  # Boolean
    (0, 2): decode_integer,  # Integer
    (0, 4): decode_octet_string,  # Octet String
    (0, 10): decode_integer,  # Enumerated
    (0, 16): decode_sequence,  # Sequence
    (0, 17): decode_sequence,  # Set
    # Application
    (1, 1): decode_bind_response,  # Bind response
    (1, 4): decode_sequence,  # Search result entry
    (1, 5): decode_sequence,  # Search result done
    (1, 7): decode_sequence,  # Modify response
    (1, 9): decode_sequence,  # Add response
    (1, 11): decode_sequence,  # Delete response
    (1, 13): decode_sequence,  # ModifyDN response
    (1, 15): decode_sequence,  # Compare response
    (1, 19): decode_sequence,  # Search result reference
    (1, 24): decode_extended_response,  # Extended response
    (1, 25): decode_intermediate_response,  # intermediate response
    (2, 3): decode_octet_string  #
}

BIND_RESPONSE_CONTEXT = {
    7: decode_octet_string  # SaslCredentials
}

EXTENDED_RESPONSE_CONTEXT = {
    10: decode_octet_string,  # ResponseName
    11: decode_octet_string  # Response Value
}

INTERMEDIATE_RESPONSE_CONTEXT = {
    0: decode_octet_string,  # IntermediateResponseName
    1: decode_octet_string  # IntermediateResponseValue
}

LDAP_MESSAGE_CONTEXT = {
    0: decode_controls,  # Controls
    3: decode_sequence  # Referral
}

CONTROLS_CONTEXT = {
    0: decode_sequence  # Control
}

[(75, 'copy.deepcopy', 'deepcopy', False, 'from copy import deepcopy\n'), (76, 'copy.deepcopy', 'deepcopy', False, 'from copy import deepcopy\n'), (80, 'pyasn1.codec.ber.encoder.Encoder', 'Encoder', False, 'from pyasn1.codec.ber.encoder import Encoder\n'), (46, 'pyasn1.compat.octets.ints2octs', 'ints2octs', False, 'from pyasn1.compat.octets import ints2octs\n'), (58, 'pyasn1.compat.octets.ints2octs', 'ints2octs', False, 'from pyasn1.compat.octets import ints2octs\n'), (59, 'pyasn1.compat.octets.ints2octs', 'ints2octs', False, 'from pyasn1.compat.octets import ints2octs\n')]