#
# ============LICENSE_START=======================================================
#  Copyright (C) 2019 Nordix Foundation.
# ================================================================================
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# SPDX-License-Identifier: Apache-2.0
# ============LICENSE_END=========================================================
#

import certifi
import os

cafile = certifi.where()
number_of_lines_to_delete = 39
count = 0
dr_cert_exists = False

with open(cafile, 'r+b', buffering=0) as outfile:
    for line in outfile.readlines()[-35:-34]:
        if '# Serial: 0x9EAEEDC0A7CEB59D'.encode() in line:
            dr_cert_exists = True
    if dr_cert_exists:
        outfile.seek(0, os.SEEK_END)
        end = outfile.tell()
        while outfile.tell() > 0:
            outfile.seek(-1, os.SEEK_CUR)
            char = outfile.read(1)
            if char == b'\n':
                count += 1
            if count == number_of_lines_to_delete:
                outfile.truncate()
                print("Removed " + str(number_of_lines_to_delete) + " lines from end of CA File")
                exit(0)
            outfile.seek(-1, os.SEEK_CUR)
    else:
        print("No DR cert in CA File to remove")

if count < number_of_lines_to_delete + 1:
    print("Number of lines in file less than number of lines to delete. Exiting...")
    exit(1)