#  Copyright (c) 2014-present, Facebook, Inc.
#  All rights reserved.
#
#  This source code is licensed under the BSD-style license found in the
#  LICENSE file in the root directory of this source tree. An additional grant
#  of patent rights can be found in the PATENTS file in the same directory.

import os
import sys

from . import pyfdt


MODULES = ["/usr/lib/x86_64-linux-gnu/opensc-pkcs11.so", "/usr/lib64/opensc-pkcs11.so"]

ENGINES = ["/usr/lib/ssl/engines", "/usr/lib64/openssl/engines/"]

TOKEN_URL = [
    "model=PKCS%2315%20emulated;manufacturer=ZeitControl",
    "serial=%s",
    "token=OpenPGP%20card%20%28User%20PIN%20%28sig%29%29",
    "id=%01",
    "object=Signature%20key",
]


def get_url(serial):
    token = TOKEN_URL
    token[1] = token[1] % (serial)
    return ";".join(token)


def clear_environment():
    if "PKCS11_MODULE" in os.environ:
        del os.environ["PKCS11_MODULE"]


def enforce_environment():
    if "PKCS11_MODULE" not in os.environ or not os.environ["PKCS11_MODULE"]:
        for mod in MODULES:
            if os.path.exists(mod):
                os.environ["PKCS11_MODULE"] = mod
                break
    if "PKCS11_MODULE" not in os.environ or not os.environ["PKCS11_MODULE"]:
        print("Cannot find OpenSC PKCS#11 module library")
        sys.exit(1)
    if "OPENSSL_ENGINES" not in os.environ or not os.environ["OPENSSL_ENGINES"]:
        for engine in ENGINES:
            if os.path.exists(mod):
                os.environ["PKCS11_MODULE"] = mod
                break
    if "OPENSSL_ENGINES" not in os.environ or not os.environ["OPENSSL_ENGINES"]:
        print("Cannot find OpenSSL engine libraries")
        sys.exit(1)