"""
Script to compare a set of X.509 certificate files
"""
import argparse
import typing

from cryptography import x509

import helpers

DEFAULT_OIDS = [
    x509.OID_BASIC_CONSTRAINTS,
    x509.OID_KEY_USAGE,
    x509.OID_EXTENDED_KEY_USAGE,
    x509.OID_AUTHORITY_KEY_IDENTIFIER,
    x509.OID_SUBJECT_KEY_IDENTIFIER,
    x509.OID_AUTHORITY_KEY_IDENTIFIER,
    x509.OID_AUTHORITY_INFORMATION_ACCESS,
    x509.OID_CRL_DISTRIBUTION_POINTS,
    x509.OID_CERTIFICATE_POLICIES,
]


def table_line(key, values):
    print(f"| {key} |", " | ".join(values), "|")


def format_duration(cert: x509.Certificate) -> str:
    return f"{cert.not_valid_before} - {cert.not_valid_after} = {(cert.not_valid_after - cert.not_valid_before).days}d"


def compare_certificates(certificates: typing.List[str]):
    parsed = {}

    for cert_filename in certificates:
        parsed[cert_filename] = helpers.parse_certificate(cert_filename)

    print("| |", " | ".join([f"`{name}`" for name in certificates]), "|")
    print("|---|" + "---|" * len(certificates))
    table_line("Subject", [parsed[fn].subject.rfc4514_string() for fn in certificates])
    table_line(
        "Issuer",
        [
            parsed[fn].issuer.rfc4514_string(
                attr_name_overrides={
                    x509.ObjectIdentifier("1.2.840.113549.1.9.1"): "emailAddress"
                }
            )
            for fn in certificates
        ],
    )
    table_line(
        "Public Key algorithm",
        [helpers.format_key_type(parsed[fn]) for fn in certificates],
    )
    table_line(
        "Hash algorithm",
        [helpers.format_hash_algorithm(parsed[fn]) for fn in certificates],
    )
    table_line(
        "Validity duration", [format_duration(parsed[fn]) for fn in certificates]
    )

    extra_oids = set()
    for cert in certificates:
        for oid in [
            ext.oid for ext in parsed[cert].extensions if ext.oid not in DEFAULT_OIDS
        ]:
            extra_oids.add(oid)

    for oid in DEFAULT_OIDS:
        table_line(
            helpers.extension_label(oid),
            [
                helpers.format_extension(parsed[fn].extensions, oid)
                for fn in certificates
            ],
        )

    for oid in extra_oids:
        table_line(
            helpers.extension_label(oid),
            [
                helpers.format_extension(parsed[fn].extensions, oid)
                for fn in certificates
            ],
        )


def main():
    parser = argparse.ArgumentParser(
        prog="compare certs",
        description="compare a certificate to a set of other certificates",
    )
    parser.add_argument("first", help="first certificates")
    parser.add_argument("others", nargs="+", help="other certificates")

    args = parser.parse_args()

    cert_list = [args.first]
    cert_list.extend(args.others)

    compare_certificates(cert_list)


if __name__ == "__main__":
    main()