import ssl

from cryptography import x509
from cryptography.hazmat.backends import default_backend
from OpenSSL import crypto


def get_cert_SANs(cert: bytes):
    cert = x509.load_pem_x509_certificate(cert, default_backend())
    san_list = []
    for extension in cert.extensions:
        if isinstance(extension.value, x509.SubjectAlternativeName):
            san = extension.value
            for name in san:
                san_list.append(name.value)
    return san_list


def generate_certificate():
    k = crypto.PKey()
    k.generate_key(crypto.TYPE_RSA, 4096)
    cert = crypto.X509()
    cert.get_subject().CN = "Gozargah"
    cert.gmtime_adj_notBefore(0)
    cert.gmtime_adj_notAfter(100 * 365 * 24 * 60 * 60)
    cert.set_issuer(cert.get_subject())
    cert.set_pubkey(k)
    cert.sign(k, "sha512")
    cert_pem = crypto.dump_certificate(crypto.FILETYPE_PEM, cert).decode("utf-8")
    key_pem = crypto.dump_privatekey(crypto.FILETYPE_PEM, k).decode("utf-8")

    return {"cert": cert_pem, "key": key_pem}


def create_secure_context(
    client_cert: str,
    client_key: str,
    trusted: str,
) -> ssl.SSLContext:
    ctx = ssl.create_default_context(cafile=trusted)
    ctx.load_cert_chain(client_cert, client_key)
    ctx.set_ciphers("ECDHE+AESGCM:ECDHE+CHACHA20:DHE+AESGCM:DHE+CHACHA20")
    ctx.set_alpn_protocols(["h2"])
    ctx.check_hostname = False
    ctx.verify_mode = ssl.CERT_NONE
    return ctx