from subprocess import PIPE
from subprocess import Popen

from saml2.extension.algsupport import DigestMethod
from saml2.extension.algsupport import SigningMethod
from saml2.sigver import get_xmlsec_binary


__author__ = "roland"

DIGEST_METHODS = {
    "hmac-md5": "http://www.w3.org/2001/04/xmldsig-more#md5",  # test framework only!
    "hmac-sha1": "http://www.w3.org/2000/09/xmldsig#sha1",
    "hmac-sha224": "http://www.w3.org/2001/04/xmldsig-more#sha224",
    "hmac-sha256": "http://www.w3.org/2001/04/xmlenc#sha256",
    "hmac-sha384": "http://www.w3.org/2001/04/xmldsig-more#sha384",
    "hmac-sha512": "http://www.w3.org/2001/04/xmlenc#sha512",
    "hmac-ripemd160": "http://www.w3.org/2001/04/xmlenc#ripemd160",
}

SIGNING_METHODS = {
    "rsa-md5": "http://www.w3.org/2001/04/xmldsig-more#rsa-md5",
    "rsa-ripemd160": "http://www.w3.org/2001/04/xmldsig-more#rsa-ripemd160",
    "rsa-sha1": "http://www.w3.org/2000/09/xmldsig#rsa-sha1",
    "rsa-sha224": "http://www.w3.org/2001/04/xmldsig-more#rsa-sha224",
    "rsa-sha256": "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256",
    "rsa-sha384": "http://www.w3.org/2001/04/xmldsig-more#rsa-sha384",
    "rsa-sha512": "http://www.w3.org/2001/04/xmldsig-more#rsa-sha512",
    "dsa-sha1": "http://www.w3.org/2000/09/xmldsig#dsa-sha1",
    "dsa-sha256": "http://www.w3.org/2009/xmldsig11#dsa-sha256",
    "ecdsa-sha1": "http://www.w3.org/2001/04/xmldsig-more#ecdsa-sha1",
    "ecdsa-sha224": "http://www.w3.org/2001/04/xmldsig-more#ecdsa-sha224",
    "ecdsa-sha256": "http://www.w3.org/2001/04/xmldsig-more#ecdsa-sha256",
    "ecdsa-sha384": "http://www.w3.org/2001/04/xmldsig-more#ecdsa-sha384",
    "ecdsa-sha512": "http://www.w3.org/2001/04/xmldsig-more#ecdsa-sha512",
}


def get_algorithm_support(xmlsec):
    com_list = [xmlsec, "--list-transforms"]
    pof = Popen(com_list, stderr=PIPE, stdout=PIPE)
    p_out, p_err = pof.communicate()
    p_out = p_out.decode("utf-8")
    p_err = p_err.decode("utf-8")

    if not p_err:
        p = p_out.splitlines()
        algs = [x.strip('"') for x in p[1].split(",")]
        digest = []
        signing = []
        for alg in algs:
            if alg in DIGEST_METHODS:
                digest.append(alg)
            elif alg in SIGNING_METHODS:
                signing.append(alg)

        return {"digest": digest, "signing": signing}

    raise SystemError(p_err)


def algorithm_support_in_metadata(xmlsec):
    if xmlsec is None:
        return []

    support = get_algorithm_support(xmlsec)
    element_list = []
    for alg in support["digest"]:
        element_list.append(DigestMethod(algorithm=DIGEST_METHODS[alg]))
    for alg in support["signing"]:
        element_list.append(SigningMethod(algorithm=SIGNING_METHODS[alg]))
    return element_list


if __name__ == "__main__":
    xmlsec = get_xmlsec_binary()
    res = get_algorithm_support(xmlsec)
    print(res)
    for a in algorithm_support_in_metadata(xmlsec):
        print(a)