import copy

from urllib.parse import urlparse

from django.conf import settings

from saml2.config import SPConfig

from saml2 import BINDING_HTTP_POST, BINDING_HTTP_REDIRECT

def is_relative(url):

    absolute = bool(urlparse(url).netloc)

    return not absolute

def absolutize(path, default_base):

    if is_absolute(path):

        return path

    else:

        return default_base + path

SAML_CONFIG = settings.SAML_CONFIG

_idp_configs = {}

_relative_paths = []

def relative_config_loader(request=None):

    host = request.get_host()

    if host in _idp_configs:

        return _idp_configs[host]

    base = request.scheme + "://" + request.get_host()

    config = copy.deepcopy(settings.SAML_CONFIG)

    endpoints = config['service']['sp']['endpoints']

    if not _relative_paths:

        if is_relative(config['entityid']):

            _relative_paths.append('entityid')

        if is_relative(endpoints['assertion_consumer_service'][0]):

            _relative_paths.append('assertion_consumer_service')

        if is_relative(endpoints['single_logout_service'][0][0]):

            _relative_paths.append('single_logout_service')

    if 'single_logout_service' in _relative_paths:

        absolute_rdir = base + endpoints['single_logout_service'][0][0]

        absolute_post = base + endpoints['single_logout_service'][1][0]

        sls_endpoint = [

            (absolute_rdir, BINDING_HTTP_REDIRECT),

            (absolute_post, BINDING_HTTP_POST)

        ]

        config['service']['sp']['endpoints']['single_logout_service'] = sls_endpoint

    if 'assertion_consumer_service' in _relative_paths:

        acs = base + endpoints['assertion_consumer_service'][0]

        config['service']['sp']['endpoints']['assertion_consumer_service'][0] = acs

    if 'entityid' in _relative_paths:

        config['entityid'] = base + config['entityid']

    conf = SPConfig()

    conf.load(config)

    _idp_configs[host] = conf

    return conf

if 'SAML_CONFIG_LOADER' in os.environ:

    SAML_CONFIG_LOADER = os.environ.get('SAML_CONFIG_LOADER')