# pylint: disable=redefined-outer-name, unused-argument, invalid-name, missing-docstring, too-many-arguments

import json
import time
import urlparse

import jwt
import pytest

from httmock import urlmatch, HTTMock
from Crypto.PublicKey import RSA
from jwkest.jwk import RSAKey

from oauth.oidc import OIDCLoginService, OAuthLoginException

@pytest.fixture(params=[True, False])
def app_config(http_client, request):
  return {
    'PREFERRED_URL_SCHEME': 'http',
    'SERVER_HOSTNAME': 'localhost',
    'FEATURE_MAILING': request.param,

    'SOMEOIDC_TEST_SERVICE': {
      'CLIENT_ID': 'foo',
      'CLIENT_SECRET': 'bar',
      'SERVICE_NAME': 'Some Cool Service',
      'SERVICE_ICON': 'http://some/icon',
      'OIDC_SERVER': 'http://fakeoidc',
      'DEBUGGING': True,
    },

    'HTTPCLIENT': http_client,
  }

@pytest.fixture()
def oidc_service(app_config):
  return OIDCLoginService(app_config, 'SOMEOIDC_TEST_SERVICE')

@pytest.fixture()
def discovery_content():
  return {
    'scopes_supported': ['profile'],
    'authorization_endpoint': 'http://fakeoidc/authorize',
    'token_endpoint': 'http://fakeoidc/token',
    'userinfo_endpoint': 'http://fakeoidc/userinfo',
    'jwks_uri': 'http://fakeoidc/jwks',
  }

@pytest.fixture()
def discovery_handler(discovery_content):
  @urlmatch(netloc=r'fakeoidc', path=r'.+openid.+')
  def handler(_, __):
    return json.dumps(discovery_content)

  return handler

@pytest.fixture(scope="module") # Slow to generate, only do it once.
def signing_key():
  private_key = RSA.generate(2048)
  jwk = RSAKey(key=private_key.publickey()).serialize()
  return {
    'id': 'somekey',
    'private_key': private_key.exportKey('PEM'),
    'jwk': jwk,
  }

@pytest.fixture()
def id_token(oidc_service, signing_key, app_config):
  token_data = {
    'iss': oidc_service.config['OIDC_SERVER'],
    'aud': oidc_service.client_id(),
    'nbf': int(time.time()),
    'iat': int(time.time()),
    'exp': int(time.time() + 600),
    'sub': 'cooluser',
  }

  token_headers = {
    'kid': signing_key['id'],
  }

  return jwt.encode(token_data, signing_key['private_key'], 'RS256', headers=token_headers)

@pytest.fixture()
def valid_code():
  return 'validcode'

@pytest.fixture()
def token_handler(oidc_service, id_token, valid_code):
  @urlmatch(netloc=r'fakeoidc', path=r'/token')
  def handler(_, request):
    params = urlparse.parse_qs(request.body)
    if params.get('redirect_uri')[0] != 'http://localhost/oauth2/someoidc/callback':
      return {'status_code': 400, 'content': 'Invalid redirect URI'}

    if params.get('client_id')[0] != oidc_service.client_id():
      return {'status_code': 401, 'content': 'Invalid client id'}

    if params.get('client_secret')[0] != oidc_service.client_secret():
      return {'status_code': 401, 'content': 'Invalid client secret'}

    if params.get('code')[0] != valid_code:
      return {'status_code': 401, 'content': 'Invalid code'}

    if params.get('grant_type')[0] != 'authorization_code':
      return {'status_code': 400, 'content': 'Invalid authorization type'}

    content = {
      'access_token': 'sometoken',
      'id_token': id_token,
    }
    return {'status_code': 200, 'content': json.dumps(content)}

  return handler

@pytest.fixture()
def jwks_handler(signing_key):
  def jwk_with_kid(kid, jwk):
    jwk = jwk.copy()
    jwk.update({'kid': kid})
    return jwk

  @urlmatch(netloc=r'fakeoidc', path=r'/jwks')
  def handler(_, __):
    content = {'keys': [jwk_with_kid(signing_key['id'], signing_key['jwk'])]}
    return {'status_code': 200, 'content': json.dumps(content)}

  return handler

@pytest.fixture()
def emptykeys_jwks_handler():
  @urlmatch(netloc=r'fakeoidc', path=r'/jwks')
  def handler(_, __):
    content = {'keys': []}
    return {'status_code': 200, 'content': json.dumps(content)}

  return handler

@pytest.fixture(params=["someusername", None])
def preferred_username(request):
  return request.param

@pytest.fixture
def userinfo_handler(oidc_service, preferred_username):
  @urlmatch(netloc=r'fakeoidc', path=r'/userinfo')
  def handler(_, __):
    content = {
      'sub': 'cooluser',
      'preferred_username':preferred_username,
      'email': 'foo@example.com',
      'email_verified': True,
    }

    return {'status_code': 200, 'content': json.dumps(content)}

  return handler

@pytest.fixture()
def invalidsub_userinfo_handler(oidc_service):
  @urlmatch(netloc=r'fakeoidc', path=r'/userinfo')
  def handler(_, __):
    content = {
      'sub': 'invalidsub',
      'preferred_username': 'someusername',
      'email': 'foo@example.com',
      'email_verified': True,
    }

    return {'status_code': 200, 'content': json.dumps(content)}

  return handler

@pytest.fixture()
def missingemail_userinfo_handler(oidc_service, preferred_username):
  @urlmatch(netloc=r'fakeoidc', path=r'/userinfo')
  def handler(_, __):
    content = {
      'sub': 'cooluser',
      'preferred_username': preferred_username,
    }

    return {'status_code': 200, 'content': json.dumps(content)}

  return handler

def test_basic_config(oidc_service):
  assert oidc_service.service_id() == 'someoidc'
  assert oidc_service.service_name() == 'Some Cool Service'
  assert oidc_service.get_icon() == 'http://some/icon'

def test_discovery(oidc_service, http_client, discovery_handler):
  with HTTMock(discovery_handler):
    assert oidc_service.authorize_endpoint() == 'http://fakeoidc/authorize?response_type=code&'
    assert oidc_service.token_endpoint() == 'http://fakeoidc/token'
    assert oidc_service.user_endpoint() == 'http://fakeoidc/userinfo'
    assert oidc_service.get_login_scopes() == ['profile']

def test_public_config(oidc_service, discovery_handler):
  with HTTMock(discovery_handler):
    assert oidc_service.get_public_config()['OIDC']
    assert oidc_service.get_public_config()['CLIENT_ID'] == 'foo'

    assert 'CLIENT_SECRET' not in oidc_service.get_public_config()
    assert 'bar' not in oidc_service.get_public_config().values()

def test_exchange_code_invalidcode(oidc_service, discovery_handler, app_config, http_client,
                                   token_handler):
  with HTTMock(token_handler, discovery_handler):
    with pytest.raises(OAuthLoginException):
      oidc_service.exchange_code_for_login(app_config, http_client, 'testcode', '')

def test_exchange_code_validcode(oidc_service, discovery_handler, app_config, http_client,
                                 token_handler, userinfo_handler, jwks_handler, valid_code,
                                 preferred_username):
  with HTTMock(jwks_handler, token_handler, userinfo_handler, discovery_handler):
    lid, lusername, lemail = oidc_service.exchange_code_for_login(app_config, http_client,
                                                                  valid_code, '')

    assert lid == 'cooluser'
    assert lemail == 'foo@example.com'

    if preferred_username is not None:
      assert lusername == preferred_username
    else:
      assert lusername == lid

def test_exchange_code_missingemail(oidc_service, discovery_handler, app_config, http_client,
                                    token_handler, missingemail_userinfo_handler, jwks_handler,
                                    valid_code, preferred_username):
  with HTTMock(jwks_handler, token_handler, missingemail_userinfo_handler, discovery_handler):
    if app_config['FEATURE_MAILING']:
      # Should fail because there is no valid email address.
      with pytest.raises(OAuthLoginException):
        oidc_service.exchange_code_for_login(app_config, http_client, valid_code, '')
    else:
      # Should succeed because, while there is no valid email address, it isn't necessary with
      # mailing disabled.
      lid, lusername, lemail = oidc_service.exchange_code_for_login(app_config, http_client,
                                                                    valid_code, '')

      assert lid == 'cooluser'
      assert lemail is None

      if preferred_username is not None:
        assert lusername == preferred_username
      else:
        assert lusername == lid

def test_exchange_code_invalidsub(oidc_service, discovery_handler, app_config, http_client,
                                  token_handler, invalidsub_userinfo_handler, jwks_handler,
                                  valid_code):
  with HTTMock(jwks_handler, token_handler, invalidsub_userinfo_handler, discovery_handler):
    # Should fail because the sub of the user info doesn't match that returned by the id_token.
    with pytest.raises(OAuthLoginException):
      oidc_service.exchange_code_for_login(app_config, http_client, valid_code, '')

def test_exchange_code_missingkey(oidc_service, discovery_handler, app_config, http_client,
                                  token_handler, userinfo_handler, emptykeys_jwks_handler,
                                  valid_code):
  with HTTMock(emptykeys_jwks_handler, token_handler, userinfo_handler, discovery_handler):
    # Should fail because the key is missing.
    with pytest.raises(OAuthLoginException):
      oidc_service.exchange_code_for_login(app_config, http_client, valid_code, '')