We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Improve the check for if the user is a host of a challenge
Currently, at https://github.com/Cloud-CV/EvalAI/blob/master/apps/hosts/utils.py#L12 we only check if the user has created the challegne and based on that we allow the challenge host to see all the submissions (for example, see this https://github.com/Cloud-CV/EvalAI/blob/master/apps/challenges/views.py#L703). We would want to change it so that anyone who is a part of the challenge host team is allowed to access information such as 'View all submissions' etc. 

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `apps/participants/urls.py`
Content:
```
1 from django.conf.urls import url
2 
3 from . import views
4 
5 urlpatterns = [
6     url(r'participant_team/(?P<pk>[0-9]+)/invite$', views.invite_participant_to_team,
7         name='invite_participant_to_team'),
8     url(r'remove_self_from_participant_team/(?P<participant_team_pk>[0-9]+)$',
9         views.remove_self_from_participant_team,
10         name='remove_self_from_participant_team'),
11     url(r'participant_team/(?P<participant_team_pk>[0-9]+)/participant/(?P<participant_pk>[0-9]+)$',
12         views.delete_participant_from_team, name='delete_participant_from_team'),
13     url(r'participant_teams/challenges/user',
14         views.get_teams_and_corresponding_challenges_for_a_participant,
15         name='get_teams_and_corresponding_challenges_for_a_participant'),
16     url(r'participant_team$', views.participant_team_list,
17         name='get_participant_team_list'),
18     url(r'participant_team/(?P<pk>[0-9]+)$',
19         views.participant_team_detail, name='get_participant_team_details'),
20 ]
21
```

Path: `apps/participants/views.py`
Content:
```
1 from django.contrib.auth.models import User
2 
3 from rest_framework import permissions, status
4 from rest_framework.decorators import (api_view,
5                                        authentication_classes,
6                                        permission_classes,
7                                        throttle_classes,)
8 from rest_framework.response import Response
9 from rest_framework_expiring_authtoken.authentication import (
10     ExpiringTokenAuthentication,)
11 from rest_framework.throttling import UserRateThrottle
12 
13 from accounts.permissions import HasVerifiedEmail
14 from base.utils import paginated_queryset
15 from challenges.models import Challenge
16 
17 from .models import (Participant, ParticipantTeam)
18 from .serializers import (InviteParticipantToTeamSerializer,
19                           ParticipantTeamSerializer,
20                           ChallengeParticipantTeam,
21                           ChallengeParticipantTeamList,
22                           ChallengeParticipantTeamListSerializer,
23                           ParticipantTeamDetailSerializer,)
24 from .utils import (get_list_of_challenges_for_participant_team,
25                     get_list_of_challenges_participated_by_a_user,)
26 
27 
28 @throttle_classes([UserRateThrottle])
29 @api_view(['GET', 'POST'])
30 @permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))
31 @authentication_classes((ExpiringTokenAuthentication,))
32 def participant_team_list(request):
33 
34     if request.method == 'GET':
35         participant_teams_id = Participant.objects.filter(user_id=request.user).values_list('team_id', flat=True)
36         participant_teams = ParticipantTeam.objects.filter(
37             id__in=participant_teams_id)
38         paginator, result_page = paginated_queryset(participant_teams, request)
39         serializer = ParticipantTeamDetailSerializer(result_page, many=True)
40         response_data = serializer.data
41         return paginator.get_paginated_response(response_data)
42 
43     elif request.method == 'POST':
44         serializer = ParticipantTeamSerializer(data=request.data,
45                                                context={'request': request})
46         if serializer.is_valid():
47             serializer.save()
48             response_data = serializer.data
49             participant_team = serializer.instance
50             participant = Participant(user=request.user,
51                                       status=Participant.SELF,
52                                       team=participant_team)
53             participant.save()
54             return Response(response_data, status=status.HTTP_201_CREATED)
55         return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
56 
57 
58 @throttle_classes([UserRateThrottle])
59 @api_view(['GET', 'PUT', 'PATCH', 'DELETE'])
60 @permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))
61 @authentication_classes((ExpiringTokenAuthentication,))
62 def participant_team_detail(request, pk):
63 
64     try:
65         participant_team = ParticipantTeam.objects.get(pk=pk)
66     except ParticipantTeam.DoesNotExist:
67         response_data = {'error': 'ParticipantTeam does not exist'}
68         return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)
69 
70     if request.method == 'GET':
71         serializer = ParticipantTeamDetailSerializer(participant_team)
72         response_data = serializer.data
73         return Response(response_data, status=status.HTTP_200_OK)
74 
75     elif request.method in ['PUT', 'PATCH']:
76 
77         if request.method == 'PATCH':
78             serializer = ParticipantTeamSerializer(participant_team, data=request.data,
79                                                    context={
80                                                        'request': request},
81                                                    partial=True)
82         else:
83             serializer = ParticipantTeamSerializer(participant_team, data=request.data,
84                                                    context={'request': request})
85         if serializer.is_valid():
86             serializer.save()
87             response_data = serializer.data
88             return Response(response_data, status=status.HTTP_200_OK)
89         else:
90             return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
91 
92     elif request.method == 'DELETE':
93         participant_team.delete()
94         return Response(status=status.HTTP_204_NO_CONTENT)
95 
96 
97 @throttle_classes([UserRateThrottle])
98 @api_view(['POST'])
99 @permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))
100 @authentication_classes((ExpiringTokenAuthentication,))
101 def invite_participant_to_team(request, pk):
102 
103     try:
104         participant_team = ParticipantTeam.objects.get(pk=pk)
105     except ParticipantTeam.DoesNotExist:
106         response_data = {'error': 'ParticipantTeam does not exist'}
107         return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)
108 
109     email = request.data.get('email')
110     try:
111         user = User.objects.get(email=email)
112     except User.DoesNotExist:
113         response_data = {'error': 'User does not exist with this email address!'}
114         return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)
115 
116     invited_user_participated_challenges = get_list_of_challenges_participated_by_a_user(
117         user).values_list("id", flat=True)
118     team_participated_challenges = get_list_of_challenges_for_participant_team(
119         [participant_team]).values_list("id", flat=True)
120 
121     if set(invited_user_participated_challenges) & set(team_participated_challenges):
122         """
123         Condition to check if the user has already participated in challenges where
124         the inviting participant has participated. If this is the case,
125         then the user cannot be invited since he cannot participate in a challenge
126         via two teams.
127         """
128         response_data = {'error': 'Sorry, cannot invite user to the team!'}
129         return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)
130 
131     serializer = InviteParticipantToTeamSerializer(data=request.data,
132                                                    context={'participant_team': participant_team,
133                                                             'request': request})
134     if serializer.is_valid():
135         serializer.save()
136         response_data = {
137             'message': 'User has been successfully added to the team!'}
138         return Response(response_data, status=status.HTTP_202_ACCEPTED)
139     return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
140 
141 
142 @throttle_classes([UserRateThrottle])
143 @api_view(['DELETE'])
144 @permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))
145 @authentication_classes((ExpiringTokenAuthentication,))
146 def delete_participant_from_team(request, participant_team_pk, participant_pk):
147     """
148     Deletes a participant from a Participant Team
149     """
150     try:
151         participant_team = ParticipantTeam.objects.get(pk=participant_team_pk)
152     except ParticipantTeam.DoesNotExist:
153         response_data = {'error': 'ParticipantTeam does not exist'}
154         return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)
155 
156     try:
157         participant = Participant.objects.get(pk=participant_pk)
158     except Participant.DoesNotExist:
159         response_data = {'error': 'Participant does not exist'}
160         return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)
161 
162     if participant_team.created_by == request.user:
163 
164         if participant.user == request.user:  # when the user tries to remove himself
165             response_data = {
166                 'error': 'You are not allowed to remove yourself since you are admin. Please delete the team if you want to do so!'}  # noqa: ignore=E501
167             return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)
168         else:
169             participant.delete()
170             return Response(status=status.HTTP_204_NO_CONTENT)
171     else:
172         response_data = {
173             'error': 'Sorry, you do not have permissions to remove this participant'}
174         return Response(response_data, status=status.HTTP_401_UNAUTHORIZED)
175 
176 
177 @throttle_classes([UserRateThrottle])
178 @api_view(['GET', ])
179 @permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))
180 @authentication_classes((ExpiringTokenAuthentication,))
181 def get_teams_and_corresponding_challenges_for_a_participant(request):
182     """
183     Returns list of teams and corresponding challenges for a participant
184     """
185     # first get list of all the participants and teams related to the user
186     participant_objs = Participant.objects.filter(user=request.user).prefetch_related('team')
187 
188     challenge_participated_teams = []
189     for participant_obj in participant_objs:
190         participant_team = participant_obj.team
191 
192         challenges = Challenge.objects.filter(
193             participant_teams=participant_team)
194 
195         if challenges.count():
196             for challenge in challenges:
197                 challenge_participated_teams.append(ChallengeParticipantTeam(
198                     challenge, participant_team))
199         else:
200             challenge = None
201             challenge_participated_teams.append(ChallengeParticipantTeam(
202                 challenge, participant_team))
203     serializer = ChallengeParticipantTeamListSerializer(ChallengeParticipantTeamList(challenge_participated_teams))
204     return Response(serializer.data, status=status.HTTP_200_OK)
205 
206 
207 @throttle_classes([UserRateThrottle])
208 @api_view(['DELETE', ])
209 @permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))
210 @authentication_classes((ExpiringTokenAuthentication,))
211 def remove_self_from_participant_team(request, participant_team_pk):
212     """
213     A user can remove himself from the participant team.
214     """
215     try:
216         participant_team = ParticipantTeam.objects.get(pk=participant_team_pk)
217     except ParticipantTeam.DoesNotExist:
218         response_data = {'error': 'ParticipantTeam does not exist!'}
219         return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)
220 
221     try:
222         participant = Participant.objects.get(user=request.user, team__pk=participant_team_pk)
223     except:
224         response_data = {'error': 'Sorry, you do not belong to this team!'}
225         return Response(response_data, status=status.HTTP_401_UNAUTHORIZED)
226 
227     if get_list_of_challenges_for_participant_team([participant_team]).exists():
228         response_data = {'error': 'Sorry, you cannot delete this team since it has taken part in challenge(s)!'}
229         return Response(response_data, status=status.HTTP_403_FORBIDDEN)
230     else:
231         participant.delete()
232         return Response(status=status.HTTP_204_NO_CONTENT)
233
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/apps/participants/urls.py b/apps/participants/urls.py
--- a/apps/participants/urls.py
+++ b/apps/participants/urls.py
@@ -10,7 +10,7 @@
         name='remove_self_from_participant_team'),
     url(r'participant_team/(?P<participant_team_pk>[0-9]+)/participant/(?P<participant_pk>[0-9]+)$',
         views.delete_participant_from_team, name='delete_participant_from_team'),
-    url(r'participant_teams/challenges/user',
+    url(r'participant_teams/challenges/(?P<challenge_pk>[0-9]+)/user$',
         views.get_teams_and_corresponding_challenges_for_a_participant,
         name='get_teams_and_corresponding_challenges_for_a_participant'),
     url(r'participant_team$', views.participant_team_list,
diff --git a/apps/participants/views.py b/apps/participants/views.py
--- a/apps/participants/views.py
+++ b/apps/participants/views.py
@@ -13,6 +13,7 @@
 from accounts.permissions import HasVerifiedEmail
 from base.utils import paginated_queryset
 from challenges.models import Challenge
+from hosts.utils import is_user_a_host_of_challenge
 
 from .models import (Participant, ParticipantTeam)
 from .serializers import (InviteParticipantToTeamSerializer,
@@ -178,13 +179,15 @@
 @api_view(['GET', ])
 @permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))
 @authentication_classes((ExpiringTokenAuthentication,))
-def get_teams_and_corresponding_challenges_for_a_participant(request):
+def get_teams_and_corresponding_challenges_for_a_participant(request, challenge_pk):
     """
     Returns list of teams and corresponding challenges for a participant
     """
     # first get list of all the participants and teams related to the user
     participant_objs = Participant.objects.filter(user=request.user).prefetch_related('team')
 
+    is_challenge_host = is_user_a_host_of_challenge(user=request.user, challenge_pk=challenge_pk)
+
     challenge_participated_teams = []
     for participant_obj in participant_objs:
         participant_team = participant_obj.team
@@ -201,7 +204,9 @@
             challenge_participated_teams.append(ChallengeParticipantTeam(
                 challenge, participant_team))
     serializer = ChallengeParticipantTeamListSerializer(ChallengeParticipantTeamList(challenge_participated_teams))
-    return Response(serializer.data, status=status.HTTP_200_OK)
+    response_data = serializer.data
+    response_data['is_challenge_host'] = is_challenge_host
+    return Response(response_data, status=status.HTTP_200_OK)
 
 
 @throttle_classes([UserRateThrottle])

{"golden_diff": "diff --git a/apps/participants/urls.py b/apps/participants/urls.py\n--- a/apps/participants/urls.py\n+++ b/apps/participants/urls.py\n@@ -10,7 +10,7 @@\n         name='remove_self_from_participant_team'),\n     url(r'participant_team/(?P<participant_team_pk>[0-9]+)/participant/(?P<participant_pk>[0-9]+)$',\n         views.delete_participant_from_team, name='delete_participant_from_team'),\n-    url(r'participant_teams/challenges/user',\n+    url(r'participant_teams/challenges/(?P<challenge_pk>[0-9]+)/user$',\n         views.get_teams_and_corresponding_challenges_for_a_participant,\n         name='get_teams_and_corresponding_challenges_for_a_participant'),\n     url(r'participant_team$', views.participant_team_list,\ndiff --git a/apps/participants/views.py b/apps/participants/views.py\n--- a/apps/participants/views.py\n+++ b/apps/participants/views.py\n@@ -13,6 +13,7 @@\n from accounts.permissions import HasVerifiedEmail\n from base.utils import paginated_queryset\n from challenges.models import Challenge\n+from hosts.utils import is_user_a_host_of_challenge\n \n from .models import (Participant, ParticipantTeam)\n from .serializers import (InviteParticipantToTeamSerializer,\n@@ -178,13 +179,15 @@\n @api_view(['GET', ])\n @permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))\n @authentication_classes((ExpiringTokenAuthentication,))\n-def get_teams_and_corresponding_challenges_for_a_participant(request):\n+def get_teams_and_corresponding_challenges_for_a_participant(request, challenge_pk):\n     \"\"\"\n     Returns list of teams and corresponding challenges for a participant\n     \"\"\"\n     # first get list of all the participants and teams related to the user\n     participant_objs = Participant.objects.filter(user=request.user).prefetch_related('team')\n \n+    is_challenge_host = is_user_a_host_of_challenge(user=request.user, challenge_pk=challenge_pk)\n+\n     challenge_participated_teams = []\n     for participant_obj in participant_objs:\n         participant_team = participant_obj.team\n@@ -201,7 +204,9 @@\n             challenge_participated_teams.append(ChallengeParticipantTeam(\n                 challenge, participant_team))\n     serializer = ChallengeParticipantTeamListSerializer(ChallengeParticipantTeamList(challenge_participated_teams))\n-    return Response(serializer.data, status=status.HTTP_200_OK)\n+    response_data = serializer.data\n+    response_data['is_challenge_host'] = is_challenge_host\n+    return Response(response_data, status=status.HTTP_200_OK)\n \n \n @throttle_classes([UserRateThrottle])\n", "issue": "Improve the check for if the user is a host of a challenge\nCurrently, at https://github.com/Cloud-CV/EvalAI/blob/master/apps/hosts/utils.py#L12 we only check if the user has created the challegne and based on that we allow the challenge host to see all the submissions (for example, see this https://github.com/Cloud-CV/EvalAI/blob/master/apps/challenges/views.py#L703). We would want to change it so that anyone who is a part of the challenge host team is allowed to access information such as 'View all submissions' etc. \n", "before_files": [{"content": "from django.conf.urls import url\n\nfrom . import views\n\nurlpatterns = [\n    url(r'participant_team/(?P<pk>[0-9]+)/invite$', views.invite_participant_to_team,\n        name='invite_participant_to_team'),\n    url(r'remove_self_from_participant_team/(?P<participant_team_pk>[0-9]+)$',\n        views.remove_self_from_participant_team,\n        name='remove_self_from_participant_team'),\n    url(r'participant_team/(?P<participant_team_pk>[0-9]+)/participant/(?P<participant_pk>[0-9]+)$',\n        views.delete_participant_from_team, name='delete_participant_from_team'),\n    url(r'participant_teams/challenges/user',\n        views.get_teams_and_corresponding_challenges_for_a_participant,\n        name='get_teams_and_corresponding_challenges_for_a_participant'),\n    url(r'participant_team$', views.participant_team_list,\n        name='get_participant_team_list'),\n    url(r'participant_team/(?P<pk>[0-9]+)$',\n        views.participant_team_detail, name='get_participant_team_details'),\n]\n", "path": "apps/participants/urls.py"}, {"content": "from django.contrib.auth.models import User\n\nfrom rest_framework import permissions, status\nfrom rest_framework.decorators import (api_view,\n                                       authentication_classes,\n                                       permission_classes,\n                                       throttle_classes,)\nfrom rest_framework.response import Response\nfrom rest_framework_expiring_authtoken.authentication import (\n    ExpiringTokenAuthentication,)\nfrom rest_framework.throttling import UserRateThrottle\n\nfrom accounts.permissions import HasVerifiedEmail\nfrom base.utils import paginated_queryset\nfrom challenges.models import Challenge\n\nfrom .models import (Participant, ParticipantTeam)\nfrom .serializers import (InviteParticipantToTeamSerializer,\n                          ParticipantTeamSerializer,\n                          ChallengeParticipantTeam,\n                          ChallengeParticipantTeamList,\n                          ChallengeParticipantTeamListSerializer,\n                          ParticipantTeamDetailSerializer,)\nfrom .utils import (get_list_of_challenges_for_participant_team,\n                    get_list_of_challenges_participated_by_a_user,)\n\n\n@throttle_classes([UserRateThrottle])\n@api_view(['GET', 'POST'])\n@permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))\n@authentication_classes((ExpiringTokenAuthentication,))\ndef participant_team_list(request):\n\n    if request.method == 'GET':\n        participant_teams_id = Participant.objects.filter(user_id=request.user).values_list('team_id', flat=True)\n        participant_teams = ParticipantTeam.objects.filter(\n            id__in=participant_teams_id)\n        paginator, result_page = paginated_queryset(participant_teams, request)\n        serializer = ParticipantTeamDetailSerializer(result_page, many=True)\n        response_data = serializer.data\n        return paginator.get_paginated_response(response_data)\n\n    elif request.method == 'POST':\n        serializer = ParticipantTeamSerializer(data=request.data,\n                                               context={'request': request})\n        if serializer.is_valid():\n            serializer.save()\n            response_data = serializer.data\n            participant_team = serializer.instance\n            participant = Participant(user=request.user,\n                                      status=Participant.SELF,\n                                      team=participant_team)\n            participant.save()\n            return Response(response_data, status=status.HTTP_201_CREATED)\n        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)\n\n\n@throttle_classes([UserRateThrottle])\n@api_view(['GET', 'PUT', 'PATCH', 'DELETE'])\n@permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))\n@authentication_classes((ExpiringTokenAuthentication,))\ndef participant_team_detail(request, pk):\n\n    try:\n        participant_team = ParticipantTeam.objects.get(pk=pk)\n    except ParticipantTeam.DoesNotExist:\n        response_data = {'error': 'ParticipantTeam does not exist'}\n        return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)\n\n    if request.method == 'GET':\n        serializer = ParticipantTeamDetailSerializer(participant_team)\n        response_data = serializer.data\n        return Response(response_data, status=status.HTTP_200_OK)\n\n    elif request.method in ['PUT', 'PATCH']:\n\n        if request.method == 'PATCH':\n            serializer = ParticipantTeamSerializer(participant_team, data=request.data,\n                                                   context={\n                                                       'request': request},\n                                                   partial=True)\n        else:\n            serializer = ParticipantTeamSerializer(participant_team, data=request.data,\n                                                   context={'request': request})\n        if serializer.is_valid():\n            serializer.save()\n            response_data = serializer.data\n            return Response(response_data, status=status.HTTP_200_OK)\n        else:\n            return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)\n\n    elif request.method == 'DELETE':\n        participant_team.delete()\n        return Response(status=status.HTTP_204_NO_CONTENT)\n\n\n@throttle_classes([UserRateThrottle])\n@api_view(['POST'])\n@permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))\n@authentication_classes((ExpiringTokenAuthentication,))\ndef invite_participant_to_team(request, pk):\n\n    try:\n        participant_team = ParticipantTeam.objects.get(pk=pk)\n    except ParticipantTeam.DoesNotExist:\n        response_data = {'error': 'ParticipantTeam does not exist'}\n        return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)\n\n    email = request.data.get('email')\n    try:\n        user = User.objects.get(email=email)\n    except User.DoesNotExist:\n        response_data = {'error': 'User does not exist with this email address!'}\n        return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)\n\n    invited_user_participated_challenges = get_list_of_challenges_participated_by_a_user(\n        user).values_list(\"id\", flat=True)\n    team_participated_challenges = get_list_of_challenges_for_participant_team(\n        [participant_team]).values_list(\"id\", flat=True)\n\n    if set(invited_user_participated_challenges) & set(team_participated_challenges):\n        \"\"\"\n        Condition to check if the user has already participated in challenges where\n        the inviting participant has participated. If this is the case,\n        then the user cannot be invited since he cannot participate in a challenge\n        via two teams.\n        \"\"\"\n        response_data = {'error': 'Sorry, cannot invite user to the team!'}\n        return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)\n\n    serializer = InviteParticipantToTeamSerializer(data=request.data,\n                                                   context={'participant_team': participant_team,\n                                                            'request': request})\n    if serializer.is_valid():\n        serializer.save()\n        response_data = {\n            'message': 'User has been successfully added to the team!'}\n        return Response(response_data, status=status.HTTP_202_ACCEPTED)\n    return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)\n\n\n@throttle_classes([UserRateThrottle])\n@api_view(['DELETE'])\n@permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))\n@authentication_classes((ExpiringTokenAuthentication,))\ndef delete_participant_from_team(request, participant_team_pk, participant_pk):\n    \"\"\"\n    Deletes a participant from a Participant Team\n    \"\"\"\n    try:\n        participant_team = ParticipantTeam.objects.get(pk=participant_team_pk)\n    except ParticipantTeam.DoesNotExist:\n        response_data = {'error': 'ParticipantTeam does not exist'}\n        return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)\n\n    try:\n        participant = Participant.objects.get(pk=participant_pk)\n    except Participant.DoesNotExist:\n        response_data = {'error': 'Participant does not exist'}\n        return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)\n\n    if participant_team.created_by == request.user:\n\n        if participant.user == request.user:  # when the user tries to remove himself\n            response_data = {\n                'error': 'You are not allowed to remove yourself since you are admin. Please delete the team if you want to do so!'}  # noqa: ignore=E501\n            return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)\n        else:\n            participant.delete()\n            return Response(status=status.HTTP_204_NO_CONTENT)\n    else:\n        response_data = {\n            'error': 'Sorry, you do not have permissions to remove this participant'}\n        return Response(response_data, status=status.HTTP_401_UNAUTHORIZED)\n\n\n@throttle_classes([UserRateThrottle])\n@api_view(['GET', ])\n@permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))\n@authentication_classes((ExpiringTokenAuthentication,))\ndef get_teams_and_corresponding_challenges_for_a_participant(request):\n    \"\"\"\n    Returns list of teams and corresponding challenges for a participant\n    \"\"\"\n    # first get list of all the participants and teams related to the user\n    participant_objs = Participant.objects.filter(user=request.user).prefetch_related('team')\n\n    challenge_participated_teams = []\n    for participant_obj in participant_objs:\n        participant_team = participant_obj.team\n\n        challenges = Challenge.objects.filter(\n            participant_teams=participant_team)\n\n        if challenges.count():\n            for challenge in challenges:\n                challenge_participated_teams.append(ChallengeParticipantTeam(\n                    challenge, participant_team))\n        else:\n            challenge = None\n            challenge_participated_teams.append(ChallengeParticipantTeam(\n                challenge, participant_team))\n    serializer = ChallengeParticipantTeamListSerializer(ChallengeParticipantTeamList(challenge_participated_teams))\n    return Response(serializer.data, status=status.HTTP_200_OK)\n\n\n@throttle_classes([UserRateThrottle])\n@api_view(['DELETE', ])\n@permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))\n@authentication_classes((ExpiringTokenAuthentication,))\ndef remove_self_from_participant_team(request, participant_team_pk):\n    \"\"\"\n    A user can remove himself from the participant team.\n    \"\"\"\n    try:\n        participant_team = ParticipantTeam.objects.get(pk=participant_team_pk)\n    except ParticipantTeam.DoesNotExist:\n        response_data = {'error': 'ParticipantTeam does not exist!'}\n        return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)\n\n    try:\n        participant = Participant.objects.get(user=request.user, team__pk=participant_team_pk)\n    except:\n        response_data = {'error': 'Sorry, you do not belong to this team!'}\n        return Response(response_data, status=status.HTTP_401_UNAUTHORIZED)\n\n    if get_list_of_challenges_for_participant_team([participant_team]).exists():\n        response_data = {'error': 'Sorry, you cannot delete this team since it has taken part in challenge(s)!'}\n        return Response(response_data, status=status.HTTP_403_FORBIDDEN)\n    else:\n        participant.delete()\n        return Response(status=status.HTTP_204_NO_CONTENT)\n", "path": "apps/participants/views.py"}], "after_files": [{"content": "from django.conf.urls import url\n\nfrom . import views\n\nurlpatterns = [\n    url(r'participant_team/(?P<pk>[0-9]+)/invite$', views.invite_participant_to_team,\n        name='invite_participant_to_team'),\n    url(r'remove_self_from_participant_team/(?P<participant_team_pk>[0-9]+)$',\n        views.remove_self_from_participant_team,\n        name='remove_self_from_participant_team'),\n    url(r'participant_team/(?P<participant_team_pk>[0-9]+)/participant/(?P<participant_pk>[0-9]+)$',\n        views.delete_participant_from_team, name='delete_participant_from_team'),\n    url(r'participant_teams/challenges/(?P<challenge_pk>[0-9]+)/user$',\n        views.get_teams_and_corresponding_challenges_for_a_participant,\n        name='get_teams_and_corresponding_challenges_for_a_participant'),\n    url(r'participant_team$', views.participant_team_list,\n        name='get_participant_team_list'),\n    url(r'participant_team/(?P<pk>[0-9]+)$',\n        views.participant_team_detail, name='get_participant_team_details'),\n]\n", "path": "apps/participants/urls.py"}, {"content": "from django.contrib.auth.models import User\n\nfrom rest_framework import permissions, status\nfrom rest_framework.decorators import (api_view,\n                                       authentication_classes,\n                                       permission_classes,\n                                       throttle_classes,)\nfrom rest_framework.response import Response\nfrom rest_framework_expiring_authtoken.authentication import (\n    ExpiringTokenAuthentication,)\nfrom rest_framework.throttling import UserRateThrottle\n\nfrom accounts.permissions import HasVerifiedEmail\nfrom base.utils import paginated_queryset\nfrom challenges.models import Challenge\nfrom hosts.utils import is_user_a_host_of_challenge\n\nfrom .models import (Participant, ParticipantTeam)\nfrom .serializers import (InviteParticipantToTeamSerializer,\n                          ParticipantTeamSerializer,\n                          ChallengeParticipantTeam,\n                          ChallengeParticipantTeamList,\n                          ChallengeParticipantTeamListSerializer,\n                          ParticipantTeamDetailSerializer,)\nfrom .utils import (get_list_of_challenges_for_participant_team,\n                    get_list_of_challenges_participated_by_a_user,)\n\n\n@throttle_classes([UserRateThrottle])\n@api_view(['GET', 'POST'])\n@permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))\n@authentication_classes((ExpiringTokenAuthentication,))\ndef participant_team_list(request):\n\n    if request.method == 'GET':\n        participant_teams_id = Participant.objects.filter(user_id=request.user).values_list('team_id', flat=True)\n        participant_teams = ParticipantTeam.objects.filter(\n            id__in=participant_teams_id)\n        paginator, result_page = paginated_queryset(participant_teams, request)\n        serializer = ParticipantTeamDetailSerializer(result_page, many=True)\n        response_data = serializer.data\n        return paginator.get_paginated_response(response_data)\n\n    elif request.method == 'POST':\n        serializer = ParticipantTeamSerializer(data=request.data,\n                                               context={'request': request})\n        if serializer.is_valid():\n            serializer.save()\n            response_data = serializer.data\n            participant_team = serializer.instance\n            participant = Participant(user=request.user,\n                                      status=Participant.SELF,\n                                      team=participant_team)\n            participant.save()\n            return Response(response_data, status=status.HTTP_201_CREATED)\n        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)\n\n\n@throttle_classes([UserRateThrottle])\n@api_view(['GET', 'PUT', 'PATCH', 'DELETE'])\n@permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))\n@authentication_classes((ExpiringTokenAuthentication,))\ndef participant_team_detail(request, pk):\n\n    try:\n        participant_team = ParticipantTeam.objects.get(pk=pk)\n    except ParticipantTeam.DoesNotExist:\n        response_data = {'error': 'ParticipantTeam does not exist'}\n        return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)\n\n    if request.method == 'GET':\n        serializer = ParticipantTeamDetailSerializer(participant_team)\n        response_data = serializer.data\n        return Response(response_data, status=status.HTTP_200_OK)\n\n    elif request.method in ['PUT', 'PATCH']:\n\n        if request.method == 'PATCH':\n            serializer = ParticipantTeamSerializer(participant_team, data=request.data,\n                                                   context={\n                                                       'request': request},\n                                                   partial=True)\n        else:\n            serializer = ParticipantTeamSerializer(participant_team, data=request.data,\n                                                   context={'request': request})\n        if serializer.is_valid():\n            serializer.save()\n            response_data = serializer.data\n            return Response(response_data, status=status.HTTP_200_OK)\n        else:\n            return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)\n\n    elif request.method == 'DELETE':\n        participant_team.delete()\n        return Response(status=status.HTTP_204_NO_CONTENT)\n\n\n@throttle_classes([UserRateThrottle])\n@api_view(['POST'])\n@permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))\n@authentication_classes((ExpiringTokenAuthentication,))\ndef invite_participant_to_team(request, pk):\n\n    try:\n        participant_team = ParticipantTeam.objects.get(pk=pk)\n    except ParticipantTeam.DoesNotExist:\n        response_data = {'error': 'ParticipantTeam does not exist'}\n        return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)\n\n    email = request.data.get('email')\n    try:\n        user = User.objects.get(email=email)\n    except User.DoesNotExist:\n        response_data = {'error': 'User does not exist with this email address!'}\n        return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)\n\n    invited_user_participated_challenges = get_list_of_challenges_participated_by_a_user(\n        user).values_list(\"id\", flat=True)\n    team_participated_challenges = get_list_of_challenges_for_participant_team(\n        [participant_team]).values_list(\"id\", flat=True)\n\n    if set(invited_user_participated_challenges) & set(team_participated_challenges):\n        \"\"\"\n        Condition to check if the user has already participated in challenges where\n        the inviting participant has participated. If this is the case,\n        then the user cannot be invited since he cannot participate in a challenge\n        via two teams.\n        \"\"\"\n        response_data = {'error': 'Sorry, cannot invite user to the team!'}\n        return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)\n\n    serializer = InviteParticipantToTeamSerializer(data=request.data,\n                                                   context={'participant_team': participant_team,\n                                                            'request': request})\n    if serializer.is_valid():\n        serializer.save()\n        response_data = {\n            'message': 'User has been successfully added to the team!'}\n        return Response(response_data, status=status.HTTP_202_ACCEPTED)\n    return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)\n\n\n@throttle_classes([UserRateThrottle])\n@api_view(['DELETE'])\n@permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))\n@authentication_classes((ExpiringTokenAuthentication,))\ndef delete_participant_from_team(request, participant_team_pk, participant_pk):\n    \"\"\"\n    Deletes a participant from a Participant Team\n    \"\"\"\n    try:\n        participant_team = ParticipantTeam.objects.get(pk=participant_team_pk)\n    except ParticipantTeam.DoesNotExist:\n        response_data = {'error': 'ParticipantTeam does not exist'}\n        return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)\n\n    try:\n        participant = Participant.objects.get(pk=participant_pk)\n    except Participant.DoesNotExist:\n        response_data = {'error': 'Participant does not exist'}\n        return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)\n\n    if participant_team.created_by == request.user:\n\n        if participant.user == request.user:  # when the user tries to remove himself\n            response_data = {\n                'error': 'You are not allowed to remove yourself since you are admin. Please delete the team if you want to do so!'}  # noqa: ignore=E501\n            return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)\n        else:\n            participant.delete()\n            return Response(status=status.HTTP_204_NO_CONTENT)\n    else:\n        response_data = {\n            'error': 'Sorry, you do not have permissions to remove this participant'}\n        return Response(response_data, status=status.HTTP_401_UNAUTHORIZED)\n\n\n@throttle_classes([UserRateThrottle])\n@api_view(['GET', ])\n@permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))\n@authentication_classes((ExpiringTokenAuthentication,))\ndef get_teams_and_corresponding_challenges_for_a_participant(request, challenge_pk):\n    \"\"\"\n    Returns list of teams and corresponding challenges for a participant\n    \"\"\"\n    # first get list of all the participants and teams related to the user\n    participant_objs = Participant.objects.filter(user=request.user).prefetch_related('team')\n\n    is_challenge_host = is_user_a_host_of_challenge(user=request.user, challenge_pk=challenge_pk)\n\n    challenge_participated_teams = []\n    for participant_obj in participant_objs:\n        participant_team = participant_obj.team\n\n        challenges = Challenge.objects.filter(\n            participant_teams=participant_team)\n\n        if challenges.count():\n            for challenge in challenges:\n                challenge_participated_teams.append(ChallengeParticipantTeam(\n                    challenge, participant_team))\n        else:\n            challenge = None\n            challenge_participated_teams.append(ChallengeParticipantTeam(\n                challenge, participant_team))\n    serializer = ChallengeParticipantTeamListSerializer(ChallengeParticipantTeamList(challenge_participated_teams))\n    response_data = serializer.data\n    response_data['is_challenge_host'] = is_challenge_host\n    return Response(response_data, status=status.HTTP_200_OK)\n\n\n@throttle_classes([UserRateThrottle])\n@api_view(['DELETE', ])\n@permission_classes((permissions.IsAuthenticated, HasVerifiedEmail))\n@authentication_classes((ExpiringTokenAuthentication,))\ndef remove_self_from_participant_team(request, participant_team_pk):\n    \"\"\"\n    A user can remove himself from the participant team.\n    \"\"\"\n    try:\n        participant_team = ParticipantTeam.objects.get(pk=participant_team_pk)\n    except ParticipantTeam.DoesNotExist:\n        response_data = {'error': 'ParticipantTeam does not exist!'}\n        return Response(response_data, status=status.HTTP_406_NOT_ACCEPTABLE)\n\n    try:\n        participant = Participant.objects.get(user=request.user, team__pk=participant_team_pk)\n    except:\n        response_data = {'error': 'Sorry, you do not belong to this team!'}\n        return Response(response_data, status=status.HTTP_401_UNAUTHORIZED)\n\n    if get_list_of_challenges_for_participant_team([participant_team]).exists():\n        response_data = {'error': 'Sorry, you cannot delete this team since it has taken part in challenge(s)!'}\n        return Response(response_data, status=status.HTTP_403_FORBIDDEN)\n    else:\n        participant.delete()\n        return Response(status=status.HTTP_204_NO_CONTENT)\n", "path": "apps/participants/views.py"}]}