from __future__ import unicode_literals

from django.shortcuts import get_object_or_404

from rest_framework import generics

from acls.models import AccessControlList
from rest_api.filters import MayanObjectPermissionsFilter
from rest_api.permissions import MayanPermission
from user_management.permissions import permission_group_view
from user_management.serializers import GroupSerializer

from .classes import Permission
from .models import Role
from .permissions import (
    permission_role_create, permission_role_delete, permission_role_edit,
    permission_role_view
)
from .serializers import (
    PermissionSerializer, RoleNewGroupListSerializer,
    RoleNewPermissionSerializer, RoleSerializer,
)


class APIPermissionList(generics.ListAPIView):
    serializer_class = PermissionSerializer
    queryset = Permission.all()

    def get(self, *args, **kwargs):
        """
        Returns a list of all the available permissions.
        """

        return super(APIPermissionList, self).get(*args, **kwargs)


class APIRoleGroupList(generics.ListCreateAPIView):
    """
    Returns a list of all the groups that belong to selected role.
    """

    mayan_object_permissions = {
        'GET': (permission_role_view,),
        'POST': (permission_role_edit,)
    }
    permission_classes = (MayanPermission,)

    def get_serializer_class(self):
        if self.request.method == 'GET':
            return GroupSerializer
        elif self.request.method == 'POST':
            return RoleNewGroupListSerializer

    def get_serializer_context(self):
        """
        Extra context provided to the serializer class.
        """
        return {
            'format': self.format_kwarg,
            'request': self.request,
            'role': self.get_role(),
            'view': self
        }

    def get_queryset(self):
        role = self.get_role()

        return AccessControlList.objects.filter_by_access(
            permission_group_view, self.request.user,
            queryset=role.groups.all()
        )

    def get_role(self):
        return get_object_or_404(Role, pk=self.kwargs['pk'])

    def perform_create(self, serializer):
        serializer.save(role=self.get_role())

    def post(self, request, *args, **kwargs):
        """
        Add a list of groups to the selected role.
        """

        return super(APIRoleGroupList, self).post(request, *args, **kwargs)


class APIRoleListView(generics.ListCreateAPIView):
    serializer_class = RoleSerializer
    queryset = Role.objects.all()

    permission_classes = (MayanPermission,)
    filter_backends = (MayanObjectPermissionsFilter,)
    mayan_object_permissions = {'GET': (permission_role_view,)}
    mayan_view_permissions = {'POST': (permission_role_create,)}

    def get(self, *args, **kwargs):
        """
        Returns a list of all the roles.
        """

        return super(APIRoleListView, self).get(*args, **kwargs)

    def post(self, *args, **kwargs):
        """
        Create a new role.
        """

        return super(APIRoleListView, self).post(*args, **kwargs)


class APIRolePermissionList(generics.ListCreateAPIView):
    """
    Returns a list of all the permissions of a role.
    """

    mayan_object_permissions = {
        'GET': (permission_role_view,),
        'POST': (permission_role_edit,)
    }
    permission_classes = (MayanPermission,)

    def get_serializer_class(self):
        if self.request.method == 'GET':
            return PermissionSerializer
        elif self.request.method == 'POST':
            return RoleNewPermissionSerializer

    def get_serializer_context(self):
        """
        Extra context provided to the serializer class.
        """
        return {
            'format': self.format_kwarg,
            'request': self.request,
            'role': self.get_role(),
            'view': self
        }

    def get_queryset(self):
        return [
            permission.volatile_permission for permission in self.get_role().permissions.all()
        ]

    def get_role(self):
        return get_object_or_404(Role, pk=self.kwargs['pk'])

    def perform_create(self, serializer):
        serializer.save(role=self.get_role())

    def post(self, request, *args, **kwargs):
        """
        Add a list of permissions to a role.
        """
        return super(APIRolePermissionList, self).post(
            request, *args, **kwargs
        )


class APIRoleView(generics.RetrieveUpdateDestroyAPIView):
    serializer_class = RoleSerializer
    queryset = Role.objects.all()

    permission_classes = (MayanPermission,)
    mayan_object_permissions = {
        'GET': (permission_role_view,),
        'PUT': (permission_role_edit,),
        'PATCH': (permission_role_edit,),
        'DELETE': (permission_role_delete,)
    }

    def delete(self, *args, **kwargs):
        """
        Delete the selected role.
        """

        return super(APIRoleView, self).delete(*args, **kwargs)

    def get(self, *args, **kwargs):
        """
        Return the details of the selected role.
        """

        return super(APIRoleView, self).get(*args, **kwargs)

    def patch(self, *args, **kwargs):
        """
        Edit the selected role.
        """

        return super(APIRoleView, self).patch(*args, **kwargs)

    def put(self, *args, **kwargs):
        """
        Edit the selected role.
        """

        return super(APIRoleView, self).put(*args, **kwargs)