from rest_framework import permissions
from rest_framework.permissions import (  # noqa: F401
    BasePermission,
    IsAuthenticated as rf_IsAuthenticated,
    IsAdminUser,
)

from backend_app.utils import is_member


class IsAuthenticated(rf_IsAuthenticated):
    def has_object_permission(self, request, view, obj):
        return self.has_permission(request, view)


class IsStaff(IsAdminUser):
    def has_object_permission(self, request, view, obj):
        return self.has_permission(request, view)


class IsDri(BasePermission):
    """
    Permission to make a viewset readonly unless the request user
    is a member of the DRI group.
    """

    def has_object_permission(self, request, view, obj):
        return self.has_permission(request, view)

    def has_permission(self, request, view):
        if request.method in permissions.SAFE_METHODS:
            return True
        else:
            return is_member("DRI", request.user)


class IsOwner(BasePermission):
    """
    Permission that checks that the requester is the owner of the object.

    The object must have an owner field that corresponds to a user, or the object
    must be the user itself.
    """

    def has_object_permission(self, request, view, obj):
        try:
            return request.user == obj.owner
        except AttributeError:
            # For the user model
            return request.user == obj

    def has_permission(self, request, view):
        return True


class IsFollower(BasePermission):
    """
    Permission that checks that the requester is a follower of the object (a list of universities).

    The object must have a "followers" field that corresponds to a list of users.
    """

    def has_object_permission(self, request, view, obj):
        return obj.followers.filter(pk=request.user.pk).exists()


class IsPublic(BasePermission):
    """
    Permission that checks that the object is public.

    The object must have a "is_public" field.
    """

    def has_object_permission(self, request, view, obj):
        return obj.is_public


class NoDelete(BasePermission):
    """
    Permission to prevent the use of the DELETE method.
    """

    def has_object_permission(self, request, view, obj):
        return self.has_permission(request, view)

    def has_permission(self, request, view):
        return request.method != "DELETE"


class NoPost(BasePermission):
    """
    Permission to disallow POST request
    """

    def has_object_permission(self, request, view, obj):
        return self.has_permission(request, view)

    def has_permission(self, request, view):
        return request.method != "POST"


class ReadOnly(BasePermission):
    """
    Permission to make a viewset read-only.
    """

    def has_object_permission(self, request, view, obj):
        """
        We absolutely need this one since it is used with "OR".
        If we don't put it, the IsOwner Or ReadOnly would pass the the has_permission on IsOwner
        and then the has_object_permission on Read_only.
        """
        return request.method in permissions.SAFE_METHODS

    def has_permission(self, request, view):
        return request.method in permissions.SAFE_METHODS