from django.conf import settings
from rest_framework.permissions import BasePermission, SAFE_METHODS

from .models import Member


class RolePermission(BasePermission):
    UNSAFE_METHODS = ('POST', 'PATCH', 'DELETE')
    unsafe_methods_check = True
    role_name = ''

    @classmethod
    def get_project_id(cls, request, view):
        return view.kwargs.get('project_id') or request.query_params.get('project_id')

    def has_permission(self, request, view):
        if request.user.is_superuser:
            return True

        if self.unsafe_methods_check and request.method in self.UNSAFE_METHODS:
            return request.user.is_superuser

        project_id = self.get_project_id(request, view)
        if not project_id and request.method in SAFE_METHODS:
            return True

        return Member.objects.has_role(project_id, request.user, self.role_name)


class IsProjectAdmin(RolePermission):
    unsafe_methods_check = False
    role_name = settings.ROLE_PROJECT_ADMIN


class IsAnnotatorAndReadOnly(RolePermission):
    role_name = settings.ROLE_ANNOTATOR


class IsAnnotator(RolePermission):
    unsafe_methods_check = False
    role_name = settings.ROLE_ANNOTATOR


class IsAnnotationApproverAndReadOnly(RolePermission):
    role_name = settings.ROLE_ANNOTATION_APPROVER


class IsAnnotationApprover(RolePermission):
    unsafe_methods_check = False
    role_name = settings.ROLE_ANNOTATION_APPROVER


IsInProjectReadOnlyOrAdmin = (IsAnnotatorAndReadOnly | IsAnnotationApproverAndReadOnly | IsProjectAdmin)
IsInProjectOrAdmin = (IsAnnotator | IsAnnotationApprover | IsProjectAdmin)