Terralego/django-geostore-routing

import types

from django.contrib.gis.geos import Point
from django.utils.translation import gettext_lazy as _
from rest_framework import status
from rest_framework.decorators import action
from rest_framework.response import Response

from ..helpers import Routing, RoutingException
from ..serializers import RoutingSerializer


class RoutingViewsSetMixin:
    @action(detail=True, methods=['post'],
            serializer_class=RoutingSerializer)
    def route(self, request, pk=None):
        layer = self.get_object()
        data = request.data
        serializer = self.serializer_class(data=data)
        response_status = status.HTTP_200_OK

        if serializer.is_valid():
            geometry = serializer.validated_data['geom']

            try:
                points = [Point(c, srid=geometry.srid) for c in geometry.coords]
                routing = Routing(points, layer)
                start_on_way, end_on_way, distance_1, distance_2, way = routing.get_linestring()

                if not way:
                    data = {"message": _("Way not available"),
                            "code": "NoRoute",
                            "routes": []}
                    return Response(data, status=response_status)

                # generate response data by using serializer, to keep serialization rules (precision / perfs.)
                response = types.SimpleNamespace()
                response.geom = None
                response.callback_id = None
                response.route = routing.get_route()
                response.way = way
                serializer = self.serializer_class(response, data=request.data)
                serializer.is_valid()
                data = serializer.data
                data['geom'] = request.data['geom']
                data['waypoints'] = [{"coordinates": start_on_way.coords, "distance": distance_1},
                                     {"coordinates": end_on_way.coords, "distance": distance_2}]
                data['callback_id'] = request.data.get('callback_id', None)

            except RoutingException as exc:
                data = {"errors": [str(exc), ]}
                response_status = status.HTTP_400_BAD_REQUEST

        else:
            data = serializer.errors
            response_status = status.HTTP_400_BAD_REQUEST
        return Response(data,
                        status=response_status)