transport-accessibility/transport_accessibility/pt_map/views.py
2024-06-17 14:26:23 +02:00

181 lines
7.6 KiB
Python

"""
Views
=====
Views reacting to Http Requests by interfacing between backend and frontend.
Functions
---------
index(request)
Home page
"""
from django.shortcuts import render
from django.http import HttpResponse, HttpResponseBadRequest, HttpResponseNotAllowed, HttpRequest
from django.core.exceptions import BadRequest, ObjectDoesNotExist
from .models import *
from .forms import *
import json
from datetime import datetime
from django.views.decorators.csrf import csrf_exempt
from .class_names import *
def get_timetable(r, trips_r, stop_sequence):
"""
Given a pt_map.models.Route, calculate the timetable for all its stops.
Parameters
----------
r : pt_map.models.Route
Route, the timetable should be calculated for
trips : dict(str, list(pt_map.Trip))
Dictionary mapping all trips to route_ids they travel on
stop_sequences : dict(str, list(str))
Dict mapping route_ids to lists of stop_ids they serve. Currently the first trip is taken as reference for stops and sequence.
Returns
-------
dict{"stop_sequence": list(str), "stop_times": dict(str, list(str)}
Dict containing two elements:
"stop_sequence" : list(str)
list of stop_ids the route serves
"stop_times" : dict(str, list(str))
dict mapping stop_ids from stop_sequence to time strings the route is serving the stop at
"""
timetable = {"stop_sequence": stop_sequence}
sts = {}
for stop in stop_sequence:
times = []
for t in trips_r:
for st in StopTime.objects.filter(trip_id=t.trip_id):
times.append(st.departure_time.strftime("%H:%M"))
sts[stop] = times
timetable["stop_times"] = sts
return timetable
def index(request):
stops = {s.stop_id: {name: getattr(s, name) for name in ['stop_name', 'stop_lat', 'stop_lon']} for s in Stop.objects.all()}
route_name = lambda r : r.route_short_name if r.route_short_name else r.route_long_name
routes = [{"route_id": r.route_id, "route_type": r.route_type, "route_name": route_name(r), "agency_id": r.agency_id.agency_id} for r in Route.objects.all()]
trips = {r["route_id"]: [t for t in Trip.objects.filter(route_id_id=r["route_id"])] for r in routes}
stop_sequences = {}
for r in routes:
seq = []
t = trips[r["route_id"]]
for s in StopTime.objects.filter(trip_id_id__exact=t[0].trip_id):
seq.append(s)
stop_sequences[r["route_id"]] = [s.stop_id.stop_id for s in sorted(seq, key=lambda st : st.stop_sequence)]
timetable = {}
if request.GET.get("timetable"):
try:
r = Route.objects.get(route_id=request.GET.get("timetable"))
timetable = get_timetable(r, trips[r.route_id], stop_sequences[r.route_id])
except Route.DoesNotExist:
print(f"Invalid request for Route with id {request.GET['timetable']}")
context = {"stops": json.dumps(stops), "routes": json.dumps(routes), "timetable": json.dumps(timetable)}
return render(request,"map.html", context)
def get_field_names(model: models.Model):
return [field.name for field in model._meta.fields]
def timetable(request):
if request.method == "GET":
try:
r = Route.objects.get(route_id=request.GET["route_id"])
trips_r = [t for t in Trip.objects.filter(route_id_id=r.route_id)]
stop_sequence = [s.stop_id.stop_id for s in sorted([s for s in StopTime.objects.filter(trip_id_id__exact=trips_r[0].trip_id)], key=lambda st : st.stop_sequence)]
timetable = get_timetable(r, trips_r, stop_sequence)
return HttpResponse(json.dumps(timetable), content_type="text/json")
except KeyError:
return HttpResponseBadRequest("route_id missing or malformed.")
except Route.DoesNotExist:
return HttpResponseBadRequest("Route not found.")
return HttpResponseNotAllowed(["GET"])
def get_pks_from_get(req_get):
result = {}
for k in req_get.keys():
if k in classes_by_primary_keys.keys():
result[classes_by_primary_keys[k]] = req_get.getlist(k)
return result
def get_obj_by_pk(mdl: models.Model, pks: list[str]):
return [obj for obj in [mdl.objects.get(**{primary_keys[mdl]: pk}) for pk in pks] if obj]
def obj_from_get(req_get) -> str:
return {mdl: get_obj_by_pk(mdl, keys) for mdl, keys in get_pks_from_get(req_get)}
def mdl_to_jsnzbl_dict(cls, obj: models.Model) -> dict:
result = {}
fields = get_field_names(cls)
for fk in fk_dict[cls]:
fields.remove(fk[1])
if getattr(obj, fk[1]):
result[fk[1]] = getattr(getattr(obj, fk[1]), primary_keys[fk[0]])
for field in fields:
if getattr(obj, field):
result[field] = getattr(obj, field)
return result
def json_from_pk(req_get) -> str:
for cpk in classes_by_primary_keys:
if req_get.get(cpk):
for key in (req_get[cpk] if isinstance(req_get[cpk], list) else [req_get[cpk]]):
obj = classes_by_primary_keys[cpk].objects.get(**{cpk: key})
for field in get_field_names(obj):
v = getattr(obj, field)
if v:
if field in [f[1] for f in foreign_keys[classes_by_primary_keys[cpk]]]:
fk = get_attr(v, field)
return json.dumps(obj)
def jsnzbl_from_get(req_get) -> str:
return {mdl._meta.object_name: [mdl_to_jsnzbl_dict(mdl, o) for o in get_obj_by_pk(mdl, keys)] for mdl, keys in get_pks_from_get(req_get).items()}
def jsnz(jsnzbl: dict):
return json.dumps(jsnzbl)
def rsp_for_json_from_get(req_get):
try:
return HttpResponse(jsnz(jsnzbl_from_get(req_get)))
except ObjectDoesNotExist:
return HttpResponseBadRequest("Object(s) not found.")
def data(request):
"""
Handle database requests from the frontend. Using Http semantics to specify what to do with the data.
Request
-------
PUT
Create a new object if no object with the given primary key exists in the database or delete and replace an existing object.
Body must be a json dict of lists of fully specified, valid models.
If primary keys are given as GET keys, they are applied to the first elements in their corresponding object lists. Primary keys in body will be ignored.
RETURN 400 if primary keys not existing.
PATCH
Modify an existing objects given the instructions in the body.
Body must be a json dict of lists of fields to change and their valid values existing objects in the database, identified by their valid primary keys as GET keys.
Primary keys in body will be ignored.
GET
Return json of models identified by primary keys.
DELETE
Delete models with given primary keys if they exist. Returns number of deleted models.
"""
if request.method == "PUT":
if not request.META["CONTENT_TYPE"] == 'application/json':
HttpResponseBadRequest('Request must be JSON.')
bdy = json.loads(request.body)
try:
obj = obj_from_get(request.GET)
except ObjectDoesNotExist:
return HttpResponseBadRequest("Did not find models corresponding to given pks.")
return HttpResponse(f"received {obj}")
elif request.method == "PATCH":
if not request.META["CONTENT_TYPE"] == 'application/json':
HttpResponseBadRequest('Request must be JSON.')
return HttpResponse(f"received {obj}")
elif request.method == "GET":
return rsp_for_json_from_get(request.GET)
return HttpResponseNotAllowed(['PUT', 'PATCH', 'GET'])