views.py

"""
Defines the views for the API
"""

# from django.shortcuts import render
from rest_framework import viewsets
from rest_framework.views import APIView
from rest_framework.response import Response
from django.shortcuts import get_object_or_404
from django.http import JsonResponse
from .pagination import PageNumberWithPageSizePagination

from .serializers import (
    SmallSportListSerializer,
    SportListSerializer,
    CriterionListSerializer,
    QuestionListSerializer,
    SingleSportSerializer,
)
from .models import Sport, Criterion, Question

# Create your views here.


class SportListView(viewsets.ModelViewSet):  # pylint: disable=too-many-ancestors
    """
    A View returning every Sport Object
    """

    serializer_class = SportListSerializer
    queryset = Sport.objects.all()


class CriterionListView(viewsets.ModelViewSet):  # pylint: disable=too-many-ancestors
    """
    A View returning every Criterion Object
    """

    serializer_class = CriterionListSerializer
    queryset = Criterion.objects.all()


class QuestionListView(viewsets.ModelViewSet):  # pylint: disable=too-many-ancestors
    """
    A View returning every Question Object
    """

    serializer_class = QuestionListSerializer
    queryset = Question.objects.all()


# Dev Notes:
# - If we want to include a View in the Router in urls.py, the View needs to be a Viewset
# - Those are mostly meant for Lists of Objects, so instead of get() and post(), list() and create() are used respectively
# https://stackoverflow.com/questions/30389248/how-can-i-register-a-single-view-not-a-viewset-on-my-router


class SmallSportListView(viewsets.ViewSet):
    """
    View for the List of Sports on the Sport Homepage
    TODO: More Documentation
    """

    authentication_classes = []

    # GET for api/admin/sport/
    def list(self, request):

        paginator = PageNumberWithPageSizePagination()
        """
        Comments on Pagination:
        Every list that needs to be paginated needs a paginator.
        Here, the Paginator object is created in the GET call.
        The Queryset which is supposed to be paginated needs to be run through the function:
        
        > new_queryset = paginator.paginate_queryset(complete_queryset, request)

        The new_queryset is a List, not a Manager, so it can be directly iterated upon.
        After the data has been worked on and run through the Serializer as normal,
        instead of returning Result(data), the paginator needs to be used again so it can add its page metadata:

        > return paginator.get_paginated_response(serializer.data)

        This function already returns a fully valid Response, so it can be directly returned.
        """

        sports = Sport.objects.all()
        sports = paginator.paginate_queryset(sports, request)
        criteria = Criterion.objects.all()
        is_filled_tuples = []

        for sport in sports:

            filled_criteria_pks = []

            # TODO: Change the way that unfilled Criteria are detected (look for value -1)
            # TODO: is_filled as function of sport
            # Get pks of Criteria which are connected to the sport
            for criterion in sport.criteria_ratings.iterator():
                filled_criteria_pks.append(criterion.pk)

            is_filled = True

            # Check every existing criterion whether it is in the generated list
            for criterion in criteria.all():
                if criterion.pk not in filled_criteria_pks:
                    # A criterion isn't filled out, so stop and set to false
                    is_filled = False
                    break

            is_filled_tuples.append((sport, is_filled))

        serializer = SmallSportListSerializer(is_filled_tuples)

        return paginator.get_paginated_response(serializer.data)

    # POST for api/admin/sport/
    def create(self, request):

        data_dict = SingleSportSerializer().to_internal_value(request)

        print(data_dict)

        new_sport = Sport.objects.create_sport()

        new_sport.name = data_dict["name"]
        new_sport.url = data_dict["url"]

        # Before writing other Database Entries for Rating, the Sport needs to be saved once
        new_sport.save()

        for criterion in data_dict["criteria"]:
            new_sport.rate(
                Criterion.objects.get(pk=criterion["pk"]), criterion["value"]
            )

        new_sport.save()

        response = SingleSportSerializer(new_sport)

        return Response(response.data)

    # GET for api/admin/sport/<id>/
    def retrieve(self, request, pk=None):

        sport = get_object_or_404(Sport, pk=pk)

        return Response(SingleSportSerializer(sport).data)

    # PUT for api/admin/sport/<id>/
    def update(self, request, pk=None):
        """
        TODO
        """

        data_dict = SingleSportSerializer().to_internal_value(request)

        sport = Sport.objects.get(pk=pk)

        print(data_dict)

        return Response({"test": "Updating a Single Entry"})

    # DELETE for api/admin/sport/<id>/
    def destroy(self, request, pk=None):

        return Response({"test": "Removing a Single Entry"})


# Dev Notes:
# - This is a singular APIView which isn't meant to expose complete lists
# - It cannot be written into the Router, as it isn't a Viewset, so it is written directly into the urls.py's urlspatterns like this:
# path(r"api/admin/single-small-sport-list", views.SmallSportListAPIView.as_view())
# - The API isn't in the list in /api/admin because of that, but needs to be called manually here:
# http://localhost:8000/api/admin/single-small-sport-list