AdventureLog/backend/server/adventures/views/adventure_view.py

from django.db import transaction
from django.core.exceptions import PermissionDenied
from django.db.models import Q, Max
from django.db.models.functions import Lower
from rest_framework import viewsets
from rest_framework.decorators import action
from rest_framework.response import Response

from adventures.models import Adventure, Category
from adventures.permissions import IsOwnerOrSharedWithFullAccess
from adventures.serializers import AdventureSerializer
from adventures.utils import pagination

class AdventureViewSet(viewsets.ModelViewSet):
    serializer_class = AdventureSerializer
    permission_classes = [IsOwnerOrSharedWithFullAccess]
    pagination_class = pagination.StandardResultsSetPagination

    def apply_sorting(self, queryset):
        order_by = self.request.query_params.get('order_by', 'updated_at')
        order_direction = self.request.query_params.get('order_direction', 'asc')
        include_collections = self.request.query_params.get('include_collections', 'true')

        valid_order_by = ['name', 'type', 'date', 'rating', 'updated_at']
        if order_by not in valid_order_by:
            order_by = 'name'

        if order_direction not in ['asc', 'desc']:
            order_direction = 'asc'

        if order_by == 'date':
            queryset = queryset.annotate(latest_visit=Max('visits__start_date')).filter(latest_visit__isnull=False)
            ordering = 'latest_visit'
        elif order_by == 'name':
            queryset = queryset.annotate(lower_name=Lower('name'))
            ordering = 'lower_name'
        elif order_by == 'rating':
            queryset = queryset.filter(rating__isnull=False)
            ordering = 'rating'
        else:
            ordering = order_by

        if order_direction == 'desc':
            ordering = f'-{ordering}'

        if order_by == 'updated_at':
            ordering = '-updated_at' if order_direction == 'asc' else 'updated_at'

        if include_collections == 'false':
            queryset = queryset.filter(collection=None)

        return queryset.order_by(ordering)

    def get_queryset(self):
        """
        Returns the queryset for the AdventureViewSet. Unauthenticated users can only
        retrieve public adventures, while authenticated users can access their own,
        shared, and public adventures depending on the action.
        """
        user = self.request.user

        if not user.is_authenticated:
            # Unauthenticated users can only access public adventures for retrieval
            if self.action == 'retrieve':
                return Adventure.objects.retrieve_adventures(user, include_public=True).order_by('-updated_at')
            return Adventure.objects.none()

        # Authenticated users: Handle retrieval separately
        include_public = self.action == 'retrieve'
        return Adventure.objects.retrieve_adventures(
            user,
            include_public=include_public,
            include_owned=True,
            include_shared=True
        ).order_by('-updated_at')

    def perform_update(self, serializer):
        adventure = serializer.save()
        if adventure.collection:
            adventure.is_public = adventure.collection.is_public
            adventure.save()

    @action(detail=False, methods=['get'])
    def filtered(self, request):
        types = request.query_params.get('types', '').split(',')
        is_visited = request.query_params.get('is_visited', 'all')

        if 'all' in types:
            types = Category.objects.filter(user_id=request.user).values_list('name', flat=True)
        else:
            if not types or not all(
                Category.objects.filter(user_id=request.user, name=type).exists() for type in types
            ):
                return Response({"error": "Invalid category or no types provided"}, status=400)

        queryset = Adventure.objects.filter(
            category__in=Category.objects.filter(name__in=types, user_id=request.user),
            user_id=request.user.id
        )

        if is_visited.lower() in ['true', 'false']:
            is_visited_bool = is_visited.lower() == 'true'
            queryset = queryset.filter(is_visited=is_visited_bool)

        queryset = self.apply_sorting(queryset)
        return self.paginate_and_respond(queryset, request)

    @action(detail=False, methods=['get'])
    def all(self, request):
        if not request.user.is_authenticated:
            return Response({"error": "User is not authenticated"}, status=400)

        include_collections = request.query_params.get('include_collections', 'false') == 'true'
        queryset = Adventure.objects.filter(
            Q(is_public=True) | Q(user_id=request.user.id),
            collection=None if not include_collections else Q()
        )

        queryset = self.apply_sorting(queryset)
        serializer = self.get_serializer(queryset, many=True)
        return Response(serializer.data)

    @action(detail=False, methods=['get'])
    def search(self, request):
        query = request.query_params.get('query', '')
        property = request.query_params.get('property', 'all')

        if len(query) < 2:
            return Response({"error": "Query must be at least 2 characters long"}, status=400)

        valid_properties = ['name', 'location', 'description', 'activity_types']
        if property not in valid_properties:
            property = 'all'

        filters = {
            'name': Q(name__icontains=query),
            'location': Q(location__icontains=query),
            'description': Q(description__icontains=query),
            'activity_types': Q(activity_types__icontains=query),
            'all': Q(name__icontains=query) | Q(description__icontains=query) |
                   Q(location__icontains=query) | Q(activity_types__icontains=query)
        }

        queryset = Adventure.objects.filter(
            filters[property] & (Q(user_id=request.user.id) | Q(is_public=True))
        )

        queryset = self.apply_sorting(queryset)
        serializer = self.get_serializer(queryset, many=True)
        return Response(serializer.data)

    def update(self, request, *args, **kwargs):
        instance = self.get_object()
        serializer = self.get_serializer(instance, data=request.data, partial=True)
        serializer.is_valid(raise_exception=True)

        new_collection = serializer.validated_data.get('collection')
        if new_collection and new_collection!=instance.collection:
            if new_collection.user_id != request.user or instance.user_id != request.user:
                raise PermissionDenied("You do not have permission to use this collection.")
        elif new_collection is None and instance.collection and instance.collection.user_id != request.user:
            raise PermissionDenied("You cannot remove the collection as you are not the owner.")

        self.perform_update(serializer)
        return Response(serializer.data)

    @transaction.atomic
    def perform_create(self, serializer):
        collection = serializer.validated_data.get('collection')

        if collection and not (collection.user_id == self.request.user or collection.shared_with.filter(id=self.request.user.id).exists()):
            raise PermissionDenied("You do not have permission to use this collection.")
        elif collection:
            serializer.save(user_id=collection.user_id, is_public=collection.is_public)
            return

        serializer.save(user_id=self.request.user, is_public=collection.is_public if collection else False)

    def paginate_and_respond(self, queryset, request):
        paginator = self.pagination_class()
        page = paginator.paginate_queryset(queryset, request)
        if page is not None:
            serializer = self.get_serializer(page, many=True)
            return paginator.get_paginated_response(serializer.data)

        serializer = self.get_serializer(queryset, many=True)
        return Response(serializer.data)