Personal Catalogue: Django & PostgreSQL — Chapter 7, Exercise 1
====================================================

TASK
Build the icontains/Q-object version of search from this chapter, then
confirm /?tag=python&q=fastapi genuinely returns only items matching
both conditions at once.

SOLUTION

1. catalogue/views.py — update ItemListView's get_queryset() and
   get_context_data():

    from django.db.models import Q

    class ItemListView(ListView):
        model = Item
        template_name = 'catalogue/item_list.html'
        context_object_name = 'items'
        paginate_by = 25

        def get_queryset(self):
            queryset = Item.objects.select_related('item_type').prefetch_related('tags')

            tag_name = self.request.GET.get('tag')
            if tag_name:
                queryset = queryset.filter(tags__name=tag_name)

            query = self.request.GET.get('q')
            if query:
                queryset = queryset.filter(Q(title__icontains=query) | Q(creator__icontains=query))

            return queryset

        def get_context_data(self, **kwargs):
            context = super().get_context_data(**kwargs)
            context['active_tag'] = self.request.GET.get('tag', '')
            context['query'] = self.request.GET.get('q', '')
            return context

2. catalogue/templates/catalogue/item_list.html — add the search form
   above the item list, with value="{{ query }}" so the box shows
   what was actually searched for after submission.

TEST SETUP AND CONFIRMATION

Add (or confirm you already have) at least one book item titled
something containing "FastAPI" that is also tagged "python", and at
least one other item that matches only the tag or only the search term
but not both (for example, a Python-tagged book with a title that
doesn't contain "fastapi", and a non-Python-tagged item whose title
does contain "fastapi").

Visit /?tag=python&q=fastapi directly. The results should include only
the item(s) satisfying both conditions - tagged "python" AND with
"fastapi" somewhere in the title or creator - excluding both of the
partial-match items described above.

WHY THIS WORKS AS AN ANSWER
----------------------------
It implements both filters exactly as chained in the chapter, and
specifically sets up test data designed to distinguish "matches both"
from "matches only one," which is the only way to actually confirm the
AND-combination behavior rather than just confirming each filter works
in isolation.