Very first attempt at a staff-facing report (items sold)

registrasion/forms.py

@@ -345,3 +345,16 @@ class VoucherForm(forms.Form):
         help_text="If you have a voucher code, enter it here",
         required=False,
     )
+
+
+# Staff-facing forms.
+
+class ProductAndCategoryForm(forms.Form):
+    product = forms.ModelMultipleChoiceField(
+        queryset=inventory.Product.objects.all(),
+        required=False,
+    )
+    category = forms.ModelMultipleChoiceField(
+        queryset=inventory.Category.objects.all(),
+        required=False,
+    )

registrasion/staff_views.py

@@ -0,0 +1,101 @@
+import forms
+
+from django.db.models import Q
+from django.shortcuts import render
+from functools import wraps
+
+from models import commerce
+
+
+'''
+
+All reports must be viewable by staff only (permissions?)
+
+Reports can have:
+
+A form
+ * Reports are all *gettable* - you can save a URL and get back to the same
+ report
+ * Fetching a report *cannot* break the underlying data.
+A table
+ * Headings
+ * Data lines
+ * Formats are pluggable
+
+'''
+
+
+class Report(object):
+
+    def __init__(self, form, headings, data):
+        self._form = form
+        self._headings = headings
+        self._data = data
+
+    @property
+    def form(self):
+        ''' Returns the form. '''
+        return self._form
+
+    @property
+    def headings(self):
+        ''' Returns the headings for the table. '''
+        return self._headings
+
+    @property
+    def data(self):
+        ''' Returns the data rows for the table. '''
+        return self._data
+
+
+def report(view):
+    ''' Decorator that converts a report view function into something that
+    displays a Report.
+
+    '''
+    print "hello"
+
+    @wraps(view)
+    def inner_view(request, *a, **k):
+        print "lol"
+        report = view(request, *a, **k)
+
+        ctx = {
+            "form": report.form,
+            "report": report,
+        }
+
+        return render(request, "registrasion/report.html", ctx)
+
+    return inner_view
+
+
+@report
+def items_sold(request):
+    ''' Summarises the items sold and discounts granted for a given set of
+    products, or products from categories. '''
+
+    print "beep"
+
+    form = forms.ProductAndCategoryForm(request.GET)
+
+    data = None
+    headings = None
+
+    if form.is_valid() and form.has_changed():
+        products = form.cleaned_data["product"]
+        categories = form.cleaned_data["category"]
+
+        # TODO augment the form to allow us to filter by invoice status.
+        line_items = commerce.LineItem.objects.filter(
+            Q(product=products) | Q(product__category=categories),
+            invoice__status=commerce.Invoice.STATUS_PAID,
+        ).select_related("invoice")
+
+        headings = ["invoice_id", "description", "quantity", "price"]
+
+        data = []
+        for line in line_items:
+            data.append([line.invoice.id, line.description, line.quantity, line.price])
+
+    return Report(form, headings, data)

registrasion/urls.py

@@ -1,4 +1,5 @@
 import views
+import staff_views
 
 from django.conf.urls import url, patterns
 
@@ -30,4 +31,5 @@ urlpatterns = [
     url(r"^register$", guided_registration, name="guided_registration"),
     url(r"^register/([0-9]+)$", guided_registration,
         name="guided_registration"),
+    url(r"^report$", staff_views.items_sold, name="items_sold"),  # TODO: rm
 ]