add listfilter for filter bills in periods

fet2020/finance/admin.py

@@ -1,7 +1,11 @@
+import logging
+from datetime import date, datetime
+
 from django.conf import settings
 from django.contrib import admin, messages
 from django.http import HttpResponseRedirect
 from django.utils.html import format_html
+from django.utils.translation import gettext_lazy as _
 from django.utils.translation import ngettext
 from segno import helpers
 
@@ -17,6 +21,121 @@ from .forms import (
 from .models import BankData, Bill, Resolution, Wiref
 from .utils import generate_pdf
 
+logger = logging.getLogger(__name__)
+
+
+class BillPeriodeFilter(admin.SimpleListFilter):
+    title = "Periode"
+    parameter_name = "period"
+
+    __lst = ()
+
+    def choices(self, changelist):
+        # Current period.
+        yield {
+            "selected": self.value() is None,
+            "query_string": changelist.get_query_string(remove=[self.parameter_name]),
+            "display": self.__lst[0][1],
+        }
+
+        # Add all other periods.
+        for lookup, title in self.__lst[1:]:
+            yield {
+                "selected": self.value() == str(lookup),
+                "query_string": changelist.get_query_string({self.parameter_name: lookup}),
+                "display": title,
+            }
+
+        # 'All' choice.
+        yield {
+            "selected": self.value() == "All",
+            "query_string": changelist.get_query_string({self.parameter_name: "All"}),
+            "display": _("All"),
+        }
+
+    def lookups(self, request, model_admin):
+        qs = model_admin.get_queryset(request).order_by("-date")
+        if qs.exists() is not True:
+            return None
+
+        count = 0
+        total_count = qs.count()
+
+        # Get first period.
+        start_year = qs.first().date.year
+
+        # Check if date of first bill is in first half of year. If yes, start of period is the
+        # year before.
+        if qs.first().date < date(start_year, 7, 1):
+            start_year -= 1
+
+        start_date = date(start_year, 7, 1)
+        end_date = date(start_year + 1, 6, 30)
+        entry_qs = qs.filter(date__range=(start_date, end_date))
+
+        # Go through all bills to get the periods.
+        while count != total_count:
+            # Set period if a bill exists.
+            if entry_qs.exists():
+                self.__lst += (
+                    (
+                        f"{start_year}-{start_year + 1}",
+                        f"Periode {start_year}-{start_year + 1}",
+                    ),
+                )
+                count += entry_qs.count()
+
+            # Get bills from next period.
+            start_year -= 1
+            start_date = date(start_year, 7, 1)
+            end_date = date(start_year + 1, 6, 30)
+            entry_qs = qs.filter(date__range=(start_date, end_date))
+
+            # If you are searching bills from 90's, something went wrong.
+            if start_year < 2000:
+                logger.info(
+                    "Something went wrong while counting. Count: %s. Totalcounter: %s",
+                    count,
+                    total_count,
+                )
+                break
+
+        return self.__lst
+
+    def queryset(self, request, queryset):
+        qs = queryset
+
+        if self.value():
+            try:
+                period = datetime.strptime(self.value()[:4], "%Y")
+            except Exception:
+                # If choice is 'All', return all bills.
+                qs = queryset
+            else:
+                # Return bills from specific old period.
+                start_year = period.year
+                start_date = date(start_year, 7, 1)
+                end_date = date(start_year + 1, 6, 30)
+                qs = queryset.filter(date__range=(start_date, end_date))
+
+        # Return bills from current period.
+        else:
+            tmp_qs = queryset.order_by("-date")
+
+            # Get first period.
+            start_year = tmp_qs.first().date.year
+
+            # Check if date of first bill is in first half of year. If yes, start of period is the
+            # year before.
+            if tmp_qs.first().date < date(start_year, 7, 1):
+                start_year -= 1
+
+            start_date = date(start_year, 7, 1)
+            end_date = date(start_year + 1, 6, 30)
+            qs = queryset.filter(date__range=(start_date, end_date))
+
+        return qs
+
 
 class BillInline(admin.TabularInline):
     form = BillInlineForm
@@ -80,7 +199,7 @@ class BillAdmin(admin.ModelAdmin):
     ]
 
     actions = ["make_cleared", "make_finished"]
-    list_filter = ["status", "affiliation", "payer"]
+    list_filter = ["status", "affiliation", "payer", BillPeriodeFilter]
     ordering = ["-id"]
     search_fields = ["purpose"]