From 0e5c0ce16fa01fd66e8cdae2d9f077de3195377e Mon Sep 17 00:00:00 2001
From: phzhik <phzhitnikov@gmail.com>
Date: Sat, 11 Nov 2023 09:51:17 +0400
Subject: [PATCH] * WIP: annotate_commission_rub

---
 store/models.py | 41 +++++++++++++++++++++++++++++------------
 1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/store/models.py b/store/models.py
index 577fdd9..3f2e8dc 100644
--- a/store/models.py
+++ b/store/models.py
@@ -277,15 +277,33 @@ class ChecklistQuerySet(models.QuerySet):
         )
 
     def annotate_commission_rub(self):
-        # FIXME: implement category commission in DB query
-        return self
+        default_commission = GlobalSettings.load().commission_rub
+        over_150k_commission = F('_price_rub') * settings.COMMISSION_OVER_150K
 
-        commission = GlobalSettings.load().commission_rub
-        return self.annotate(_commission_rub=Case(
-            When(GreaterThan(F("_price_rub"), 150_000), then=F("_price_rub") * settings.COMMISSION_OVER_150K),
-            default=commission,
-            output_field=DecimalField()
-        ))
+        category_commission_is_zero_and_parent_present = (
+                (Q(category__commission__isnull=True) | Q(category__commission=0)) & Q(category__parent__isnull=False)
+        )
+
+        return self.annotate(
+            _category_commission_percent=Case(
+                When(category_commission_is_zero_and_parent_present, then=F('category__parent__commission')),
+                default=F('category__commission')
+            ),
+
+            _category_commission=F('_category_commission_percent') * F('_price_rub') / 100,
+
+            _over_150k_commission=Case(
+                When(GreaterThan(F("_price_rub"), 150_000), then=over_150k_commission),
+                default=0,
+                output_field=DecimalField()
+            ),
+
+            _commission_rub=Case(
+                When(price_snapshot_id__isnull=False, then=F('price_snapshot__commission_rub')),
+                default=Max(default_commission, F('_over_150k_commission'), F('_category_commission')),
+                output_field=DecimalField()
+            ),
+        )
 
 
 class PriceSnapshot(models.Model):
@@ -485,10 +503,9 @@ class Checklist(models.Model):
 
     @property
     def commission_rub(self) -> Decimal:
-        # FIXME: implement category commission in DB query
-        # # Prefer annotated field
-        # if hasattr(self, '_commission_rub'):
-        #     return self._commission_rub
+        # Prefer annotated field
+        if hasattr(self, '_commission_rub'):
+            return self._commission_rub
 
         # Prefer saved value
         if self.price_snapshot_id: