some first models of pos & add required to attributes

apps/product/signals.py

@@ -1,8 +1,18 @@
 from django.db.models import Sum
 from django.db.models.signals import post_save, post_delete
 from django.dispatch import receiver
-from .models import QuotaDistribution, Quota, Product
-from apps.warehouse.models import InventoryQuotaSaleTransaction
+from .models import (
+    QuotaDistribution,
+    Quota,
+    Product,
+    ProductStats,
+    QuotaStats
+)
+from apps.warehouse.models import (
+    InventoryQuotaSaleTransaction,
+    InventoryEntry
+)
+from django.db import models
 
 
 def recalculate_remaining_amount(quota):
@@ -22,15 +32,113 @@ def update_quota_remaining(sender, instance, **kwargs):
 
 
 def update_product_stats(instance: Product):
-    pass
+    """ update all stats of product  """
+
+    if hasattr(instance, 'stats'):
+        stat = instance.stats
+    else:
+        stat = ProductStats.objects.create(product=instance)
+
+    # number of quotas
+    quotas_count = instance.quotas.filter(is_closed=False).count()  # noqa
+
+    # total weight of product that assigned in quota
+    active_quotas_weight = instance.quotas.filter(is_closed=False).aggregate(
+        total=models.Sum('quota_weight')
+    )['total'] or 0
+
+    closed_quotas_weight = instance.quotas.filter(is_closed=True).aggregate(  # noqa
+        total=models.Sum('quota_weight')
+    )['total'] or 0
+
+    total_quotas_weight = instance.quotas.all().aggregate(  # noqa
+        total=models.Sum('quota_weight')
+    )['total'] or 0
+
+    # total remaining weight of product quotas
+    total_remaining_quotas_weight = instance.quotas.filter(is_closed=False).aggregate(  # noqa
+        total=models.Sum('remaining_weight')
+    )['total'] or 0
+
+    # product total distributed weight from quota
+    total_distributed_weight = QuotaDistribution.objects.filter(
+        quota__product_id=instance.id,
+        quota__is_closed=False
+    ).aggregate(total_weight=models.Sum('weight'))['total_weight'] or 0
+
+    # total sold of product from quota
+    total_sold = QuotaDistribution.objects.filter(
+        quota__product_id=instance.id,
+        quota__is_closed=False
+    ).aggregate(total_sold=models.Sum('been_sold'))['total_sold'] or 0
+
+    # total entry from product to inventory
+    total_warehouse_entry = QuotaDistribution.objects.filter(
+        quota__product_id=instance.id,
+        quota__is_closed=False
+    ).aggregate(total_entry=models.Sum('warehouse_entry'))['total_entry'] or 0
+
+    stat.quotas_number = quotas_count
+    stat.active_quotas_weight = active_quotas_weight
+    stat.closed_quotas_weight = closed_quotas_weight
+    stat.total_quota_weight = total_quotas_weight
+    stat.total_remaining = total_remaining_quotas_weight
+    stat.total_distributed_weight = total_distributed_weight
+    stat.total_warehouse_entry = total_warehouse_entry
+    stat.total_sold = total_sold
+    stat.save(update_fields=[
+        "quotas_number",
+        "active_quotas_weight",
+        "closed_quotas_weight",
+        "total_quota_weight",
+        "total_remaining",
+        "total_distributed_weight",
+        "total_warehouse_entry",
+        "total_sold",
+    ])
 
 
 def update_quota_stats(instance: Quota):
-    pass
+    """ update all stats of quota """
+
+    if hasattr(instance, 'stats'):
+        stat = instance.stats
+    else:
+        stat = QuotaStats.objects.create(quota=instance)
+
+    total_distributed = instance.quota_distributed
+    total_remaining = instance.remaining_weight
+
+    # total entry to inventory from quota
+    total_inventory = InventoryEntry.objects.filter(
+        distribution__quota=instance
+    ).aggregate(
+        total_inventory=models.Sum('weight')
+    )['total_inventory'] or 0
+
+    # total sale of distributions from quota
+    total_sale = instance.distributions_assigned.filter(
+        quota__is_closed=False
+    ).aggregate(total_sale=models.Sum('been_sold'))['total_sale'] or 0
+
+    stat.total_distributed = total_distributed
+    stat.remaining = total_remaining
+    stat.total_inventory = total_inventory
+    stat.total_sale = total_sale
+    stat.save(update_fields=[
+        "total_distributed",
+        "remaining",
+        "total_inventory",
+        "total_sale",
+    ])
 
 
 @receiver([post_save, post_delete], sender=QuotaDistribution)
 @receiver([post_save, post_delete], sender=InventoryQuotaSaleTransaction)
 def update_stats_on_change(sender, instance, **kwargs):
-    update_product_stats(instance)
-    update_quota_stats(instance)
+    if sender == QuotaDistribution:
+        update_product_stats(instance.quota.product)
+        update_quota_stats(instance.quota)
+    elif sender == InventoryQuotaSaleTransaction:
+        update_product_stats(instance.quota_distribution.quota.product)
+        update_quota_stats(instance.quota_distribution.quota)