Initial commit: Django inventory system

myproject/inventory/admin.py

@@ -0,0 +1,19 @@
+from django.contrib import admin
+from .models import Stock, StockMovement
+
+
+class StockAdmin(admin.ModelAdmin):
+    list_display = ('product', 'quantity_available', 'quantity_reserved', 'updated_at')
+    list_filter = ('updated_at',)
+    search_fields = ('product__name', 'product__sku')
+
+
+class StockMovementAdmin(admin.ModelAdmin):
+    list_display = ('product', 'change', 'reason', 'order', 'created_at')
+    list_filter = ('reason', 'created_at')
+    search_fields = ('product__name', 'order__id')
+    date_hierarchy = 'created_at'
+
+
+admin.site.register(Stock, StockAdmin)
+admin.site.register(StockMovement, StockMovementAdmin)

myproject/inventory/apps.py

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+from django.apps import AppConfig
+
+
+class InventoryConfig(AppConfig):
+    default_auto_field = 'django.db.models.BigAutoField'
+    name = 'inventory'

myproject/inventory/migrations/0001_initial.py

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+# Generated by Django 5.2.7 on 2025-10-21 14:41
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+        ('orders', '0001_initial'),
+        ('products', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Stock',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('quantity_available', models.DecimalField(decimal_places=3, default=0, max_digits=10, verbose_name='Доступное количество')),
+                ('quantity_reserved', models.DecimalField(decimal_places=3, default=0, max_digits=10, verbose_name='Зарезервированное количество')),
+                ('updated_at', models.DateTimeField(auto_now=True, verbose_name='Дата обновления')),
+                ('product', models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, related_name='stock', to='products.product', verbose_name='Товар')),
+            ],
+            options={
+                'verbose_name': 'Остаток на складе',
+                'verbose_name_plural': 'Остатки на складе',
+                'indexes': [models.Index(fields=['product'], name='inventory_s_product_4c1da7_idx')],
+            },
+        ),
+        migrations.CreateModel(
+            name='StockMovement',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('change', models.DecimalField(decimal_places=3, max_digits=10, verbose_name='Изменение')),
+                ('reason', models.CharField(choices=[('purchase', 'Закупка'), ('sale', 'Продажа'), ('write_off', 'Списание'), ('adjustment', 'Корректировка')], max_length=20, verbose_name='Причина')),
+                ('created_at', models.DateTimeField(auto_now_add=True, verbose_name='Дата создания')),
+                ('order', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='stock_movements', to='orders.order', verbose_name='Заказ')),
+                ('product', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='movements', to='products.product', verbose_name='Товар')),
+            ],
+            options={
+                'verbose_name': 'Движение товара',
+                'verbose_name_plural': 'Движения товаров',
+                'indexes': [models.Index(fields=['product'], name='inventory_s_product_cbdc37_idx'), models.Index(fields=['created_at'], name='inventory_s_created_05ebf5_idx')],
+            },
+        ),
+    ]

myproject/inventory/models.py

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+from django.db import models
+from products.models import Product
+
+
+class Stock(models.Model):
+    """
+    Остатки по каждому товару.
+    """
+    product = models.OneToOneField(Product, on_delete=models.CASCADE, 
+                                  related_name='stock', verbose_name="Товар")
+    quantity_available = models.DecimalField(max_digits=10, decimal_places=3, default=0,
+                                            verbose_name="Доступное количество")
+    quantity_reserved = models.DecimalField(max_digits=10, decimal_places=3, default=0,
+                                           verbose_name="Зарезервированное количество")
+    updated_at = models.DateTimeField(auto_now=True, verbose_name="Дата обновления")
+
+    class Meta:
+        verbose_name = "Остаток на складе"
+        verbose_name_plural = "Остатки на складе"
+        indexes = [
+            models.Index(fields=['product']),
+        ]
+
+    def __str__(self):
+        return f"{self.product.name} - {self.quantity_available}"
+
+    @property
+    def quantity_free(self):
+        """Свободное количество (доступное минус зарезервированное)"""
+        return self.quantity_available - self.quantity_reserved
+
+
+class StockMovement(models.Model):
+    """
+    Журнал всех складских операций (приход, списание, коррекция).
+    """
+    REASON_CHOICES = [
+        ('purchase', 'Закупка'),
+        ('sale', 'Продажа'),
+        ('write_off', 'Списание'),
+        ('adjustment', 'Корректировка'),
+    ]
+
+    product = models.ForeignKey(Product, on_delete=models.CASCADE, 
+                               related_name='movements', verbose_name="Товар")
+    change = models.DecimalField(max_digits=10, decimal_places=3, verbose_name="Изменение")
+    reason = models.CharField(max_length=20, choices=REASON_CHOICES, verbose_name="Причина")
+    order = models.ForeignKey('orders.Order', on_delete=models.SET_NULL, null=True, blank=True,
+                             related_name='stock_movements', verbose_name="Заказ")
+    created_at = models.DateTimeField(auto_now_add=True, verbose_name="Дата создания")
+
+    class Meta:
+        verbose_name = "Движение товара"
+        verbose_name_plural = "Движения товаров"
+        indexes = [
+            models.Index(fields=['product']),
+            models.Index(fields=['created_at']),
+        ]
+
+    def __str__(self):
+        return f"{self.product.name}: {self.change} ({self.reason})"

myproject/inventory/tests.py

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+from django.test import TestCase
+
+# Create your tests here.

myproject/inventory/views.py

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+from django.shortcuts import render
+
+# Create your views here.