Django_Basic_Manufacturing/sales/models.py
2025-08-17 21:42:40 +07:00

249 lines
8.6 KiB
Python

from django.db import models
from django.core.validators import MinValueValidator
from django.utils.translation import gettext_lazy as _
from decimal import Decimal
class Customer(models.Model):
"""Customer information"""
CUSTOMER_TYPE_CHOICES = [
('retail', 'Retail'),
('wholesale', 'Wholesale'),
('distributor', 'Distributor'),
('corporate', 'Corporate'),
]
name = models.CharField(max_length=200)
code = models.CharField(max_length=50, unique=True, help_text='Unique customer code')
customer_type = models.CharField(max_length=20, choices=CUSTOMER_TYPE_CHOICES, default='retail')
# Contact information
contact_person = models.CharField(max_length=100, blank=True)
email = models.EmailField(blank=True)
phone = models.CharField(max_length=20, blank=True)
address = models.TextField(blank=True)
# Business information
tax_id = models.CharField(max_length=50, blank=True)
payment_terms = models.CharField(max_length=100, blank=True, help_text='e.g., Net 30, Net 60')
credit_limit = models.DecimalField(
max_digits=12,
decimal_places=2,
default=0,
validators=[MinValueValidator(Decimal('0'))]
)
# Status
is_active = models.BooleanField(default=True)
rating = models.IntegerField(
choices=[(i, i) for i in range(1, 6)],
default=3,
help_text='Customer rating from 1-5'
)
# Timestamps
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)
class Meta:
ordering = ['name']
verbose_name = _('Customer')
verbose_name_plural = _('Customers')
def __str__(self):
return f"{self.name} ({self.code})"
def get_total_sales(self):
"""Get total sales to this customer"""
return self.sale_orders.aggregate(
total=models.Sum('total_amount')
)['total'] or Decimal('0')
class SaleOrder(models.Model):
"""Sales order model"""
ORDER_STATUS = [
('draft', 'Draft'),
('confirmed', 'Confirmed'),
('shipped', 'Shipped'),
('delivered', 'Delivered'),
('cancelled', 'Cancelled'),
]
order_number = models.CharField(max_length=50, unique=True, help_text='Unique sales order number')
customer = models.ForeignKey(Customer, on_delete=models.CASCADE, related_name='sale_orders')
date = models.DateField()
expected_delivery_date = models.DateField(blank=True, null=True)
status = models.CharField(max_length=20, choices=ORDER_STATUS, default='draft')
# Financial information
subtotal = models.DecimalField(
max_digits=12,
decimal_places=2,
default=0,
validators=[MinValueValidator(Decimal('0'))]
)
tax_amount = models.DecimalField(
max_digits=12,
decimal_places=2,
default=0,
validators=[MinValueValidator(Decimal('0'))]
)
discount_amount = models.DecimalField(
max_digits=12,
decimal_places=2,
default=0,
validators=[MinValueValidator(Decimal('0'))]
)
shipping_cost = models.DecimalField(
max_digits=12,
decimal_places=2,
default=0,
validators=[MinValueValidator(Decimal('0'))]
)
total_amount = models.DecimalField(
max_digits=12,
decimal_places=2,
default=0,
validators=[MinValueValidator(Decimal('0'))]
)
# Additional information
notes = models.TextField(blank=True)
terms_conditions = models.TextField(blank=True)
# User tracking
created_by = models.ForeignKey('users.CustomUser', on_delete=models.SET_NULL, null=True)
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)
class Meta:
ordering = ['-date', '-created_at']
verbose_name = _('Sales Order')
verbose_name_plural = _('Sales Orders')
def __str__(self):
return f"SO-{self.order_number} - {self.customer.name}"
def save(self, *args, **kwargs):
"""Override save to calculate total amount"""
self.total_amount = self.subtotal + self.tax_amount - self.discount_amount + self.shipping_cost
super().save(*args, **kwargs)
def get_item_count(self):
"""Get total number of items in this sales order"""
return self.items.count()
def is_overdue(self):
"""Check if delivery is overdue"""
if self.expected_delivery_date and self.status not in ['delivered', 'cancelled']:
from django.utils import timezone
return timezone.now().date() > self.expected_delivery_date
return False
def get_profit_margin(self):
"""Calculate profit margin for this order"""
total_cost = Decimal('0')
for item in self.items.all():
if item.product.cost_price:
total_cost += item.quantity * item.product.cost_price
if total_cost > 0:
return ((self.total_amount - total_cost) / total_cost) * 100
return Decimal('0')
class SaleOrderItem(models.Model):
"""Individual items in sales orders"""
sale_order = models.ForeignKey(SaleOrder, on_delete=models.CASCADE, related_name='items')
product = models.ForeignKey('inventory.Product', on_delete=models.CASCADE, related_name='sale_order_items')
quantity = models.DecimalField(
max_digits=10,
decimal_places=2,
validators=[MinValueValidator(Decimal('0.01'))]
)
unit_price = models.DecimalField(
max_digits=10,
decimal_places=2,
validators=[MinValueValidator(Decimal('0'))]
)
discount_percent = models.DecimalField(
max_digits=5,
decimal_places=2,
default=0,
validators=[MinValueValidator(Decimal('0'))],
help_text='Discount percentage (0-100)'
)
total_price = models.DecimalField(
max_digits=12,
decimal_places=2,
validators=[MinValueValidator(Decimal('0'))]
)
# Additional information
description = models.CharField(max_length=200, blank=True)
notes = models.TextField(blank=True)
class Meta:
verbose_name = _('Sales Order Item')
verbose_name_plural = _('Sales Order Items')
def __str__(self):
return f"{self.sale_order.order_number} - {self.product.name} ({self.quantity})"
def save(self, *args, **kwargs):
"""Override save to calculate total price and update stock"""
# Calculate total price with discount
discount_amount = (self.unit_price * self.quantity * self.discount_percent) / 100
self.total_price = (self.unit_price * self.quantity) - discount_amount
super().save(*args, **kwargs)
# Update sales order subtotal
self.sale_order.subtotal = self.sale_order.items.aggregate(
total=models.Sum('total_price')
)['total'] or Decimal('0')
self.sale_order.save()
# Update product stock if order is confirmed or shipped
if self.sale_order.status in ['confirmed', 'shipped', 'delivered']:
# Create stock movement
from inventory.models import StockMovement
StockMovement.objects.create(
product=self.product,
movement_type='sale',
quantity=self.quantity,
unit_price=self.unit_price,
reference_type='SaleOrder',
reference_id=self.sale_order.id,
date=self.sale_order.date,
notes=f"Sale order {self.sale_order.order_number}",
created_by=self.sale_order.created_by
)
class DeliveryNote(models.Model):
"""Delivery note for shipped sales orders"""
delivery_number = models.CharField(max_length=50, unique=True)
sale_order = models.ForeignKey(SaleOrder, on_delete=models.CASCADE, related_name='deliveries')
delivery_date = models.DateField()
# Delivery details
shipping_method = models.CharField(max_length=100, blank=True)
tracking_number = models.CharField(max_length=100, blank=True)
notes = models.TextField(blank=True)
# User tracking
delivered_by = models.ForeignKey('users.CustomUser', on_delete=models.SET_NULL, null=True)
# Timestamps
created_at = models.DateTimeField(auto_now_add=True)
class Meta:
ordering = ['-delivery_date']
verbose_name = _('Delivery Note')
verbose_name_plural = _('Delivery Notes')
def __str__(self):
return f"DN-{self.delivery_number} for SO-{self.sale_order.order_number}"