from django.db import models
from django.contrib.auth.models import User
from inventory.models import Product

class CustomerOrder(models.Model):
    order_number = models.CharField(max_length=20, unique=True, editable=False)
    customer = models.ForeignKey(User, on_delete=models.CASCADE, related_name='customer_orders')  # Link to the customer placing the order
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    total_amount = models.DecimalField(max_digits=10, decimal_places=2)
    status = models.CharField(max_length=20, choices=[
        ('Pending', 'Pending'),
        ('Processing', 'Processing'),
        ('Shipped', 'Shipped'),
        ('Completed', 'Completed'),
        ('Cancelled', 'Cancelled'),
    ], default='Pending')

    def save(self, *args, **kwargs):
        if not self.order_number:
            max_id = CustomerOrder.objects.aggregate(max_id=models.Max('id'))['max_id']
            new_id = max_id + 1 if max_id else 1
            self.order_number = f'CUST{new_id:06d}'
        super().save(*args, **kwargs)

    def __str__(self):
        return self.order_number


class CustomerOrderItem(models.Model):
    order = models.ForeignKey(CustomerOrder, related_name='items', on_delete=models.CASCADE)
    product = models.ForeignKey(Product, on_delete=models.CASCADE, related_name='customer_order_items')
    quantity = models.PositiveIntegerField()
    price = models.DecimalField(max_digits=10, decimal_places=2)  # Price at the time of purchase

    def __str__(self):
        return f"{self.product.name} ({self.quantity})"