from django.db import models
from django.db import transaction
from django.utils import timezone
from django.contrib.auth.models import User
import uuid

class UserProfile(models.Model):
    ROLE_CHOICES = [
        ('manager', 'Manager'),
        ('cashier', 'Cashier'),
    ]
    user = models.OneToOneField(User, on_delete=models.CASCADE, related_name='profile')
    role = models.CharField(max_length=10, choices=ROLE_CHOICES, default='cashier')

    def __str__(self):
        return f"{self.user.username} - {self.get_role_display()}"

class Ingredient(models.Model):
    name = models.CharField(max_length=100, unique=True)
    stock_quantity = models.DecimalField(max_digits=10, decimal_places=2, default=0.00)
    unit = models.CharField(max_length=20, default="grams")

    def __str__(self):
        return f"{self.name} ({self.stock_quantity} {self.unit})"

class MenuItem(models.Model):
    name = models.CharField(max_length=100, unique=True)
    price = models.DecimalField(max_digits=10, decimal_places=2)
    description = models.TextField(blank=True)
    image_url = models.URLField(blank=True, null=True)
    is_active = models.BooleanField(default=True)

    def __str__(self):
        return self.name

class MenuItemIngredient(models.Model):
    menu_item = models.ForeignKey(MenuItem, related_name='ingredients', on_delete=models.CASCADE)
    ingredient = models.ForeignKey(Ingredient, on_delete=models.CASCADE)
    quantity_required = models.DecimalField(max_digits=10, decimal_places=2)

    def __str__(self):
        return f"{self.quantity_required} {self.ingredient.unit} of {self.ingredient.name} for {self.menu_item.name}"

class Order(models.Model):
    order_number = models.CharField(max_length=12, unique=True, editable=False)
    created_at = models.DateTimeField(default=timezone.now)
    total_price = models.DecimalField(max_digits=10, decimal_places=2, default=0.00)
    customer_notes = models.TextField(blank=True)
    
    def save(self, *args, **kwargs):
        if not self.order_number:
            self.order_number = str(uuid.uuid4().hex[:8]).upper()
        super().save(*args, **kwargs)

    def __str__(self):
        return f"Order {self.order_number}"

class OrderItem(models.Model):
    order = models.ForeignKey(Order, related_name='items', on_delete=models.CASCADE)
    menu_item = models.ForeignKey(MenuItem, on_delete=models.PROTECT)
    quantity = models.PositiveIntegerField(default=1)
    price_at_order = models.DecimalField(max_digits=10, decimal_places=2)

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