from django.db import models

class Ingredient(models.Model):
    name = models.CharField(max_length=128)

    def __str__(self):
        return self.name

class Recipe(models.Model):
    name = models.CharField(max_length=128)
    ingredients = models.ManyToManyField(Ingredient, through='IngredientUsage')

    def __str__(self):
        return self.name

class Step(models.Model):
    recipe = models.ForeignKey(Recipe, on_delete=models.CASCADE)
    step = models.PositiveSmallIntegerField()
    protocol = models.TextField(default='')

class IngredientUsage(models.Model):
    recipe = models.ForeignKey(Recipe, on_delete=models.CASCADE)
    ingredient = models.ForeignKey(Ingredient, on_delete=models.CASCADE)
    quantity = models.CharField(max_length=64)