Randomly generate data under conditions for sqlite

As part of creating a machine learning exercise, I have an sqlite database that looks like this: The "Pizza", "DateDimension" and "Customer" tables are already populated, there are 5 different pizzas and 10 customers. How could I generate random data for the sales table, but give conditions to create a pattern? For example, on Monday/Tuesday a random sales figure between 15 and 25, on the other days of the week a random sales figure between 10 and 20, between 20 and 30 on the weekend. Knowing that for a day, a sale of 15 pizzas would be for the customer of ID=1 a sale of 2 pizzas of ID=2 and 4 pizzas of ID=3, for the customer of ID=2 a sale of 3 pizzas of ID=2, and
for the ID=3 customer a sale of 3 pizzas of ID=4 and 3 pizzas of ID=2. This makes a total of 15 pizzas, of which 8 ID=2 pizzas, 4 ID=3 pizzas, 3 ID=4 pizzas, divided between three customers. I don't know if I'm clear enough in my explanations, basically we need a random number of pizza sales for each day, and that this number is itself randomly split between the types of pizza and the customers, under certain conditions in order to follow a pattern in the number of sales per day.