We have three models: Customer, Order, and Coffee.

A Customer has many Orders, a Coffee has many Orders, and an Order belongs to a Coffee and to a Customer.

Customer - Coffee is a many to many relationship.

a Customer should have a name

a Coffee should have a title

an Order should have a price

Which is the single source of truth? (aka which table will have the columns for the foreign keys)

Order#customer

• return the Customer instance for this order

Order#coffee

• return the Coffee instance for this order

Order#receipt

• instance method. puts a message formatted like: {customer name} ordered a {coffee title} for ${price}

Customer#orders

• returns a collection of all Order instances for this customer

Customer#coffees

• returns a collection of all Coffee instances for this customer

Customer.names

• class method that returns a collection with all of the customer names

Customer#order_coffee(coffee_title, price)

• instance method that takes in a coffee title and price and will create an order with that coffee and price
• should put out the order receipt

Customer#total_purchases_amount

• instance method that returns the cost of all of the Customer's coffee orders

Customer#dislike_coffee(coffee_title)

• instance method that takes in a coffee_title, finds the last order for that coffee and removes it.
• puts a message formatted like: {customer name} has been refunded ${price}

Coffee#orders

• returns a collection of all Order instances for this coffee

Coffee#customers

• returns a collection of all Customer instances who ordered this coffee

Coffee#unique_customer_names

• returns an array with all of the customers names who have ordered the coffee

Coffee.most_ordered

• returns the Coffee instance that was ordered the most

• class method that returns the order instance that was the most expensive.
• if there are multiple, return the first