Assumptions:

Tanks:

Tanks contain an ingredient. They can be modified by setting/adding a new amount or by acquiring an element. This replaces pumps that added no functionality to the program.

Ingredients:

Ingredients can be mutated only by splitting them. They return a new object with asked amount and subtract their one.

Heater:

Heater returns heated object. Used only for milk.

Evaporator:

It evaporates water and returns steam (water with evaporated set to true)

Grounder:

Grounder returns grounded coffee (coffee grain with grounded set to true)

Pot:

The coffee pot takes grounded coffee and steam and combines them to the coffee essence (water with a coffee extract)

Milk Module

It can check whether its tank has a proper amount of milk or whether is overflown and prepare heated and foamed milk.

Water Module

It can check whether its tank has a proper amount of water or whether is overflown and prepare steam needed to flush it through coffee pot in coffee module.

Coffee Module

It can check whether its tank has a proper amount of coffee or whether is overflown, ground coffee needed by coffee pot and accept steam and that coffee to prepare coffee essence

Wastes Module

It can only check whether it is full.

How to run

In Intellij:

Install lombok plugin

Run CoffeeMachineApplication

Use GET requests on http://localhost:8080/coffee with param coffeeKind where CoffeeKind = { "Americano", "Espresso", "Latte", "Cappuccino" } - the capitalization doesn't matter.

The return value is in the form:

{
  water: <int>,
  coffeeExtract: <int>,
  milk: <int>,
  withFoam: <boolean>
}

At the start of the application all the tanks are empty. They can be refilled by sending a PUT request on /tanks/{tank} with amount param, tank = {water, milk, coffee}.

To empty wastes bin send PUT request on /tanks/wastes with no params.