espresso-machine.md

Espresso Machine Interface

We drink a lot of coffee in the office, we spent 600 pounds on a professional coffee machine, buy the best beans and used to have a coffee can mountain until we destroyed it playing bowling with the office swivel chairs at a party...

You challenge is to take the interface below and write a class this implements and fully complies to this interface

We have already written a set of unit tests which will be used to test your implementation

• You MUST NOT change any of the existing methods defined in the interface
• You should not print or display anything
• You may add additional methods to your implementation
• Exceptions are listed in the order they should be thrown
• The standard WaterContainer contains 2 litres but other sizes can be attached. common sizes are the 10 litre or mains water supply
• The standard BeanContainer holds 50 beans but other sizes can be attached. a 200 bean container is common.

Code

Beans Container Interface

interface BeansContainer
 {
   /**
    * Adds beans to the container
    *
    * @param integer $numSpoons number of spoons of beans
    * @throws ContainerFullException, EspressoMachineContainerException
    *
    * @return void
    */
   public function addBeans($numSpoons);
   /**
    * Get $numSpoons from the container
    *
    * @throws EspressoMachineContainerException
    * @param integer $numSpoons number of spoons of beans
    * @return integer
    */
   public function useBeans($numSpoons);
   /**
    * Returns the number of spoons of beans left in the container
    *
    * @return integer
    */
   public function getBeans();
 }

Water Container Interface

interface WaterContainer
 {
   /**
    * Adds water to the coffee machine's water tank
    *
    * @param float $litres
    * @throws ContainerFullException, EspressoMachineContainerException
    *
    * @return void
    */
   public function addWater($litres);
   /**
    * Use $litres from the container
    *
    * @throws EspressoMachineContainerException
    * @param float $litres
    * @return integer
    */
   public function useWater($litres);
   /**
    * Returns the volume of water left in the container
    *
    * @return float number of litres
    */
   public function getWater();
 }

Espresso Machine Interface

 /**
  * A single espresso uses 1 spoon of beans and 0.05 litres of water
  * A double espresso uses 2 spoons of beans and 0.10 litres of water
  *
  * The machine MUST be descaled after every 5 litres of Espresso made
  *    Descaling uses 1 litres of water
  *    You CANNOT make coffee while the machine needs descaling
  *    The machine will start with no beans or water in its containers
  *
  */
 interface EspressoMachineInterface extends BeansContainer, WaterContainer
 {
   /**
    * Runs the process to descale the machine
    * so the machine can be used make coffee
    * uses 1 litre of water
    *
    * @throws NoWaterException
    *
    * @return void
    */
   public function descale();
   /**
    * Runs the process for making Espresso
    *
    * @throws DescaleNeededException, NoBeansException, NoWaterException
    *
    * @return float of litres of coffee made
    */
   public function makeEspresso();
   /**
    * @see makeEspresso
    * @throws DescaleNeededException, NoBeansException, NoWaterException
    *
    * @return float of litres of coffee made
    */
   public function makeDoubleEspresso();
   /**
    * This method controls what is displayed on the screen of the machine
    * Returns ONE of the following human readable statuses in the following preference order:
    *
    * Descale needed
    * Add beans and water
    * Add beans
    * Add water
    * {Integer} Espressos left
    *
    * Please note you should return "Add water" if the machine needs descaling and doesn't have enough water
    *
    * @return string
    */
   public function getStatus();
   /**
    * @param BeansContainer $container
    */
   public function setBeansContainer(BeansContainer $container);
   /**
    * @return BeansContainer
    */
   public function getBeansContainer();
   /**
    * @param WaterContainer $container
    */
   public function setWaterContainer(WaterContainer $container);
   /**
    * @return WaterContainer
    */
   public function getWaterContainer();
 }

Exceptions

 class EspressoMachineException extends Exception {}
 class NoWaterException extends EspressoMachineException {}
 class NoBeansException extends EspressoMachineException {}
 class DescaleNeededException extends EspressoMachineException {}
 class EspressoMachineContainerException extends Exception {}
 class ContainerFullException extends EspressoMachineContainerException {}