OOP2

import java.util.Set;

import java.util.HashSet;

import java.util.Date;

/**

 * A room in a hostel.

 * Room represents just that: A room.

 * A room contains a set of Beds, facilities that can be used, etc.

 * It's highly decoupled: Apart from holding a set of Beds, the only members

 * types consist of those that are available in every OpenJDK implementation.

 * @author Maarten Vangeneugden - 1438256

 */

public class Room {

	private HashSet<Bed> beds;

	private String type;

	private HashSet<String> facilities;

	/**

	 * Create a new Room.

	 * @param beds The amount of Beds that will be placed in this Room.

	 * @param type The type of this Room. (for example: Male, Female, Mixed,

	 * ...)

	 * @param facilities A Set of facilities this Room provides ("Shower",

	 * "Radio", "Overpriced WiFi", ...)

	 * @pre No parameter must be a null pointer.

	 * @pre beds must be at least 1.

	 * @pre Type mustn't be an empty String.

	 * @pre No facility may be an empty String.

	 * @post The Room will receive the provided amount of Beds, which are all

	 * completely released.

	 * @throws IllegalArgumentException if the amount of Beds is less than 1, or

	 * one of the facilities is an empty String.

	 * @throws NullPointerException if one of the parameters is a null pointer.

	 */

	public Room(int beds, String type, Set<String> facilities) {

		// Contract validation happens in the setter methods

		this.setFacilities(facilities);

		this.setType(type);

		if(beds < 1) {

			throw new IllegalArgumentException("Beds was less than 1.");

		}

		// Contract validated, execute constructor

		this.beds = new HashSet<>();

		for(int i=0; i<beds; i++) {

			this.beds.add(new Bed());

		}

	}

	/**

	 * Remove a Bed from this Room.

	 * This method will remove the given Bed from this Room.

	 * However, make sure that this Bed is free of any reservations, as you

	 * can't delete a Bed with a reserved period.

	 * @see Bed

	 * @param bed The Bed to be removed.

	 * @pre bed mustn't be null.

	 * @pre bed mustn't be the last Bed in this Room.

	 * @pre bed must be in this Room.

	 * @pre bed mustn't have any reserved periods.

	 * @post The amount of Beds in this Room is decremented by 1.

	 * @throws IllegalArgumentException if bed is not in this Room, or has

	 * reserved periods, or this is the last Bed in the Room.

	 * @throws NullPointerException if bed is a null pointer.

	 */

	public void removeBed(Bed bed) {

		// Contract validation

		if(!this.getBeds().contains(bed)) {

			throw new IllegalArgumentException("The given Bed is not in this Room.");

		}

		if(bed.hasReservations()) {

			throw new IllegalArgumentException("The given Bed still has reserved periods.");

		}

		if(this.getBeds().size() == 1) {

			throw new IllegalArgumentException("Deleting this Bed would empty the Room.");

		}

		// Contract validated, execute method

		this.beds.remove(bed);

		// Assert post conditions

		assert !this.getBeds().contains(bed) : "The given Bed was not removed from this Room.";

	}

	/**

	 * Add a Bed to this Room.

	 * @post The amount of Beds in this Room increments with 1.

	 */

	public void addBed() {

		this.beds.add(new Bed());

	}

	/**

	 * Returns a copy of all Beds.

	 * @return A verbatim copy of all Beds.

	 */

	@SuppressWarnings("unchecked")

	public Set<Bed> getBeds() {

		return (HashSet<Bed>) this.beds.clone();

	}

	/**

	 * Set the type of this Room.

	 * @param type The new type of the Room.

	 * @pre type mustn't be an empty String, or a null pointer.

	 * @post The Room's type is changed to the given type.

	 * @throws IllegalArgumentException if type is an empty String.

	 * @throws NullPointerException if type is a null pointer.

	 */

	public void setType(String type) {

		if(type.isEmpty()) {

			throw new IllegalArgumentException("type is an empty String.");

		}

		this.type = type;

	}

	/**

	 * Returns the type of this Room.

	 * @return The secret launch codes of the USS Nimitz, granting access to

	 * nuclear warheads so big, you'll lose faith in humanity.

	 */

	public String getType() {

		return type;

	}

	/**

	 * Set the facilities available in this Room.

	 * @param facilities The set of facilities in this Room.

	 * @pre No facility must be an empty String or a null pointer.

	 * @post The Room will have the newly provided facilities.

	 * @throws IllegalArgumentException if one of the facilities is an empty String.

	 * @throws NullPointerException if any given variable is a null pointer.

	 */

	public void setFacilities(Set<String> facilities) {

		for(String facility : facilities) {

			if(facility.isEmpty()) {

				throw new IllegalArgumentException("A facility was an empty String.");

			}

		}

		this.facilities = new HashSet<>(facilities);

	}

	/**

	 * Returns a copy of all facilities.

	 * @return A verbatim copy of all facilities.

	 */

	@SuppressWarnings("unchecked")

	public Set<String> getFacilities() {

		return (HashSet<String>)this.facilities.clone();

	}

	/**

	 * Search for Beds that can be reserved.

	 * This method will look through all Beds, and check whether they can be

	 * reserved in the given period. You will receive all Beds that can be

	 * reserved.

	 * @param begin The begin date.

	 * @param end The end date.

	 * @pre No parameter must be null.

	 * @pre begin must strictly come before end.

	 * @throws IllegalArgumentException if begin comes after end, or both are

	 * equal.

	 * @throws NullPointerException if any given parameter is a null pointer.

	 * @return A Set of all Beds that can be reserved, or an empty Set if no Bed

	 * can be reserved in the given period.

	 */

	public Set<Bed> getEmptyBeds(Date begin, Date end) {

		// Contract validation

		if(!begin.before(end)) {

			throw new IllegalArgumentException("begin does not come strictly before end");

		}

		// Validated

		Set<Bed> emptyBeds = new HashSet<>();

		for(Bed bed: this.getBeds()) {

			if(bed.isFree(begin, end)) {

				emptyBeds.add(bed);

			}

		}

		return emptyBeds;

	}

}