package de.fhdw.wtf.persistence.meta;
   
   import java.math.BigInteger;
   
   import de.fhdw.wtf.persistence.exception.PersistenceException;
   import de.fhdw.wtf.persistence.facade.ObjectFacade;
   
   /**
    * A class to represent any Integer Value in the database. Intger Values are instances of Integer Type.
   * 
   */
  public class IntegerValue extends Object { // NOPMD: Object != java.lang.Object
  
  	/**
  	 * If there are values which are not already fetched the database is asked.
  	 */
  	private static ObjectFacade facade;
  	
  	/**
  	 * set the ObjectFacade, because when there are values which are not already fetched the database is asked.
  	 * 
  	 * @param objectFacade
  	 */
  	public static void setObjectFacade(final ObjectFacade objectFacade) {
  		facade = objectFacade;
  	}
  	
  	/**
  	 * The value of the integer.
  	 */
  	private BigInteger value;
  	
  	/**
  	 * The id of the integer in the database.
  	 */
  	private Long id;
  	
  	/**
  	 * Constructor for a new integer value. This constructor could be used if only the id is knwown. The value will be
  	 * fetched from the database.
  	 * 
  	 * @param id
  	 *            A valid id of an integer value, which is present in the database.
  	 */
  	public IntegerValue(final long id) {
  		super(IntegerType.getInstance());
  		this.id = id;
  	}
  	
  	/**
  	 * Constructor for a new integer value. This constructor could be used if only a value is known. The id in the
  	 * database will be determined automatically.
  	 * 
  	 * @param value
  	 *            An integer value.
  	 */
  	public IntegerValue(final BigInteger value) {
  		super(IntegerType.getInstance());
  		this.value = value;
  	}
  	
  	/**
  	 * Constructor for an integer value if id and value are knwown.
  	 * 
  	 * @param id
  	 *            The id of the integer value in the database.
  	 * @param value
  	 *            The value of the integer value.
  	 */
  	public IntegerValue(final Long id, final BigInteger value) {
  		super(IntegerType.getInstance());
  		this.id = id;
  		this.value = value;
  	}
  	
  	/**
  	 * Getter for value. Lazy loads the value from the database if its unset.
  	 * 
  	 * @return Provides the value of this Integer Value Object.
  	 */
  	public BigInteger getValue() {
  		if (this.value == null) {
  			try {
  				this.value = facade.getIntForId(this.getId());
  			} catch (final PersistenceException e) {
  				throw new Error(e);
  			}
  		}
  		return this.value;
  	}
  	
  	/**
  	 * Getter for Id. Lazy loads the Id from the database if unset.
  	 */
  	@Override
  	public long getId() {
  		if (this.id == null) {
  			try {
  				this.id = facade.getIdForInteger(this.getValue());
 			} catch (final PersistenceException e) {
 				throw new Error(e);
 			}
 		}
 		return this.id;
 	}
 	
 	@Override
 	public boolean isTheSameAs(final java.lang.Object other) {
 		if (!(other instanceof IntegerValue)) {
 			return false;
 		}
 		
 		return this.getId() == ((IntegerValue) other).getId();
 	}
 	
 }