/**
 * 
 */
package de.fhswf.in.inf.java1.aufgabe5;

import java.math.BigDecimal;

/**
 * An implementation of the Konto class wich represents a bank account.
 *
 * @author $Author: $
 * @version $Revision: $, $Date: $ UTC
 */
public class Konto
{

   private BigDecimal guthaben;

   private BigDecimal dispo;

   private Person besitzer;

   /**
    * Creates an account with an owner, a dispo and an initial balance.
    *
    * @param besitzer
    *           Owner of the account
    * @param dispo
    *           Dispo of the account
    * @param guthaben
    *           Initial balance of the account
    */
   public Konto(Person besitzer, BigDecimal dispo, BigDecimal guthaben)
   {

      if (besitzer == null)
      {
         throw new IllegalArgumentException("Besitzer can't be null");
      }
      if (dispo == null)
      {
         throw new IllegalArgumentException("Dispo can't be null");
      }
      if (guthaben == null)
      {
         throw new IllegalArgumentException("Guthaben can't be null");
      }

      this.besitzer = besitzer;
      this.dispo = dispo;
      this.guthaben = guthaben;

   }

   /**
    * Function for withdrawing money from the account.
    *
    * @param betrag
    *           Amount of cash to be withdrawn
    */
   public void abheben(BigDecimal betrag)
   {
      if (betrag == null)
      {
         throw new IllegalArgumentException("Betrag can't be null");
      }
      if (betrag.compareTo(BigDecimal.ZERO) < 0)
      {
         throw new IllegalArgumentException("Betrag can't be negative");
      }
      if (guthaben.add(dispo).compareTo(betrag) < 0)
      {
         throw new IllegalArgumentException("Betrag surpasses dispo limit");
      }

      guthaben = guthaben.subtract(betrag);
   }

   /**
    * Function to deposit money into the account.
    *
    * @param betrag
    *           Amount of cash to be disposed
    */
   public void einzahlen(BigDecimal betrag)
   {
      if (betrag == null)
      {
         throw new IllegalArgumentException("Betrag can't be null");
      }
      if (betrag.compareTo(BigDecimal.ZERO) < 0)
      {
         throw new IllegalArgumentException("Betrag can't be negative");
      }

      guthaben = guthaben.add(betrag);
   }

   /**
    * Returns the actual balance.
    *
    * @return Returns the actual balance.
    */
   public BigDecimal getKontostand()
   {
      return guthaben;
   }

   /**
    * Just to get the owners name.
    *
    * @return Returns the owners name.
    */
   public String getBesitzer()
   {
      return besitzer.getName();
   }

}