package cse1030.labtest1;

/**
 * A class that represents an amount of Canadian money in dollars and cents.
 * The class also keeps track of the total amount of dollars and cents in
 * circulation. When money is created, the total amount of money in
 * circulation is increased by the value of the created money. When an
 * amount of money is modified, the total amount of money in circulation is
 * updated with the change in the value of the money.
 * 
 * <p>
 * The <code>Money</code> class keeps track of two values:
 * <ol>
 * <li>the number of dollars in circulation</li>
 * <li>the number of cents in circulation</li>
 * </ol>
 * 
 * <p>
 * Each <code>Money</code> object keeps track of two values:
 * <ol>
 * <li>the number of dollars in <code>this</code> money object</li>
 * <li>the number of cents in <code>this</code> money object</li>
 * </ol>
 * 
 * @author CSE1030
 *
 */
public class Money
{
	private static int totalDollars = 0;
	private static int totalCents = 0;
	
	private int dollars;
	private int cents;
	
	/**
	 * Construct a money object having 0 dollars and 0 cents.
	 */
	public Money()
	{
		this(0, 0);
	}
	
	/**
	 * Construct a money object given the amount of dollars and amount of cents.
	 * Updates the total of amount of money in circulation.
	 * 
	 * @param dollars The amount of dollars.
	 * @param cents The amount of cents.
	 * @throws IllegalArgumentException if dollars < 0 or cents < 0.
	 */
	public Money(int dollars, int cents)
	{
		if( !this.setDollars(dollars) )
		{
			throw new IllegalArgumentException("dollars is negative");
		}
		else if( !this.setCents(cents) )
		{
			throw new IllegalArgumentException("cents is negative");
		}
	}
	
	/**
	 * Set the amount of dollars. If <code>dollars < 0</code> then the
	 * state of the object is unchanged from its current value and false
	 * is returned. If <code>dollars >= 0</code> then the state of the object is
	 * updated, the total amount of money in circulation is updated,
	 * and true is returned.
	 * 
	 * <p>The total amount of money in circulation is updated with the
	 * change in the value of dollars for this money object. For example,
	 * suppose the number of dollars for a money object <code>m</code>
	 * is 10; then <code>m.setDollars(15)</code> will increase the total amount of
	 * money in circulation by 5 dollars.
	 * 
	 * @param dollars The amount of dollars.
	 * @return true if dollars >= 0; false otherwise.
	 */
	public boolean setDollars(int dollars)
	{
		boolean ok = false;
		if (dollars >= 0)
		{
			Money.totalDollars -= this.getDollars();
			Money.totalDollars += dollars;
			this.dollars = dollars;
			ok = true;
		}
		return ok;
	}
	
	/**
	 * Set the amount of cents. If <code>cents < 0</code> then the
	 * state of the object is unchanged from its current value and false
	 * is returned. If <code>cents >= 0</code> then the state of the object is
	 * updated, the total amount of money in circulation is updated,
	 * and true is returned.
	 * 
	 * <p>The total amount of money in circulation is updated with the
	 * change in the value of cents for this money object. For example,
	 * suppose the number of cents for a money object <code>m</code>
	 * is 50; then <code>m.setCents(30)</code> will decrease the total amount of
	 * money in circulation by 20 cents.
	 * 
	 * @param cents The amount of cents.
	 * @return true if cents >= 0; false otherwise.
	 */
	public boolean setCents(int cents)
	{
		boolean ok = false;
		if (cents >= 0)
		{
			Money.totalCents -= this.getCents();
			Money.totalCents += cents;
			this.cents = cents;
			ok = true;
		}
		return ok;
	}
	
	/**
	 * Get the amount of dollars represented by this object.
	 * (ignoring the number of cents). For example, for a money
	 * object representing 10 dollars and 55 cents this method
	 * would return 10.
	 * 
	 * @return The number of dollars.
	 */
	public int getDollars()
	{
		return this.dollars;
	}
	
	/**
	 * Get the amount of cents represented by this object
	 * (ignoring the number of dollars). For example, for a money
	 * object representing 10 dollars and 55 cents this method
	 * would return 55.
	 * 
	 * @return The number of cents.
	 */
	public int getCents()
	{
		return this.cents;
	}
	
	/**
	 * Get the total amount of dollars in circulation.
	 * 
	 * @return The number of dollars in circulation.
	 */
	public static int getDollarsInCirculation()
	{
		return Money.totalDollars;
	}
	
	/**
	 * Get the total amount of cents in circulation.
	 * 
	 * @return The number of cents in circulation.
	 */
	public static int getCentsInCirculation()
	{
		return Money.totalCents;
	}
	
	/**
	 * Creates a string representation of a money object. The string
	 * is the number of dollars followed by " dollars and " followed by
	 * the number of cents followed by " cents".
	 * 
	 * @return The string representation of the object.
	 */
	@Override public String toString()
	{
		return this.getDollars() + " dollars and " + this.getCents() + " cents";
	}


}