Adding a Money entity.

src/org/leumasjaffe/charsheet/entity/Money.java

@@ -0,0 +1,48 @@
+package org.leumasjaffe.charsheet.entity;
+
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.experimental.FieldDefaults;
+
+@AllArgsConstructor
+@Data
+@FieldDefaults(level=AccessLevel.PRIVATE)
+public class Money implements Comparable<Money> {
+	int pp, gp, sp, cp;
+	
+	Money sum( final Money other ) {
+		return new Money(pp + other.pp, gp + other.gp, sp + other.sp, cp + other.cp);
+	}
+	
+	Money subtract( final Money other ) {
+		final Money tmp = new Money(pp + other.pp, gp + other.gp, sp + other.sp, cp + other.cp);
+		tmp.rebalance( );
+		return tmp;
+	}
+	
+	private void rebalance( ) {
+		if ( pp < 0 ) { gp += 10 * pp; pp = 0; }
+		if ( gp < 0 ) { sp += 10 * gp; gp = 0; }
+		if ( sp < 0 ) { cp += 10 * sp; sp = 0; }
+		if ( cp < 0 ) { int tmp = (int) Math.ceil( cp / 10.0 ); sp -= tmp; cp += 10 * tmp; }
+		if ( sp < 0 ) { int tmp = (int) Math.ceil( sp / 10.0 ); gp -= tmp; sp += 10 * tmp; }
+		if ( gp < 0 ) { int tmp = (int) Math.ceil( gp / 10.0 ); pp -= tmp; gp += 10 * tmp; }
+	}
+
+	@Override
+	public int compareTo(Money o) {
+		return Integer.compare(asCopper(), o.asCopper());
+	}
+	
+	public static Money fromCopper(int cp) {
+		final int pp = cp / 1000; cp -= pp * 1000;
+		final int gp = cp / 100; cp -= gp * 100;
+		final int sp = cp / 10; cp -= sp * 10;
+		return new Money(pp, gp, sp, cp);
+	}
+
+	public int asCopper() {
+		return cp + sp * 10 + gp * 100 + pp * 1000;
+	}
+}