Implement commissions

src/main/java/emu/nebula/game/inventory/ItemRewardList.java

@@ -0,0 +1,21 @@
+package emu.nebula.game.inventory;
+
+import java.util.ArrayList;
+
+public class ItemRewardList extends ArrayList<ItemRewardParam> {
+    private static final long serialVersionUID = -4317949564663392685L;
+
+    public ItemRewardList() {
+        super();
+    }
+    
+    public ItemParamMap generateRewards() {
+        var map = new ItemParamMap();
+        
+        for (var param : this) {
+            map.add(param.getId(), param.getRandomCount());
+        }
+        
+        return map;
+    }
+}

src/main/java/emu/nebula/game/inventory/ItemRewardParam.java

@@ -0,0 +1,25 @@
+package emu.nebula.game.inventory;
+
+import emu.nebula.util.Utils;
+import lombok.Getter;
+
+@Getter
+public class ItemRewardParam {
+    public int id;
+    public int min;
+    public int max;
+    
+    public ItemRewardParam(int id, int min, int max) {
+        this.id = id;
+        this.min = min;
+        this.max = max;
+    }
+    
+    public int getRandomCount() {
+        if (this.min == this.max) {
+            return this.min;
+        }
+        
+        return Utils.randomRange(this.min, this.max);
+    }
+}