Adds XP at the end of a battle and checks for leveling up

lib/goby/battle/battle.rb

@@ -37,8 +37,18 @@ def determine_winner
         end
       end
 
-      #If @entity_a is dead return @entity_b, otherwise return @entity_a
-      entity_a.stats[:hp] <=0 ? entity_b : entity_a
+      # If @entity_a is dead set winner to @entity_b, otherwise @entity_a
+      winner = entity_a.stats[:hp] <=0 ? entity_b : entity_a
+      # Sets loser to entity with 0 or less hp
+      loser = entity_a.stats[:hp] <=0 ? entity_a : entity_b
+      if winner.class != Monster
+        # Gain XP based on opponent
+        gain_xp(winner, loser)
+        # Check if winner can level up
+        winner.check_level
+        # return winner
+      end
+      winner
     end
 
     private
@@ -64,7 +74,42 @@ def someone_dead?
       entity_a.stats[:hp] <= 0 || entity_b.stats[:hp] <= 0
     end
 
+    # Gain XP based on defeated opponent
+    #
+    # @param [Entity] the winner of the battle
+    # @param [Entity] the loser of the battle
+    # @return [Integer] the amount of xp gained
+    def gain_xp(winner, loser)
+      # Monsters should not level up fighting players
+      if winner.class != Monster
+        # Different Mechanics for monster vs pvp
+        if loser.class == Monster
+          # Gain monsters XP
+          xp = winner[:xp] + loser[:xp]
+        else
+          # Calculate XP gain based on level difference
+          level_diff = winner[:level] - loser[:level]
+          # About 10 victories to level up
+          if level_diff == 0
+            xp = (winner.nextLevel(winner[:level]) * 0.01).floor
+          # 10% more XP for each level down
+          elsif level_diff > 0
+            xp = (winner.nextLevel(winner[:level]) * 0.01 * level_diff).floor
+          else
+            amount = 0.01-0.001 * level_diff
+            # Minimum XP gain
+            if amount <= 0
+              amount = 0.001
+            end
+            xp = (winner.nextLevel(winner[:level]) * amount).floor
+          end
+        end
+        winner.set_stats(xp: xp)
+      end
+      xp
+    end
+
     attr_reader :entity_a, :entity_b
   end
 
-end
+end

lib/goby/entity/entity.rb

@@ -246,6 +246,8 @@ def set_stats(passed_in_stats)
     end
 
     #calculates XP needed to reach the next level
+    #
+    # @param [Integer] :current level of the entity
     def nextLevel(level)
       #set for growth rate
       exponent = 1.5