Battles with monsters in mazes now drop items

src/main/java/emu/lunarcore/data/GameData.java

@@ -36,6 +36,7 @@ public class GameData {
     private static Int2ObjectMap<EquipmentPromotionExcel> equipmentPromotionExcelMap = new Int2ObjectOpenHashMap<>();
     private static Int2ObjectMap<MazeBuffExcel> mazeBuffExcelMap = new Int2ObjectOpenHashMap<>();
     private static Int2ObjectMap<CocoonExcel> cocoonExcelMap = new Int2ObjectOpenHashMap<>();
+    private static Int2ObjectMap<MonsterDropExcel> monsterDropExcelMap = new Int2ObjectOpenHashMap<>();
     
     private static Int2ObjectMap<PlayerLevelExcel> playerLevelExcelMap = new Int2ObjectOpenHashMap<>();
     private static Int2ObjectMap<ExpTypeExcel> expTypeExcelMap = new Int2ObjectOpenHashMap<>();
@@ -117,4 +118,8 @@ public class GameData {
     public static CocoonExcel getCocoonExcel(int cocoonId, int worldLevel) {
         return cocoonExcelMap.get((cocoonId << 8) + worldLevel);
     }
+    
+    public static MonsterDropExcel getMonsterDropExcel(int monsterNpcId, int worldLevel) {
+        return monsterDropExcelMap.get((monsterNpcId << 4) + worldLevel);
+    }
 }

src/main/java/emu/lunarcore/data/excel/MonsterDropExcel.java

@@ -0,0 +1,24 @@
+package emu.lunarcore.data.excel;
+
+import java.util.List;
+
+import emu.lunarcore.data.GameResource;
+import emu.lunarcore.data.ResourceType;
+import emu.lunarcore.data.common.ItemParam;
+import lombok.Getter;
+
+@Getter
+@ResourceType(name = {"MonsterDrop.json"})
+public class MonsterDropExcel extends GameResource {
+    private int MonsterTemplateID;
+    private int WorldLevel;
+    private int AvatarExpReward;
+    
+    private List<ItemParam> DisplayItemList;
+    
+    @Override
+    public int getId() {
+        return (MonsterTemplateID << 4) + WorldLevel;
+    }
+
+}

src/main/java/emu/lunarcore/game/battle/Battle.java

@@ -5,10 +5,12 @@ import java.util.Collection;
 import java.util.List;
 
 import emu.lunarcore.data.GameData;
+import emu.lunarcore.data.common.ItemParam;
 import emu.lunarcore.data.excel.MazeBuffExcel;
 import emu.lunarcore.data.excel.StageExcel;
 import emu.lunarcore.game.avatar.GameAvatar;
 import emu.lunarcore.game.enums.StageType;
+import emu.lunarcore.game.inventory.GameItem;
 import emu.lunarcore.game.player.Player;
 import emu.lunarcore.game.player.PlayerLineup;
 import emu.lunarcore.game.scene.entity.EntityMonster;
@@ -17,6 +19,7 @@ import emu.lunarcore.proto.SceneMonsterOuterClass.SceneMonster;
 import emu.lunarcore.proto.SceneMonsterWaveOuterClass.SceneMonsterWave;
 import emu.lunarcore.util.Utils;
 
+import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
 import it.unimi.dsi.fastutil.ints.IntList;
 import lombok.Getter;
 
@@ -28,6 +31,7 @@ public class Battle {
     private final List<EntityMonster> npcMonsters;
     private final List<MazeBuff> buffs;
     private final List<StageExcel> stages;
+    private final List<GameItem> drops;
     private final long timestamp;
     
     private Battle(Player player, PlayerLineup lineup) {
@@ -37,6 +41,7 @@ public class Battle {
         this.npcMonsters = new ArrayList<>();
         this.buffs = new ArrayList<>();
         this.stages = new ArrayList<>();
+        this.drops = new ArrayList<>();
         this.timestamp = System.currentTimeMillis();
     }
     
@@ -84,6 +89,8 @@ public class Battle {
         return count;
     }
     
+    // Battle buffs
+    
     public MazeBuff addBuff(int buffId, int ownerIndex) {
         return addBuff(buffId, ownerIndex, 0xffffffff);
     }
@@ -102,6 +109,51 @@ public class Battle {
         this.buffs.clear();
     }
     
+    // Drops
+    
+    public void calculateDrops() {
+        // TODO this isnt the right way drops are calculated on the official server... but its good enough for now
+        if (this.getNpcMonsters().size() == 0) {
+            return;
+        }
+        
+        var dropMap = new Int2IntOpenHashMap();
+        
+        // Get drops from monsters
+        for (EntityMonster monster : this.getNpcMonsters()) {
+            var dropExcel = GameData.getMonsterDropExcel(monster.getExcel().getId(), monster.getWorldLevel());
+            if (dropExcel == null || dropExcel.getDisplayItemList() == null) {
+                continue;
+            }
+            
+            for (ItemParam param : dropExcel.getDisplayItemList()) {
+                int id = param.getId();
+                int count = Utils.randomRange(0, 3);
+                
+                if (id == 2) {
+                    count = dropExcel.getAvatarExpReward();
+                }
+                
+                dropMap.put(id, count + dropMap.get(id));
+            }
+        }
+        
+        for (var entry : dropMap.int2IntEntrySet()) {
+            if (entry.getIntValue() <= 0) {
+                continue;
+            }
+            
+            // Create item and add it to player
+            GameItem item = new GameItem(entry.getIntKey(), entry.getIntValue());
+
+            if (getPlayer().getInventory().addItem(item)) {
+               this.getDrops().add(item);
+            }
+        }
+    }
+    
+    // Serialization
+    
     public SceneBattleInfo toProto() {
         // Build battle info
         var proto = SceneBattleInfo.newInstance()

src/main/java/emu/lunarcore/game/battle/BattleService.java

@@ -179,10 +179,10 @@ public class BattleService extends BaseGameService {
         player.sendPacket(new PacketStartCocoonStageScRsp(battle, cocoonId, wave));
     }
 
-    public void finishBattle(Player player, BattleEndStatus result, RepeatedMessage<AvatarBattleInfo> battleAvatars) {
+    public Battle finishBattle(Player player, BattleEndStatus result, RepeatedMessage<AvatarBattleInfo> battleAvatars) {
         // Sanity check to make sure player is in a battle
         if (!player.isInBattle()) {
-            return;
+            return null;
         }
         
         // Get battle object and setup variables
@@ -199,6 +199,8 @@ public class BattleService extends BaseGameService {
                 for (var monster : battle.getNpcMonsters()) {
                     player.getScene().removeEntity(monster);
                 }
+                // Drops
+                battle.calculateDrops();
             }
             case BATTLE_END_LOSE -> {
                 // Set avatar hp to 20% if the player's party is downed
@@ -247,6 +249,7 @@ public class BattleService extends BaseGameService {
         
         // Done - Clear battle object from player
         player.setBattle(null);
+        return battle;
     }
 
     public void reEnterBattle(Player player, int stageId) {

src/main/java/emu/lunarcore/server/packet/recv/HandlerPVEBattleResultCsReq.java

@@ -1,5 +1,6 @@
 package emu.lunarcore.server.packet.recv;
 
+import emu.lunarcore.game.battle.Battle;
 import emu.lunarcore.proto.PVEBattleResultCsReqOuterClass.PVEBattleResultCsReq;
 import emu.lunarcore.server.game.GameSession;
 import emu.lunarcore.server.packet.CmdId;
@@ -14,13 +15,17 @@ public class HandlerPVEBattleResultCsReq extends PacketHandler {
     public void handle(GameSession session, byte[] header, byte[] data) throws Exception {
         var req = PVEBattleResultCsReq.parseFrom(data);
 
-        session.getServer().getBattleService().finishBattle(
+        Battle battle = session.getServer().getBattleService().finishBattle(
                 session.getPlayer(),
                 req.getEndStatus(),
                 req.getStt().getBattleAvatarList()
         );
 
-        session.send(new PacketPVEBattleResultScRsp(req));
+        if (battle != null) {
+            session.send(new PacketPVEBattleResultScRsp(req, battle));
+        } else {
+            session.send(new PacketPVEBattleResultScRsp());
+        }
     }
 
 }

src/main/java/emu/lunarcore/server/packet/send/PacketPVEBattleResultScRsp.java

@@ -1,5 +1,7 @@
 package emu.lunarcore.server.packet.send;
 
+import emu.lunarcore.game.battle.Battle;
+import emu.lunarcore.game.inventory.GameItem;
 import emu.lunarcore.proto.ItemListOuterClass.ItemList;
 import emu.lunarcore.proto.PVEBattleResultCsReqOuterClass.PVEBattleResultCsReq;
 import emu.lunarcore.proto.PVEBattleResultScRspOuterClass.PVEBattleResultScRsp;
@@ -7,14 +9,31 @@ import emu.lunarcore.server.packet.BasePacket;
 import emu.lunarcore.server.packet.CmdId;
 
 public class PacketPVEBattleResultScRsp extends BasePacket {
-
-    public PacketPVEBattleResultScRsp(PVEBattleResultCsReq req) {
+    
+    public PacketPVEBattleResultScRsp() {
         super(CmdId.PVEBattleResultScRsp);
 
+        var data = PVEBattleResultScRsp.newInstance()
+                .setRetcode(1);
+
+        this.setData(data);
+    }
+
+    public PacketPVEBattleResultScRsp(PVEBattleResultCsReq req, Battle battle) {
+        super(CmdId.PVEBattleResultScRsp);
+        
+        // Item drop list data
+        ItemList dropData = ItemList.newInstance();
+        
+        for (GameItem drop : battle.getDrops()) {
+            dropData.addItemList(drop.toProto());
+        }
+
+        // Battle result
         var data = PVEBattleResultScRsp.newInstance()
                 .setUnk1(ItemList.newInstance())
-                .setUnk2(ItemList.newInstance())
                 .setUnk3(ItemList.newInstance())
+                .setDropData(dropData)
                 .setResVersion(Integer.toString(req.getClientResVersion()))
                 .setBinVersion("")
                 .setBattleId(req.getBattleId())