Implement achievements properly

src/main/java/emu/nebula/server/handlers/HandlerAchievementRewardReceiveReq.java

@@ -0,0 +1,28 @@
+package emu.nebula.server.handlers;
+
+import emu.nebula.net.NetHandler;
+import emu.nebula.net.NetMsgId;
+import emu.nebula.proto.AchievementRewardReceive.AchievementRewardReq;
+import emu.nebula.net.HandlerId;
+import emu.nebula.net.GameSession;
+
+@HandlerId(NetMsgId.achievement_reward_receive_req)
+public class HandlerAchievementRewardReceiveReq extends NetHandler {
+
+    @Override
+    public byte[] handle(GameSession session, byte[] message) throws Exception {
+        // Parse request
+        var req = AchievementRewardReq.parseFrom(message);
+        
+        // Claim rewards
+        var change = session.getPlayer().getAchievementManager().recvRewards(req.getIds());
+        
+        if (change == null) {
+            return session.encodeMsg(NetMsgId.achievement_reward_receive_failed_ack);
+        }
+        
+        // Encode and send
+        return session.encodeMsg(NetMsgId.achievement_reward_receive_succeed_ack, change.toProto());
+    }
+
+}