Implement gacha banners (not newbie)

src/main/java/emu/nebula/game/gacha/GachaManager.java

@@ -0,0 +1,46 @@
+package emu.nebula.game.gacha;
+
+import java.util.Collection;
+
+import emu.nebula.Nebula;
+import emu.nebula.data.resources.GachaDef;
+import emu.nebula.game.player.Player;
+import emu.nebula.game.player.PlayerManager;
+
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
+
+public class GachaManager extends PlayerManager {
+    private final Int2ObjectMap<GachaBannerInfo> bannerInfos;
+    private boolean loaded;
+    
+    public GachaManager(Player player) {
+        super(player);
+        this.bannerInfos = new Int2ObjectOpenHashMap<>();
+    }
+    
+    public synchronized Collection<GachaBannerInfo> getBannerInfos() {
+        return this.bannerInfos.values();
+    }
+    
+    public synchronized GachaBannerInfo getBannerInfo(GachaDef gachaData) {
+        if (!this.loaded) {
+            this.loadFromDatabase();
+        }
+        
+        return this.bannerInfos.computeIfAbsent(
+                gachaData.getId(), 
+                i -> new GachaBannerInfo(this.getPlayer(), gachaData)
+        );
+    }
+    
+    private void loadFromDatabase() {
+        var db = Nebula.getGameDatabase();
+        
+        db.getObjects(GachaBannerInfo.class, "playerUid", getPlayerUid()).forEach(bannerInfo -> {
+            this.bannerInfos.put(bannerInfo.getBannerId(), bannerInfo);
+        });
+        
+        this.loaded = true;
+    }
+}