feat: support multiplayer mode in teapot (#2317)

src/main/java/emu/grasscutter/game/home/HomeWorld.java

@@ -0,0 +1,162 @@
+package emu.grasscutter.game.home;
+
+import emu.grasscutter.game.entity.EntityTeam;
+import emu.grasscutter.game.player.Player;
+import emu.grasscutter.game.world.Scene;
+import emu.grasscutter.game.world.World;
+import emu.grasscutter.net.packet.BasePacket;
+import emu.grasscutter.net.proto.ChatInfoOuterClass;
+import emu.grasscutter.server.game.GameServer;
+import emu.grasscutter.server.packet.send.PacketDelTeamEntityNotify;
+import emu.grasscutter.server.packet.send.PacketPlayerChatNotify;
+import lombok.Getter;
+
+import java.util.List;
+
+public class HomeWorld extends World {
+    @Getter
+    private final GameHome home;
+
+    public HomeWorld(GameServer server, Player owner) {
+        super(server, owner);
+
+        this.home = owner.isOnline() ? owner.getHome() : GameHome.getByUid(owner.getUid());
+        server.registerHomeWorld(this);
+    }
+
+    @Override
+    public synchronized void addPlayer(Player player) {
+        // Check if player already in
+        if (this.getPlayers().contains(player)) {
+            return;
+        }
+
+        // Remove player from prev world
+        if (player.getWorld() != null) {
+            player.getWorld().removePlayer(player);
+        }
+
+        // Register
+        player.setWorld(this);
+        this.getPlayers().add(player);
+
+        // Set player variables
+        if (this.getHost().equals(player)) {
+            player.setPeerId(1);
+            this.getGuests().forEach(player1 -> player1.setPeerId(player1.getPeerId() + 1));
+        } else {
+            player.setPeerId(this.getNextPeerId());
+        }
+
+        player.getTeamManager().setEntity(new EntityTeam(player));
+
+        // Copy main team to multiplayer team
+        if (this.isMultiplayer()) {
+            player
+                .getTeamManager()
+                .getMpTeam()
+                .copyFrom(
+                    player.getTeamManager().getCurrentSinglePlayerTeamInfo(),
+                    player.getTeamManager().getMaxTeamSize());
+            player.getTeamManager().setCurrentCharacterIndex(0);
+
+            if (!player.equals(this.getHost())) {
+                this.broadcastPacket(
+                    new PacketPlayerChatNotify(
+                        player,
+                        0,
+                        ChatInfoOuterClass.ChatInfo.SystemHint.newBuilder()
+                            .setType(ChatInfoOuterClass.ChatInfo.SystemHintType.SYSTEM_HINT_TYPE_CHAT_ENTER_WORLD.getNumber())
+                            .build()));
+            }
+        }
+
+        // Add to scene
+        var scene = this.getSceneById(player.getSceneId());
+        scene.addPlayer(player);
+
+        // Info packet for other players
+        if (this.getPlayers().size() > 1) {
+            this.updatePlayerInfos(player);
+        }
+    }
+
+    @Override
+    public synchronized void removePlayer(Player player) {
+        // Remove team entities
+        this.broadcastPacket(
+            new PacketDelTeamEntityNotify(
+                player.getSceneId(),
+                this.getPlayers().stream()
+                    .map(
+                        p ->
+                            p.getTeamManager().getEntity() == null
+                                ? 0
+                                : p.getTeamManager().getEntity().getId())
+                    .toList()));
+
+        // Deregister
+        this.getPlayers().remove(player);
+        player.setWorld(null);
+
+        // Remove from scene
+        Scene scene = this.getSceneById(player.getSceneId());
+        scene.removePlayer(player);
+
+        // Info packet for other players
+        if (this.getPlayers().size() > 0) {
+            this.updatePlayerInfos(player);
+        }
+
+        this.broadcastPacket(
+            new PacketPlayerChatNotify(
+                player,
+                0,
+                ChatInfoOuterClass.ChatInfo.SystemHint.newBuilder()
+                    .setType(ChatInfoOuterClass.ChatInfo.SystemHintType.SYSTEM_HINT_TYPE_CHAT_LEAVE_WORLD.getNumber())
+                    .build()));
+    }
+
+    @Override
+    public int getNextPeerId() {
+        return this.getPlayers().size() + 1;
+    }
+
+    @Override
+    public synchronized void setHost(Player host) {
+        super.setHost(host);
+    }
+
+    @Override
+    public final boolean isMultiplayer() {
+        return true;
+    }
+
+    @Override
+    public final boolean isPaused() {
+        return false;
+    }
+
+    @Override
+    public final boolean isTimeLocked() {
+        return false;
+    }
+
+    public int getOwnerUid() {
+        return this.getHost().getUid();
+    }
+
+    public List<Player> getGuests() {
+        return this.getPlayers().stream().filter(player -> !player.equals(this.getHost())).toList();
+    }
+
+    public boolean isInHome(Player player) {
+        return this.getPlayers().contains(player);
+    }
+
+    public void sendPacketToHostIfOnline(BasePacket basePacket) {
+        if (this.getHost().isOnline()) {
+            this.getHost().sendPacket(basePacket);
+        }
+    }
+}