Separate the dispatch and game servers (pt. 1)

gacha is still broken, handbook still needs to be done

src/main/java/emu/grasscutter/server/dispatch/DispatchClient.java

@@ -0,0 +1,138 @@
+package emu.grasscutter.server.dispatch;
+
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import emu.grasscutter.Grasscutter;
+import emu.grasscutter.server.game.GameServer;
+import emu.grasscutter.server.http.handlers.GachaHandler;
+import emu.grasscutter.utils.Crypto;
+import lombok.Getter;
+import org.java_websocket.WebSocket;
+import org.java_websocket.client.WebSocketClient;
+import org.java_websocket.handshake.ServerHandshake;
+import org.slf4j.Logger;
+
+import java.net.ConnectException;
+import java.net.URI;
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.BiConsumer;
+import java.util.function.Consumer;
+
+import static emu.grasscutter.config.Configuration.DISPATCH_INFO;
+
+public final class DispatchClient extends WebSocketClient implements IDispatcher {
+    @Getter private final Logger logger
+        = Grasscutter.getLogger();
+    @Getter private final Map<Integer, BiConsumer<WebSocket, JsonElement>> handlers
+        = new HashMap<>();
+
+    @Getter private final Map<Integer, List<Consumer<JsonElement>>> callbacks
+        = new HashMap<>();
+
+    public DispatchClient(URI serverUri) {
+        super(serverUri);
+
+        // Mark this client as authenticated.
+        this.setAttachment(true);
+
+        this.registerHandler(PacketIds.GachaHistoryReq, this::fetchGachaHistory);
+    }
+
+    /**
+     * Handles the gacha history request packet sent by the client.
+     *
+     * @param socket The socket the packet was received from.
+     * @param object The packet data.
+     */
+    private void fetchGachaHistory(WebSocket socket, JsonElement object) {
+        var message = IDispatcher.decode(object);
+        var accountId = message.get("accountId").getAsString();
+        var page = message.get("page").getAsInt();
+        var type = message.get("gachaType").getAsInt();
+
+        // Create a response object.
+        var response = new JsonObject();
+
+        // Find a player with the specified account ID.
+        var player = Grasscutter.getGameServer()
+            .getPlayerByAccountId(accountId);
+        if (player == null) {
+            response.addProperty("retcode", 1);
+            this.sendMessage(PacketIds.GachaHistoryRsp, response);
+            return;
+        }
+
+        // Fetch the gacha records.
+        GachaHandler.fetchGachaRecords(
+            player, response, page, type);
+
+        // Send the response.
+        this.sendMessage(PacketIds.GachaHistoryRsp, response);
+    }
+
+    /**
+     * Sends a serialized encrypted message to the server.
+     *
+     * @param message The message to send.
+     */
+    public void sendMessage(int packetId, Object message) {
+        var serverMessage = this.encodeMessage(packetId, message);
+        // Serialize the message into JSON.
+        var serialized = JSON.toJson(serverMessage)
+            .getBytes(StandardCharsets.UTF_8);
+        // Encrypt the message.
+        Crypto.xor(serialized, DISPATCH_INFO.encryptionKey);
+        // Send the message.
+        this.send(serialized);
+    }
+
+    @Override
+    public void onOpen(ServerHandshake handshake) {
+        // Attempt to handshake with the server.
+        this.sendMessage(PacketIds.LoginNotify, DISPATCH_INFO.dispatchKey);
+
+        this.getLogger().info("Dispatch connection opened.");
+    }
+
+    @Override
+    public void onMessage(String message) {
+        this.getLogger().debug("Received dispatch message from server:\n{}",
+            message);
+    }
+
+    @Override
+    public void onMessage(ByteBuffer bytes) {
+        this.handleMessage(this, bytes.array());
+    }
+
+    @Override
+    public void onClose(int code, String reason, boolean remote) {
+        this.getLogger().info("Dispatch connection closed.");
+
+        // Attempt to reconnect.
+        new Thread(() -> {
+            try {
+                // Wait 5 seconds before reconnecting.
+                Thread.sleep(5000L);
+            } catch (Exception ignored) { }
+
+            // Attempt to reconnect.
+            Grasscutter.getGameServer().setDispatchClient(
+                new DispatchClient(GameServer.getDispatchUrl()));
+            Grasscutter.getGameServer().getDispatchClient().connect();
+        }).start();
+    }
+
+    @Override
+    public void onError(Exception ex) {
+        if (ex instanceof ConnectException) {
+            this.getLogger().info("Failed to reconnect, trying again in 5s...");
+        } else {
+            this.getLogger().error("Dispatch connection error.", ex);
+        }
+    }
+}