src/game/java/net/minecraft/client/quickplay/QuickPlay.java

package net.minecraft.client.quickplay;

import com.mojang.realmsclient.RealmsMainScreen;
import com.mojang.realmsclient.client.RealmsClient;
import com.mojang.realmsclient.dto.RealmsServer;
import com.mojang.realmsclient.dto.RealmsServerList;
import com.mojang.realmsclient.exception.RealmsServiceException;
import com.mojang.realmsclient.gui.screens.RealmsLongRunningMcoTaskScreen;
import com.mojang.realmsclient.util.task.GetServerDetailsTask;
import net.minecraft.client.Minecraft;
import net.minecraft.client.gui.screens.ConnectScreen;
import net.minecraft.client.gui.screens.DisconnectedScreen;
import net.minecraft.client.gui.screens.Screen;
import net.minecraft.client.gui.screens.TitleScreen;
import net.minecraft.client.gui.screens.multiplayer.JoinMultiplayerScreen;
import net.minecraft.client.gui.screens.worldselection.SelectWorldScreen;
import net.minecraft.client.main.GameConfig;
import net.minecraft.client.multiplayer.ServerData;
import net.minecraft.client.multiplayer.ServerList;
import net.minecraft.client.multiplayer.resolver.ServerAddress;
import net.minecraft.client.resources.language.I18n;
import net.minecraft.network.chat.Component;
import net.minecraft.util.StringUtil;
import net.minecraftforge.api.distmarker.Dist;
import net.minecraftforge.api.distmarker.OnlyIn;

@OnlyIn(Dist.CLIENT)
public class QuickPlay {
    public static final Component ERROR_TITLE = Component.translatable("quickplay.error.title");
    private static final Component INVALID_IDENTIFIER = Component.translatable("quickplay.error.invalid_identifier");
    private static final Component REALM_CONNECT = Component.translatable("quickplay.error.realm_connect");
    private static final Component REALM_PERMISSION = Component.translatable("quickplay.error.realm_permission");
    private static final Component TO_TITLE = Component.translatable("gui.toTitle");
    private static final Component TO_WORLD_LIST = Component.translatable("gui.toWorld");
    private static final Component TO_REALMS_LIST = Component.translatable("gui.toRealms");

    public static void connect(Minecraft p_279319_, GameConfig.QuickPlayData p_279291_, RealmsClient p_279322_) {
        String s = p_279291_.singleplayer();
        String s1 = p_279291_.multiplayer();
        String s2 = p_279291_.realms();
        if (!StringUtil.isBlank(s)) {
            joinSingleplayerWorld(p_279319_, s);
        } else if (!StringUtil.isBlank(s1)) {
            joinMultiplayerWorld(p_279319_, s1);
        } else if (!StringUtil.isBlank(s2)) {
            joinRealmsWorld(p_279319_, p_279322_, s2);
        }
    }

    private static void joinSingleplayerWorld(Minecraft p_279420_, String p_279459_) {
        if (!p_279420_.getLevelSource().levelExists(p_279459_)) {
            Screen screen = new SelectWorldScreen(new TitleScreen());
            p_279420_.setScreen(new DisconnectedScreen(screen, ERROR_TITLE, INVALID_IDENTIFIER, TO_WORLD_LIST));
        } else {
            p_279420_.createWorldOpenFlows().openWorld(p_279459_, () -> p_279420_.setScreen(new TitleScreen()));
        }
    }

    private static void joinMultiplayerWorld(Minecraft p_279276_, String p_279128_) {
        ServerList serverlist = new ServerList(p_279276_);
        serverlist.load();
        ServerData serverdata = serverlist.get(p_279128_);
        if (serverdata == null) {
            serverdata = new ServerData(I18n.get("selectServer.defaultName"), p_279128_, ServerData.Type.OTHER);
            serverlist.add(serverdata, true);
            serverlist.save();
        }

        ServerAddress serveraddress = ServerAddress.parseString(p_279128_);
        ConnectScreen.startConnecting(new JoinMultiplayerScreen(new TitleScreen()), p_279276_, serveraddress, serverdata, true, null);
    }

    private static void joinRealmsWorld(Minecraft p_279320_, RealmsClient p_279468_, String p_279371_) {
        long i;
        RealmsServerList realmsserverlist;
        try {
            i = Long.parseLong(p_279371_);
            realmsserverlist = p_279468_.listRealms();
        } catch (NumberFormatException numberformatexception) {
            Screen screen1 = new RealmsMainScreen(new TitleScreen());
            p_279320_.setScreen(new DisconnectedScreen(screen1, ERROR_TITLE, INVALID_IDENTIFIER, TO_REALMS_LIST));
            return;
        } catch (RealmsServiceException realmsserviceexception) {
            Screen screen = new TitleScreen();
            p_279320_.setScreen(new DisconnectedScreen(screen, ERROR_TITLE, REALM_CONNECT, TO_TITLE));
            return;
        }

        RealmsServer realmsserver = realmsserverlist.servers.stream().filter(p_279424_ -> p_279424_.id == i).findFirst().orElse(null);
        if (realmsserver == null) {
            Screen screen2 = new RealmsMainScreen(new TitleScreen());
            p_279320_.setScreen(new DisconnectedScreen(screen2, ERROR_TITLE, REALM_PERMISSION, TO_REALMS_LIST));
        } else {
            TitleScreen titlescreen = new TitleScreen();
            GetServerDetailsTask getserverdetailstask = new GetServerDetailsTask(titlescreen, realmsserver);
            p_279320_.setScreen(new RealmsLongRunningMcoTaskScreen(titlescreen, getserverdetailstask));
        }
    }
}