fabric-carpet/src/main/java/carpet/patches/EntityPlayerMPFake.java

package carpet.patches;

import carpet.CarpetSettings;
import com.mojang.authlib.GameProfile;
import net.minecraft.block.entity.SkullBlockEntity;
import net.minecraft.entity.Entity;
import net.minecraft.entity.player.PlayerEntity;
import net.minecraft.item.ItemStack;
import net.minecraft.network.packet.s2c.play.EntityPositionS2CPacket;
import net.minecraft.network.packet.s2c.play.EntitySetHeadYawS2CPacket;
import net.minecraft.network.packet.s2c.play.PlayerListS2CPacket;
import net.minecraft.entity.damage.DamageSource;
import net.minecraft.entity.player.HungerManager;
import net.minecraft.network.NetworkSide;
import net.minecraft.text.Text;
import net.minecraft.text.TranslatableText;
import net.minecraft.server.MinecraftServer;
import net.minecraft.server.ServerTask;
import net.minecraft.server.network.ServerPlayerEntity;
import net.minecraft.server.world.ServerWorld;
import net.minecraft.util.UserCache;
import net.minecraft.util.registry.RegistryKey;
import net.minecraft.world.GameMode;
import net.minecraft.world.World;
import carpet.fakes.ServerPlayerEntityInterface;
import carpet.utils.Messenger;

import java.util.concurrent.atomic.AtomicReference;

@SuppressWarnings("EntityConstructor")
public class EntityPlayerMPFake extends ServerPlayerEntity
{
    public Runnable fixStartingPosition = () -> {};
    public boolean isAShadow;

    public static EntityPlayerMPFake createFake(String username, MinecraftServer server, double d0, double d1, double d2, double yaw, double pitch, RegistryKey<World> dimensionId, GameMode gamemode, boolean flying)
    {
        //prolly half of that crap is not necessary, but it works
        ServerWorld worldIn = server.getWorld(dimensionId);
        UserCache.setUseRemote(false);
        GameProfile gameprofile;
        try {
            gameprofile = server.getUserCache().findByName(username).orElse(null); //findByName  .orElse(null)
        }
        finally {
            UserCache.setUseRemote(server.isDedicated() && server.isOnlineMode());
        }
        if (gameprofile == null)
        {
            if (!CarpetSettings.allowSpawningOfflinePlayers)
            {
                return null;
            } else {
                gameprofile = new GameProfile(PlayerEntity.getOfflinePlayerUuid(username), username);
            }
        }
        if (gameprofile.getProperties().containsKey("textures"))
        {
            AtomicReference<GameProfile> result = new AtomicReference<>();
            SkullBlockEntity.loadProperties(gameprofile, result::set);
            gameprofile = result.get();
        }
        EntityPlayerMPFake instance = new EntityPlayerMPFake(server, worldIn, gameprofile, false);
        instance.fixStartingPosition = () -> instance.refreshPositionAndAngles(d0, d1, d2, (float) yaw, (float) pitch);
        server.getPlayerManager().onPlayerConnect(new NetworkManagerFake(NetworkSide.SERVERBOUND), instance);
        instance.teleport(worldIn, d0, d1, d2, (float)yaw, (float)pitch);
        instance.setHealth(20.0F);
        instance.unsetRemoved();
        instance.stepHeight = 0.6F;
        instance.interactionManager.changeGameMode(gamemode);
        server.getPlayerManager().sendToDimension(new EntitySetHeadYawS2CPacket(instance, (byte) (instance.headYaw * 256 / 360)), dimensionId);//instance.dimension);
        server.getPlayerManager().sendToDimension(new EntityPositionS2CPacket(instance), dimensionId);//instance.dimension);
        //instance.world.getChunkManager(). updatePosition(instance);
        instance.dataTracker.set(PLAYER_MODEL_PARTS, (byte) 0x7f); // show all model layers (incl. capes)
        instance.getAbilities().flying = flying;
        return instance;
    }

    public static EntityPlayerMPFake createShadow(MinecraftServer server, ServerPlayerEntity player)
    {
        player.getServer().getPlayerManager().remove(player);
        player.networkHandler.disconnect(new TranslatableText("multiplayer.disconnect.duplicate_login"));
        ServerWorld worldIn = player.getWorld();//.getWorld(player.dimension);
        GameProfile gameprofile = player.getGameProfile();
        EntityPlayerMPFake playerShadow = new EntityPlayerMPFake(server, worldIn, gameprofile, true);
        server.getPlayerManager().onPlayerConnect(new NetworkManagerFake(NetworkSide.SERVERBOUND), playerShadow);

        playerShadow.setHealth(player.getHealth());
        playerShadow.networkHandler.requestTeleport(player.getX(), player.getY(), player.getZ(), player.getYaw(), player.getPitch());
        playerShadow.interactionManager.changeGameMode(player.interactionManager.getGameMode());
        ((ServerPlayerEntityInterface) playerShadow).getActionPack().copyFrom(((ServerPlayerEntityInterface) player).getActionPack());
        playerShadow.stepHeight = 0.6F;
        playerShadow.dataTracker.set(PLAYER_MODEL_PARTS, player.getDataTracker().get(PLAYER_MODEL_PARTS));


        server.getPlayerManager().sendToDimension(new EntitySetHeadYawS2CPacket(playerShadow, (byte) (player.headYaw * 256 / 360)), playerShadow.world.getRegistryKey());
        server.getPlayerManager().sendToAll(new PlayerListS2CPacket(PlayerListS2CPacket.Action.ADD_PLAYER, playerShadow));
        //player.world.getChunkManager().updatePosition(playerShadow);
        playerShadow.getAbilities().flying = player.getAbilities().flying;
        return playerShadow;
    }

    private EntityPlayerMPFake(MinecraftServer server, ServerWorld worldIn, GameProfile profile, boolean shadow)
    {
        super(server, worldIn, profile);
        isAShadow = shadow;
    }

    @Override
    protected void onEquipStack(ItemStack stack)
    {
        if (!isUsingItem()) super.onEquipStack(stack);
    }

    @Override
    public void kill()
    {
        kill(Messenger.s("Killed"));
    }

    public void kill(Text reason)
    {
        shakeOff();
        this.server.send(new ServerTask(this.server.getTicks(), () -> {
            this.networkHandler.onDisconnected(reason);
        }));
    }

    @Override
    public void tick()
    {
        if (this.getServer().getTicks() % 10 == 0)
        {
            this.networkHandler.syncWithPlayerPosition();
            //this.world.getChunkManager().updatePosition(this);
            onTeleportationDone(); //<- causes hard crash but would need to be done to enable portals // not as of 1.17
        }
        try
        {
            super.tick();
            this.playerTick();
        }
        catch (NullPointerException ignored)
        {
            // happens with that paper port thingy - not sure what that would fix, but hey
            // the game not gonna crash violently.
        }


    }

    private void shakeOff()
    {
        if (getVehicle() instanceof PlayerEntity) stopRiding();
        for (Entity passenger : getPassengersDeep())
        {
            if (passenger instanceof PlayerEntity) passenger.stopRiding();
        }
    }

    @Override
    public void onDeath(DamageSource cause)
    {
        shakeOff();
        super.onDeath(cause);
        setHealth(20);
        this.hungerManager = new HungerManager();
        kill(this.getDamageTracker().getDeathMessage());
    }

    @Override
    public String getIp()
    {
        return "127.0.0.1";
    }
}