PLayer portal rescue with fake blocks replacing portal

src/main/java/org/samo_lego/simpleauth/SimpleAuth.java

@@ -157,6 +157,9 @@ public class SimpleAuth implements DedicatedServerModInitializer {
 		if(config.main.spawnOnJoin)
 			teleportPlayer(player, false);
 
+		// Updating chunk if needed (if portal rescue action happened)
+		if(deauthenticatedUsers.get(convertUuid(player)).wasInPortal)
+
 		deauthenticatedUsers.remove(convertUuid(player));
 
 		// Player no longer needs to be invisible and invulnerable

src/main/java/org/samo_lego/simpleauth/event/AuthEventHandler.java

@@ -6,6 +6,7 @@ import net.minecraft.block.Blocks;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.item.ItemStack;
 import net.minecraft.network.packet.c2s.play.ChatMessageC2SPacket;
+import net.minecraft.network.packet.s2c.play.BlockUpdateS2CPacket;
 import net.minecraft.server.PlayerManager;
 import net.minecraft.server.network.ServerPlayerEntity;
 import net.minecraft.text.LiteralText;
@@ -13,15 +14,13 @@ import net.minecraft.text.Text;
 import net.minecraft.util.ActionResult;
 import net.minecraft.util.TypedActionResult;
 import net.minecraft.util.math.BlockPos;
-import net.minecraft.world.World;
+import org.samo_lego.simpleauth.mixin.BlockUpdateS2CPacketAccess;
 import org.samo_lego.simpleauth.storage.PlayerCache;
 
 import java.net.SocketAddress;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import static net.minecraft.block.NetherPortalBlock.AXIS;
-import static net.minecraft.util.math.Direction.Axis.Z;
 import static org.samo_lego.simpleauth.SimpleAuth.*;
 import static org.samo_lego.simpleauth.utils.UuidConverter.convertUuid;
 
@@ -92,6 +91,10 @@ public class AuthEventHandler {
             }
             // Invalidating session
             playerCache.wasAuthenticated = false;
+            if(playerCache.isRegistered)
+                player.sendMessage(new LiteralText(config.lang.loginRequired), false);
+            else
+                player.sendMessage(new LiteralText(config.lang.notRegistered), false);
         }
         else
             deauthenticatePlayer(player);
@@ -99,73 +102,26 @@ public class AuthEventHandler {
         if(config.main.spawnOnJoin)
             teleportPlayer(player, true);
 
+
         // Tries to rescue player from nether portal
         if(config.main.tryPortalRescue && player.getBlockState().getBlock().equals(Blocks.NETHER_PORTAL)) {
-            boolean wasSuccessful = false;
+            PlayerCache newPlayerCache = deauthenticatedUsers.get(uuid);
+            BlockPos pos = player.getBlockPos();
 
-            BlockState portalState = player.getBlockState();
-            World world = player.getEntityWorld();
+            // Faking portal blocks to be air
+            BlockUpdateS2CPacket feetPacket = new BlockUpdateS2CPacket();
+            ((BlockUpdateS2CPacketAccess) feetPacket).setState(new BlockState(Blocks.AIR, null));
+            ((BlockUpdateS2CPacketAccess) feetPacket).setBlockPos(pos);
+            player.networkHandler.sendPacket(feetPacket);
 
-            double x = player.getX();
-            double y = player.getY();
-            double z = player.getZ();
+            BlockUpdateS2CPacket headPacket = new BlockUpdateS2CPacket();
+            ((BlockUpdateS2CPacketAccess) headPacket).setState(new BlockState(Blocks.AIR, null));
+            ((BlockUpdateS2CPacketAccess) headPacket).setBlockPos(pos.up());
+            player.networkHandler.sendPacket(headPacket);
 
-            if(portalState.get(AXIS) == Z) {
-                // Player should be put to eastern or western block
-                if( // Checking towards east
-                        world.getBlockState(new BlockPos(x + 1, y, z)).isAir() &&
-                        world.getBlockState(new BlockPos(x + 1, y + 1, z)).isAir() &&
-                        (
-                            world.getBlockState(new BlockPos(x + 1, y - 1, z)).isOpaque() ||
-                            world.getBlockState(new BlockPos(x + 1, y - 1, z)).hasSolidTopSurface(world, new BlockPos(x + 1, y - 1, z), player)
-                        )
-                ) {
-                    x++; // Towards east
-                    wasSuccessful = true;
-                }
-
-                else if( // Checking towards south
-                        world.getBlockState(new BlockPos(x - 1, y, z)).isAir() &&
-                        world.getBlockState(new BlockPos(x - 1, y + 1, z)).isAir() &&
-                        (
-                            world.getBlockState(new BlockPos(x - 1, y - 1, z)).isOpaque() ||
-                            world.getBlockState(new BlockPos(x - 1, y - 1, z)).hasSolidTopSurface(world, new BlockPos(x - 1, y - 1, z), player)
-                        )
-                ) {
-                    x--; // Towards south
-                    wasSuccessful = true;
-                }
-            }
-            else {
-                // Player should be put to northern or southern block
-                if( // Checking towards south
-                        world.getBlockState(new BlockPos(x, y, z + 1)).isAir() &&
-                        world.getBlockState(new BlockPos(x, y + 1, z + 1)).isAir() &&
-                        (
-                            world.getBlockState(new BlockPos(x, y - 1, z + 1)).isOpaque() ||
-                            world.getBlockState(new BlockPos(x, y - 1, z + 1)).hasSolidTopSurface(world, new BlockPos(x, y - 1, z + 1), player)
-                        )
-                ) {
-                    z++; // Towards south
-                    wasSuccessful = true;
-                }
-
-                else if( // Checking towards north
-                        world.getBlockState(new BlockPos(x, y, z - 1)).isAir() &&
-                        world.getBlockState(new BlockPos(x, y + 1, z - 1)).isAir() &&
-                        (
-                            world.getBlockState(new BlockPos(x, y - 1, z - 1)).isOpaque() ||
-                            world.getBlockState(new BlockPos(x, y - 1, z - 1)).hasSolidTopSurface(world, new BlockPos(x, y - 1, z - 1), player)
-                        )
-                ) {
-                    z--; // Towards north
-                    wasSuccessful = true;
-                }
-            }
-            if(wasSuccessful) {
-                player.teleport(x, y, z);
-                player.sendMessage(successfulPortalRescue, false);
-            }
+            // Teleporting player to the middle of the block
+            player.teleport(pos.getX() + 0.5, pos.getY(), pos.getZ() + 0.5);
+            newPlayerCache.wasInPortal = true;
         }
     }
 

src/main/java/org/samo_lego/simpleauth/mixin/BlockUpdateS2CPacketAccess.java

@@ -0,0 +1,16 @@
+package org.samo_lego.simpleauth.mixin;
+
+import net.minecraft.block.BlockState;
+import net.minecraft.network.packet.s2c.play.BlockUpdateS2CPacket;
+import net.minecraft.util.math.BlockPos;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.gen.Accessor;
+
+@Mixin(BlockUpdateS2CPacket.class)
+public interface BlockUpdateS2CPacketAccess {
+    @Accessor("state")
+    void setState(BlockState state);
+
+    @Accessor("pos")
+    void setBlockPos(BlockPos pos);
+}

src/main/java/org/samo_lego/simpleauth/storage/PlayerCache.java

@@ -23,6 +23,7 @@ public class PlayerCache {
     public double lastZ;
 
     private static final Gson gson = new Gson();
+    public boolean wasInPortal;
 
 
     public PlayerCache(String uuid, ServerPlayerEntity player) {
@@ -90,5 +91,6 @@ public class PlayerCache {
         }
         this.wasAuthenticated = false;
         this.loginTries = 0;
+        this.wasInPortal = false;
     }
 }

src/main/resources/mixins.simpleauth.json

@@ -2,9 +2,9 @@
   "required": true,
   "package": "org.samo_lego.simpleauth.mixin",
   "compatibilityLevel": "JAVA_8",
-  "mixins": [
-  ],
+  "mixins": [],
   "server": [
+    "BlockUpdateS2CPacketAccess",
     "MixinPlayerEntity",
     "MixinPlayerManager",
     "MixinServerPlayNetworkHandler",