refactor: improvements to place block core (so-called "deploy core")

- after 5 tries of failed deploy core attempts, it falls back to using chat instead. this happens a lot when you `/tp` to somewhere underground where the player's surroundings are covered with blocks and command blocks don't get executed for some reason
- i'm using the obd sex mod way of determining block positions now
- the deploy core block now gets set to the previous block only when the core is CONFIRMED to be filled, and not just a fixed 100ms waiting time after placed

i hope this is enough to fix troubles, if there are more issues i'll try to fix them

src/main/java/land/chipmunk/chipmunkmod/modules/CommandCore.java

@@ -1,11 +1,13 @@
 package land.chipmunk.chipmunkmod.modules;
 
+import it.unimi.dsi.fastutil.objects.Object2ObjectArrayMap;
 import land.chipmunk.chipmunkmod.ChipmunkMod;
 import land.chipmunk.chipmunkmod.listeners.Listener;
 import land.chipmunk.chipmunkmod.listeners.ListenerManager;
 import net.minecraft.block.Block;
 import net.minecraft.block.BlockState;
 import net.minecraft.block.CommandBlock;
+import net.minecraft.block.FallingBlock;
 import net.minecraft.block.entity.CommandBlockBlockEntity;
 import net.minecraft.client.MinecraftClient;
 import net.minecraft.client.network.ClientPlayNetworkHandler;
@@ -23,17 +25,18 @@ import net.minecraft.network.packet.c2s.play.CreativeInventoryActionC2SPacket;
 import net.minecraft.network.packet.c2s.play.UpdateCommandBlockC2SPacket;
 import net.minecraft.network.packet.c2s.play.UpdateSelectedSlotC2SPacket;
 import net.minecraft.registry.Registries;
+import net.minecraft.registry.tag.BlockTags;
 import net.minecraft.state.property.Property;
 import net.minecraft.util.Hand;
+import net.minecraft.util.Pair;
 import net.minecraft.util.Util;
 import net.minecraft.util.hit.BlockHitResult;
-import net.minecraft.util.math.BlockBox;
+import net.minecraft.util.math.*;
-import net.minecraft.util.math.BlockPos;
-import net.minecraft.util.math.Direction;
-import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.chunk.Chunk;
 import net.minecraft.world.dimension.DimensionType;
 
+import java.util.Collections;
+import java.util.Map;
 import java.util.Timer;
 import java.util.TimerTask;
 import java.util.concurrent.CompletableFuture;
@@ -51,8 +54,10 @@ public class CommandCore implements Listener {
     public boolean runFillCommand = true;
     public boolean alreadyFilled = false;
 
+    private final Map<BlockPos, String> pendingSetBlockCommands = Collections.synchronizedMap(new Object2ObjectArrayMap<>());
     private Timer timer;
     private boolean shouldRefill = false;
+    private int refillTriesUsingPlaceBlock = 0;
     private DimensionType oldDimension;
 
     public CommandCore (final MinecraftClient client) {
@@ -103,7 +108,30 @@ public class CommandCore implements Listener {
 
         check();
 
-        if (!shouldRefill) return;
+        if (!shouldRefill) {
+            refillTriesUsingPlaceBlock = 0;
+            synchronized (pendingSetBlockCommands) {
+                if (pendingSetBlockCommands.isEmpty()) return;
+                for (final Map.Entry<BlockPos, String> entry : pendingSetBlockCommands.entrySet()) {
+                    final BlockPos blockPos = entry.getKey();
+                    final String block = entry.getValue();
+
+                    run(
+                            String.format(
+                                    "setblock %d %d %d %s",
+
+                                    blockPos.getX(),
+                                    blockPos.getY(),
+                                    blockPos.getZ(),
+
+                                    block
+                            )
+                    );
+                }
+                pendingSetBlockCommands.clear();
+            }
+            return;
+        }
 
         refill();
 
@@ -189,8 +217,17 @@ public class CommandCore implements Listener {
 
     public void refill () {
         final ClientPlayNetworkHandler networkHandler = client.getNetworkHandler();
+        final ClientPlayerEntity player = client.player;
 
-        if (!runFillCommand || client.world == null || networkHandler == null || withPos == null) return;
+        if (
+                !runFillCommand
+                        || player == null
+                        || !player.isInCreativeMode()
+                        || !player.hasPermissionLevel(2)
+                        || client.world == null
+                        || networkHandler == null
+                        || withPos == null
+        ) return;
 
         final Chunk chunk = client.world.getChunk(withPos.getCenter());
 
@@ -208,7 +245,13 @@ public class CommandCore implements Listener {
                 withPos.getMaxZ()
         );
 
+        if (refillTriesUsingPlaceBlock > 5) {
+            networkHandler.sendChatCommand(command);
+            refillTriesUsingPlaceBlock = 0;
+        } else {
             runPlaceBlock(command);
+            refillTriesUsingPlaceBlock++;
+        }
     }
 
     public void incrementCurrentBlock () {
@@ -360,29 +403,24 @@ public class CommandCore implements Listener {
 
         final DimensionType dimensionType = world.getDimension();
 
+        final ClientPlayerInteractionManager interactionManager = client.interactionManager;
+        if (interactionManager == null) return;
+
+        // stolen from two five hundred million dollars
+
+        final Pair<BlockPos, BlockState> pair = findBlockLocation();
+
         if (
-                player.getPos().getY() < dimensionType.minY()
+                pair == null
-                        || player.getPos().getY() > dimensionType.height() + dimensionType.minY()
+                        || pair.getLeft().getY() < dimensionType.minY()
+                        || pair.getLeft().getY() > dimensionType.height() + dimensionType.minY()
         ) {
             networkHandler.sendChatCommand(command);
             return;
         }
 
-        final ClientPlayerInteractionManager interactionManager = client.interactionManager;
+        final BlockPos position = pair.getLeft();
-        if (interactionManager == null) return;
+        final BlockState oldBlockState = pair.getRight();
-
-        final float yaw = player.getYaw();
-        final float pitch = player.getPitch();
-
-        // Anti Block when flying around
-        final BlockPos position = player.getBlockPos().add(
-                (int) Math.round(3 * Math.cos(Math.toRadians(yaw))),
-                3 * (pitch < 0 ? -1 : 1),
-                (int) Math.round(3 * Math.sin(Math.toRadians(yaw)))
-        );
-
-        // stolen from two five hundred million dollars
-        final BlockState oldBlockState = world.getBlockState(position);
 
         final int freeHotBarSlot = player.getInventory().getEmptySlot();
         final int slot = 36 + freeHotBarSlot;
@@ -430,43 +468,57 @@ public class CommandCore implements Listener {
         }
         connection.send(new CreativeInventoryActionC2SPacket(slot, oldStack));
 
-        final Timer timer = new Timer();
+        final StringBuilder oldBlockString = new StringBuilder(Registries.BLOCK.getId(oldBlockState.getBlock()).toString());
-
-        final TimerTask task = new TimerTask() {
-            @Override
-            public void run () {
-                final StringBuilder command = new StringBuilder(
-                        String.format(
-                                "setblock %d %d %d %s",
-
-                                position.getX(),
-                                position.getY(),
-                                position.getZ(),
-
-                                Registries.BLOCK.getId(oldBlockState.getBlock())
-                        )
-                );
-
         if (!oldBlockState.getProperties().isEmpty()) {
-                    command.append('[');
+            oldBlockString.append('[');
 
             for (final Property<?> property : oldBlockState.getProperties()) {
-                        command.append(property.getName())
+                oldBlockString.append(property.getName())
                         .append('=')
                         .append(Util.getValueAsString(property, property.getValues().getLast())) // water[level=15] instead of water[level=0,level=1,....,level=15]
                         .append(',');
             }
 
-                    command.deleteCharAt(command.length() - 1);
+            oldBlockString.deleteCharAt(oldBlockString.length() - 1);
 
-                    command.append(']');
+            oldBlockString.append(']');
         }
 
-                CommandCore.this.run(command.toString());
+        pendingSetBlockCommands.put(position, oldBlockString.toString());
     }
-        };
 
-        timer.schedule(task, 100); // assuming the core has already been filled at this point
+    // also from two five hundred million dollars
+    private Pair<BlockPos, BlockState> findBlockLocation () {
+        final ClientPlayerEntity player = client.player;
+        if (player == null) return null;
+        final BlockPos position = player.getBlockPos();
+        final Box boundingBox = player.getBoundingBox();
+        boundingBox.expand(1.0);
+        for (int x = position.getX() - 2; x <= position.getX() + 2; x++) {
+            for (int y = position.getY() - 2; y <= position.getY() + 2; y++) {
+                for (int z = position.getZ() - 2; z <= position.getZ() + 2; z++) {
+                    final BlockPos blockPos = new BlockPos(x, y, z);
+                    if (!player.canInteractWithBlockAt(blockPos, 1.0)) continue;
+                    // we don't want to place a block inside ourselves
+                    if (boundingBox.intersects(new Vec3d(blockPos), new Vec3d(blockPos))) continue;
+                    final BlockState blockState = player.getWorld().getBlockState(blockPos);
+                    if (blockState.getBlock() instanceof FallingBlock) continue;
+                    final boolean replaceable = blockState.isIn(BlockTags.REPLACEABLE);
+                    if (
+                            !replaceable
+                                    && !blockState.isIn(BlockTags.AXE_MINEABLE)
+                                    && !blockState.isIn(BlockTags.HOE_MINEABLE)
+                                    && !blockState.isIn(BlockTags.SHOVEL_MINEABLE)
+                                    && !blockState.isIn(BlockTags.PICKAXE_MINEABLE)
+                    ) {
+                        continue;
+                    }
+                    return new Pair<>(blockPos, blockState);
+                }
+            }
+        }
+
+        return null;
     }
 
     public void cleanup () {