Add ComputerCraft integration to Train Signals

- Makes computer-controlled signals unable to be changed by external
  factors
- Emit CC event train_signal_state_change with the new state as
  parameter whenever the signal changes
- Add CC getState() function to get the current signal state
- Add CC isForcedRed()/setForcedRed(forced) functions to force the
  signal to be red, replacing redstone control
- Add CC getSignalType()/cycleSignalType() function to change the
  signal signal type in the same manner as using the wrench
- Add CC listBlockingTrainNames() function to list names of trains
  blocking the track group ahead of the signal

src/generated/resources/assets/create/lang/en_us.json

@@ -3052,6 +3052,7 @@
   "create.track_signal.cannot_change_mode": "Unable to switch mode of this Signal",
   "create.track_signal.mode_change.cross_signal": "-> Allow passage if section fully traversable",
   "create.track_signal.mode_change.entry_signal": "-> Allow passage if section unoccupied",
+  "create.track_signal.mode_controlled_by_computer": "Signal mode is controlled by computer",
   "create.track_target.clear": "Cleared track selection",
   "create.track_target.invalid": "Cannot target this track here",
   "create.track_target.missing": "Right-click the targeted train track first",

src/main/java/com/simibubi/create/compat/computercraft/AbstractComputerBehaviour.java

@@ -1,5 +1,9 @@
 package com.simibubi.create.compat.computercraft;
 
+import org.jetbrains.annotations.NotNull;
+
+
+import com.simibubi.create.compat.computercraft.events.ComputerEvent;
 import com.simibubi.create.foundation.blockEntity.SmartBlockEntity;
 import com.simibubi.create.foundation.blockEntity.behaviour.BehaviourType;
 import com.simibubi.create.foundation.blockEntity.behaviour.BlockEntityBehaviour;
@@ -49,6 +53,8 @@ public class AbstractComputerBehaviour extends BlockEntityBehaviour {
 		return hasAttachedComputer;
 	}
 
+	public void prepareComputerEvent(@NotNull ComputerEvent event) {}
+
 	@Override
 	public BehaviourType<?> getType() {
 		return TYPE;

src/main/java/com/simibubi/create/compat/computercraft/events/ComputerEvent.java

@@ -0,0 +1,3 @@
+package com.simibubi.create.compat.computercraft.events;
+
+public interface ComputerEvent {}

src/main/java/com/simibubi/create/compat/computercraft/events/SignalStateChangeEvent.java

@@ -0,0 +1,13 @@
+package com.simibubi.create.compat.computercraft.events;
+
+import com.simibubi.create.content.trains.signal.SignalBlockEntity;
+
+public class SignalStateChangeEvent implements ComputerEvent {
+
+	public SignalBlockEntity.SignalState state;
+
+	public SignalStateChangeEvent(SignalBlockEntity.SignalState state) {
+		this.state = state;
+	}
+
+}

src/main/java/com/simibubi/create/compat/computercraft/implementation/ComputerBehaviour.java

@@ -1,19 +1,26 @@
 package com.simibubi.create.compat.computercraft.implementation;
 
+import org.jetbrains.annotations.NotNull;
+
+
 import com.simibubi.create.compat.computercraft.AbstractComputerBehaviour;
+import com.simibubi.create.compat.computercraft.events.ComputerEvent;
 import com.simibubi.create.compat.computercraft.implementation.peripherals.DisplayLinkPeripheral;
 import com.simibubi.create.compat.computercraft.implementation.peripherals.NixieTubePeripheral;
 import com.simibubi.create.compat.computercraft.implementation.peripherals.SequencedGearshiftPeripheral;
+import com.simibubi.create.compat.computercraft.implementation.peripherals.SignalPeripheral;
 import com.simibubi.create.compat.computercraft.implementation.peripherals.SpeedControllerPeripheral;
 import com.simibubi.create.compat.computercraft.implementation.peripherals.SpeedGaugePeripheral;
 import com.simibubi.create.compat.computercraft.implementation.peripherals.StationPeripheral;
 import com.simibubi.create.compat.computercraft.implementation.peripherals.StressGaugePeripheral;
+import com.simibubi.create.compat.computercraft.implementation.peripherals.SyncedPeripheral;
 import com.simibubi.create.content.kinetics.gauge.SpeedGaugeBlockEntity;
 import com.simibubi.create.content.kinetics.gauge.StressGaugeBlockEntity;
 import com.simibubi.create.content.kinetics.speedController.SpeedControllerBlockEntity;
 import com.simibubi.create.content.kinetics.transmission.sequencer.SequencedGearshiftBlockEntity;
 import com.simibubi.create.content.redstone.displayLink.DisplayLinkBlockEntity;
 import com.simibubi.create.content.redstone.nixieTube.NixieTubeBlockEntity;
+import com.simibubi.create.content.trains.signal.SignalBlockEntity;
 import com.simibubi.create.content.trains.station.StationBlockEntity;
 import com.simibubi.create.foundation.blockEntity.SmartBlockEntity;
 
@@ -30,15 +37,15 @@ public class ComputerBehaviour extends AbstractComputerBehaviour {
 	protected static final Capability<IPeripheral> PERIPHERAL_CAPABILITY =
 		CapabilityManager.get(new CapabilityToken<>() {
 		});
-	LazyOptional<IPeripheral> peripheral;
-	NonNullSupplier<IPeripheral> peripheralSupplier;
+	LazyOptional<SyncedPeripheral<?>> peripheral;
+	NonNullSupplier<SyncedPeripheral<?>> peripheralSupplier;
 
 	public ComputerBehaviour(SmartBlockEntity te) {
 		super(te);
 		this.peripheralSupplier = getPeripheralFor(te);
 	}
 
-	public static NonNullSupplier<IPeripheral> getPeripheralFor(SmartBlockEntity be) {
+	public static NonNullSupplier<SyncedPeripheral<?>> getPeripheralFor(SmartBlockEntity be) {
 		if (be instanceof SpeedControllerBlockEntity scbe)
 			return () -> new SpeedControllerPeripheral(scbe, scbe.targetSpeed);
 		if (be instanceof DisplayLinkBlockEntity dlbe)
@@ -47,6 +54,8 @@ public class ComputerBehaviour extends AbstractComputerBehaviour {
 			return () -> new NixieTubePeripheral(ntbe);
 		if (be instanceof SequencedGearshiftBlockEntity sgbe)
 			return () -> new SequencedGearshiftPeripheral(sgbe);
+		if (be instanceof SignalBlockEntity sbe)
+			return () -> new SignalPeripheral(sbe);
 		if (be instanceof SpeedGaugeBlockEntity sgbe)
 			return () -> new SpeedGaugePeripheral(sgbe);
 		if (be instanceof StressGaugeBlockEntity sgbe)
@@ -76,4 +85,10 @@ public class ComputerBehaviour extends AbstractComputerBehaviour {
 			peripheral.invalidate();
 	}
 
+	@Override
+	public void prepareComputerEvent(@NotNull ComputerEvent event) {
+		if (peripheral != null)
+			peripheral.ifPresent(p -> p.prepareComputerEvent(event));
+	}
+
 }

src/main/java/com/simibubi/create/compat/computercraft/implementation/peripherals/SignalPeripheral.java

@@ -0,0 +1,104 @@
+package com.simibubi.create.compat.computercraft.implementation.peripherals;
+
+import java.util.Map;
+import java.util.UUID;
+
+import org.jetbrains.annotations.NotNull;
+
+
+import com.simibubi.create.Create;
+import com.simibubi.create.compat.computercraft.events.ComputerEvent;
+import com.simibubi.create.compat.computercraft.events.SignalStateChangeEvent;
+import com.simibubi.create.compat.computercraft.implementation.CreateLuaTable;
+import com.simibubi.create.content.trains.entity.Train;
+import com.simibubi.create.content.trains.signal.SignalBlock;
+import com.simibubi.create.content.trains.signal.SignalBlockEntity;
+import com.simibubi.create.content.trains.signal.SignalBoundary;
+import com.simibubi.create.content.trains.signal.SignalEdgeGroup;
+
+import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
+import net.createmod.catnip.data.Iterate;
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.level.Level;
+
+public class SignalPeripheral extends SyncedPeripheral<SignalBlockEntity> {
+
+	public SignalPeripheral(SignalBlockEntity blockEntity) {
+		super(blockEntity);
+	}
+
+	@LuaFunction
+	public final String getState() {
+		return blockEntity.getState().toString();
+	}
+
+	@LuaFunction
+	public final boolean isForcedRed() {
+		return blockEntity.getBlockState().getValue(SignalBlock.POWERED);
+	}
+
+	@LuaFunction(mainThread = true)
+	public final void setForcedRed(boolean powered) {
+		Level level = blockEntity.getLevel();
+		if (level != null)
+			level.setBlock(blockEntity.getBlockPos(),
+					blockEntity.getBlockState().setValue(SignalBlock.POWERED, powered), 2);
+	}
+
+	@LuaFunction
+	public final CreateLuaTable listBlockingTrainNames() throws LuaException {
+		SignalBoundary signal = blockEntity.getSignal();
+		if (signal == null)
+			throw new LuaException("no signal");
+		CreateLuaTable trainList = new CreateLuaTable();
+		int trainCounter = 1;
+		for (boolean current : Iterate.trueAndFalse) {
+			Map<BlockPos, Boolean> set = signal.blockEntities.get(current);
+			if (!set.containsKey(blockEntity.getBlockPos()))
+				continue;
+			UUID group = signal.groups.get(current);
+			Map<UUID, SignalEdgeGroup> signalEdgeGroups = Create.RAILWAYS.signalEdgeGroups;
+			SignalEdgeGroup signalEdgeGroup = signalEdgeGroups.get(group);
+			for (Train train : signalEdgeGroup.trains) {
+				trainList.put(trainCounter, train.name.getString());
+				trainCounter += 1;
+			}
+		}
+		return trainList;
+	}
+
+	@LuaFunction
+	public final String getSignalType() throws LuaException {
+		SignalBoundary signal = blockEntity.getSignal();
+		if (signal != null) {
+			return signal.getTypeFor(blockEntity.getBlockPos()).toString();
+		} else {
+			throw new LuaException("no signal");
+		}
+	}
+
+	@LuaFunction(mainThread = true)
+	public final void cycleSignalType() throws LuaException {
+		SignalBoundary signal = blockEntity.getSignal();
+		if (signal != null) {
+			signal.cycleSignalType(blockEntity.getBlockPos());
+		} else {
+			throw new LuaException("no signal");
+		}
+	}
+
+	@Override
+	public void prepareComputerEvent(@NotNull ComputerEvent event) {
+		if (event instanceof SignalStateChangeEvent ssce) {
+			queueEvent("train_signal_state_change", ssce.state.toString());
+		}
+	}
+
+	@NotNull
+	@Override
+	public String getType() {
+		return "Create_Signal";
+	}
+
+}

src/main/java/com/simibubi/create/compat/computercraft/implementation/peripherals/SyncedPeripheral.java

@@ -8,6 +8,7 @@ import org.jetbrains.annotations.Nullable;
 
 import com.simibubi.create.AllPackets;
 import com.simibubi.create.compat.computercraft.AttachedComputerPacket;
+import com.simibubi.create.compat.computercraft.events.ComputerEvent;
 import com.simibubi.create.compat.computercraft.implementation.ComputerBehaviour;
 import com.simibubi.create.foundation.blockEntity.SmartBlockEntity;
 
@@ -61,4 +62,21 @@ public abstract class SyncedPeripheral<T extends SmartBlockEntity> implements IP
 		return this == other;
 	}
 
+	public void prepareComputerEvent(@NotNull ComputerEvent event) {}
+
+	/**
+	 * Queue an event to all attached computers. Adds the peripheral attachment name as 1st event argument, followed by
+	 * any optional arguments passed to this method.
+	 */
+	protected void queueEvent(@NotNull String event, @Nullable Object... arguments) {
+		Object[] sourceAndArgs = new Object[arguments.length + 1];
+		System.arraycopy(arguments, 0, sourceAndArgs, 1, arguments.length);
+		synchronized (computers) {
+			for (IComputerAccess computer : computers) {
+				sourceAndArgs[0] = computer.getAttachmentName();
+				computer.queueEvent(event, sourceAndArgs);
+			}
+		}
+	}
+
 }

src/main/java/com/simibubi/create/content/trains/signal/SignalBlock.java

@@ -1,5 +1,8 @@
 package com.simibubi.create.content.trains.signal;
 
+import java.util.Optional;
+import java.util.Random;
+
 import javax.annotation.Nullable;
 
 import com.simibubi.create.AllBlockEntityTypes;
@@ -76,7 +79,12 @@ public class SignalBlock extends Block implements IBE<SignalBlockEntity>, IWrenc
 		if (pLevel.isClientSide)
 			return;
 		boolean powered = pState.getValue(POWERED);
-		if (powered == pLevel.hasNeighborSignal(pPos))
+		Optional<SignalBlockEntity> ste = getBlockEntityOptional(pLevel, pPos);
+		boolean neighborPowered = false;
+		if (ste.isEmpty() || !ste.get().computerBehaviour.hasAttachedComputer()) {
+			powered = pLevel.hasNeighborSignal(pPos);
+		}
+		if (powered == neighborPowered)
 			return;
 		if (powered) {
 			pLevel.scheduleTick(pPos, this, 4);
@@ -87,7 +95,8 @@ public class SignalBlock extends Block implements IBE<SignalBlockEntity>, IWrenc
 
 	@Override
 	public void tick(BlockState pState, ServerLevel pLevel, BlockPos pPos, RandomSource pRand) {
-		if (pState.getValue(POWERED) && !pLevel.hasNeighborSignal(pPos))
+		Optional<SignalBlockEntity> ste = getBlockEntityOptional(pLevel, pPos);
+		if ((ste.isEmpty() || !ste.get().computerBehaviour.hasAttachedComputer()) && pState.getValue(POWERED) && !pLevel.hasNeighborSignal(pPos))
 			pLevel.setBlock(pPos, pState.cycle(POWERED), 2);
 	}
 
@@ -108,8 +117,13 @@ public class SignalBlock extends Block implements IBE<SignalBlockEntity>, IWrenc
 		if (level.isClientSide)
 			return InteractionResult.SUCCESS;
 		withBlockEntityDo(level, pos, ste -> {
-			SignalBoundary signal = ste.getSignal();
 			Player player = context.getPlayer();
+			if (ste.computerBehaviour.hasAttachedComputer()) {
+				if (player != null)
+					player.displayClientMessage(CreateLang.translateDirect("track_signal.mode_controlled_by_computer"), true);
+				return;
+			}
+			SignalBoundary signal = ste.getSignal();
 			if (signal != null) {
 				signal.cycleSignalType(pos);
 				if (player != null)

src/main/java/com/simibubi/create/content/trains/signal/SignalBlockEntity.java

@@ -3,8 +3,12 @@ package com.simibubi.create.content.trains.signal;
 import java.util.List;
 
 import javax.annotation.Nullable;
+import org.jetbrains.annotations.NotNull;
 
 import com.simibubi.create.api.contraption.transformable.TransformableBlockEntity;
+import com.simibubi.create.compat.computercraft.AbstractComputerBehaviour;
+import com.simibubi.create.compat.computercraft.ComputerCraftProxy;
+import com.simibubi.create.compat.computercraft.events.SignalStateChangeEvent;
 import com.simibubi.create.content.contraptions.StructureTransform;
 import com.simibubi.create.content.trains.graph.EdgePointType;
 import com.simibubi.create.content.trains.signal.SignalBlock.SignalType;
@@ -14,11 +18,14 @@ import com.simibubi.create.foundation.blockEntity.behaviour.BlockEntityBehaviour
 
 import net.createmod.catnip.nbt.NBTHelper;
 import net.minecraft.core.BlockPos;
+import net.minecraft.core.Direction;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.entity.BlockEntityType;
 import net.minecraft.world.level.block.state.BlockState;
 import net.minecraft.world.phys.AABB;
+import net.minecraftforge.common.capabilities.Capability;
+import net.minecraftforge.common.util.LazyOptional;
 
 public class SignalBlockEntity extends SmartBlockEntity implements TransformableBlockEntity {
 
@@ -48,6 +55,7 @@ public class SignalBlockEntity extends SmartBlockEntity implements Transformable
 	private OverlayState overlay;
 	private int switchToRedAfterTrainEntered;
 	private boolean lastReportedPower;
+	public AbstractComputerBehaviour computerBehaviour;
 
 	public SignalBlockEntity(BlockEntityType<?> type, BlockPos pos, BlockState state) {
 		super(type, pos, state);
@@ -86,6 +94,7 @@ public class SignalBlockEntity extends SmartBlockEntity implements Transformable
 	public void addBehaviours(List<BlockEntityBehaviour> behaviours) {
 		edgePoint = new TrackTargetingBehaviour<>(this, EdgePointType.SIGNAL);
 		behaviours.add(edgePoint);
+		behaviours.add(computerBehaviour = ComputerCraftProxy.behaviour(this));
 	}
 
 	@Override
@@ -152,9 +161,24 @@ public class SignalBlockEntity extends SmartBlockEntity implements Transformable
 			return;
 		this.state = state;
 		switchToRedAfterTrainEntered = state == SignalState.GREEN || state == SignalState.YELLOW ? 15 : 0;
+		if (computerBehaviour.hasAttachedComputer())
+			computerBehaviour.prepareComputerEvent(new SignalStateChangeEvent(state));
 		notifyUpdate();
 	}
 
+	@Override
+	public <T> @NotNull LazyOptional<T> getCapability(@NotNull Capability<T> cap, Direction side) {
+		if (computerBehaviour.isPeripheralCap(cap))
+			return computerBehaviour.getPeripheralCapability();
+		return super.getCapability(cap, side);
+	}
+
+	@Override
+	public void invalidateCaps() {
+		super.invalidateCaps();
+		computerBehaviour.removePeripheral();
+	}
+
 	@Override
 	protected AABB createRenderBoundingBox() {
 		return new AABB(worldPosition, edgePoint.getGlobalPosition()).inflate(2);

src/main/resources/assets/create/lang/default/interface.json

@@ -997,6 +997,7 @@
 	"create.track_signal.cannot_change_mode": "Unable to switch mode of this Signal",
 	"create.track_signal.mode_change.entry_signal": "-> Allow passage if section unoccupied",
 	"create.track_signal.mode_change.cross_signal": "-> Allow passage if section fully traversable",
+	"create.track_signal.mode_controlled_by_computer": "Signal mode is controlled by computer",
 
 	"create.contraption.controls.start_controlling": "Now controlling: %1$s",
 	"create.contraption.controls.stop_controlling": "Stopped controlling contraption",

src/main/resources/assets/create/lang/es_es.json

@@ -2597,6 +2597,7 @@
   "create.track_signal.cannot_change_mode": "No se puede cambiar el modo de esta señal",
   "create.track_signal.mode_change.cross_signal": "-> Permitir entrada si la sección se puede atravesar por completo",
   "create.track_signal.mode_change.entry_signal": "-> Permitir entrada si la sección está desocupada",
+  "create.track_signal.mode_controlled_by_computer": "El modo de esta señal está siendo controlado por un ordenador",
   "create.track_target.clear": "Selección de vía borrada",
   "create.track_target.invalid": "No se puede marcar esta vía como objetivo",
   "create.track_target.missing": "Primero haz clic derecho en la vía objetivo",

src/main/resources/assets/create/lang/es_mx.json

@@ -2594,6 +2594,7 @@
   "create.track_signal.cannot_change_mode": "No se puede cambiar el modo de esta señal",
   "create.track_signal.mode_change.cross_signal": "-> Permitir entrada si la sección se puede atravesar por completo",
   "create.track_signal.mode_change.entry_signal": "-> Permitir entrada si la sección está desocupada",
+  "create.track_signal.mode_controlled_by_computer": "El modo de esta señal está siendo controlado por un ordenador",
   "create.track_target.clear": "Selección de vía borrada",
   "create.track_target.invalid": "No se puede marcar esta vía como objetivo",
   "create.track_target.missing": "Primero haz clic derecho en la vía objetivo",

src/main/resources/assets/create/lang/fr_fr.json

@@ -2597,6 +2597,7 @@
   "create.track_signal.cannot_change_mode": "Incapable de changer le mode de ce signal",
   "create.track_signal.mode_change.cross_signal": "-> Autoriser le passage si la section est entièrement traversable",
   "create.track_signal.mode_change.entry_signal": "-> Autoriser le passage si la section est inoccupée",
+  "create.track_signal.mode_controlled_by_computer": "Le mode de ce signal est contrôlé par un ordinateur",
   "create.track_target.clear": "Sélection du rail effacée",
   "create.track_target.invalid": "Ne peut pas cibler ce rail ici",
   "create.track_target.missing": "Faites clic droit sur le rail ciblé d'abord",