Add switches

src/main/java/net/shadowfacts/phycon/api/PacketSink.java

@@ -1,6 +1,7 @@
 package net.shadowfacts.phycon.api;
 
 import net.shadowfacts.phycon.api.packet.Packet;
+import net.shadowfacts.phycon.api.util.MACAddress;
 import org.jetbrains.annotations.NotNull;
 
 /**
@@ -8,6 +9,9 @@ import org.jetbrains.annotations.NotNull;
  */
 public interface PacketSink {
 
+	@NotNull
+	MACAddress getMACAddress();
+
 	void handle(@NotNull Packet packet);
 
 }

src/main/kotlin/net/shadowfacts/phycon/init/PhyBlockEntities.kt

@@ -7,6 +7,8 @@ import net.minecraft.util.Identifier
 import net.minecraft.util.registry.Registry
 import net.shadowfacts.phycon.network.block.netinterface.InterfaceBlock
 import net.shadowfacts.phycon.network.block.netinterface.InterfaceBlockEntity
+import net.shadowfacts.phycon.network.block.netswitch.SwitchBlock
+import net.shadowfacts.phycon.network.block.netswitch.SwitchBlockEntity
 import net.shadowfacts.phycon.network.block.terminal.TerminalBlock
 import net.shadowfacts.phycon.network.block.terminal.TerminalBlockEntity
 
@@ -17,6 +19,7 @@ object PhyBlockEntities {
 
 	val INTERFACE = create(::InterfaceBlockEntity, PhyBlocks.INTERFACE)
 	val TERMINAL = create(::TerminalBlockEntity, PhyBlocks.TERMINAL)
+	val SWITCH = create(::SwitchBlockEntity, PhyBlocks.SWITCH)
 
 	private fun <T: BlockEntity> create(builder: () -> T, block: Block): BlockEntityType<T> {
 		return BlockEntityType.Builder.create(builder, arrayOf(block)).build(null)
@@ -25,6 +28,7 @@ object PhyBlockEntities {
 	fun init() {
 		register(InterfaceBlock.ID, INTERFACE)
 		register(TerminalBlock.ID, TERMINAL)
+		register(SwitchBlock.ID, SWITCH)
 	}
 
 	private fun register(id: Identifier, type: BlockEntityType<*>) {

src/main/kotlin/net/shadowfacts/phycon/init/PhyBlocks.kt

@@ -4,6 +4,7 @@ import net.minecraft.block.Block
 import net.minecraft.util.Identifier
 import net.minecraft.util.registry.Registry
 import net.shadowfacts.phycon.network.block.netinterface.InterfaceBlock
+import net.shadowfacts.phycon.network.block.netswitch.SwitchBlock
 import net.shadowfacts.phycon.network.block.terminal.TerminalBlock
 
 /**
@@ -13,10 +14,12 @@ object PhyBlocks {
 
 	val INTERFACE = InterfaceBlock()
 	val TERMINAL = TerminalBlock()
+	val SWITCH = SwitchBlock()
 
 	fun init() {
 		register(InterfaceBlock.ID, INTERFACE)
 		register(TerminalBlock.ID, TERMINAL)
+		register(SwitchBlock.ID, SWITCH)
 	}
 
 	private fun register(id: Identifier, block: Block) {

src/main/kotlin/net/shadowfacts/phycon/init/PhyItems.kt

@@ -5,6 +5,7 @@ import net.minecraft.item.Item
 import net.minecraft.util.Identifier
 import net.minecraft.util.registry.Registry
 import net.shadowfacts.phycon.network.block.netinterface.InterfaceBlock
+import net.shadowfacts.phycon.network.block.netswitch.SwitchBlock
 import net.shadowfacts.phycon.network.block.terminal.TerminalBlock
 
 /**
@@ -14,10 +15,12 @@ object PhyItems {
 
 	val INTERFACE = BlockItem(PhyBlocks.INTERFACE, Item.Settings())
 	val TERMINAL = BlockItem(PhyBlocks.TERMINAL, Item.Settings())
+	val SWITCH = BlockItem(PhyBlocks.SWITCH, Item.Settings())
 
 	fun init() {
 		register(InterfaceBlock.ID, INTERFACE)
 		register(TerminalBlock.ID, TERMINAL)
+		register(SwitchBlock.ID, SWITCH)
 	}
 
 	private fun register(id: Identifier, item: Item) {

src/main/kotlin/net/shadowfacts/phycon/network/DeviceBlockEntity.kt

@@ -20,13 +20,17 @@ abstract class DeviceBlockEntity(type: BlockEntityType<*>): BlockEntity(type), T
 
 	private val sendQueue = LinkedList<Pair<Packet, WeakReference<PacketSink>>>()
 
+	override fun getMACAddress(): MACAddress {
+		return macAddress
+	}
+
 	override fun handle(packet: Packet) {
 		if (acceptsPacket(packet)) {
 			handlePacket(packet)
 		}
 	}
 
-	abstract fun handlePacket(packet: Packet)
+	protected abstract fun handlePacket(packet: Packet)
 
 	fun acceptsPacket(packet: Packet): Boolean {
 		return when (packet.destination.type) {
@@ -56,7 +60,11 @@ abstract class DeviceBlockEntity(type: BlockEntityType<*>): BlockEntity(type), T
 	}
 
 	fun enqueueToAll(packet: Packet) {
-		sendQueue.addAll(NetworkUtil.findDestinations(world!!, pos).map { packet to WeakReference(it) })
+		enqueueToAll(packet, NetworkUtil.findDestinations(world!!, pos))
+	}
+
+	fun enqueueToAll(packet: Packet, destinations: Iterable<PacketSink>) {
+		sendQueue.addAll(destinations.map { packet to WeakReference(it) })
 	}
 
 	override fun tick() {

src/main/kotlin/net/shadowfacts/phycon/network/NetworkUtil.kt

@@ -13,11 +13,15 @@ import java.util.*
  */
 object NetworkUtil {
 
-	fun findDestinations(world: World, startPos: BlockPos): List<PacketSink> {
+	fun findDestinations(world: World, startPos: BlockPos, direction: Direction? = null): List<PacketSink> {
 		val results = LinkedList<PacketSink>()
 		val visited = hashSetOf(startPos)
 		val queue = LinkedList<BlockPos>()
+		if (direction != null) {
+			queue.add(startPos.offset(direction))
+		} else {
 			addAdjacent(queue, visited, startPos)
+		}
 
 		while (queue.isNotEmpty()) {
 			val pos = queue.pop()

src/main/kotlin/net/shadowfacts/phycon/network/block/netswitch/SwitchBlock.kt

@@ -0,0 +1,27 @@
+package net.shadowfacts.phycon.network.block.netswitch
+
+import alexiil.mc.lib.attributes.AttributeList
+import alexiil.mc.lib.attributes.AttributeProvider
+import net.minecraft.block.BlockState
+import net.minecraft.block.Material
+import net.minecraft.util.Identifier
+import net.minecraft.util.math.BlockPos
+import net.minecraft.world.BlockView
+import net.minecraft.world.World
+import net.shadowfacts.phycon.PhysicalConnectivity
+import net.shadowfacts.phycon.block.BlockWithEntity
+
+/**
+ * @author shadowfacts
+ */
+class SwitchBlock: BlockWithEntity<SwitchBlockEntity>(Settings.of(Material.METAL)), AttributeProvider {
+	companion object {
+		val ID = Identifier(PhysicalConnectivity.MODID, "switch")
+	}
+
+	override fun createBlockEntity(world: BlockView) = SwitchBlockEntity()
+
+	override fun addAllAttributes(world: World, pos: BlockPos, state: BlockState, to: AttributeList<*>) {
+		to.offer(getBlockEntity(world, pos))
+	}
+}

src/main/kotlin/net/shadowfacts/phycon/network/block/netswitch/SwitchBlockEntity.kt

@@ -0,0 +1,62 @@
+package net.shadowfacts.phycon.network.block.netswitch
+
+import net.minecraft.util.math.Direction
+import net.shadowfacts.phycon.api.PacketSink
+import net.shadowfacts.phycon.api.packet.Packet
+import net.shadowfacts.phycon.api.util.MACAddress
+import net.shadowfacts.phycon.init.PhyBlockEntities
+import net.shadowfacts.phycon.network.DeviceBlockEntity
+import net.shadowfacts.phycon.network.NetworkUtil
+import java.lang.RuntimeException
+import javax.print.attribute.standard.Destination
+
+/**
+ * @author shadowfacts
+ */
+class SwitchBlockEntity: DeviceBlockEntity(PhyBlockEntities.SWITCH) {
+
+	private val macTable = mutableMapOf<MACAddress, Direction>()
+
+	override fun handlePacket(packet: Packet) {
+		throw RuntimeException("Unreachable")
+	}
+
+	override fun handle(packet: Packet) {
+		if (packet.destination == MACAddress.BROADCAST) {
+			val allDestinations = NetworkUtil.findDestinations(world!!, pos).filter { it.macAddress != packet.source }
+			enqueueToAll(packet, allDestinations)
+		} else {
+			val direction = macTable[packet.destination]
+			if (direction != null) {
+				val dest = findDestination(direction)
+				if (dest != null && packet.destination == dest.macAddress) {
+					enqueue(packet, dest)
+					return
+				}
+			}
+			flood(packet)
+		}
+	}
+
+	private fun findDestination(direction: Direction): PacketSink? {
+		val allDestinations = NetworkUtil.findDestinations(world!!, pos, direction)
+		if (allDestinations.size > 1) {
+			// todo: do this better
+			println("Can't send packet, multiple destinations: $allDestinations")
+			return null
+		}
+		return allDestinations.firstOrNull()
+	}
+
+	private fun flood(packet: Packet) {
+		for (dir in Direction.values()) {
+			val dest = findDestination(dir)
+			if (dest != null && packet.destination == dest.macAddress) {
+				macTable[packet.destination] = dir
+				enqueue(packet, dest)
+				break
+			}
+		}
+	}
+
+}