Send remainder of partially-inserted stacks back to source

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

@@ -0,0 +1,15 @@
+package net.shadowfacts.phycon.api;
+
+import net.shadowfacts.phycon.api.packet.Packet;
+
+/**
+ * @author shadowfacts
+ */
+public interface PacketSource {
+	// todo: better name for this
+	void sendToSingle(Packet packet);
+
+	void sendToAll(Packet packet);
+
+	void sendToAll(Packet packet, Iterable<PacketSink> destinations);
+}

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

@@ -4,18 +4,16 @@ import net.minecraft.block.BlockState
 import net.minecraft.block.entity.BlockEntity
 import net.minecraft.block.entity.BlockEntityType
 import net.minecraft.nbt.CompoundTag
-import net.minecraft.util.Tickable
 import net.shadowfacts.phycon.api.PacketSink
+import net.shadowfacts.phycon.api.PacketSource
 import net.shadowfacts.phycon.api.packet.Packet
 import net.shadowfacts.phycon.api.util.MACAddress
 import net.shadowfacts.phycon.network.packet.DeviceRemovedPacket
-import java.lang.ref.WeakReference
-import java.util.*
 
 /**
  * @author shadowfacts
  */
-abstract class DeviceBlockEntity(type: BlockEntityType<*>): BlockEntity(type), PacketSink {
+abstract class DeviceBlockEntity(type: BlockEntityType<*>): BlockEntity(type), PacketSink, PacketSource {
 
 	var macAddress = MACAddress.random()
 		protected set
@@ -48,8 +46,7 @@ abstract class DeviceBlockEntity(type: BlockEntityType<*>): BlockEntity(type), P
 		destination.handle(packet)
 	}
 
-	// todo: better name for this
+	override fun sendToSingle(packet: Packet) {
-	fun sendToSingle(packet: Packet) {
 		val destinations = NetworkUtil.findDestinations(world!!, pos)
 		if (destinations.size != 1) {
 			// todo: handle this better
@@ -59,11 +56,11 @@ abstract class DeviceBlockEntity(type: BlockEntityType<*>): BlockEntity(type), P
 		send(packet, destinations.first())
 	}
 
-	fun sendToAll(packet: Packet) {
+	override fun sendToAll(packet: Packet) {
 		sendToAll(packet, NetworkUtil.findDestinations(world!!, pos))
 	}
 
-	fun sendToAll(packet: Packet, destinations: Iterable<PacketSink>) {
+	override fun sendToAll(packet: Packet, destinations: Iterable<PacketSink>) {
 		destinations.forEach {
 			it.handle(packet)
 		}

src/main/kotlin/net/shadowfacts/phycon/network/block/netinterface/InterfaceBlockEntity.kt

@@ -4,17 +4,19 @@ import alexiil.mc.lib.attributes.SearchOptions
 import alexiil.mc.lib.attributes.Simulation
 import alexiil.mc.lib.attributes.item.GroupedItemInv
 import alexiil.mc.lib.attributes.item.ItemAttributes
-import net.minecraft.entity.ItemEntity
+import net.minecraft.item.ItemStack
 import net.minecraft.util.math.Direction
 import net.shadowfacts.phycon.api.packet.Packet
 import net.shadowfacts.phycon.init.PhyBlockEntities
 import net.shadowfacts.phycon.network.DeviceBlockEntity
+import net.shadowfacts.phycon.network.component.ItemStackPacketHandler
+import net.shadowfacts.phycon.network.component.handleItemStack
 import net.shadowfacts.phycon.network.packet.*
 
 /**
  * @author shadowfacts
  */
-class InterfaceBlockEntity: DeviceBlockEntity(PhyBlockEntities.INTERFACE) {
+class InterfaceBlockEntity: DeviceBlockEntity(PhyBlockEntities.INTERFACE), ItemStackPacketHandler {
 
 	private val facing: Direction
 		get() = world!!.getBlockState(pos)[InterfaceBlock.FACING]
@@ -73,21 +75,14 @@ class InterfaceBlockEntity: DeviceBlockEntity(PhyBlockEntities.INTERFACE) {
 		}
 	}
 
-	private fun handleItemStack(packet: ItemStackPacket) {
+	override fun doHandleItemStack(packet: ItemStackPacket): ItemStack {
 		val inventory = getInventory()
 		if (inventory != null) {
 			val remaining = inventory.insert(packet.stack)
-			if (!remaining.isEmpty) {
+			// whatever could not be inserted will be sent back to the packet's source
-				// todo: should this send whatever was left back to the terminal instead of dropping it?
+			return remaining
-				// todo: calculate entity spawn point by finding non-obstructed location
-				val entity = ItemEntity(world!!, pos.x.toDouble(), pos.y + 1.0, pos.z.toDouble(), remaining)
-				world!!.spawnEntity(entity)
-			}
 		} else {
-			// todo: should the stack back to the terminal instead of dropping it?
+			return packet.stack
-			// todo: calculate entity spawn point by finding non-obstructed location
-			val entity = ItemEntity(world!!, pos.x.toDouble(), pos.y + 1.0, pos.z.toDouble(), packet.stack)
-			world!!.spawnEntity(entity)
 		}
 	}
 

src/main/kotlin/net/shadowfacts/phycon/network/block/terminal/TerminalBlockEntity.kt

@@ -7,7 +7,6 @@ import it.unimi.dsi.fastutil.ints.Int2ObjectArrayMap
 import net.fabricmc.fabric.api.block.entity.BlockEntityClientSerializable
 import net.fabricmc.fabric.api.screenhandler.v1.ExtendedScreenHandlerFactory
 import net.minecraft.block.BlockState
-import net.minecraft.entity.ItemEntity
 import net.minecraft.entity.player.PlayerEntity
 import net.minecraft.entity.player.PlayerInventory
 import net.minecraft.inventory.Inventory
@@ -25,6 +24,8 @@ import net.shadowfacts.phycon.api.util.MACAddress
 import net.shadowfacts.phycon.init.PhyBlockEntities
 import net.shadowfacts.phycon.network.DeviceBlockEntity
 import net.shadowfacts.phycon.network.block.netinterface.InterfaceBlockEntity
+import net.shadowfacts.phycon.network.component.ItemStackPacketHandler
+import net.shadowfacts.phycon.network.component.handleItemStack
 import net.shadowfacts.phycon.network.packet.*
 import java.util.*
 import kotlin.math.min
@@ -32,7 +33,7 @@ import kotlin.math.min
 /**
  * @author shadowfacts
  */
-class TerminalBlockEntity: DeviceBlockEntity(PhyBlockEntities.TERMINAL), InventoryChangedListener, BlockEntityClientSerializable, Tickable {
+class TerminalBlockEntity: DeviceBlockEntity(PhyBlockEntities.TERMINAL), InventoryChangedListener, BlockEntityClientSerializable, Tickable, ItemStackPacketHandler {
 
 	companion object {
 		val LOCATE_REQUEST_TIMEOUT = 40 // ticks
@@ -89,18 +90,15 @@ class TerminalBlockEntity: DeviceBlockEntity(PhyBlockEntities.TERMINAL), Invento
 		}
 	}
 
-	private fun handleItemStack(packet: ItemStackPacket) {
+	override fun doHandleItemStack(packet: ItemStackPacket): ItemStack {
 		val remaining = internalBuffer.insertFromNetwork(packet.stack)
-		if (!remaining.isEmpty) {
-			// todo: calculate entity spawn point by finding non-obstructed location
-			val entity = ItemEntity(world!!, pos.x.toDouble(), pos.y + 1.0, pos.z.toDouble(), remaining)
-			world!!.spawnEntity(entity)
-		}
 
 		// this happens outside the normal update loop because by receiving the item stack packet
 		// we "know" how much the count in the source inventory has changed
 		updateNetItems()
 		sync()
+
+		return remaining
 	}
 
 	private fun handleCapacity(packet: CapacityPacket) {

src/main/kotlin/net/shadowfacts/phycon/network/component/ItemStackPacketHandler.kt

@@ -0,0 +1,31 @@
+package net.shadowfacts.phycon.network.component
+
+import net.minecraft.block.entity.BlockEntity
+import net.minecraft.entity.ItemEntity
+import net.minecraft.item.ItemStack
+import net.shadowfacts.phycon.api.PacketSink
+import net.shadowfacts.phycon.api.PacketSource
+import net.shadowfacts.phycon.network.packet.ItemStackPacket
+
+/**
+ * @author shadowfacts
+ */
+interface ItemStackPacketHandler: PacketSink, PacketSource {
+	fun doHandleItemStack(packet: ItemStackPacket): ItemStack
+}
+
+fun <BE> BE.handleItemStack(packet: ItemStackPacket) where BE: BlockEntity, BE: ItemStackPacketHandler {
+	// todo: is 5 a good number?
+	// the max bounce count should always be odd, so the item is spawned in-world at the
+	if (packet.bounceCount == 5) {
+		// todo: calculate entity spawn point by finding non-obstructed location
+		val entity = ItemEntity(world!!, pos.x.toDouble(), pos.y + 1.0, pos.z.toDouble(), packet.stack)
+		world!!.spawnEntity(entity)
+		return
+	}
+	val remainder = doHandleItemStack(packet)
+	// if there are any items remaining, send them back to the source with incremented bounce count
+	if (!remainder.isEmpty) {
+		sendToSingle(ItemStackPacket(remainder, packet.bounceCount + 1, macAddress, packet.source))
+	}
+}

src/main/kotlin/net/shadowfacts/phycon/network/packet/ItemStackPacket.kt

@@ -6,5 +6,6 @@ import net.shadowfacts.phycon.api.util.MACAddress
 /**
  * @author shadowfacts
  */
-class ItemStackPacket(val stack: ItemStack, source: MACAddress, destination: MACAddress): BasePacket(source, destination) {
+class ItemStackPacket(val stack: ItemStack, val bounceCount: Int, source: MACAddress, destination: MACAddress): BasePacket(source, destination) {
+	constructor(stack: ItemStack, source: MACAddress, destination: MACAddress): this(stack, 0, source, destination)
 }