Improve Miner handling of excess items

src/main/kotlin/net/shadowfacts/phycon/network/block/miner/MinerBlockEntity.kt

@@ -14,7 +14,11 @@ import net.shadowfacts.phycon.api.packet.Packet
 import net.shadowfacts.phycon.api.util.IPAddress
 import net.shadowfacts.phycon.init.PhyBlockEntities
 import net.shadowfacts.phycon.network.DeviceBlockEntity
+import net.shadowfacts.phycon.network.block.terminal.TerminalBlockEntity
+import net.shadowfacts.phycon.network.component.NetworkStackDispatcher
 import net.shadowfacts.phycon.network.component.NetworkStackProvider
+import net.shadowfacts.phycon.network.component.handleItemStack
+import net.shadowfacts.phycon.network.component.spawnItemStack
 import net.shadowfacts.phycon.network.packet.*
 import kotlin.math.min
 
@@ -22,18 +26,24 @@ import kotlin.math.min
  * @author shadowfacts
  */
 class MinerBlockEntity: DeviceBlockEntity(PhyBlockEntities.MINER),
-	NetworkStackProvider {
+	NetworkStackProvider,
+	NetworkStackDispatcher<MinerBlockEntity.PendingInsertion> {
 
 	private val facing: Direction
 		get() = cachedState[MinerBlock.FACING]
 
 	private val invProxy = MinerInvProxy(this)
 
+	override val pendingInsertions = mutableListOf<PendingInsertion>()
+	override val dispatchStackTimeout = TerminalBlockEntity.INSERTION_TIMEOUT
+
 	override fun handle(packet: Packet) {
 		when (packet) {
 			is RequestInventoryPacket -> handleRequestInventory(packet)
 			is LocateStackPacket -> handleLocateStack(packet)
 			is ExtractStackPacket -> handleExtractStack(packet)
+			is CapacityPacket -> handleCapacity(packet)
+			is ItemStackPacket -> handleItemStack(packet)
 		}
 	}
 
@@ -50,7 +60,7 @@ class MinerBlockEntity: DeviceBlockEntity(PhyBlockEntities.MINER),
 
 	private fun handleExtractStack(packet: ExtractStackPacket) {
 		// always recalculate immediately before breaking
-		val drops = invProxy.getDrops(true)
+		val drops = invProxy.getDrops(recalculate = true)
 		if (invProxy.getAmount(packet.stack) > 0) {
 			world!!.breakBlock(pos.offset(facing), false)
 
@@ -77,11 +87,18 @@ class MinerBlockEntity: DeviceBlockEntity(PhyBlockEntities.MINER),
 			// dump any remaining drops into the network
 			for (droppedStack in drops) {
 				if (droppedStack.isEmpty) continue
-				sendPacket(ItemStackPacket(droppedStack, ipAddress, IPAddress.BROADCAST))
+				dispatchItemStack(droppedStack)
 			}
 		}
 	}
 
+	override fun doHandleItemStack(packet: ItemStackPacket): ItemStack {
+		// miner can't receive stacks, so remaining is the entire packet stack
+		return packet.stack
+	}
+
+	override fun createPendingInsertion(stack: ItemStack) = PendingInsertion(stack, counter)
+
 	class MinerInvProxy(val miner: MinerBlockEntity): GroupedItemInvView {
 		private var cachedState: BlockState? = null
 		private var cachedDrops: List<ItemStack>? = null
@@ -96,7 +113,7 @@ class MinerBlockEntity: DeviceBlockEntity(PhyBlockEntities.MINER),
 		fun getDrops(recalculate: Boolean = false): List<ItemStack> {
 			val targetPos = pos.offset(facing)
 			val realState = world.getBlockState(targetPos)
-			// todo: does BlockState.equals actually work?
+			// todo: does BlockState.equals actually work or is reference equality fine for BlockStates?
 			if (cachedDrops == null || realState != cachedState || recalculate) {
 				cachedState = realState
 				val be = if (realState.block.hasBlockEntity()) world.getBlockEntity(targetPos) else null
@@ -124,4 +141,7 @@ class MinerBlockEntity: DeviceBlockEntity(PhyBlockEntities.MINER),
 		}
 	}
 
+	class PendingInsertion(stack: ItemStack, timestamp: Long): NetworkStackDispatcher.PendingInsertion<PendingInsertion>(stack, timestamp) {
+	}
+
 }

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

@@ -161,12 +161,11 @@ class TerminalBlockEntity: DeviceBlockEntity(PhyBlockEntities.TERMINAL),
 
 	private fun finishPendingRequests() {
 		if (world!!.isClient) return
+		if (pendingRequests.isEmpty()) return
 
-		for (request in pendingRequests) {
-			if (request.isFinishable(counter)) {
-				stackLocateRequestCompleted(request)
-			}
-		}
+		val finishable = pendingRequests.filter { it.isFinishable(counter) }
+		// stackLocateRequestCompleted removes the object from pendingRequests
+		finishable.forEach(::stackLocateRequestCompleted)
 	}
 
 	fun addObserver() {

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

@@ -14,13 +14,11 @@ interface ItemStackPacketHandler: PacketSink, PacketSource {
 	fun doHandleItemStack(packet: ItemStackPacket): ItemStack
 }
 
-fun <BE> BE.handleItemStack(packet: ItemStackPacket) where BE: BlockEntity, BE: ItemStackPacketHandler {
+fun <Self> Self.handleItemStack(packet: ItemStackPacket) where Self: BlockEntity, Self: 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)
+		spawnItemStack(packet.stack)
 		return
 	}
 	val remainder = doHandleItemStack(packet)
@@ -28,4 +26,10 @@ fun <BE> BE.handleItemStack(packet: ItemStackPacket) where BE: BlockEntity, BE:
 	if (!remainder.isEmpty) {
 		sendPacket(ItemStackPacket(remainder, packet.bounceCount + 1, ipAddress, packet.source))
 	}
+}
+
+fun <Self> Self.spawnItemStack(stack: ItemStack) where Self: BlockEntity, Self: ItemStackPacketHandler {
+	// todo: calculate entity spawn point by finding non-obstructed location
+	val entity = ItemEntity(world!!, pos.x.toDouble(), pos.y + 1.0, pos.z.toDouble(), stack)
+	world!!.spawnEntity(entity)
 }

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

@@ -72,9 +72,10 @@ interface NetworkStackDispatcher<Insertion: NetworkStackDispatcher.PendingInsert
 
 fun <Self, Insertion: NetworkStackDispatcher.PendingInsertion<Insertion>> Self.finishTimedOutPendingInsertions() where Self: BlockEntity, Self: NetworkStackDispatcher<Insertion> {
 	if (world!!.isClient) return
+	if (pendingInsertions.isEmpty()) return
 
-	for (insertion in pendingInsertions) {
-		if (!insertion.isFinishable(this)) continue
-		finishInsertion(insertion)
-	}
+	val finishable = pendingInsertions.filter { it.isFinishable(this) }
+	// finishInsertion removes the object from pendingInsertions
+	finishable.forEach(::finishInsertion)
+	// todo: if a timed-out insertion can't be finished, we should probably retry after some time (exponential backoff?)
 }