Terminal: Merge stacks into buffer where possible

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

@@ -21,6 +21,7 @@ import net.shadowfacts.phycon.network.DeviceBlockEntity
 import net.shadowfacts.phycon.network.block.netinterface.InterfaceBlockEntity
 import net.shadowfacts.phycon.network.packet.*
 import net.shadowfacts.phycon.util.fromTag
+import net.shadowfacts.phycon.util.insert
 import net.shadowfacts.phycon.util.toTag
 import java.util.*
 import kotlin.math.min
@@ -83,17 +84,13 @@ class TerminalBlockEntity: DeviceBlockEntity(PhyBlockEntities.TERMINAL), Invento
 	}
 
 	private fun handleItemStack(packet: ItemStackPacket) {
-		// todo: handle merging stacks into the buffer better?
-		for (i in 0 until internalBuffer.invSize) {
-			if (internalBuffer.getInvStack(i).isEmpty) {
-				internalBuffer.setInvStack(i, packet.stack)
-				return
-			}
-		}
+		val remaining = internalBuffer.insert(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(), packet.stack)
+			val entity = ItemEntity(world!!, pos.x.toDouble(), pos.y + 1.0, pos.z.toDouble(), remaining)
 			world!!.spawnEntity(entity)
 		}
+	}
 
 	private fun updateNetItems() {
 		cachedNetItems.clear()

src/main/kotlin/net/shadowfacts/phycon/util/BasicInventoryExtensions.kt

@@ -1,10 +1,12 @@
 package net.shadowfacts.phycon.util
 
+import alexiil.mc.lib.attributes.item.ItemStackUtil
 import net.minecraft.inventory.BasicInventory
 import net.minecraft.item.ItemStack
 import net.minecraft.nbt.CompoundTag
 import net.minecraft.nbt.ListTag
 import java.lang.RuntimeException
+import kotlin.math.min
 
 /**
  * @author shadowfacts
@@ -32,3 +34,30 @@ fun BasicInventory.fromTag(list: ListTag) {
 		setInvStack(slot, stack)
 	}
 }
+
+fun BasicInventory.insert(stack: ItemStack, slot: Int): ItemStack {
+	@Suppress("NAME_SHADOWING") val stack = stack.copy()
+	val current = getInvStack(slot)
+	if (current.isEmpty) {
+		setInvStack(slot, stack)
+		return ItemStack.EMPTY
+	} else if (ItemStackUtil.areEqualIgnoreAmounts(stack, current)) {
+		val toTransfer = min(current.maxCount - current.count, stack.count)
+		current.count += toTransfer
+		stack.count -= toTransfer
+		return stack
+	} else {
+		return stack
+	}
+}
+
+fun BasicInventory.insert(stack: ItemStack): ItemStack {
+	var remaining = stack
+	for (slot in 0 until invSize) {
+		remaining = insert(stack, slot)
+		if (remaining.isEmpty) {
+			break
+		}
+	}
+	return remaining
+}