Fix various issues with relays

CHANGELOG.md

@@ -24,7 +24,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 - The upkeep penalty for holding a truename in a wisp is now (properly) documented.
 - Mote Nexus and Relay have been added to the Hex Casting creative mode tab.
 - Increased the cost of Phase Block to prevent short durations being castable for free.
-- Updated zh_cn translations, by ChuijkYahus in [#187](https://github.com/FallingColors/Hexal/pull/187), [#199](https://github.com/FallingColors/Hexal/pull/199), and [#206](https://github.com/FallingColors/Hexal/pull/206).
+- Updated zh_cn translations, by ChuijkYahus in [#187](https://github.com/FallingColors/Hexal/pull/187), [#199](https://github.com/FallingColors/Hexal/pull/199), [#206](https://github.com/FallingColors/Hexal/pull/206), and [#228](https://github.com/FallingColors/Hexal/pull/228).
 - Wisps can now consume themselves for free to cleanly self-destruct.
 - Moved certain lang keys for type iotas from Hexal into MoreIotas, since MoreIotas is what actually implements type iotas.
 - Phase Block now ensures that the caster has permission to break the target block.
@@ -34,6 +34,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 - Fixed internal error when an entity-anchored gate can't find its entity, by Dominik-Pawelec in [#204](https://github.com/FallingColors/Hexal/pull/204).
 - Fixed Bind Storage - Temp permanently unbinding the caster when given a non-nexus block, by pythonmcpi in [#218](https://github.com/FallingColors/Hexal/pull/218).
+- Fixed a variety of issues related to transferring media through linked Relays.
 - Fixed the Trade spell requiring input items in a specific order for two-item trades.
 - Fixed broken/missing lang keys for `list.double` and `list.vec`.
 - Fixed the listed cost for Summon Projectile Wisp being incorrect.
@@ -44,6 +45,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 - Fixed the Relay block not dropping when broken.
 - Fixed an error when a playerless caster tries to create a link.
 - Fixed an error when passing null or an empty mote to Use Item On.
+- Fixed an error when breaking a Relay linked to multiple other Relays.
 - Fixed a variety of broken lang keys in the config menu.
 - Fixed Trade allowing trades even when not enough input items were present.
 

Common/src/main/java/ram/talia/hexal/common/blocks/entity/BlockEntityRelay.kt

@@ -51,6 +51,8 @@ class BlockEntityRelay(pos: BlockPos, val state: BlockState) : HexBlockEntity(He
     private val nonRelaysLinkedDirectly: LazyILinkableSet = LazyILinkableSet()
     private var mediaExchangersLinkedDirectly: LazyILinkableSet = LazyILinkableSet()
 
+    fun sameNetwork(other: BlockEntityRelay): Boolean = other.relayNetwork == this.relayNetwork
+
     fun setPigment(pigment: FrozenPigment, level: Level) = relayNetwork.setPigment(pigment, level.gameTime)
 
     fun serverTick() {
@@ -213,20 +215,21 @@ class BlockEntityRelay(pos: BlockPos, val state: BlockState) : HexBlockEntity(He
             other.setChanged()
         } else {
             // remove from list of non-relays linked to network.
+            // only decrement counts if removal succeeded (it could fail if tick() already handled the removal)
             nonRelaysLinkedDirectly.remove(other)
-            relayNetwork.nonRelays.remove(other)
-            relayNetwork.numNonRelays -= 1
+            relayNetwork.nonRelays.remove(other).let { if (it) relayNetwork.numNonRelays -= 1 }
             setChanged()
             if (other.currentMediaLevel() != -1L) {
                 mediaExchangersLinkedDirectly.remove(other)
-                relayNetwork.mediaExchangers.remove(other)
-                relayNetwork.numMediaExchangers -= 1
+                relayNetwork.mediaExchangers.remove(other).let { if (it) relayNetwork.numMediaExchangers -= 1 }
             }
         }
     }
 
     fun disconnectAll() {
-        for (relay in relaysLinkedDirectly)
+        // kotlin docs claim that MutableSet supports concurrent modification, so the toMutableList shouldn't be needed,
+        // but from my testing it throws ConcurrentModificationException anyway if that's not there
+        for (relay in relaysLinkedDirectly.toMutableList())
             relay.getRelay(level)?.let { unlink(it) }
     }
 
@@ -419,16 +422,21 @@ class BlockEntityRelay(pos: BlockPos, val state: BlockState) : HexBlockEntity(He
 
         fun acceptMedia(other: ILinkable, sentMedia: Long) {
             var remainingMedia = sentMedia
+            // distribute incoming media to all other linked objects
             for (mediaAcceptor in mediaExchangers.shuffled()) {
                 if (other == mediaAcceptor)
                     continue
 
-                val toSend = mediaAcceptor.canAcceptMedia(root, computedAverageMedia)
+                val averageMediaWithoutAcceptor = (computedAverageMedia * numMediaExchangers - mediaAcceptor.currentMediaLevel()) / (numMediaExchangers - 1)
+                val toSend = mediaAcceptor.canAcceptMedia(root, averageMediaWithoutAcceptor)
                 mediaAcceptor.acceptMedia(root, min(toSend, remainingMedia))
                 remainingMedia -= min(toSend, remainingMedia)
                 if (remainingMedia <= 0)
                     break
             }
+            // if there's any media left over, send it back where it came from
+            if (remainingMedia > 0)
+                other.acceptMedia(root, remainingMedia)
 
             linkablesAcceptedFromThisTick.add(other)
         }

Common/src/main/java/ram/talia/hexal/common/entities/BaseCastingWisp.kt

@@ -36,6 +36,7 @@ import ram.talia.hexal.api.casting.wisp.triggers.WispTriggerRegistry
 import ram.talia.hexal.api.mulBounded
 import ram.talia.hexal.api.nbt.SerialisedIota
 import ram.talia.hexal.client.sounds.WispCastingSoundInstance
+import ram.talia.hexal.common.blocks.entity.BlockEntityRelay
 import ram.talia.hexal.common.lib.HexalSounds
 import ram.talia.hexal.common.network.MsgWispCastSoundS2C
 import ram.talia.hexal.xplat.IXplatAbstractions
@@ -270,8 +271,16 @@ abstract class BaseCastingWisp(entityType: EntityType<out BaseCastingWisp>, worl
 	fun blackListContains(other: ILinkable): Boolean = blackListTransferMedia.contains(other)
 	fun whiteListContains(other: ILinkable): Boolean = whiteListTransferMedia.contains(other)
 
-	private fun shouldBlockTransfer(other: ILinkable): Boolean
-		= blackListTransferMedia.contains(other) || (other.owner() != this.owner() && !whiteListTransferMedia.contains(other))
+	private fun shouldBlockTransfer(other: ILinkable): Boolean {
+		if (other is BlockEntityRelay) {
+			for (blEntry in blackListTransferMedia)
+				if (blEntry is BlockEntityRelay && blEntry.sameNetwork(other)) return true
+			for (wlEntry in whiteListTransferMedia)
+				if (wlEntry is BlockEntityRelay && wlEntry.sameNetwork(other)) return false
+			return true
+		}
+		return blackListTransferMedia.contains(other) || (other.owner() != this.owner() && !whiteListTransferMedia.contains(other))
+	}
 
 	override fun currentMediaLevel(): Long = media