4 files changed, 79 insertions, 6 deletions
diff --git a/src/main/kotlin/moe/nea/ledger/ItemChange.kt b/src/main/kotlin/moe/nea/ledger/ItemChange.kt
index 186a4e3..fda709c 100644
--- a/src/main/kotlin/moe/nea/ledger/ItemChange.kt
+++ b/src/main/kotlin/moe/nea/ledger/ItemChange.kt
@@ -59,6 +59,7 @@ data class ItemChange(
 		}
 
 		fun unpairGain(pair: Pair<ItemId, Double>) = unpair(ChangeDirection.GAINED, pair)
+		fun unpairLose(pair: Pair<ItemId, Double>) = unpair(ChangeDirection.LOST, pair)
 
 		fun gain(itemId: ItemId, amount: Number): ItemChange {
 			return ItemChange(itemId, amount.toDouble(), ChangeDirection.GAINED)
diff --git a/src/main/kotlin/moe/nea/ledger/ItemIdProvider.kt b/src/main/kotlin/moe/nea/ledger/ItemIdProvider.kt
index 30610e9..72f1d09 100644
--- a/src/main/kotlin/moe/nea/ledger/ItemIdProvider.kt
+++ b/src/main/kotlin/moe/nea/ledger/ItemIdProvider.kt
@@ -29,16 +29,24 @@ class ItemIdProvider {
 
 	private val knownNames = mutableMapOf<String, ItemId>()
 
+	fun createLookupTagFromDisplayName(itemName: String): String {
+		return itemName.unformattedString().trim().lowercase()
+	}
+
+	fun saveKnownItem(itemName: String, itemId: ItemId) {
+		knownNames[createLookupTagFromDisplayName(itemName)] = itemId
+	}
+
 	@SubscribeEvent
 	fun onDataLoaded(event: ExternalDataProvider.DataLoaded) {
 		event.provider.itemNames.forEach { (itemId, itemName) ->
-			knownNames[itemName.unformattedString().trim()] = ItemId(itemId)
+			saveKnownItem(itemName, ItemId(itemId))
 		}
 	}
 
 	@SubscribeEvent
 	fun onRegistrationFinished(event: RegistrationFinishedEvent) {
-		MinecraftForge.EVENT_BUS.post(ExtraSupplyIdEvent(knownNames::put))
+		MinecraftForge.EVENT_BUS.post(ExtraSupplyIdEvent(::saveKnownItem))
 	}
 
 	@SubscribeEvent(priority = EventPriority.HIGH)
@@ -63,7 +71,7 @@ class ItemIdProvider {
 		name = name.trim()
 		val id = stack.getInternalId()
 		if (id != null && name.isNotBlank()) {
-			knownNames[name] = id
+			saveKnownItem(name, id)
 		}
 	}
 
@@ -84,7 +92,7 @@ class ItemIdProvider {
 
 	// TODO: make use of colour
 	fun findForName(name: String, fallbackToGenerated: Boolean = true): ItemId? {
-		var id = knownNames[name]
+		var id = knownNames[createLookupTagFromDisplayName(name)]
 		if (id == null && fallbackToGenerated) {
 			id = generateName(name)
 		}
diff --git a/src/main/kotlin/moe/nea/ledger/ItemUtil.kt b/src/main/kotlin/moe/nea/ledger/ItemUtil.kt
index 949f58a..a3d8162 100644
--- a/src/main/kotlin/moe/nea/ledger/ItemUtil.kt
+++ b/src/main/kotlin/moe/nea/ledger/ItemUtil.kt
@@ -1,5 +1,6 @@
 package moe.nea.ledger
 
+import net.minecraft.inventory.IInventory
 import net.minecraft.item.ItemStack
 import net.minecraft.nbt.NBTTagCompound
 
@@ -37,7 +38,10 @@ class PetInfo {
 
 fun ItemStack.getPetId(): String? {
 	val petInfoStr = getExtraAttributes().getString("petInfo")
-	val petInfo = runCatching { Ledger.gson.fromJson(petInfoStr, PetInfo::class.java) }.getOrNull() // TODO: error reporting to sentry
+	val petInfo = runCatching {
+		Ledger.gson.fromJson(petInfoStr,
+		                     PetInfo::class.java)
+	}.getOrNull() // TODO: error reporting to sentry
 	if (petInfo?.type == null || petInfo.tier == null) return null
 	return petInfo.type + ";" + rarityToIndex(petInfo.tier ?: "")
 }
@@ -62,6 +66,22 @@ fun ItemStack.getLore(): List<String> {
 }
 
 
+fun IInventory.asIterable(): Iterable<ItemStack?> = object : Iterable<ItemStack?> {
+	override fun iterator(): Iterator<ItemStack?> {
+		return object : Iterator<ItemStack?> {
+			var i = 0
+			override fun hasNext(): Boolean {
+				return i < this@asIterable.sizeInventory
+			}
+
+			override fun next(): ItemStack? {
+				if (!hasNext()) throw NoSuchElementException("$i is out of range for inventory ${this@asIterable}")
+				return this@asIterable.getStackInSlot(i++)
+			}
+		}
+	}
+}
+
 fun ItemStack.getDisplayNameU(): String {
 	val nbt = this.tagCompound ?: NBTTagCompound()
 	val extraAttributes = nbt.getCompoundTag("display")
diff --git a/src/main/kotlin/moe/nea/ledger/modules/NpcDetection.kt b/src/main/kotlin/moe/nea/ledger/modules/NpcDetection.kt
index 5906562..c17cdc8 100644
--- a/src/main/kotlin/moe/nea/ledger/modules/NpcDetection.kt
+++ b/src/main/kotlin/moe/nea/ledger/modules/NpcDetection.kt
@@ -7,9 +7,16 @@ import moe.nea.ledger.LedgerEntry
 import moe.nea.ledger.LedgerLogger
 import moe.nea.ledger.SHORT_NUMBER_PATTERN
 import moe.nea.ledger.TransactionType
+import moe.nea.ledger.asIterable
+import moe.nea.ledger.events.BeforeGuiAction
 import moe.nea.ledger.events.ChatReceived
+import moe.nea.ledger.getDisplayNameU
+import moe.nea.ledger.getInternalId
+import moe.nea.ledger.getLore
 import moe.nea.ledger.parseShortNumber
+import moe.nea.ledger.unformattedString
 import moe.nea.ledger.useMatcher
+import moe.nea.ledger.utils.ErrorUtil
 import moe.nea.ledger.utils.di.Inject
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent
 import java.util.regex.Pattern
@@ -21,7 +28,44 @@ class NpcDetection @Inject constructor(val ledger: LedgerLogger, val ids: ItemId
 	val npcSellPattern =
 		Pattern.compile("You sold (?<what>.*) (x(?<count>$SHORT_NUMBER_PATTERN) )?for (?<coins>$SHORT_NUMBER_PATTERN) Coins?!")
 
-	// TODO: IMPROVE BUYING FROM NPC TO INCLUDE ITEMS OTHER THAN COINS (KUUDRA KEYS ARE CHEAP)
+	// You bought InfiniDirt™ Wand!
+	// You bought Prismapump x4!
+	val npcBuyWithItemPattern =
+		"You bought (?<what>.*?)!".toPattern()
+	var storedPurchases = mutableMapOf<String, List<ItemChange>>()
+
+	@SubscribeEvent
+	fun onClick(event: BeforeGuiAction) {
+		(event.chestSlots?.lowerChestInventory?.asIterable() ?: listOf())
+			.filterNotNull().forEach {
+				val name = it.getDisplayNameU().unformattedString()
+				val id = it.getInternalId() ?: return@forEach
+				val count = it.stackSize
+				val cost = ids.findCostItemsFromSpan(it.getLore())
+				storedPurchases[name] = listOf(ItemChange.gain(id, count)) + cost.map { ItemChange.unpairLose(it) }
+			}
+	}
+
+	@Inject
+	lateinit var errorUtil: ErrorUtil
+
+	@SubscribeEvent
+	fun onBarteredItemBought(event: ChatReceived) {
+		npcBuyWithItemPattern.useMatcher(event.message) {
+			val changes = storedPurchases[group("what")]
+			if (changes == null) {
+				errorUtil.reportAdHoc("Item bought for items without associated cost")
+			}
+			storedPurchases.clear()
+			ledger.logEntry(
+				LedgerEntry(
+					TransactionType.NPC_BUY,
+					event.timestamp,
+					changes ?: listOf()
+				)
+			)
+		}
+	}
 
 	@SubscribeEvent
 	fun onNpcBuy(event: ChatReceived) {