PhysicalConnectivity/src/main/kotlin/net/shadowfacts/phycon/block/terminal/CraftingTerminalBlockEntity.kt

package net.shadowfacts.phycon.block.terminal

import alexiil.mc.lib.attributes.item.ItemStackCollections
import alexiil.mc.lib.attributes.item.ItemStackUtil
import net.fabricmc.fabric.api.screenhandler.v1.ExtendedScreenHandlerFactory
import net.minecraft.block.BlockState
import net.minecraft.entity.player.PlayerEntity
import net.minecraft.entity.player.PlayerInventory
import net.minecraft.inventory.SimpleInventory
import net.minecraft.item.ItemStack
import net.minecraft.nbt.NbtCompound
import net.minecraft.network.PacketByteBuf
import net.minecraft.screen.ScreenHandler
import net.minecraft.server.network.ServerPlayerEntity
import net.minecraft.text.TranslatableText
import net.minecraft.util.math.BlockPos
import net.shadowfacts.phycon.init.PhyBlockEntities
import net.shadowfacts.phycon.packet.ItemStackPacket
import net.shadowfacts.phycon.packet.LocateStackPacket
import net.shadowfacts.phycon.packet.RequestInventoryPacket
import net.shadowfacts.phycon.util.fromTag
import net.shadowfacts.phycon.util.toTag
import java.util.LinkedList
import kotlin.math.min

/**
 * @author shadowfacts
 */
class CraftingTerminalBlockEntity(pos: BlockPos, state: BlockState): AbstractTerminalBlockEntity(PhyBlockEntities.CRAFTING_TERMINAL, pos, state) {

	val craftingInv = SimpleInventory(9)

	private val completedCraftingStackRequests = LinkedList<CraftingStackLocateRequest>()

	override fun onActivate(player: PlayerEntity) {
		if (!world!!.isClient) {
			updateAndSync()

			inventoryCache.clear()
			sendPacket(RequestInventoryPacket(ipAddress))
			val factory = object: ExtendedScreenHandlerFactory {
				override fun createMenu(syncId: Int, playerInv: PlayerInventory, player: PlayerEntity): ScreenHandler? {
					return CraftingTerminalScreenHandler(syncId, playerInv, this@CraftingTerminalBlockEntity)
				}

				override fun getDisplayName() = TranslatableText("block.phycon.crafting_terminal")

				override fun writeScreenOpeningData(player: ServerPlayerEntity, buf: PacketByteBuf) {
					buf.writeBlockPos(this@CraftingTerminalBlockEntity.pos)
				}
			}
			player.openHandledScreen(factory)
		}
	}

	fun requestItemsForCrafting(maxAmount: Int) {
		val amounts = ItemStackCollections.map<IntArray>()

		for (i in 0 until craftingInv.size()) {
			val craftingInvStack = craftingInv.getStack(i)
			if (craftingInvStack.isEmpty) continue
			if (craftingInvStack.count >= craftingInvStack.maxCount) continue

			if (craftingInvStack !in amounts) amounts[craftingInvStack] = IntArray(9) { 0 }
			amounts[craftingInvStack]!![i] = min(maxAmount, craftingInvStack.maxCount - craftingInvStack.count)
		}

		for ((stack, amountPerSlot) in amounts) {
			val total = amountPerSlot.sum()
			val request = CraftingStackLocateRequest(stack, total, counter, amountPerSlot)
			pendingRequests.add(request)
			sendPacket(LocateStackPacket(stack, ipAddress))
		}
	}

	override fun stackLocateRequestCompleted(request: StackLocateRequest) {
		if (request is CraftingStackLocateRequest) {
			completedCraftingStackRequests.add(request)
		}

		super.stackLocateRequestCompleted(request)
	}

	override fun doHandleItemStack(packet: ItemStackPacket): ItemStack {
		val craftingReq = completedCraftingStackRequests.find { ItemStackUtil.areEqualIgnoreAmounts(it.stack, packet.stack) }
		if (craftingReq != null) {
			var remaining = packet.stack.copy()

			for (i in 0 until craftingInv.size()) {
				val currentStack = craftingInv.getStack(i)
				if (currentStack.count >= currentStack.maxCount) continue
				if (!ItemStackUtil.areEqualIgnoreAmounts(currentStack, remaining)) continue

				val toInsert = minOf(remaining.count, currentStack.maxCount - currentStack.count, craftingReq.amountPerSlot[i])
				currentStack.count += toInsert
				remaining.count -= toInsert
				craftingReq.amountPerSlot[i] -= toInsert
				craftingReq.received += toInsert

				if (remaining.isEmpty) {
					break
				}
			}

			if (craftingReq.amountPerSlot.sum() == 0 || craftingReq.received >= craftingReq.totalResultAmount) {
				completedCraftingStackRequests.remove(craftingReq)
			}

			if (!remaining.isEmpty) {
				remaining = internalBuffer.insert(remaining, TerminalBufferInventory.Mode.FROM_NETWORK)
			}

			updateAndSync()

			return remaining
		} else {
			return super.doHandleItemStack(packet)
		}
	}

	override fun toCommonTag(tag: NbtCompound) {
		super.toCommonTag(tag)
		tag.put("CraftingInv", craftingInv.toTag())
	}

	override fun fromCommonTag(tag: NbtCompound) {
		super.fromCommonTag(tag)
		craftingInv.fromTag(tag.getList("CraftingInv", 10))
	}

	class CraftingStackLocateRequest(
		stack: ItemStack,
		amount: Int,
		timestamp: Long,
		val amountPerSlot: IntArray,
	): StackLocateRequest(stack, amount, timestamp) {
		var received: Int = 0
	}

}