PhysicalConnectivity/src/main/kotlin/net/shadowfacts/phycon/block/inserter/InserterScreenHandler.kt

package net.shadowfacts.phycon.block.inserter

import net.minecraft.entity.player.PlayerEntity
import net.minecraft.entity.player.PlayerInventory
import net.minecraft.inventory.Inventory
import net.minecraft.item.ItemStack
import net.minecraft.network.PacketByteBuf
import net.minecraft.screen.ScreenHandler
import net.minecraft.screen.slot.Slot
import net.minecraft.screen.slot.SlotActionType
import net.minecraft.util.Identifier
import net.shadowfacts.phycon.PhysicalConnectivity
import net.shadowfacts.phycon.init.PhyBlocks
import net.shadowfacts.phycon.init.PhyScreens
import kotlin.math.min

/**
 * @author shadowfacts
 */
class InserterScreenHandler(
	syncId: Int,
	playerInv: PlayerInventory,
	val inserter: InserterBlockEntity,
): ScreenHandler(PhyScreens.INSERTER_SCREEN_HANDLER, syncId) {

	companion object {
		val ID = Identifier(PhysicalConnectivity.MODID, "inserter")
	}

	private val fakeInv = FakeInventory(inserter)

	constructor(syncId: Int, playerInv: PlayerInventory, buf: PacketByteBuf):
			this(
				syncId,
				playerInv,
				PhyBlocks.INSERTER.getBlockEntity(playerInv.player.world, buf.readBlockPos())!!
			)

	init {
		// fake slot
		addSlot(FakeSlot(fakeInv, 31, 20))

		// player inv
		for (y in 0 until 3) {
			for (x in 0 until 9) {
				addSlot(Slot(playerInv, x + y * 9 + 9, 8 + x * 18, 51 + y * 18))
			}
		}

		// hotbar
		for (x in 0 until 9) {
			addSlot(Slot(playerInv, x, 8 + x * 18, 109))
		}
	}

	private fun stackToExtractChanged() {
		inserter.amountToExtract = min(inserter.stackToExtract.maxCount, inserter.amountToExtract)
	}

	override fun canUse(player: PlayerEntity): Boolean {
		return true
	}

	override fun onSlotClick(slotId: Int, clickData: Int, actionType: SlotActionType, player: PlayerEntity): ItemStack {
		// fake slot
		if (slotId == 0) {
			if (player.inventory.cursorStack.isEmpty) {
				inserter.stackToExtract = ItemStack.EMPTY
			} else {
				val copy = player.inventory.cursorStack.copy()
				copy.count = 1
				inserter.stackToExtract = copy
			}
			stackToExtractChanged()
		}
		return super.onSlotClick(slotId, clickData, actionType, player)
	}

	override fun transferSlot(player: PlayerEntity, slotId: Int): ItemStack {
		val slot = slots[slotId]
		val copy = slot.stack.copy()
		copy.count = 1
		inserter.stackToExtract = copy
		stackToExtractChanged()
		return ItemStack.EMPTY
	}

	class FakeSlot(inv: FakeInventory, x: Int, y: Int): Slot(inv, 0, x, y) {
		override fun canInsert(stack: ItemStack) = false

		override fun setStack(stack: ItemStack) {
		}

		override fun canTakeItems(player: PlayerEntity) = false
	}

	class FakeInventory(val inserter: InserterBlockEntity): Inventory {
		override fun clear() {
			inserter.stackToExtract = ItemStack.EMPTY
		}

		override fun size() = 1

		override fun isEmpty() = inserter.stackToExtract.isEmpty

		override fun getStack(i: Int): ItemStack {
			return if (i == 0) inserter.stackToExtract else ItemStack.EMPTY
		}

		override fun removeStack(i: Int, j: Int) = ItemStack.EMPTY

		override fun removeStack(i: Int) = ItemStack.EMPTY

		override fun setStack(i: Int, itemStack: ItemStack?) {}

		override fun markDirty() {}

		override fun canPlayerUse(playerEntity: PlayerEntity?) = true

	}

}