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

package net.shadowfacts.phycon.network.block.terminal

import alexiil.mc.lib.attributes.item.ItemStackUtil
import net.minecraft.inventory.SimpleInventory
import net.minecraft.item.ItemStack
import kotlin.math.min

/**
 * @author shadowfacts
 */
class TerminalBufferInventory(size: Int): SimpleInventory(size) {

	enum class Mode {
		TO_NETWORK, FROM_NETWORK, UNASSIGNED
	}

	private val modes = Array(size) { Mode.UNASSIGNED }

	fun insertFromNetwork(stack: ItemStack): ItemStack {
		var remaining = stack.copy()
		for (slot in 0 until size()) {
			if (modes[slot] == Mode.TO_NETWORK) continue

			remaining = insertFromNetwork(stack, slot)

			if (remaining.isEmpty) {
				break
			}
		}
		return remaining
	}

	private fun insertFromNetwork(stack: ItemStack, slot: Int): ItemStack {
		val mode = modes[slot]
		if (mode == Mode.TO_NETWORK) return stack
		val current = getStack(slot)
		if (current.isEmpty) {
			setStack(slot, stack)
			modes[slot] = Mode.FROM_NETWORK
			return ItemStack.EMPTY
		} else if (ItemStackUtil.areEqualIgnoreAmounts(stack, current)) {
			val toTransfer = min(current.maxCount - current.count, stack.count)
			current.count += toTransfer
			stack.count -= toTransfer
			modes[slot] = Mode.FROM_NETWORK
			return stack
		} else {
			return stack
		}
	}

	override fun setStack(slot: Int, stack: ItemStack) {
		if (stack.isEmpty) {
			modes[slot] = Mode.UNASSIGNED
		}
		super.setStack(slot, stack)
	}

}