Add wooden hopper inventory interaction

src/main/kotlin/net/shadowfacts/extrahoppers/block/wood/WoodHopperBlockEntity.kt

@@ -1,10 +1,155 @@
 package net.shadowfacts.extrahoppers.block.wood
 
 import net.minecraft.block.entity.BlockEntity
+import net.minecraft.block.entity.Hopper
+import net.minecraft.block.entity.HopperBlockEntity
+import net.minecraft.entity.player.PlayerEntity
+import net.minecraft.inventory.Inventories
+import net.minecraft.inventory.Inventory
+import net.minecraft.inventory.SidedInventory
+import net.minecraft.item.ItemStack
+import net.minecraft.nbt.CompoundTag
+import net.minecraft.util.DefaultedList
 import net.minecraft.util.Tickable
+import net.minecraft.util.math.Direction
 import net.shadowfacts.extrahoppers.init.EHBlockEntities
+import net.shadowfacts.extrahoppers.util.toVec3d
 
-class WoodHopperBlockEntity: BlockEntity(EHBlockEntities.WOOD_HOPPER), Tickable {
-    override fun tick() {
+class WoodHopperBlockEntity: BlockEntity(EHBlockEntities.WOOD_HOPPER), Inventory, Hopper, Tickable {
+    companion object {
+        val TRANSFER_COOLDOWN = 40
     }
-}
+
+    var inventory: DefaultedList<ItemStack> = DefaultedList.ofSize(1, ItemStack.EMPTY)
+        private set
+    var transferCooldown = -1
+    var lastTickTime = 0L
+
+    override fun toTag(tag: CompoundTag): CompoundTag {
+        Inventories.toTag(tag, inventory)
+        tag.putInt("transferCooldown", transferCooldown)
+        return super.toTag(tag)
+    }
+
+    override fun fromTag(tag: CompoundTag) {
+        super.fromTag(tag)
+        inventory.clear()
+        Inventories.fromTag(tag, inventory)
+        transferCooldown = tag.getInt("transferCooldown")
+    }
+
+    override fun tick() {
+        val world = world
+        if (world == null || world.isClient) return
+
+        transferCooldown -= 1
+        lastTickTime = world.time
+        if (transferCooldown <= 0) {
+            transferCooldown = 0
+            insertAndExtract()
+        }
+    }
+
+    fun insertAndExtract() {
+        val world = world
+        if (world == null || world.isClient) return
+
+        var didWork = false
+        if (!isInvEmpty && insert()) {
+            didWork = true
+        }
+        if (!isFull() && HopperBlockEntity.extract(this)) {
+            didWork = true
+        }
+
+        if (didWork) {
+            transferCooldown = TRANSFER_COOLDOWN
+            markDirty()
+        }
+    }
+
+    fun insert(): Boolean {
+        val outputInv = getOutputInventory() ?: return false
+
+        val insertionSide = cachedState.get(WoodHopperBlock.FACING).opposite
+        if (isInventoryFull(outputInv, insertionSide)) return false
+
+        for (slot in 0 until invSize) {
+            if (getInvStack(slot).isEmpty) continue
+
+            val stackCopy = getInvStack(slot).copy()
+
+            val remaining = HopperBlockEntity.transfer(this, outputInv, takeInvStack(slot, 1), insertionSide)
+            if (remaining.isEmpty) {
+                outputInv.markDirty()
+                return true
+            }
+
+            setInvStack(slot, stackCopy)
+        }
+
+        return false
+    }
+
+    fun isFull(): Boolean {
+        return inventory.none(ItemStack::isEmpty)
+    }
+
+    fun getOutputInventory(): Inventory? {
+        val facing = cachedState.get(WoodHopperBlock.FACING)
+        return HopperBlockEntity.getInventoryAt(world!!, pos.offset(facing))
+    }
+
+    fun inventorySlots(inv: Inventory, side: Direction): Sequence<Int> {
+        return if (inv is SidedInventory) {
+            inv.getInvAvailableSlots(side).asSequence()
+        } else {
+            (0 until inv.invSize).asSequence()
+        }
+    }
+
+    fun isInventoryFull(inv: Inventory, side: Direction): Boolean {
+        val slots = inventorySlots(inv, side)
+        return slots.map(inv::getInvStack).none(ItemStack::isEmpty)
+    }
+
+    // Inventory
+
+    override fun getInvSize() = inventory.size
+
+    override fun takeInvStack(slot: Int, amount: Int): ItemStack {
+        return Inventories.splitStack(inventory, slot, amount)
+    }
+
+    override fun isInvEmpty() = inventory.isEmpty()
+
+    override fun getInvStack(slot: Int) = inventory[slot]
+
+    override fun clear() {
+        inventory.clear()
+    }
+
+    override fun setInvStack(slot: Int, stack: ItemStack) {
+        inventory[slot] = stack
+    }
+
+    override fun removeInvStack(slot: Int): ItemStack {
+        return Inventories.removeStack(inventory, slot)
+    }
+
+    override fun canPlayerUseInv(player: PlayerEntity): Boolean {
+        return if (world?.getBlockEntity(pos) != this) {
+            false
+        } else {
+            val distance = player.squaredDistanceTo(this.pos.toVec3d())
+            distance < 64
+        }
+    }
+
+    // Hopper
+
+    override fun getHopperX() = pos.x.toDouble()
+    override fun getHopperY() = pos.y.toDouble()
+    override fun getHopperZ() = pos.z.toDouble()
+
+}

src/main/kotlin/net/shadowfacts/extrahoppers/util/blockpos.kt

@@ -0,0 +1,8 @@
+package net.shadowfacts.extrahoppers.util
+
+import net.minecraft.util.math.BlockPos
+import net.minecraft.util.math.Vec3d
+
+fun BlockPos.toVec3d(): Vec3d {
+    return Vec3d(x + 0.5, y + 0.5, z + 0.5)
+}