VoxeLibre/mods/ITEMS/mcl_hoppers/init.lua

local S = minetest.get_translator(minetest.get_current_modname())
local F = minetest.formspec_escape
local C = minetest.colorize

local LOGGING_ON = minetest.settings:get_bool("mcl_logging_hoppers", false)
local function mcl_log(message)
	if LOGGING_ON then
		mcl_util.mcl_log(message, "[Hoppers]", true)
	end
end

--[[ BEGIN OF NODE DEFINITIONS ]]

local mcl_hoppers_formspec = table.concat({
	"size[9,7]",
	"label[2,0;"..F(C(mcl_formspec.label_color, S("Hopper"))).."]",
	"list[context;main;2,0.5;5,1;]",
	mcl_formspec.get_itemslot_bg(2,0.5,5,1),
	"label[0,2;"..F(C(mcl_formspec.label_color, S("Inventory"))).."]",
	"list[current_player;main;0,2.5;9,3;9]",
	mcl_formspec.get_itemslot_bg(0,2.5,9,3),
	"list[current_player;main;0,5.74;9,1;]",
	mcl_formspec.get_itemslot_bg(0,5.74,9,1),
	"listring[context;main]",
	"listring[current_player;main]"
})

-- Downwards hopper (base definition)

---@type node_definition
local def_hopper = {
	inventory_image = "mcl_hoppers_item.png",
	wield_image = "mcl_hoppers_item.png",
	groups = {pickaxey = 1, container = 2, deco_block = 1, hopper = 1},
	drawtype = "nodebox",
	paramtype = "light",
	-- FIXME: mcl_hoppers_hopper_inside.png is unused by hoppers.
	tiles = {
		"mcl_hoppers_hopper_inside.png^mcl_hoppers_hopper_top.png",
		"mcl_hoppers_hopper_outside.png",
		"mcl_hoppers_hopper_outside.png",
		"mcl_hoppers_hopper_outside.png",
		"mcl_hoppers_hopper_outside.png",
		"mcl_hoppers_hopper_outside.png",
	},
	node_box = {
		type = "fixed",
		fixed = {
			--funnel walls
			{-0.5, 0.0, 0.4, 0.5, 0.5, 0.5},
			{0.4, 0.0, -0.5, 0.5, 0.5, 0.5},
			{-0.5, 0.0, -0.5, -0.4, 0.5, 0.5},
			{-0.5, 0.0, -0.5, 0.5, 0.5, -0.4},
			--funnel base
			{-0.5, 0.0, -0.5, 0.5, 0.1, 0.5},
			--spout
			{-0.3, -0.3, -0.3, 0.3, 0.0, 0.3},
			{-0.1, -0.3, -0.1, 0.1, -0.5, 0.1},
		},
	},
	selection_box = {
		type = "fixed",
		fixed = {
			--funnel
			{-0.5, 0.0, -0.5, 0.5, 0.5, 0.5},
			--spout
			{-0.3, -0.3, -0.3, 0.3, 0.0, 0.3},
			{-0.1, -0.3, -0.1, 0.1, -0.5, 0.1},
		},
	},
	is_ground_content = false,

	on_construct = function(pos)
		local meta = minetest.get_meta(pos)
		meta:set_string("formspec", mcl_hoppers_formspec)
		local inv = meta:get_inventory()
		inv:set_size("main", 5)
	end,

	after_dig_node = function(pos, oldnode, oldmetadata, digger)
		local meta = minetest.get_meta(pos)
		local meta2 = meta:to_table()
		meta:from_table(oldmetadata)
		local inv = meta:get_inventory()
		for i = 1, inv:get_size("main") do
			local stack = inv:get_stack("main", i)
			if not stack:is_empty() then
				local p = vector.offset(pos, math.random(0, 10) / 10 - 0.5, 0, math.random(0, 10) / 10 - 0.5)
				minetest.add_item(p, stack)
			end
		end
		meta:from_table(meta2)
	end,
	allow_metadata_inventory_move = function(pos, from_list, from_index, to_list, to_index, count, player)
		local name = player:get_player_name()
		if minetest.is_protected(pos, name) then
			minetest.record_protection_violation(pos, name)
			return 0
		else
			return count
		end
	end,
	allow_metadata_inventory_take = function(pos, listname, index, stack, player)
		local name = player:get_player_name()
		if minetest.is_protected(pos, name) then
			minetest.record_protection_violation(pos, name)
			return 0
		else
			return stack:get_count()
		end
	end,
	allow_metadata_inventory_put = function(pos, listname, index, stack, player)
		local name = player:get_player_name()
		if minetest.is_protected(pos, name) then
			minetest.record_protection_violation(pos, name)
			return 0
		else
			return stack:get_count()
		end
	end,
	on_metadata_inventory_move = function(pos, from_list, from_index, to_list, to_index, count, player)
		minetest.log("action", player:get_player_name() ..
			" moves stuff in mcl_hoppers at " .. minetest.pos_to_string(pos))
	end,
	on_metadata_inventory_put = function(pos, listname, index, stack, player)
		minetest.log("action", player:get_player_name() ..
			" moves stuff to mcl_hoppers at " .. minetest.pos_to_string(pos))
	end,
	on_metadata_inventory_take = function(pos, listname, index, stack, player)
		minetest.log("action", player:get_player_name() ..
			" takes stuff from mcl_hoppers at " .. minetest.pos_to_string(pos))
	end,
	sounds = mcl_sounds.node_sound_metal_defaults(),

	_mcl_blast_resistance = 4.8,
	_mcl_hardness = 3,
}

-- Redstone variants (on/off) of downwards hopper.
-- Note a hopper is enabled when it is *not* supplied with redstone power and disabled when it is supplied with redstone power.

-- Enabled downwards hopper
local def_hopper_enabled = table.copy(def_hopper)
def_hopper_enabled.description = S("Hopper")
def_hopper_enabled._tt_help = S("5 inventory slots") ..
	"\n" .. S("Collects items from above, moves items to container below") .. "\n" ..
	S("Can be disabled with redstone power")
def_hopper_enabled._doc_items_longdesc = S("Hoppers are containers with 5 inventory slots. They collect dropped items from above, take items from a container above and attempt to put its items it into an adjacent container. Hoppers can go either downwards or sideways. Hoppers interact with chests, droppers, dispensers, shulker boxes, furnaces and hoppers.")
	.. "\n\n" ..

	S("Hoppers interact with containers the following way:") .. "\n" ..
	S("• Furnaces: Hoppers from above will put items into the source slot. Hoppers from below take items from the output slot. They also take items from the fuel slot when they can't be used as a fuel. Sideway hoppers that point to the furnace put items into the fuel slot")
	.. "\n" ..
	S("• Ender chests: No interaction.") .. "\n" ..
	S("• Other containers: Normal interaction.") .. "\n\n" ..

	S("Hoppers can be disabled when supplied with redstone power. Disabled hoppers don't move items.")
def_hopper_enabled._doc_items_usagehelp = S("To place a hopper vertically, place it on the floor or a ceiling. To place it sideways, place it at the side of a block. Use the hopper to access its inventory.")
def_hopper_enabled.on_place = function(itemstack, placer, pointed_thing)
	local upos = pointed_thing.under
	local apos = pointed_thing.above

	local uposnode = minetest.get_node(upos)
	local uposnodedef = minetest.registered_nodes[uposnode.name]
	if not uposnodedef then return itemstack end
	-- Use pointed node's on_rightclick function first, if present
	if placer and not placer:get_player_control().sneak then
		if uposnodedef and uposnodedef.on_rightclick then
			return uposnodedef.on_rightclick(pointed_thing.under, uposnode, placer, itemstack) or itemstack
		end
	end

	local x = upos.x - apos.x
	local z = upos.z - apos.z

	local fake_itemstack = ItemStack(itemstack)
	local param2
	if x == -1 then
		fake_itemstack:set_name("mcl_hoppers:hopper_side")
		param2 = 0
	elseif x == 1 then
		fake_itemstack:set_name("mcl_hoppers:hopper_side")
		param2 = 2
	elseif z == -1 then
		fake_itemstack:set_name("mcl_hoppers:hopper_side")
		param2 = 3
	elseif z == 1 then
		fake_itemstack:set_name("mcl_hoppers:hopper_side")
		param2 = 1
	end
	local itemstack, _ = minetest.item_place_node(fake_itemstack, placer, pointed_thing, param2)
	itemstack:set_name("mcl_hoppers:hopper")
	return itemstack
end
def_hopper_enabled.mesecons = {
	effector = {
		action_on = function(pos, node)
			minetest.swap_node(pos, {name = "mcl_hoppers:hopper_disabled", param2 = node.param2})
		end,
	},
}

minetest.register_node("mcl_hoppers:hopper", def_hopper_enabled)

---Disabled downwards hopper
---@type node_definition
local def_hopper_disabled = table.copy(def_hopper)
def_hopper_disabled.description = S("Disabled Hopper")
def_hopper_disabled.inventory_image = nil
def_hopper_disabled._doc_items_create_entry = false
def_hopper_disabled.groups.not_in_creative_inventory = 1
def_hopper_disabled.drop = "mcl_hoppers:hopper"
def_hopper_disabled.mesecons = {
	effector = {
		action_off = function(pos, node)
			minetest.swap_node(pos, {name = "mcl_hoppers:hopper", param2 = node.param2})
		end,
	},
}

minetest.register_node("mcl_hoppers:hopper_disabled", def_hopper_disabled)



local on_rotate
if minetest.get_modpath("screwdriver") then
	on_rotate = screwdriver.rotate_simple
end

---Sidewars hopper (base definition)
---@type node_definition
local def_hopper_side = {
	_doc_items_create_entry = false,
	drop = "mcl_hoppers:hopper",
	groups = {pickaxey = 1, container = 2, not_in_creative_inventory = 1, hopper = 2},
	drawtype = "nodebox",
	paramtype = "light",
	paramtype2 = "facedir",
	tiles = {
		"mcl_hoppers_hopper_inside.png^mcl_hoppers_hopper_top.png",
		"mcl_hoppers_hopper_outside.png",
		"mcl_hoppers_hopper_outside.png",
		"mcl_hoppers_hopper_outside.png",
		"mcl_hoppers_hopper_outside.png",
		"mcl_hoppers_hopper_outside.png",
	},
	node_box = {
		type = "fixed",
		fixed = {
			--funnel walls
			{-0.5, 0.0, 0.4, 0.5, 0.5, 0.5},
			{0.4, 0.0, -0.5, 0.5, 0.5, 0.5},
			{-0.5, 0.0, -0.5, -0.4, 0.5, 0.5},
			{-0.5, 0.0, -0.5, 0.5, 0.5, -0.4},
			--funnel base
			{-0.5, 0.0, -0.5, 0.5, 0.1, 0.5},
			--spout
			{-0.3, -0.3, -0.3, 0.3, 0.0, 0.3},
			{-0.5, -0.3, -0.1, 0.1, -0.1, 0.1},
		},
	},
	selection_box = {
		type = "fixed",
		fixed = {
			--funnel
			{-0.5, 0.0, -0.5, 0.5, 0.5, 0.5},
			--spout
			{-0.3, -0.3, -0.3, 0.3, 0.0, 0.3},
			{-0.5, -0.3, -0.1, 0.1, -0.1, 0.1},
		},
	},
	is_ground_content = false,

	on_construct = function(pos)
		local meta = minetest.get_meta(pos)
		meta:set_string("formspec", mcl_hoppers_formspec)
		local inv = meta:get_inventory()
		inv:set_size("main", 5)
	end,

	after_dig_node = function(pos, oldnode, oldmetadata, digger)
		local meta = minetest.get_meta(pos)
		local meta2 = meta
		meta:from_table(oldmetadata)
		local inv = meta:get_inventory()
		for i = 1, inv:get_size("main") do
			local stack = inv:get_stack("main", i)
			if not stack:is_empty() then
				local p = vector.offset(pos, math.random(0, 10) / 10 - 0.5, 0, math.random(0, 10) / 10 - 0.5)
				minetest.add_item(p, stack)
			end
		end
		meta:from_table(meta2:to_table())
	end,
	allow_metadata_inventory_move = function(pos, from_list, from_index, to_list, to_index, count, player)
		local name = player:get_player_name()
		if minetest.is_protected(pos, name) then
			minetest.record_protection_violation(pos, name)
			return 0
		else
			return count
		end
	end,
	allow_metadata_inventory_take = function(pos, listname, index, stack, player)
		local name = player:get_player_name()
		if minetest.is_protected(pos, name) then
			minetest.record_protection_violation(pos, name)
			return 0
		else
			return stack:get_count()
		end
	end,
	allow_metadata_inventory_put = function(pos, listname, index, stack, player)
		local name = player:get_player_name()
		if minetest.is_protected(pos, name) then
			minetest.record_protection_violation(pos, name)
			return 0
		else
			return stack:get_count()
		end
	end,
	on_metadata_inventory_move = function(pos, from_list, from_index, to_list, to_index, count, player)
		minetest.log("action", player:get_player_name() ..
			" moves stuff in mcl_hoppers at " .. minetest.pos_to_string(pos))
	end,
	on_metadata_inventory_put = function(pos, listname, index, stack, player)
		minetest.log("action", player:get_player_name() ..
			" moves stuff to mcl_hoppers at " .. minetest.pos_to_string(pos))
	end,
	on_metadata_inventory_take = function(pos, listname, index, stack, player)
		minetest.log("action", player:get_player_name() ..
			" takes stuff from mcl_hoppers at " .. minetest.pos_to_string(pos))
	end,
	on_rotate = on_rotate,
	sounds = mcl_sounds.node_sound_metal_defaults(),

	_mcl_blast_resistance = 4.8,
	_mcl_hardness = 3,
}

---@type node_definition
local def_hopper_side_enabled = table.copy(def_hopper_side)
def_hopper_side_enabled.description = S("Side Hopper")
def_hopper_side_enabled.mesecons = {
	effector = {
		action_on = function(pos, node)
			minetest.swap_node(pos, {name = "mcl_hoppers:hopper_side_disabled", param2 = node.param2})
		end,
	},
}
minetest.register_node("mcl_hoppers:hopper_side", def_hopper_side_enabled)

---@type node_definition
local def_hopper_side_disabled = table.copy(def_hopper_side)
def_hopper_side_disabled.description = S("Disabled Side Hopper")
def_hopper_side_disabled.mesecons = {
	effector = {
		action_off = function(pos, node)
			minetest.swap_node(pos, {name = "mcl_hoppers:hopper_side", param2 = node.param2})
		end,
	},
}
minetest.register_node("mcl_hoppers:hopper_side_disabled", def_hopper_side_disabled)

--[[ END OF NODE DEFINITIONS ]]

local function hopper_pull_from_mc(mc_ent, dest_pos, inv_size)
	local inv = mcl_entity_invs.load_inv(mc_ent, inv_size)
	if not inv then
		mcl_log("No inv")
		return false
	end

	local dest_meta = minetest.get_meta(dest_pos)
	local dest_inv = dest_meta:get_inventory()
	if not dest_inv then
		mcl_log("No dest inv")
		return
	end

	mcl_log("inv. size: " .. mc_ent._inv_size)
	for i = 1, mc_ent._inv_size, 1 do
		local stack = inv:get_stack("main", i)

		mcl_log("i: " .. tostring(i))
		mcl_log("Name: [" .. tostring(stack:get_name()) .. "]")
		mcl_log("Count: " .. tostring(stack:get_count()))
		mcl_log("stack max: " .. tostring(stack:get_stack_max()))

		if not stack:get_name() or stack:get_name() ~= "" then
			if dest_inv:room_for_item("main", stack:peek_item()) then
				mcl_log("Room so unload")
				dest_inv:add_item("main", stack:take_item())
				inv:set_stack("main", i, stack)

				-- Take one item and stop until next time
				return
			else
				mcl_log("no Room")
			end

		else
			mcl_log("nothing there")
		end
	end
end

local function hopper_push_to_mc(mc_ent, dest_pos, inv_size)
	local dest_inv = mcl_entity_invs.load_inv(mc_ent, inv_size)
	if not dest_inv then
		mcl_log("No inv")
		return false
	end

	local meta = minetest.get_meta(dest_pos)
	local inv = meta:get_inventory()
	if not inv then
		mcl_log("No dest inv")
		return
	end

	mcl_log("inv. size: " .. mc_ent._inv_size)
	for i = 1, mc_ent._inv_size, 1 do
		local stack = inv:get_stack("main", i)

		mcl_log("i: " .. tostring(i))
		mcl_log("Name: [" .. tostring(stack:get_name()) .. "]")
		mcl_log("Count: " .. tostring(stack:get_count()))
		mcl_log("stack max: " .. tostring(stack:get_stack_max()))

		if not stack:get_name() or stack:get_name() ~= "" then
			if dest_inv:room_for_item("main", stack:peek_item()) then
				mcl_log("Room so unload")
				dest_inv:add_item("main", stack:take_item())
				inv:set_stack("main", i, stack)

				-- Take one item and stop until next time
				return
			else
				mcl_log("no Room")
			end

		else
			mcl_log("nothing there")
		end
	end
end

--[[ BEGIN OF ABM DEFINITONS ]]

minetest.register_abm({
	label = "Hoppers pull from minecart hoppers",
	nodenames = {"mcl_hoppers:hopper", "mcl_hoppers:hopper_side"},
	interval = 0.5,
	chance = 1,
	action = function(pos, node, active_object_count, active_object_count_wider)
		mcl_log("ABM for: " .. minetest.pos_to_string(pos))
		local objs = minetest.get_objects_inside_radius(pos, 3)

		if objs and #objs > 0 then
			for k, v in pairs(objs) do
				local entity = v:get_luaentity()
				if entity and entity.name then
					--mcl_log("Name of object near: " .. tostring(entity.name))

					if entity.name == "mcl_minecarts:hopper_minecart" or entity.name == "mcl_minecarts:chest_minecart" then
						local hm_pos = entity.object:get_pos()
						mcl_log("We have a minecart with inventory close: " .. minetest.pos_to_string(hm_pos))

						--if hm_pos.y == pos.y + 1 then mcl_log("y is correct") end
						--if (hm_pos.x >= pos.x - DIST_FROM_MC and hm_pos.x <= pos.x + DIST_FROM_MC) then mcl_log("x is within range") end
						--if (hm_pos.z >= pos.z - DIST_FROM_MC and hm_pos.z <= pos.z + DIST_FROM_MC) then mcl_log("z is within range") end

						local DIST_FROM_MC = 1.5
						if (hm_pos.y == pos.y + 1)
							and (hm_pos.x >= pos.x - DIST_FROM_MC and hm_pos.x <= pos.x + DIST_FROM_MC)
							and (hm_pos.z >= pos.z - DIST_FROM_MC and hm_pos.z <= pos.z + DIST_FROM_MC) then
							mcl_log("Minecart close enough")
							if entity.name == "mcl_minecarts:hopper_minecart" then
								hopper_pull_from_mc(entity, pos, 5)
							elseif entity.name == "mcl_minecarts:chest_minecart" then
								hopper_pull_from_mc(entity, pos, 27)
							end
						elseif (hm_pos.y == pos.y - 1)
							and (hm_pos.x >= pos.x - DIST_FROM_MC and hm_pos.x <= pos.x + DIST_FROM_MC)
							and (hm_pos.z >= pos.z - DIST_FROM_MC and hm_pos.z <= pos.z + DIST_FROM_MC) then
							mcl_log("Minecart close enough")
							if entity.name == "mcl_minecarts:hopper_minecart" then
								hopper_push_to_mc(entity, pos, 5)
							elseif entity.name == "mcl_minecarts:chest_minecart" then
								hopper_push_to_mc(entity, pos, 27)
							end
						end
					end
				else
					mcl_log("no entity")
				end
			end
		else
			mcl_log("objs missing")
		end
	end,
})

-- Make hoppers suck in dropped items
minetest.register_abm({
	label = "Hoppers suck in dropped items",
	nodenames = {"mcl_hoppers:hopper", "mcl_hoppers:hopper_side"},
	interval = 1.0,
	chance = 1,
	action = function(pos, node, active_object_count, active_object_count_wider)
		local abovenode = minetest.get_node(vector.offset(pos, 0, 1, 0))
		if not minetest.registered_items[abovenode.name] then return end
		-- Don't bother checking item enties if node above is a container (should save some CPU)
		if minetest.get_item_group(abovenode.name, "container") ~= 0 then
			return
		end
		local meta = minetest.get_meta(pos)
		local inv = meta:get_inventory()

		for _, object in pairs(minetest.get_objects_inside_radius(pos, 2)) do
			if not object:is_player() and object:get_luaentity() and object:get_luaentity().name == "__builtin:item" and
				not object:get_luaentity()._removed then
				if inv and inv:room_for_item("main", ItemStack(object:get_luaentity().itemstring)) then
					-- Item must get sucked in when the item just TOUCHES the block above the hopper
					-- This is the reason for the Y calculation.
					-- Test: Items on farmland and slabs get sucked, but items on full blocks don't
					local posob = object:get_pos()
					local posob_miny = posob.y + object:get_properties().collisionbox[2]
					if math.abs(posob.x - pos.x) <= 0.5 and (posob_miny - pos.y < 1.5 and posob.y - pos.y >= 0.3) then
						inv:add_item("main", ItemStack(object:get_luaentity().itemstring))
						object:get_luaentity().itemstring = ""
						object:remove()
					end
				end
			end
		end
	end,
})

---Returns true if itemstack is fuel, but not for lava bucket if destination already has one
---@param itemstack ItemStack
---@param src_inventory InvRef
---@param src_list string
---@param dst_inventory InvRef
---@param dst_list string
---@return boolean
local function is_transferrable_fuel(itemstack, src_inventory, src_list, dst_inventory, dst_list)
	if mcl_util.is_fuel(itemstack) then
		if itemstack:get_name() == "mcl_buckets:bucket_lava" then
			return dst_inventory:is_empty(dst_list)
		else
			return true
		end
	else
		return false
	end
end

minetest.register_abm({
	label = "Hopper/container item exchange",
	nodenames = {"mcl_hoppers:hopper"},
	neighbors = {"group:container"},
	interval = 1.0,
	chance = 1,
	action = function(pos, node, active_object_count, active_object_count_wider)
		-- Get node pos' for item transfer
		local uppos   = vector.offset(pos, 0, 1, 0)
		local downpos = vector.offset(pos, 0, -1, 0)

		-- Suck an item from the container above into the hopper
		local upnode = minetest.get_node(uppos)
		if not minetest.registered_nodes[upnode.name] then return end
		local g = minetest.get_item_group(upnode.name, "container")
		local sucked = mcl_util.move_item_container(uppos, pos)

		-- Also suck in non-fuel items from furnace fuel slot
		if not sucked and g == 4 then
			local finv = minetest.get_inventory({type = "node", pos = uppos})
			if finv and not mcl_util.is_fuel(finv:get_stack("fuel", 1)) then
				mcl_util.move_item_container(uppos, pos, "fuel")
			end
		end

		-- Move an item from the hopper into container below
		local downnode = minetest.get_node(downpos)
		if not minetest.registered_nodes[downnode.name] then return end
		mcl_util.move_item_container(pos, downpos)
	end,
})

minetest.register_abm({
	label = "Side-hopper/container item exchange",
	nodenames = {"mcl_hoppers:hopper_side"},
	neighbors = {"group:container"},
	interval = 1.0,
	chance = 1,
	action = function(pos, node, active_object_count, active_object_count_wider)
		-- Determine to which side the hopper is facing, get nodes
		local face = minetest.get_node(pos).param2
		local front = {}
		if face == 0 then
			front = vector.offset(pos, -1, 0, 0)
		elseif face == 1 then
			front = vector.offset(pos, 0, 0, 1)
		elseif face == 2 then
			front = vector.offset(pos, 1, 0, 0)
		elseif face == 3 then
			front = vector.offset(pos, 0, 0, -1)
		end
		local above = vector.offset(pos, 0, 1, 0)

		local frontnode = minetest.get_node(front)
		if not minetest.registered_nodes[frontnode.name] then return end

		-- Suck an item from the container above into the hopper
		local abovenode = minetest.get_node(above)
		if not minetest.registered_nodes[abovenode.name] then return end
		local g = minetest.get_item_group(abovenode.name, "container")
		local sucked = mcl_util.move_item_container(above, pos)

		-- Also suck in non-fuel items from furnace fuel slot
		if not sucked and g == 4 then
			local finv = minetest.get_inventory({type = "node", pos = above})
			if finv and not mcl_util.is_fuel(finv:get_stack("fuel", 1)) then
				mcl_util.move_item_container(above, pos, "fuel")
			end
		end

		-- Move an item from the hopper into the container to which the hopper points to
		local g = minetest.get_item_group(frontnode.name, "container")
		if g == 2 or g == 3 or g == 5 or g == 6 then
			mcl_util.move_item_container(pos, front)
		elseif g == 4 then
			-- Put fuel into fuel slot
			local sinv = minetest.get_inventory({type = "node", pos = pos})
			local dinv = minetest.get_inventory({type = "node", pos = front})
			local slot_id, _ = mcl_util.get_eligible_transfer_item_slot(sinv, "main", dinv, "fuel", is_transferrable_fuel)
			if slot_id then
				mcl_util.move_item_container(pos, front, nil, slot_id, "fuel")
			end
		end
	end
})

if minetest.get_modpath("mcl_composters") then
	minetest.register_abm({
		label = "Bonemeal extraction from composter",
		nodenames = {"mcl_hoppers:hopper", "mcl_hoppers:hopper_side"},
		neighbors = {"mcl_composters:composter_ready"},
		interval = 1.0,
		chance = 1,
		action = function(pos, node, active_object_count, active_object_count_wider)
			local uppos = vector.offset(pos, 0, 1, 0)
			--local downpos = vector.offset(pos, 0, -1, 0)

			-- Get bonemeal from composter above
			local upnode = minetest.get_node(uppos)
			if upnode.name == "mcl_composters:composter_ready" then
				local meta = minetest.get_meta(pos)
				local inv = meta:get_inventory()

				minetest.swap_node(uppos, {name = "mcl_composters:composter"})

				inv:add_item("main", "mcl_bone_meal:bone_meal")
			end
		end,
	})

	---@param node node
	---@return integer?
	---@nodiscard
	local function composter_level(node)
		local nn = node.name
		if nn == "mcl_composters:composter" then
			return 0
		elseif nn == "mcl_composters:composter_1" then
			return 1
		elseif nn == "mcl_composters:composter_2" then
			return 2
		elseif nn == "mcl_composters:composter_3" then
			return 3
		elseif nn == "mcl_composters:composter_4" then
			return 4
		elseif nn == "mcl_composters:composter_5" then
			return 5
		elseif nn == "mcl_composters:composter_6" then
			return 6
		elseif nn == "mcl_composters:composter_7" then
			return 7
		else
			return nil
		end
	end

	for i = 1, 7 do
		assert(composter_level({name = "mcl_composters:composter_" .. i}) == i)
	end

	assert(composter_level({name = "mcl_composters:composter"}) == 0)
	assert(composter_level({name = "mcl_composters:some_other_node"}) == nil)

	minetest.register_abm({
		label = "Add compostable items on composter",
		nodenames = {"mcl_hoppers:hopper"},
		neighbors = {
			"mcl_composters:composter",
			"mcl_composters:composter_1",
			"mcl_composters:composter_2",
			"mcl_composters:composter_3",
			"mcl_composters:composter_4",
			"mcl_composters:composter_5",
			"mcl_composters:composter_6",
			"mcl_composters:composter_7",
		},
		interval = 1.0,
		chance = 1,
		action = function(pos, node, active_object_count, active_object_count_wider)
			--local uppos = vector.offset(pos, 0, 1, 0)
			local downpos = vector.offset(pos, 0, -1, 0)

			local downnode = minetest.get_node(downpos)

			---@type integer|string|nil
			local level = composter_level(downnode)

			--Consume compostable items and update composter below
			if level then
				local meta = minetest.get_meta(pos)
				local inv = meta:get_inventory()

				for i = 1, 5 do
					local stack = inv:get_stack("main", i)
					local compchance = minetest.get_item_group(stack:get_name(), "compostability")

					if compchance > 0 then
						stack:take_item()
						inv:set_stack("main", i, stack)

						if compchance >= math.random(0, 100) then
							mcl_dye.add_bone_meal_particle(vector.offset(downpos, 0, level / 8, 0))
							if level < 7 then
								level = level + 1
							else
								level = "ready"
							end
							minetest.swap_node(downpos, {name = "mcl_composters:composter_" .. level})
						end
						break
					end
				end
			end
		end,
	})
end

minetest.register_craft({
	output = "mcl_hoppers:hopper",
	recipe = {
		{"mcl_core:iron_ingot", "", "mcl_core:iron_ingot"},
		{"mcl_core:iron_ingot", "mcl_chests:chest", "mcl_core:iron_ingot"},
		{"", "mcl_core:iron_ingot", ""},
	},
})

-- Add entry aliases for the Help
if minetest.get_modpath("doc") then
	doc.add_entry_alias("nodes", "mcl_hoppers:hopper", "nodes", "mcl_hoppers:hopper_side")
end

-- Legacy
minetest.register_alias("mcl_hoppers:hopper_item", "mcl_hoppers:hopper")

minetest.register_lbm({
	label = "Update hopper formspecs (0.60.0",
	name = "mcl_hoppers:update_formspec_0_60_0",
	nodenames = {"group:hopper"},
	run_at_every_load = false,
	action = function(pos, node)
		local meta = minetest.get_meta(pos)
		meta:set_string("formspec", mcl_hoppers_formspec)
	end,
})