local chest = minetest.get_content_id("mcl_chests:chest")

local mcl_hoppers_formspec =
	"size[9,7]"..
	"background[-0.19,-0.25;9.41,10.48;mcl_hoppers_inventory.png]"..
	mcl_vars.inventory_header..
	"list[current_name;main;2,0.5;5,1;]"..
	"list[current_player;main;0,2.5;9,3;9]"..
	"list[current_player;main;0,5.74;9,1;]"..
	"listring[current_name;main]"..
	"listring[current_player;main]"

minetest.register_node("mcl_hoppers:hopper", {
	description = "Hopper",
	inventory_image = "mcl_hoppers_item.png",
	_doc_items_longdesc = [[Hoppers are containers with 5 inventory slots. They collect dropped items from above, take items from a container above and attempts 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.

Hoppers interact with containers the following way:
• 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 put items into the fuel slot
• Ender chests: Hoppers don't interact with ender chests
• Other containers: Hoppers interact with them normally]],
	_doc_items_usagehelp = "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. Remember you can place at usable blocks (such as chests) with sneak + right-click. The hopper will keep its orientation when the blocks around it are changed. To access the hopper's inventory, rightclick it.",
	wield_image = "mcl_hoppers_item.png",
	groups = {pickaxey=1, container=2,deco_block=1,},
	drawtype = "nodebox",
	paramtype = "light",
	sunlight_propagates = true,
	tiles = {"mcl_hoppers_hopper_inside.png^mcl_hoppers_hopper_top.png", "mcl_hoppers_hopper_outside.png", "mcl_hoppers_hopper_outside.png", "mcl_hoppers_hopper_inside.png", "mcl_hoppers_hopper_outside.png", "mcl_hoppers_hopper_outside.png"},
	selection_box = {type="regular"},
	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},
			},
		},
	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,

	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 bpos
		if uposnodedef.buildable_to then
			bpos = upos
		else
			local aposnodedef = minetest.registered_nodes[minetest.get_node(apos).name]
			if not aposnodedef then return itemstack end
			if aposnodedef.buildable_to then
				bpos = apos
			end
		end

		if bpos == nil then
			return itemstack
		end

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

		if x == -1 then
			minetest.set_node(bpos, {name="mcl_hoppers:hopper_side", param2=0})
		elseif x == 1 then
			minetest.set_node(bpos, {name="mcl_hoppers:hopper_side", param2=2})
		elseif z == -1 then
			minetest.set_node(bpos, {name="mcl_hoppers:hopper_side", param2=3})
		elseif z == 1 then
			minetest.set_node(bpos, {name="mcl_hoppers:hopper_side", param2=1})
		else
			minetest.set_node(bpos, {name="mcl_hoppers:hopper", param2=0})
		end
		if not minetest.setting_getbool("creative_mode") then
			itemstack:take_item()
		end
		return itemstack
	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 = {x=pos.x+math.random(0, 10)/10-0.5, y=pos.y, z=pos.z+math.random(0, 10)/10-0.5}
				minetest.add_item(p, stack)
			end
		end
		meta:from_table(meta2:to_table())
	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 = 24,
	_mcl_hardness = 3,
})

minetest.register_node("mcl_hoppers:hopper_side", {
	description = "Hopper (Side)",
	_doc_items_create_entry = false,
	drop = "mcl_hoppers:hopper",
	groups = {pickaxey=1, container=2,not_in_creative_inventory=1},
	drawtype = "nodebox",
	paramtype = "light",
	sunlight_propagates = true,
	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_inside.png", "mcl_hoppers_hopper_outside.png", "mcl_hoppers_hopper_outside.png"},
	selection_box = {type="regular"},
	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},
			},
		},
	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 = {x=pos.x+math.random(0, 10)/10-0.5, y=pos.y, z=pos.z+math.random(0, 10)/10-0.5}
				minetest.add_item(p, stack)
			end
		end
		meta:from_table(meta2:to_table())
	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 = 24,
	_mcl_hardness = 3,
})

-- 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({x=pos.x, y=pos.y+1, z=pos.z})
		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.registered_items[abovenode.name].groups.container then
			return
		end
		local meta = minetest.get_meta(pos)
		local inv = meta:get_inventory()

		for _,object in ipairs(minetest.get_objects_inside_radius(pos, 2)) do
			if not object:is_player() and object:get_luaentity() and object:get_luaentity().name == "__builtin:item" 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:getpos()
					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,
})

-- Iterates through all items in the given inventory and
-- return the slot of the first item which matches a condition
local get_eligible_transfer_item = function(src_inventory, src_list, dst_inventory, dst_list, condition)
	local size = src_inventory:get_size(src_list)
	local stack
	for i=1, size do
		stack = src_inventory:get_stack(src_list, i)
		if not stack:is_empty() and condition(stack, src_inventory, src_list, dst_inventory, dst_list) then
			return i
		end
	end
	return nil
end

-- Returns true if given itemstack is a shulker box
local is_not_shulker_box = function(itemstack)
	local g = minetest.get_item_group(itemstack:get_name(), "shulker_box")
	return g == 0 or g == nil
end

-- Returns true if itemstack is fuel, but not for lava bucket if destination already has one
local is_transferrable_fuel = function(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 = {x=pos.x,y=pos.y+1,z=pos.z}
		local downpos = {x=pos.x,y=pos.y-1,z=pos.z}

		-- 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.registered_nodes[upnode.name].groups.container
		if g == 2 or g == 3 or g == 5 or g == 6 then
			-- Typical container inventory
			mcl_util.move_item_container(uppos, "main", -1, pos)
		elseif g == 4 then
			-- Furnace output
			mcl_util.move_item_container(uppos, "dst", -1, pos)

			-- Also suck in non-fuel items from fuel slot
			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, "fuel", -1, pos)
			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
		g = minetest.registered_nodes[downnode.name].groups.container
		local slot_id = -1
		if g == 3 then
			-- For shulker boxes, only select non-shulker boxes
			local sinv = minetest.get_inventory({type="node", pos = pos})
			local dinv = minetest.get_inventory({type="node", pos = downpos})
			slot_id = get_eligible_transfer_item(sinv, "main", dinv, "main", is_not_shulker_box)
		end
		if slot_id then
			mcl_util.move_item_container(pos, "main", slot_id, downpos)
			if g == 4 then
				-- Start furnace's timer function, it will sort out whether furnace can burn or not.
				minetest.get_node_timer(downpos):start(1.0)
			end
		end
	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 = {x=pos.x-1,y=pos.y,z=pos.z}
		elseif face == 1 then
			front = {x=pos.x,y=pos.y,z=pos.z+1}
		elseif face == 2 then
			front = {x=pos.x+1,y=pos.y,z=pos.z}
		elseif face == 3 then
			front = {x=pos.x,y=pos.y,z=pos.z-1}
		end
		local above = {x=pos.x,y=pos.y+1,z=pos.z}

		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.registered_nodes[abovenode.name].groups.container
		if g == 4 then
			-- Furnace output
			mcl_util.move_item_container(above, "dst", -1, pos)
		else
			-- Typical container inventory
			mcl_util.move_item_container(above, "main", -1, pos)
		end

		-- Move an item from the hopper into the container to which the hopper points to
		local g = minetest.registered_nodes[frontnode.name].groups.container
		if g == 2 or g == 5 or g == 6 then
			mcl_util.move_item_container(pos, "main", -1, front)
		elseif g == 3 then
			-- Put non-shulker boxes into shulker box
			local sinv = minetest.get_inventory({type="node", pos = pos})
			local dinv = minetest.get_inventory({type="node", pos = front})
			local slot_id = get_eligible_transfer_item(sinv, "main", dinv, "main", is_not_shulker_box)
			if slot_id then
				mcl_util.move_item_container(pos, "main", slot_id, front)
			end
		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, stack = get_eligible_transfer_item(sinv, "main", dinv, "fuel", is_transferrable_fuel)
			if slot_id then
				mcl_util.move_item_container(pos, "main", slot_id, front, "fuel")
			end
			-- Start furnace's timer function, it will sort out whether furnace can burn or not.
			minetest.get_node_timer(front):start(1.0)
		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")