.lua

bucket = {}

bucket.place = {} -- list of liquids to place

bucket.fill = {} -- list of liquids to loop over and set to air

bucket.name = {} -- list of bucket names to return after using the empty bucket

function bucket.give_filled(itemstack2, user2, ltype)
	local inv = user2:get_inventory()
	
	if inv:room_for_item("main", {name=ltype}) then
		inv:add_item("main", ltype)
	else
		local pos = user:getpos()
		pos.y = math.floor(pos.y + 0.5)
		core.add_item(pos, ltype)
	end
end

minetest.register_craftitem("bucket:bucket", {
	description = "Empty Bucket",
	inventory_image = "bucket_bucket.png",
	liquids_pointable = true,
	stack_max = 256,
	on_place = function(itemstack, user, pointed_thing)
		
		local loop = 0
		
		local return_item = tostring(user:get_wielded_item()).." "..tostring(user:get_wielded_item():get_count())
		local stack_count = user:get_wielded_item():get_count()
		print(tostring(minetest.get_node(pointed_thing.under).name))
		
		if pointed_thing.type ~= "node" then --sanity checks, or autonomous nodes acting as players ;)
			return
		end
		
		while bucket.count >= loop do
			
			loop = loop + 1
			
			if minetest.get_node(pointed_thing.under).name == bucket.fill[loop] then
				return_item = bucket.name[loop].." 1"
			
				if user:get_wielded_item():get_count() > 1 then
					
					bucket.give_filled(itemstack, user, bucket.name[loop])
				
					return_item = "bucket:bucket "..tostring(stack_count-1)
				end
				
			end
			
		end
		
		minetest.add_node(pointed_thing.under, {name="air"})
		
		return ItemStack(return_item)
	end,
})

-- how to register a filled bucket:

--[[

	name (string) refers to the item name of the bucket, eg:
	"lava", "water", "decay_water", the after result will look like this, eg:
	"bucket:lava", "bucket:water", "bucket:decay_water"
	
	image (string) refers to the inventory image used to display the bucket, eg:
	"bucket_water.png" or "bucket_empty.png^water_overlay.png"
	
	liquid_source (string) is the node name of the liquid source block that the
	empty bucket should pick up, eg:
	"core:water_source", "core:lava_source", "core:acid_source"
	
	desc (string) is the description of the filled bucket, eg:
	"Lava Bucket", "Bucket of Water", "Bucket of Lava"
	
	to_place (string) is the node name of the water source that the bucket should place,
	eg: "core:water_source" "core:lava_source"
	
]]--

bucket.count = 0

function bucket.register_bucket(name, image, liquid_source, desc, to_place)
	
	bucket.count = bucket.count + 1
	
	bucket.fill[bucket.count] = liquid_source
	
	bucket.place[bucket.count] = to_place
	
	bucket.name[bucket.count] = "bucket:"..name.."_bucket",
	
	minetest.register_craftitem("bucket:"..name.."_bucket", {
		description = desc,
		inventory_image = image,
		stack_max = 1,
		liquids_pointable = true,
	})
end

bucket.register_bucket("water", "bucket_water.png", "core:water_source", "Bucket of Water", "core:water_source")