-- modified and adapted from pipeworks mod by VanessaE
-- by rnd
-- disabled timers and on/off button, now autocrafter is only activated by signal

local autocrafterCache = {}  -- caches some recipe data to avoid to call the slow function minetest.get_craft_result() every second

local craft_time = 1

local function count_index(invlist)
	local index = {}
	for _, stack in pairs(invlist) do
		if not stack:is_empty() then
			local stack_name = stack:get_name()
			index[stack_name] = (index[stack_name] or 0) + stack:get_count()
		end
	end
	return index
end

local function get_item_info(stack)
	local name = stack:get_name()
	local def = minetest.registered_items[name]
	local description = def and def.description or "Unknown item"
	return description, name
end

local function get_craft(pos, inventory, hash)
	local hash = hash or minetest.hash_node_position(pos)
	local craft = autocrafterCache[hash]
	if not craft then
		local recipe = inventory:get_list("recipe")
		local output, decremented_input = minetest.get_craft_result({method = "normal", width = 3, items = recipe})
		craft = {recipe = recipe, consumption=count_index(recipe), output = output, decremented_input = decremented_input}
		autocrafterCache[hash] = craft
	end
	return craft
end

local function autocraft(inventory, craft)
	if not craft then return false end
	local output_item = craft.output.item

	-- check if we have enough room in dst
	if not inventory:room_for_item("dst", output_item) then	return false end
	local consumption = craft.consumption
	local inv_index = count_index(inventory:get_list("src"))
	-- check if we have enough material available
	for itemname, number in pairs(consumption) do
		if (not inv_index[itemname]) or inv_index[itemname] < number then return false end
	end
	-- consume material
	for itemname, number in pairs(consumption) do
		for i = 1, number do -- We have to do that since remove_item does not work if count > stack_max
			inventory:remove_item("src", ItemStack(itemname))
		end
	end

	-- craft the result into the dst inventory and add any "replacements" as well
	inventory:add_item("dst", output_item)
	for i = 1, 9 do
		inventory:add_item("dst", craft.decremented_input.items[i])
	end
	return true
end

-- returns false to stop the timer, true to continue running
-- is started only from start_autocrafter(pos) after sanity checks and cached recipe
local function run_autocrafter(pos, elapsed)
	local meta = minetest.get_meta(pos)
	local inventory = meta:get_inventory()
	local craft = get_craft(pos, inventory)
	local output_item = craft.output.item
	-- only use crafts that have an actual result
	if output_item:is_empty() then
		meta:set_string("infotext", "unconfigured Autocrafter: unknown recipe")
		return false
	end

	for step = 1, math.floor(elapsed/craft_time) do
		local continue = autocraft(inventory, craft)
		if not continue then return false end
	end
	return true
end

local function start_crafter(pos) -- rnd we dont need timer anymore
	-- local meta = minetest.get_meta(pos)
	-- if meta:get_int("enabled") == 1 then
		-- local timer = minetest.get_node_timer(pos)
		-- if not timer:is_started() then
			-- timer:start(craft_time)
		-- end
	-- end
end

local function after_inventory_change(pos)
	start_crafter(pos)
end

-- note, that this function assumes allready being updated to virtual items
-- and doesn't handle recipes with stacksizes > 1
local function after_recipe_change(pos, inventory)
	local meta = minetest.get_meta(pos)
	-- if we emptied the grid, there's no point in keeping it running or cached
	if inventory:is_empty("recipe") then
		--minetest.get_node_timer(pos):stop()
		autocrafterCache[minetest.hash_node_position(pos)] = nil
		meta:set_string("infotext", "unconfigured Autocrafter")
		return
	end
	local recipe_changed = false
	local recipe = inventory:get_list("recipe")

	local hash = minetest.hash_node_position(pos)
	local craft = autocrafterCache[hash]

	if craft then
		-- check if it changed
		local cached_recipe = craft.recipe
		for i = 1, 9 do
			if recipe[i]:get_name() ~= cached_recipe[i]:get_name() then
				autocrafterCache[hash] = nil -- invalidate recipe
				craft = nil
				break
			end
		end
	end

	craft = craft or get_craft(pos, inventory, hash)
	local output_item = craft.output.item
	local description, name = get_item_info(output_item)
	meta:set_string("infotext", string.format("'%s' Autocrafter (%s)", description, name))
	inventory:set_stack("output", 1, output_item)

	after_inventory_change(pos)
end

-- clean out unknown items and groups, which would be handled like unknown items in the crafting grid
-- if minetest supports query by group one day, this might replace them
-- with a canonical version instead
local function normalize(item_list)
	for i = 1, #item_list do
		local name = item_list[i]
		if not minetest.registered_items[name] then
			item_list[i] = ""
		end
	end
	return item_list
end

local function on_output_change(pos, inventory, stack)
	if not stack then
		inventory:set_list("output", {})
		inventory:set_list("recipe", {})
	else
		local input = minetest.get_craft_recipe(stack:get_name())
		if not input.items or input.type ~= "normal" then return end
		local items, width = normalize(input.items), input.width
		local item_idx, width_idx = 1, 1
		for i = 1, 9 do
			if width_idx <= width then
				inventory:set_stack("recipe", i, items[item_idx])
				item_idx = item_idx + 1
			else
				inventory:set_stack("recipe", i, ItemStack(""))
			end
			width_idx = (width_idx < 3) and (width_idx + 1) or 1
		end
		-- we'll set the output slot in after_recipe_change to the actual result of the new recipe
	end
	after_recipe_change(pos, inventory)
end

-- returns false if we shouldn't bother attempting to start the timer again after this
local function update_meta(meta, enabled)
	--local state = enabled and "on" or "off"
	--meta:set_int("enabled", enabled and 1 or 0)
	meta:set_string("formspec",
		"size[8,11]"..
		"list[context;recipe;0,0;3,3;]"..
		"image[3,1;1,1;gui_hb_bg.png^[colorize:#141318:255]"..
		"list[context;output;3,1;1,1;]"..
		--"image_button[3,2;1,1;pipeworks_button_" .. state .. ".png;" .. state .. ";;;false;pipeworks_button_interm.png]" .. -- rnd disable button
		"list[context;src;0,3.5;8,3;]"..
		"list[context;dst;4,0;4,3;]"..
		default.gui_bg..
		default.gui_bg_img..
		default.gui_slots..
		default.get_hotbar_bg(0,7)..
		"list[current_player;main;0,7;8,4;]"..
		"listring[context;dst]"..
		"listring[current_player;main]"..
		"listring[context;src]"..
		"listring[current_player;main]"..
		"listring[context;recipe]"..
		"listring[current_player;main]"
	)

	-- toggling the button doesn't quite call for running a recipe change check
	-- so instead we run a minimal version for infotext setting only
	-- this might be more written code, but actually executes less
	local output = meta:get_inventory():get_stack("output", 1)
	if output:is_empty() then -- doesn't matter if paused or not
		meta:set_string("infotext", "unconfigured Autocrafter: Place items for recipe top left. To operate place required items in bottom space (src inventory) and activated with keypad signal. Obtain crafted item from top right (dst inventory).")
		return false
	end

	local description, name = get_item_info(output)
	local infotext = enabled and string.format("'%s' Autocrafter (%s)", description, name)
				or string.format("paused '%s' Autocrafter", description)

	meta:set_string("infotext", infotext)
	return enabled
end

-- 1st version of the autocrafter had actual items in the crafting grid
-- the 2nd replaced these with virtual items, dropped the content on update and set "virtual_items" to string "1"
-- the third added an output inventory, changed the formspec and added a button for enabling/disabling
-- so we work out way backwards on this history and update each single case to the newest version
local function upgrade_autocrafter(pos, meta)
	local meta = meta or minetest.get_meta(pos)
	local inv = meta:get_inventory()

	if inv:get_size("output") == 0 then -- we are version 2 or 1
		inv:set_size("output", 1)
		-- migrate the old autocrafters into an "enabled" state
		update_meta(meta, true)

		if meta:get_string("virtual_items") == "1" then -- we are version 2
			-- we allready dropped stuff, so lets remove the metadatasetting (we are not being called again for this node)
			meta:set_string("virtual_items", "")
		else -- we are version 1
			local recipe = inv:get_list("recipe")
			if not recipe then return end
			for idx, stack in ipairs(recipe) do
				if not stack:is_empty() then
					minetest.item_drop(stack, "", pos)
					stack:set_count(1)
					stack:set_wear(0)
					inv:set_stack("recipe", idx, stack)
				end
			end
		end

		-- update the recipe, cache, and start the crafter
		autocrafterCache[minetest.hash_node_position(pos)] = nil
		after_recipe_change(pos, inv)
	end
end

minetest.register_node("basic_machines:autocrafter", {
	description = "Autocrafter", 
	drawtype = "normal", 
	tiles = {"basic_machines_autocrafter.png"}, 
	sounds = default.node_sound_stone_defaults(),
	groups = {cracky=3, mesecon_effector_on = 1},
	on_construct = function(pos)
		local meta = minetest.get_meta(pos)
		local inv = meta:get_inventory()
		inv:set_size("src", 3*8)
		inv:set_size("recipe", 3*3)
		inv:set_size("dst", 4*3)
		inv:set_size("output", 1)
		update_meta(meta, false)
	end,
	on_receive_fields = function(pos, formname, fields, sender)

		if minetest.is_protected(pos, sender:get_player_name()) then
			minetest.record_protection_violation(pos, sender:get_player_name())
			return
		end

		--if not pipeworks.may_configure(pos, sender) then return end
		local meta = minetest.get_meta(pos)
		if fields.on then
			update_meta(meta, false)
			--minetest.get_node_timer(pos):stop()
		elseif fields.off then
			if update_meta(meta, true) then
				start_crafter(pos)
			end
		end
	end,
	can_dig = function(pos, player)
		upgrade_autocrafter(pos)
		local meta = minetest.get_meta(pos)
		local inv = meta:get_inventory()
		return (inv:is_empty("src") and inv:is_empty("dst"))
	end, 
	after_place_node = function(pos, placer) -- rnd : set owner
		local meta = minetest.get_meta(pos);
		meta:set_string("owner", placer:get_player_name());
	end,
	--after_place_node = pipeworks.scan_for_tube_objects,
	--after_dig_node = function(pos)
		--pipeworks.scan_for_tube_objects(pos)
	--end,
	on_destruct = function(pos)
		autocrafterCache[minetest.hash_node_position(pos)] = nil
	end,
	allow_metadata_inventory_put = function(pos, listname, index, stack, player)

		if minetest.is_protected(pos, player:get_player_name()) then
			minetest.record_protection_violation(pos, player:get_player_name())
			return 0
		end

		--if not pipeworks.may_configure(pos, player) then return 0 end
		local meta = minetest.get_meta(pos);if meta:get_string("owner")~=player:get_player_name() then return 0 end -- rnd
		
		upgrade_autocrafter(pos)
		local inv = minetest.get_meta(pos):get_inventory()
		if listname == "recipe" then
			stack:set_count(1)
			inv:set_stack(listname, index, stack)
			after_recipe_change(pos, inv)
			return 0
		elseif listname == "output" then
			on_output_change(pos, inv, stack)
			return 0
		end
		after_inventory_change(pos)
		return stack:get_count()
	end,
	allow_metadata_inventory_take = function(pos, listname, index, stack, player)

		if minetest.is_protected(pos, player:get_player_name()) then
			minetest.record_protection_violation(pos, player:get_player_name())
			return 0
		end

		--if not pipeworks.may_configure(pos, player) then
			-- minetest.log("action", string.format("%s attempted to take from autocrafter at %s", player:get_player_name(), minetest.pos_to_string(pos)))
			-- return 0
		-- end
		local meta = minetest.get_meta(pos);if meta:get_string("owner")~=player:get_player_name() then return 0 end -- rnd
		
		upgrade_autocrafter(pos)
		local inv = minetest.get_meta(pos):get_inventory()
		if listname == "recipe" then
			inv:set_stack(listname, index, ItemStack(""))
			after_recipe_change(pos, inv)
			return 0
		elseif listname == "output" then
			on_output_change(pos, inv, nil)
			return 0
		end
		after_inventory_change(pos)
		return stack:get_count()
	end,
	allow_metadata_inventory_move = function(pos, from_list, from_index, to_list, to_index, count, player)
		return 0; -- no internal inventory moves!
	end,
	
	mesecons = {effector = {  -- rnd: run machine when activated by signal
		action_on = function (pos, node,ttl) 
		if type(ttl)~="number" then ttl = 1 end
		if ttl<0 then return end -- machines_TTL prevents infinite recursion
		run_autocrafter(pos, craft_time);
	end,
	
		can_dig = function(pos)
			local meta = minetest.get_meta(pos);
			local inv = meta:get_inventory();
			
			if not (inv:is_empty("src")) or not (inv:is_empty("dst")) then return false end -- all inv must be empty to be dug
			
			return true
			
		end

	}
	}
	
	--on_timer = run_autocrafter -- rnd
})

minetest.register_craft( {
	output = "basic_machines:autocrafter",
	recipe = {
			{ "default:steel_ingot", "default:mese_crystal", "default:steel_ingot" },
			{ "default:diamondblock", "default:steel_ingot", "default:diamondblock" },
			{ "default:steel_ingot", "default:mese_crystal", "default:steel_ingot" }
	},
})