--[[
Minetest Mod Storage Drawers - A Mod adding storage drawers

Copyright (C) 2018 isaiah658
Copyright (C) 2017 LNJ <git@lnj.li>

MIT License

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
]]--

--[[ The gist of how the drawers mod stores data is that there are entities 
and the drawer node itself. The entities are needed to allow having multiple 
drawers in one node. The entities and node each store metadata about the item 
counts and such. It is necessary to change both at once otherwise in some cases 
the entity values are used and in other cases the node metadata is used.

The gist of how the controller works is this. The drawer controller scans the 
adjacent tiles (length and height is configurable) and puts the item names and 
other info such as coordinates and the visualid of the entity in a table. That 
table is saved in the controllers metadata. The table is used to help prevent 
needing to scan all the drawers to deposit an item in certain situations. The 
table is only updated on an as needed basis, not by a specific time/interval. 
Controllers that have no items will not continue scanning drawers. ]]--

-- Load support for intllib.
local MP = core.get_modpath(core.get_current_modname())
local S, NS = dofile(MP.."/intllib.lua")

local function controller_can_dig(pos, player)
	local meta = core.get_meta(pos);
	local inv = meta:get_inventory()
	return inv:is_empty("src")
end

local function controller_allow_metadata_inventory_put(pos, listname, index, stack, player)
	if core.is_protected(pos, player:get_player_name()) then
		return 0
	end
	if listname == "src" then
		return stack:get_count()
	end
end

local function controller_allow_metadata_inventory_move(pos, from_list, from_index, to_list, to_index, count, player)
	local meta = core.get_meta(pos)
	local inv = meta:get_inventory()
	local stack = inv:get_stack(from_list, from_index)
	return controller_allow_metadata_inventory_put(pos, to_list, to_index, stack, player)
end

local function controller_allow_metadata_inventory_take(pos, listname, index, stack, player)
	if core.is_protected(pos, player:get_player_name()) then
		return 0
	end
	return stack:get_count()
end

local function controller_formspec(pos, meta_current_state)
	local formspec = 
		"size[8,8.5]"..
		default.gui_bg..
		default.gui_bg_img..
		default.gui_slots..
		"label[0,0;" .. S("Current State: ") .. meta_current_state .. "]" ..
		"list[current_name;src;3.5,1.75;1,1;]"..
		"list[current_player;main;0,4.25;8,1;]"..
		"list[current_player;main;0,5.5;8,3;8]"..
		"listring[current_player;main]"..
		"listring[current_name;src]"..
		"listring[current_player;main]"..
		default.get_hotbar_bg(0, 4.25)
	return formspec
end

local function index_drawers(pos)
	--[[ The pos parameter is the controllers position
	
	We store the item name as a string key and the value is a table with position x,
	position y, position z, and visualid. Those are all strings as well with the 
	values assigned to them that way we don't need to worry about the ordering of 
	the table. The count and max count are not stored as those values have a high 
	potential of being outdated quickly. It's better to grab the values from the 
	drawer when needed so you know you are working with accurate numbers.
	
	Indexing starts on the row (meaning same y coordinate) of the controller on the 
	adjacent sides and moves each column on the same y level. A row is searched until 
	it either hits the max length setting size or until a node that isn't a drawer is 
	indexed and then moves up on (y coordinate increases by 1) and starts the process 
	until the y coord is reaches the max height or until a node that isn't a drawer 
	is indexed and at the point it stops indexing all together. This makes it so all 
	drawers need to be next to each other on the rows without spacing or other blocks 
	in between. ]]--
	
	local drawers_table_index = {}
	local x_or_z_axis = 1
	
	-- Variables for managing the max length and max height that is searched in each adjacent direction from the controller
	-- These could potentially be exposed to the user through the formspec, allowed to bigger with upgrades, etc
	local max_search_length = 8
	local max_search_height = 8
	
	-- Index the x axis and z axis in both the positive and negative directions
	for x_z = 1,4 do
		for y = 1,max_search_height do
			for x_or_z = 1,max_search_length do
				-- x_z if for controlling which axis and direction is being searched
				-- x_or_z is for the column in each row that is searched
				-- x_or_z_axis is used for breaking out of the loop if the first block searched in a row is not a drawer
				x_or_z_axis = x_or_z
				local drawer_pos
				-- If x_z is 1, we check the positive x axis
				if x_z == 1 then
					drawer_pos = {x = pos.x + x_or_z, y = pos.y + y - 1, z = pos.z}
				-- If x_z is 2, we check the negative x axis
				elseif x_z == 2 then
					drawer_pos = {x = pos.x - x_or_z, y = pos.y + y - 1, z = pos.z}
				-- If x_z is 3, we check the positive z axis
				elseif x_z == 3 then
					drawer_pos = {x = pos.x, y = pos.y + y - 1, z = pos.z + x_or_z}
				-- If x_z is 4, we check the negative z axis
				elseif x_z == 4 then
					drawer_pos = {x = pos.x, y = pos.y + y - 1, z = pos.z - x_or_z}
				end
				local drawer_meta = core.get_meta(drawer_pos)
				local drawer_node = core.get_node(drawer_pos)
				
				-- There might be a better way to know if the node is a drawer other than matching a string in the node name
				-- Can't trust metadata only in case another mod has a block with the same metadata strings
				if string.match(drawer_node.name, 'drawers:') and drawer_node.name ~= "drawers:controller" and drawer_meta ~= nil then
					for i = 0,4 do
						-- This is needed for the special case where drawers that store one item don't have an id appended to them
						local visualid = i
						if i == 0 then
							visualid = ""
						end
						local drawer_meta_name = drawer_meta:get_string("name" .. visualid)
						local drawer_meta_entity_infotext = drawer_meta:get_string("entity_infotext" .. visualid)
						-- Only one empty drawer needs to be indexed because everything is indexed again when an item isn't found in the index
						if drawer_meta_name == "" and not drawers_table_index["empty"] and drawer_meta_entity_infotext ~= "" then
							drawers_table_index["empty"] = {drawer_pos_x = drawer_pos.x, drawer_pos_y = drawer_pos.y, drawer_pos_z = drawer_pos.z, visualid = visualid}
						elseif drawer_meta_name ~= "" then
							-- If we already indexed this item previously, check which drawer has the most space and have that one be the one indexed
							if drawers_table_index[drawer_meta_name] then
								local indexed_drawer_meta = core.get_meta({x = drawers_table_index[drawer_meta_name]["drawer_pos_x"], y = drawers_table_index[drawer_meta_name]["drawer_pos_y"], z = drawers_table_index[drawer_meta_name]["drawer_pos_z"]})
								local indexed_drawer_meta_count = indexed_drawer_meta:get_int("count" .. drawers_table_index[drawer_meta_name]["visualid"])
								local indexed_drawer_meta_max_count = indexed_drawer_meta:get_int("max_count" .. drawers_table_index[drawer_meta_name]["visualid"])
								local drawer_meta_count = drawer_meta:get_int("count" .. visualid)
								local drawer_meta_max_count = drawer_meta:get_int("max_count" .. visualid)
								-- If the already indexed drawer has less space, we override the table index for that item with the new drawer
								if indexed_drawer_meta_max_count - indexed_drawer_meta_count < drawer_meta_max_count - drawer_meta_count then
									drawers_table_index[drawer_meta_name] = {drawer_pos_x = drawer_pos.x, drawer_pos_y = drawer_pos.y, drawer_pos_z = drawer_pos.z, visualid = visualid}
								end
							else
								drawers_table_index[drawer_meta_name] = {drawer_pos_x = drawer_pos.x, drawer_pos_y = drawer_pos.y, drawer_pos_z = drawer_pos.z, visualid = visualid}
							end
							-- If the drawer contained something and was a drawer type that only holds one item, stop the loop as there is no need to search through other drawer types
							if i == 0 then
								break
							end
						end
					end
				-- If the node isn't a drawer or doesn't have metadata, we break the loop to stop searching the row
				else
					break
				end
			end
			-- If we break out of the above loop while x or z is 1, it means the first block searched in a row did not contain a drawer.
			-- All searching for an axis is stopped when a row starts with a non-drawer.
			if x_or_z_axis == 1 then
				break
			end
		end
	end
	
	return drawers_table_index
end

local function controller_node_timer(pos, elapsed)
	-- Inizialize metadata
	local meta = core.get_meta(pos)
	local meta_current_state = meta:get_string("current_state")
	local meta_times_ran_while_jammed = meta:get_float("times_ran_while_jammed")
	local meta_jammed_item_name = meta:get_string("jammed_item_name")
	local inv = meta:get_inventory()
	local src = inv:get_stack("src", 1)
	local src_name = src:get_name()
	
	--[[ There are four scenarios for the item slot in the controller. 
	1: No item is in the controller. 
	2: Item is not stackable. 
	3. Item is allowed and there is either an existing drawer for that item with room or an empty drawer. 
	4: Item is allowed, but there is no room.
	
	There are three different possibilities for "current_state". 
	1: "running" which means means it's operating normally. 
	2: "stopped" meaning the controller makes no attempt to put in the item possibly due to being unallowed for various reasons. 
	3: "jammed" meaning the item is allowed in to drawers, but there was no space to deposit it last time it ran. ]]--
	
	--[[ If current state is jammed, the item that jammed it is the same item in the 
	src inv slot, and the amount of times ran while jammed is 8 or higher, we 
	set the current state to stopped. Will possibly want to make an option in the 
	formspec to ignore this an continue running if the user plans on using the 
	system in a way that may cause frequent jams making it a hassle to manually 
	clear it each time ]]--
	if meta_current_state == "jammed" and meta_jammed_item_name == src_name and meta_times_ran_while_jammed >= 8 then
		meta:set_string("current_state", "stopped")
		meta:set_string("formspec", controller_formspec(pos, S("Stopped")))
		return true
	end
	
	-- If current state is stopped, and the item that jammed it is the same item in the src inv slot, we don't do anything
	if meta_current_state == "stopped" and meta_jammed_item_name == src_name then
		return true
	end
	
	-- If current state is stopped, and the item that jammed it is not the same item in the src inv slot, we set the current state to running and clear the jam counter
	if meta_current_state == "stopped" and meta_jammed_item_name ~= src_name then
		meta:set_string("current_state", "running")
		meta:set_string("formspec", controller_formspec(pos, S("Running")))
		meta:set_float("times_ran_while_jammed", 0)
	end
	
	-- If no item is in the controller, nothing is searched and current_state is set to running and no jams
	if inv:is_empty("src") then
		meta:set_string("current_state", "running")
		meta:set_string("formspec", controller_formspec(pos, S("Running")))
		meta:set_float("times_ran_while_jammed", 0)
		return true
	end
	
	-- If a non stackable item is in the controller, such as a written book, set the current_state to stopped because they are not allowed in drawers
	if src:get_stack_max() == 1 then
		meta:set_string("current_state", "stopped")
		meta:set_string("formspec", controller_formspec(pos, S("Stopped")))
		meta:set_string("jammed_item_name", src_name)
		meta:set_float("times_ran_while_jammed", 1)
		return true
	end
	
	-- If the index has not been created, the item isn't in the index, the item in the drawer is no longer the same item in the index, or the item is in the index but it's full, run the index_drawers function
	local drawers_table_index = core.deserialize(meta:get_string("drawers_table_index"))
	-- If the index has not been created
	if not drawers_table_index then
		drawers_table_index = index_drawers(pos)
		meta:set_string("drawers_table_index", core.serialize(drawers_table_index))
	-- If the item isn't in the index
	elseif not drawers_table_index[src_name] then
		drawers_table_index = index_drawers(pos)
		meta:set_string("drawers_table_index", core.serialize(drawers_table_index))
	-- If the item is in the index but either the name that was indexed is not the same as what is currently in the drawer or the drawer is full
	elseif drawers_table_index[src_name] then
		local visualid = drawers_table_index[src_name]["visualid"]
		local indexed_drawer_meta = core.get_meta({x = drawers_table_index[src_name]["drawer_pos_x"], y = drawers_table_index[src_name]["drawer_pos_y"], z = drawers_table_index[src_name]["drawer_pos_z"]})
		local indexed_drawer_meta_name = indexed_drawer_meta:get_string("name" .. visualid)
		local indexed_drawer_meta_count = indexed_drawer_meta:get_int("count" .. visualid)
		local indexed_drawer_meta_max_count = indexed_drawer_meta:get_int("max_count" .. visualid)
		if indexed_drawer_meta_name ~= src_name or indexed_drawer_meta_count >= indexed_drawer_meta_max_count then
			drawers_table_index = index_drawers(pos)
			meta:set_string("drawers_table_index", core.serialize(drawers_table_index))
		end
	end
	
	-- This might not be needed, but my concern is if the above indexing takes enough time, there could be a "race condition" where the item in the src inventory is no longer the same item when we checked before or the quantity of the items changed so I'm having it grab the item stack again just in case
	-- If a race condition does occur, items could be lost or duplicated
	src = inv:get_stack("src", 1)
	src_name = src:get_name()
	local src_count = src:get_count()
	local src_stack_max = src:get_stack_max()
	
	-- At this point, the item either was in the index or everything was reindexed so we check again
	-- If there is a drawer with the item and it isn't full, we will put the items we can in to it
	if drawers_table_index[src_name] then
		local indexed_drawer_pos = {x = drawers_table_index[src_name]["drawer_pos_x"], y = drawers_table_index[src_name]["drawer_pos_y"], z = drawers_table_index[src_name]["drawer_pos_z"]}
		local visualid = drawers_table_index[src_name]["visualid"]
		local indexed_drawer_meta = core.get_meta(indexed_drawer_pos)
		local indexed_drawer_meta_name = indexed_drawer_meta:get_string("name" .. visualid)
		local indexed_drawer_meta_count = indexed_drawer_meta:get_int("count" .. visualid)
		local indexed_drawer_meta_max_count = indexed_drawer_meta:get_int("max_count" .. visualid)
		-- If the the item in the drawer is the same as the one we are trying to store, the drawer is not full, and the drawer entity is loaded, we will put the items in the drawer
		if indexed_drawer_meta_name == src_name and indexed_drawer_meta_count < indexed_drawer_meta_max_count and drawers.drawer_visuals[core.serialize(indexed_drawer_pos)] then
			local leftover = drawers.drawer_insert_object(indexed_drawer_pos, nil, src, nil)
			inv:set_stack("src", 1, leftover)
			-- Set the controller metadata
			meta:set_string("current_state", "running")
			meta:set_string("formspec", controller_formspec(pos, S("Running")))
			meta:set_float("times_ran_while_jammed", 0)
		else
			meta:set_string("current_state", "jammed")
			meta:set_string("formspec", controller_formspec(pos, S("Jammed")))
			meta:set_string("jammed_item_name", src_name)
			meta:set_float("times_ran_while_jammed", meta_times_ran_while_jammed + 1)
		end
	elseif drawers_table_index["empty"] then
		local indexed_drawer_pos = {x = drawers_table_index["empty"]["drawer_pos_x"], y = drawers_table_index["empty"]["drawer_pos_y"], z = drawers_table_index["empty"]["drawer_pos_z"]}
		local visualid = drawers_table_index["empty"]["visualid"]
		local indexed_drawer_meta = core.get_meta(indexed_drawer_pos)
		local indexed_drawer_meta_name = indexed_drawer_meta:get_string("name" .. visualid)
		-- If the drawer is still empty and the drawer entity is loaded, we will put the items in the drawer
		if indexed_drawer_meta_name == "" and drawers.drawer_visuals[core.serialize(indexed_drawer_pos)] then
			local leftover = drawers.drawer_insert_object(indexed_drawer_pos, nil, src, nil)
			inv:set_stack("src", 1, leftover)
			-- Add the item to the drawers table index and set the empty one to nil
			drawers_table_index["empty"]  = nil
			drawers_table_index[src_name] = {drawer_pos_x = indexed_drawer_pos.x, drawer_pos_y = indexed_drawer_pos.y, drawer_pos_z = indexed_drawer_pos.z, visualid = visualid}
			-- Set the controller metadata
			meta:set_string("current_state", "running")
			meta:set_string("formspec", controller_formspec(pos, S("Running")))
			meta:set_float("times_ran_while_jammed", 0)
			meta:set_string("drawers_table_index", core.serialize(drawers_table_index))
		else
			meta:set_string("current_state", "jammed")
			meta:set_string("formspec", controller_formspec(pos, S("Jammed")))
			meta:set_string("jammed_item_name", src_name)
			meta:set_float("times_ran_while_jammed", meta_times_ran_while_jammed + 1)
		end
	else
		meta:set_string("current_state", "jammed")
		meta:set_string("formspec", controller_formspec(pos, S("Jammed")))
		meta:set_string("jammed_item_name", src_name)
		meta:set_float("times_ran_while_jammed", meta_times_ran_while_jammed + 1)
	end
	
	return true
end

-- Set the controller definition using a table to allow for pipeworks and potentially other mod support
local controller_def = {}
controller_def.description = S("Drawer Controller")
controller_def.tiles = {"drawer_controller_top_bottom.png", "drawer_controller_top_bottom.png", "drawer_controller_side.png", "drawer_controller_side.png", "drawer_controller_side.png", "drawer_controller_side.png"}
controller_def.can_dig = controller_can_dig
controller_def.groups = {cracky = 3, level = 2}
controller_def.on_construct = function(pos)
	local meta = core.get_meta(pos)
	local inv = meta:get_inventory()
	inv:set_size('src', 1)
	meta:set_string("current_state", "running")
	meta:set_float("times_ran_while_jammed", 0)
	meta:set_string("jammed_item_name", "")
	meta:set_string("drawers_table_index", "")
	meta:set_string("formspec", controller_formspec(pos, S("Running")))
	local timer = core.get_node_timer(pos)
	timer:start(7)
end
controller_def.on_blast = function(pos)
	local drops = {}
	default.get_inventory_drops(pos, "src", drops)
	drops[#drops+1] = "drawers:controller"
	core.remove_node(pos)
	return drops
end
controller_def.on_timer = controller_node_timer
controller_def.allow_metadata_inventory_put = controller_allow_metadata_inventory_put
controller_def.allow_metadata_inventory_move = controller_allow_metadata_inventory_move
controller_def.allow_metadata_inventory_take = controller_allow_metadata_inventory_take

-- Mostly copied from the drawers in the drawer mod to add pipeworks support
if core.get_modpath("pipeworks") and pipeworks then
	controller_def.groups.tubedevice = 1
	controller_def.groups.tubedevice_receiver = 1
	controller_def.tube = controller_def.tube or {}
	controller_def.tube.insert_object = function(pos, node, stack, tubedir)
		local meta = core.get_meta(pos)
		local inv = meta:get_inventory()
		return inv:add_item("src", stack)
	end
	controller_def.tube.can_insert = function(pos, node, stack, tubedir)
		local meta = core.get_meta(pos)
		local inv = meta:get_inventory()
		return inv:room_for_item("src", stack)
	end
	controller_def.tube.connect_sides = {left = 1, right = 1, back = 1, front = 1,
		top = 1, bottom = 1}
	controller_def.after_place_node = pipeworks.after_place
	controller_def.after_dig_node = pipeworks.after_dig
end

core.register_node('drawers:controller', controller_def)

-- Because the rest of the drawers mod doesn't have a hard depend on default, I changed the recipe to have an alternative
if core.get_modpath("default") and default then
	core.register_craft({
		output = 'drawers:controller',
		recipe = {
			{'default:steel_ingot', 'default:diamond', 'default:steel_ingot'},
			{'default:tin_ingot', 'group:drawer', 'default:copper_ingot'},
			{'default:steel_ingot', 'default:diamond', 'default:steel_ingot'},
		}
	})
elseif core.get_modpath("mcl_core") and mcl_core then
	core.register_craft({
		output = 'drawers:controller',
		recipe = {
			{'mcl_core:iron_ingot', 'mcl_core:diamond', 'mcl_core:iron_ingot'},
			{'mcl_core:gold_ingot', 'group:drawer', 'mcl_core:gold_ingot'},
			{'mcl_core:iron_ingot', 'mcl_core:diamond', 'mcl_core:iron_ingot'},
		}
	})
else
	core.register_craft({
		output = 'drawers:controller',
		recipe = {
			{'group:stone', 'group:stone', 'group:stone'},
			{'group:stone', 'group:drawer', 'group:stone'},
			{'group:stone', 'group:stone', 'group:stone'},
		}
	})
end