--[[

	TechAge
	=======

	Copyright (C) 2019 Joachim Stolberg

	LGPLv2.1+
	See LICENSE.txt for more information

	TA2/TA3/TA4 Distributor
	
]]--

-- for lazy programmers
local M = minetest.get_meta
local N = minetest.get_node
-- Consumer Related Data
local CRD = function(pos) return (minetest.registered_nodes[minetest.get_node(pos).name] or {}).consumer end

local S = techage.S

local SRC_INV_SIZE = 8

local COUNTDOWN_TICKS = 10
local STANDBY_TICKS = 10
local CYCLE_TIME = 4

local function formspec(self, pos, mem)
	local filter = minetest.deserialize(M(pos):get_string("filter")) or {false,false,false,false}
	return "size[10.5,8.5]"..
	default.gui_bg..
	default.gui_bg_img..
	default.gui_slots..
	"list[context;src;0,0;2,4;]"..
	"image[2,1.5;1,1;techage_form_arrow.png]"..
	"image_button[2,3;1,1;"..self:get_state_button_image(mem)..";state_button;]"..
	"checkbox[3,0;filter1;On;"..dump(filter[1]).."]"..
	"checkbox[3,1;filter2;On;"..dump(filter[2]).."]"..
	"checkbox[3,2;filter3;On;"..dump(filter[3]).."]"..
	"checkbox[3,3;filter4;On;"..dump(filter[4]).."]"..
	"image[4,0;0.3,1;techage_inv_red.png]"..
	"image[4,1;0.3,1;techage_inv_green.png]"..
	"image[4,2;0.3,1;techage_inv_blue.png]"..
	"image[4,3;0.3,1;techage_inv_yellow.png]"..
	"list[context;red;4.5,0;6,1;]"..
	"list[context;green;4.5,1;6,1;]"..
	"list[context;blue;4.5,2;6,1;]"..
	"list[context;yellow;4.5,3;6,1;]"..
	"list[current_player;main;1.25,4.5;8,4;]"..
	"listring[context;src]"..
	"listring[current_player;main]"..
	default.get_hotbar_bg(1.25,4.5)
end


--local Side2Color = {B="red", L="green", F="blue", R="yellow"}
local SlotColors = {"red", "green", "blue", "yellow"}
local Num2Ascii = {"B", "L", "F", "R"} 
local FilterCache = {} -- local cache for filter settings

local function filter_settings(pos)
	local meta = M(pos)
	local param2 = minetest.get_node(pos).param2
	local inv = meta:get_inventory()
	local filter = minetest.deserialize(meta:get_string("filter")) or {false,false,false,false}
	local ItemFilter = {}  -- {<item:name> = {dir,...}]
	local OpenPorts = {}  -- {dir, ...}
	
	-- collect all filter settings
	for idx,slot in ipairs(SlotColors) do
		if filter[idx] == true then
			local side = Num2Ascii[idx]
			local out_dir = techage.side_to_outdir(side, param2)
			if inv:is_empty(slot) then
				table.insert(OpenPorts, out_dir)
			else
				for _,stack in ipairs(inv:get_list(slot)) do
					local name = stack:get_name()
					if name ~= "" then
						if not ItemFilter[name] then
							ItemFilter[name] = {}
						end
						table.insert(ItemFilter[name], out_dir)
					end
				end
			end
		end
	end
	
	FilterCache[minetest.hash_node_position(pos)] = {
		ItemFilter = ItemFilter, 
		OpenPorts = OpenPorts,
	}
end

-- Return filter table and list of open ports.
-- (see test data)
local function get_filter_settings(pos)
--	local ItemFilter = {
--		["default:dirt"] = {1,2},
--		["default:cobble"] = {4},
--	}
--	local OpenPorts = {3}
--	return ItemFilter, OpenPorts
	
	local hash = minetest.hash_node_position(pos)
	if FilterCache[hash] == nil then
		filter_settings(pos)
	end
	return FilterCache[hash].ItemFilter, FilterCache[hash].OpenPorts
end


local function allow_metadata_inventory_put(pos, listname, index, stack, player)
	local inv = M(pos):get_inventory()
	local list = inv:get_list(listname)
	
	if minetest.is_protected(pos, player:get_player_name()) then
		return 0
	end
	if listname == "src" then
		CRD(pos).State:start_if_standby(pos)
		return stack:get_count()
	elseif stack:get_count() == 1 and 
			(list[index]:get_count() == 0 or stack:get_name() ~= list[index]:get_name()) then
		filter_settings(pos)
		return 1
	end
	return 0
end

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

local function allow_metadata_inventory_move(pos, from_list, from_index, to_list, to_index, count, player)
	local meta = M(pos)
	local inv = meta:get_inventory()
	local stack = inv:get_stack(from_list, from_index)
	return allow_metadata_inventory_put(pos, to_list, to_index, stack, player)
end


local function push_item(pos, filter, item_name, num_items, mem)
	local idx = 1
	local num_pushed = 0
	local num_ports = #filter
	local amount = math.floor(math.max((num_items + 1) / num_ports, 1))
	local successful = false
	while num_pushed < num_items do
		local push_dir = filter[idx]
		local num_to_push = math.min(amount, num_items - num_pushed)
		if techage.push_items(pos, push_dir, ItemStack(item_name.." "..num_to_push)) then
			num_pushed = num_pushed + num_to_push
			successful = true
			mem.port_counter[push_dir] = (mem.port_counter[push_dir] or 0) + num_to_push
		end
		idx = idx + 1
		if idx > num_ports then
			idx = 1
			if not successful then break end
		end
	end
	return num_pushed
end

-- move items to output slots
local function distributing(pos, inv, crd, mem)
	local item_filter, open_ports = get_filter_settings(pos)
	local sum_num_pushed = 0
	local num_pushed = 0
	
	-- start searching after last position
	local offs = mem.last_index or 1
	
	for i = 1, SRC_INV_SIZE do
		local idx = ((i + offs - 1) % 8) + 1
		local stack = inv:get_stack("src", idx)
		local item_name = stack:get_name()
		local num_items = stack:get_count()
		local num_to_push = math.min(crd.num_items - sum_num_pushed, num_items)
		num_pushed = 0
		
		if item_filter[item_name] then
			-- Push items based on filter
			num_pushed = push_item(pos, item_filter[item_name], item_name, num_to_push, mem)
		end
		if num_pushed == 0 and #open_ports > 0 then
			-- Push items based on open ports
			num_pushed = push_item(pos, open_ports, item_name, num_to_push, mem)
		end
			
		sum_num_pushed = sum_num_pushed + num_pushed
		stack:take_item(num_pushed)
		inv:set_stack("src", idx, stack)
		if sum_num_pushed >= crd.num_items then 
			mem.last_index = idx
			break 
		end
	end
	
	if num_pushed == 0 then
		crd.State:blocked(pos, mem)
	else
		crd.State:keep_running(pos, mem, COUNTDOWN_TICKS, 1)
	end
end

-- move items to the output slots
local function keep_running(pos, elapsed)
	local mem = tubelib2.get_mem(pos)
	mem.port_counter = mem.port_counter or {}
	local crd = CRD(pos)
	local inv = M(pos):get_inventory()
	if not inv:is_empty("src") then
		distributing(pos, inv, crd, mem)
	else
		crd.State:idle(pos, mem)
	end
	return crd.State:is_active(mem)
end

local function on_receive_fields(pos, formname, fields, player)
	if minetest.is_protected(pos, player:get_player_name()) then
		return
	end
	local meta = M(pos)
	local crd = CRD(pos)
	local filter = minetest.deserialize(meta:get_string("filter"))
	if fields.filter1 ~= nil then
		filter[1] = fields.filter1 == "true"
	elseif fields.filter2 ~= nil then
		filter[2] = fields.filter2 == "true"
	elseif fields.filter3 ~= nil then
		filter[3] = fields.filter3 == "true"
	elseif fields.filter4 ~= nil then
		filter[4] = fields.filter4 == "true"
	end
	meta:set_string("filter", minetest.serialize(filter))
	
	filter_settings(pos)
	
	local mem = tubelib2.get_mem(pos)
	if fields.state_button ~= nil then
		crd.State:state_button_event(pos, mem, fields)
	else
		meta:set_string("formspec", formspec(crd.State, pos, mem))
	end
end

-- techage command to turn on/off filter channels
local function change_filter_settings(pos, slot, val)
	local slots = {["red"] = 1, ["green"] = 2, ["blue"] = 3, ["yellow"] = 4}
	local meta = M(pos)
	local filter = minetest.deserialize(meta:get_string("filter"))
	local num = slots[slot] or 1
	if num >= 1 and num <= 4 then
		filter[num] = val == "on"
	end
	meta:set_string("filter", minetest.serialize(filter))
	
	filter_settings(pos)
	
	local mem = tubelib2.get_mem(pos)
	meta:set_string("formspec", formspec(CRD(pos).State, pos, mem))
	return true
end

local function can_dig(pos, player)
	if minetest.is_protected(pos, player:get_player_name()) then
		return false
	end
	local inv = M(pos):get_inventory()
	return inv:is_empty("src")
end

local tiles = {}
-- '#' will be replaced by the stage number
-- '{power}' will be replaced by the power PNG
tiles.pas = {
	-- up, down, right, left, back, front
	"techage_filling_ta#.png^techage_appl_distri.png^techage_frame_ta#_top.png",
	"techage_filling_ta#.png^techage_frame_ta#.png",
	"techage_filling_ta#.png^techage_frame_ta#.png^techage_appl_distri_yellow.png",
	"techage_filling_ta#.png^techage_frame_ta#.png^techage_appl_distri_green.png",
	"techage_filling_ta#.png^techage_frame_ta#.png^techage_appl_distri_red.png",
	"techage_filling_ta#.png^techage_frame_ta#.png^techage_appl_distri_blue.png",
}
tiles.act = {
	-- up, down, right, left, back, front
	{
		image = "techage_filling4_ta#.png^techage_appl_distri4.png^techage_frame4_ta#_top.png",
		backface_culling = false,
		animation = {
			type = "vertical_frames",
			aspect_w = 32,
			aspect_h = 32,
			length = 1.0,
		},
	},
	"techage_filling_ta#.png^techage_frame_ta#.png",
	"techage_filling_ta#.png^techage_frame_ta#.png^techage_appl_distri_yellow.png",
	"techage_filling_ta#.png^techage_frame_ta#.png^techage_appl_distri_green.png",
	"techage_filling_ta#.png^techage_frame_ta#.png^techage_appl_distri_red.png",
	"techage_filling_ta#.png^techage_frame_ta#.png^techage_appl_distri_blue.png",
}

local tubing = {
	on_pull_item = function(pos, in_dir, num)
		local inv = M(pos):get_inventory()
		return techage.get_items(inv, "src", num)
	end,
	on_push_item = function(pos, in_dir, stack)
		local inv = M(pos):get_inventory()
		CRD(pos).State:start_if_standby(pos)
		return techage.put_items(inv, "src", stack)
	end,
	on_unpull_item = function(pos, in_dir, stack)
		local inv = M(pos):get_inventory()
		return techage.put_items(inv, "src", stack)
	end,
	on_recv_message = function(pos, topic, payload)
		if topic == "filter" then
			return change_filter_settings(pos, payload.slot, payload.val)
		elseif topic == "counter" then
			local meta = minetest.get_meta(pos)
			return minetest.deserialize(meta:get_string("item_counter")) or 
					{red=0, green=0, blue=0, yellow=0}
		elseif topic == "clear_counter" then
			local meta = minetest.get_meta(pos)
			meta:set_string("item_counter", minetest.serialize({red=0, green=0, blue=0, yellow=0}))
		else		
			local resp = CRD(pos).State:on_receive_message(pos, topic, payload)
			if resp then
				return resp
			else
				return "unsupported"
			end
		end
	end,
	
	on_node_load = function(pos)
		CRD(pos).State:on_node_load(pos)
	end,
}

local node_name_ta2, node_name_ta3, node_name_ta4 = 
	techage.register_consumer("distributor", S("Distributor"), tiles, {
		cycle_time = CYCLE_TIME,
		standby_ticks = STANDBY_TICKS,
		formspec = formspec,
		tubing = tubing,
		after_place_node = function(pos, placer)
			local meta = M(pos)
			local filter = {false,false,false,false}
			meta:set_string("filter", minetest.serialize(filter))
			local inv = meta:get_inventory()
			inv:set_size('src', 8)
			inv:set_size('yellow', 6)
			inv:set_size('green', 6)
			inv:set_size('red', 6)
			inv:set_size('blue', 6)
		end,
		can_dig = can_dig,
		node_timer = keep_running,
		on_receive_fields = on_receive_fields,
		allow_metadata_inventory_put = allow_metadata_inventory_put,
		allow_metadata_inventory_move = allow_metadata_inventory_move,
		allow_metadata_inventory_take = allow_metadata_inventory_take,
		
		on_metadata_inventory_move = function(pos, from_list, from_index, to_list)
			if from_list ~= "src" or to_list ~= "src" then
				filter_settings(pos)
			end
		end,
		on_metadata_inventory_put = function(pos, listname)
			if listname ~= "src" then
				filter_settings(pos)
			end
		end,
		on_metadata_inventory_take = function(pos, listname)
			if listname ~= "src" then
				filter_settings(pos)
			end
		end,
		
		groups = {choppy=2, cracky=2, crumbly=2},
		sounds = default.node_sound_wood_defaults(),
		num_items = {0,4,12,36},
	})

minetest.register_craft({
	output = node_name_ta2.." 2",
	recipe = {
		{"group:wood", "techage:iron_ingot", "group:wood"},
		{"techage:tubeS", "default:mese_crystal", "techage:tubeS"},
		{"group:wood", "techage:iron_ingot", "group:wood"},
	},
})

minetest.register_craft({
	output = node_name_ta3,
	recipe = {
		{"", "techage:iron_ingot", ""},
		{"", node_name_ta2, ""},
		{"", "techage:vacuum_tube", ""},
	},
})

local help = S("The Distributor works as filter and pusher. It allows to divide and distribute incoming items into the 4 output ports. "..
	"The channels can be switched on/off and individually configured with up to 6 item types. "..
	"The filter passes the configured items and restrains all others. "..
	"Unconfigured but activated filters are used for items, which do not fit to all other filters. "..
	"If the Distributor can’t push an item into a block with an inventory (such as a chest) because that inventory is full, "..
	"but there is one open and unconfigured output, it will use this output port.")

techage.register_entry_page("ta2", "distributor",
	S("TA2 Distributor"), 
	help..S("@nThe Distributor tries to push 4 items every 2 seconds."),
	"techage:ta2_distributor_pas")

techage.register_entry_page("ta3m", "distributor",
	S("TA3 Distributor"), 
	help..S("@nThe Distributor tries to push 12 items every 2 seconds."),
	"techage:ta3_distributor_pas")