--[[

	TechAge
	=======

	Copyright (C) 2019 Joachim Stolberg

	LGPLv2.1+
	See LICENSE.txt for more information
	
	TA2 Steam Engine Flywheel

]]--

-- for lazy programmers
local S = function(pos) if pos then return minetest.pos_to_string(pos) end end
local P = minetest.string_to_pos
local M = minetest.get_meta

-- Load support for intllib.
local MP = minetest.get_modpath("techage")
local I,_ = dofile(MP.."/intllib.lua")

local STANDBY_TICKS = 4
local COUNTDOWN_TICKS = 4
local CYCLE_TIME = 8
local POWER_CAPACITY = 25

local Axle = techage.Axle

local function formspec(self, pos, mem)
	return "size[8,7]"..
		default.gui_bg..
		default.gui_bg_img..
		default.gui_slots..
		"image[6,0.5;1,2;"..techage.power.formspec_power_bar(POWER_CAPACITY, mem.power_result).."]"..
		"image_button[5,1;1,1;".. self:get_state_button_image(mem) ..";state_button;]"..
		"button[2,1.5;2,1;update;"..I("Update").."]"..
		"list[current_player;main;0,3;8,4;]"..
		default.get_hotbar_bg(0, 3)
end

local function start_cylinder(pos, on, mem)
	if not on then
		if mem.handle then
			minetest.sound_stop(mem.handle)
			mem.handle = nil
		end
	end
	local pos2 = techage.get_pos(pos, 'L')
	local ndef = minetest.registered_nodes[minetest.get_node(pos2).name]
	if ndef and ndef.start_cylinder then
		return ndef.start_cylinder(pos2, on)
	end
	return false
end

local function can_start(pos, mem, state)
	return start_cylinder(pos, true, mem)
end

local function play_sound(pos)
	local mem = tubelib2.get_mem(pos)
	if mem.techage_state == techage.RUNNING then
		mem.handle = minetest.sound_play("techage_steamengine", {
			pos = pos, 
			gain = 0.5,
			max_hear_distance = 10})
		minetest.after(2, play_sound, pos)
	end
end

local function start_node(pos, mem, state)
	techage.power.power_distribution(pos)
	if mem.power_result > 0 then
		techage.switch_axles(pos, true)
		play_sound(pos)
	end
end

local function stop_node(pos, mem, state)
	start_cylinder(pos, false, mem)
	techage.power.power_distribution(pos)
	techage.switch_axles(pos, false)
end

local State = techage.NodeStates:new({
	node_name_passive = "techage:flywheel",
	node_name_active = "techage:flywheel_on",
	cycle_time = CYCLE_TIME,
	standby_ticks = STANDBY_TICKS,
	formspec_func = formspec,
	can_start = can_start,
	start_node = start_node,
	stop_node = stop_node,
})

-- Pass1: Power balance calculation
local function on_power_pass1(pos, mem)
	if State:is_active(mem) then
		return -POWER_CAPACITY
	end
	return 0
end	
		
-- Pass2: Power balance adjustment
local function on_power_pass2(pos, mem, sum)
	return 0
end

-- Pass3: Power balance result
local function on_power_pass3(pos, mem, sum)
	mem.power_result = sum
end

local function distibuting(pos, mem)
	if mem.power_result > 0 then
		State:keep_running(pos, mem, COUNTDOWN_TICKS)
	else
		State:fault(pos, mem)	
		start_cylinder(pos, false, mem)
		techage.power.power_distribution(pos)
	end
end

local function node_timer(pos, elapsed)
	local mem = tubelib2.get_mem(pos)
	local pos2 = techage.get_pos(pos, 'L')
	if minetest.get_node(pos2).name == "techage:cylinder_on" and tubelib2.get_mem(pos2).running then
		distibuting(pos, mem)
	else
		State:fault(pos, mem)	
		start_cylinder(pos, false, mem)
		techage.power.power_distribution(pos)
	end
	return 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 mem = tubelib2.get_mem(pos)
	State:state_button_event(pos, mem, fields)
	
	if fields.update then
		M(pos):set_string("formspec", formspec(State, pos, mem))
	end
end

local function on_rightclick(pos)
	local mem = tubelib2.get_mem(pos)
	M(pos):set_string("formspec", formspec(State, pos, mem))
end

minetest.register_node("techage:flywheel", {
	description = I("TA2 Flywheel"),
	tiles = {
		-- up, down, right, left, back, front
		"techage_filling_ta2.png^techage_frame_ta2.png",
		"techage_filling_ta2.png^techage_frame_ta2.png",
		"techage_filling_ta2.png^techage_axle_clutch.png^techage_frame_ta2.png",
		"techage_filling_ta2.png^techage_appl_open.png^techage_frame_ta2.png",
		"techage_filling_ta2.png^techage_frame_ta2.png^techage_flywheel.png",
		"techage_filling_ta2.png^techage_frame_ta2.png^techage_flywheel.png^[transformFX]",
	},
	
	on_construct = tubelib2.init_mem,
	
	after_place_node = function(pos, placer)
		local mem = tubelib2.get_mem(pos)
		State:node_init(pos, mem, "")
		on_rightclick(pos)
	end,

	after_dig_node = function(pos, oldnode, oldmetadata, digger)
		State:after_dig_node(pos, oldnode, oldmetadata, digger)
	end,
	
	on_receive_fields = on_receive_fields,
	on_rightclick = on_rightclick,
	on_timer = node_timer,

	drop = "",
	paramtype2 = "facedir",
	groups = {cracky=2, crumbly=2, choppy=2},
	on_rotate = screwdriver.disallow,
	is_ground_content = false,
	sounds = default.node_sound_wood_defaults(),
})

minetest.register_node("techage:flywheel_on", {
	description = I("TA2 Flywheel"),
	tiles = {
		-- up, down, right, left, back, front
		"techage_filling_ta2.png^techage_frame_ta2.png",
		"techage_filling_ta2.png^techage_frame_ta2.png",
		{
			image = "techage_filling4_ta2.png^techage_axle_clutch4.png^techage_frame4_ta2.png",
			backface_culling = false,
			animation = {
				type = "vertical_frames",
				aspect_w = 32,
				aspect_h = 32,
				length = 0.6,
			},
		},
		"techage_filling_ta2.png^techage_appl_open.png^techage_frame_ta2.png",
		{
			image = "techage_filling8_ta2.png^techage_frame8_ta2.png^techage_flywheel8.png",
			backface_culling = false,
			animation = {
				type = "vertical_frames",
				aspect_w = 32,
				aspect_h = 32,
				length = 1.2,
			},
		},
		{
			image = "techage_filling8_ta2.png^techage_frame8_ta2.png^techage_flywheel8.png^[transformFX]",
			backface_culling = false,
			animation = {
				type = "vertical_frames",
				aspect_w = 32,
				aspect_h = 32,
				length = 1.2,
			},
		},
	},
	
	on_receive_fields = on_receive_fields,
	on_rightclick = on_rightclick,
	on_timer = node_timer,

	drop = "",
	paramtype2 = "facedir",
	groups = {not_in_creative_inventory=1},
	diggable = false,
	on_rotate = screwdriver.disallow,
	is_ground_content = false,
	sounds = default.node_sound_wood_defaults(),
})

techage.power.register_node({"techage:flywheel", "techage:flywheel_on"}, {
	on_power_pass1 = on_power_pass1,
	on_power_pass2 = on_power_pass2,
	on_power_pass3 = on_power_pass3,
	conn_sides = {"R"},
	power_network = Axle,
})

minetest.register_craft({
	output = "techage:flywheel",
	recipe = {
		{"basic_materials:steel_bar", "dye:red", "default:wood"},
		{"", "basic_materials:gear_steel", "techage:axle"},
		{"default:wood", "techage:iron_ingot", "basic_materials:steel_bar"},
	},
})

minetest.register_lbm({
	label = "[techage] Steam engine sound",
	name = "techage:steam_engine",
	nodenames = {"techage:flywheel_on"},
	run_at_every_load = true,
	action = function(pos, node)
		play_sound(pos)
		minetest.get_node_timer(pos):start(CYCLE_TIME)
	end
})

techage.register_help_page(I("TA2 Flywheel"), 
I([[Part of the steam engine.
Has to be placed side by side
with the TA2 Cylinder.
Used to turn on/off the steam engine.
Connect the Flywheel with your TA2 machines
by means of Axles and Gearboxes
(see TA2 Steam Engine)]]), "techage:flywheel")