//TODO: Put this under a common parent type with freezers to cut down on the copypasta
#define HEATER_PERF_MULT 2.5

/obj/machinery/atmospherics/unary/heater
	name = "gas heating system"
	desc = "Heats gas when connected to a pipe network"
	icon = 'icons/obj/Cryogenic2_vr.dmi'
	icon_state = "heater_0"
	density = 1
	anchored = 1
	use_power = USE_POWER_OFF
	idle_power_usage = 5			//5 Watts for thermostat related circuitry
	circuit = /obj/item/weapon/circuitboard/unary_atmos/heater

	var/max_temperature = T20C + 680
	var/internal_volume = 600	//L

	var/max_power_rating = 20000	//power rating when the usage is turned up to 100
	var/power_setting = 100

	var/set_temperature = T20C	//thermostat
	var/heating = 0		//mainly for icon updates

/obj/machinery/atmospherics/unary/heater/New()
	..()
	component_parts = list()
	component_parts += new /obj/item/weapon/stock_parts/matter_bin(src)
	component_parts += new /obj/item/weapon/stock_parts/capacitor(src)
	component_parts += new /obj/item/weapon/stock_parts/capacitor(src)
	component_parts += new /obj/item/stack/cable_coil(src, 5)

	RefreshParts()

/obj/machinery/atmospherics/unary/heater/atmos_init()
	if(node)
		return

	var/node_connect = dir

	//check that there is something to connect to
	for(var/obj/machinery/atmospherics/target in get_step(src, node_connect))
		if(can_be_node(target, 1))
			node = target
			break

	if(check_for_obstacles())
		node = null

	if(node)
		update_icon()


/obj/machinery/atmospherics/unary/heater/update_icon()
	if(node)
		if(use_power && heating)
			icon_state = "heater_1"
		else
			icon_state = "heater"
	else
		icon_state = "heater_0"
	return


/obj/machinery/atmospherics/unary/heater/process()
	..()

	if(stat & (NOPOWER|BROKEN) || !use_power)
		heating = 0
		update_icon()
		return

	if(network && air_contents.total_moles && air_contents.temperature < set_temperature)
		air_contents.add_thermal_energy(power_rating * HEATER_PERF_MULT)
		use_power(power_rating)

		heating = 1
		network.update = 1
	else
		heating = 0

	update_icon()

/obj/machinery/atmospherics/unary/heater/attack_ai(mob/user as mob)
	ui_interact(user)

/obj/machinery/atmospherics/unary/heater/attack_hand(mob/user as mob)
	ui_interact(user)

/obj/machinery/atmospherics/unary/heater/ui_interact(mob/user, ui_key = "main", var/datum/nanoui/ui = null, var/force_open = 1)
	// this is the data which will be sent to the ui
	var/data[0]
	data["on"] = use_power ? 1 : 0
	data["gasPressure"] = round(air_contents.return_pressure())
	data["gasTemperature"] = round(air_contents.temperature)
	data["minGasTemperature"] = 0
	data["maxGasTemperature"] = round(max_temperature)
	data["targetGasTemperature"] = round(set_temperature)
	data["powerSetting"] = power_setting

	var/temp_class = "normal"
	if(air_contents.temperature > (T20C+40))
		temp_class = "bad"
	data["gasTemperatureClass"] = temp_class

	// update the ui if it exists, returns null if no ui is passed/found
	ui = SSnanoui.try_update_ui(user, src, ui_key, ui, data, force_open)
	if(!ui)
		// the ui does not exist, so we'll create a new() one
        // for a list of parameters and their descriptions see the code docs in \code\modules\nano\nanoui.dm
		ui = new(user, src, ui_key, "freezer.tmpl", "Gas Heating System", 440, 300)
		// when the ui is first opened this is the data it will use
		ui.set_initial_data(data)
		// open the new ui window
		ui.open()
		// auto update every Master Controller tick
		ui.set_auto_update(1)

/obj/machinery/atmospherics/unary/heater/Topic(href, href_list)
	if(..())
		return 1
	if(href_list["toggleStatus"])
		update_use_power(!use_power)
		update_icon()
	if(href_list["temp"])
		var/amount = text2num(href_list["temp"])
		if(amount > 0)
			set_temperature = min(set_temperature + amount, max_temperature)
		else
			set_temperature = max(set_temperature + amount, 0)
	if(href_list["setPower"]) //setting power to 0 is redundant anyways
		var/new_setting = between(0, text2num(href_list["setPower"]), 100)
		set_power_level(new_setting)

	add_fingerprint(usr)

//upgrading parts
/obj/machinery/atmospherics/unary/heater/RefreshParts()
	..()
	var/cap_rating = 0
	var/bin_rating = 0

	for(var/obj/item/weapon/stock_parts/P in component_parts)
		if(istype(P, /obj/item/weapon/stock_parts/capacitor))
			cap_rating += P.rating
		if(istype(P, /obj/item/weapon/stock_parts/matter_bin))
			bin_rating += P.rating

	max_power_rating = initial(max_power_rating) * cap_rating / 2
	max_temperature = max(initial(max_temperature) - T20C, 0) * ((bin_rating * 4 + cap_rating) / 5) + T20C
	air_contents.volume = max(initial(internal_volume) - 200, 0) + 200 * bin_rating
	set_power_level(power_setting)

/obj/machinery/atmospherics/unary/heater/proc/set_power_level(var/new_power_setting)
	power_setting = new_power_setting
	power_rating = max_power_rating * (power_setting/100)

/obj/machinery/atmospherics/unary/heater/attackby(var/obj/item/O as obj, var/mob/user as mob)
	if(default_deconstruction_screwdriver(user, O))
		return
	if(default_deconstruction_crowbar(user, O))
		return
	if(default_part_replacement(user, O))
		return

	..()

/obj/machinery/atmospherics/unary/heater/examine(mob/user)
	..(user)
	if(panel_open)
		to_chat(user, "The maintenance hatch is open.")