//
// Gravity Generator
//

GLOBAL_LIST_EMPTY(gravity_generators) // We will keep track of this by adding new gravity generators to the list, and keying it with the z level.

#define POWER_IDLE 0
#define POWER_UP 1
#define POWER_DOWN 2

#define GRAV_NEEDS_SCREWDRIVER 0
#define GRAV_NEEDS_WELDING 1
#define GRAV_NEEDS_PLASTEEL 2
#define GRAV_NEEDS_WRENCH 3

//
// Abstract Generator
//

/obj/machinery/gravity_generator
	name = "gravitational generator"
	desc = "A device which produces a graviton field when set up."
	icon = 'icons/obj/machines/gravity_generator.dmi'
	density = TRUE
	move_resist = INFINITY
	use_power = NO_POWER_USE
	resistance_flags = INDESTRUCTIBLE | LAVA_PROOF | FIRE_PROOF | UNACIDABLE | ACID_PROOF
	var/sprite_number = 0

/obj/machinery/gravity_generator/safe_throw_at(atom/target, range, speed, mob/thrower, spin = TRUE, diagonals_first = FALSE, datum/callback/callback, force = MOVE_FORCE_STRONG, gentle = FALSE)
	return FALSE

/obj/machinery/gravity_generator/ex_act(severity, target, origin)
	if(severity >= EXPLODE_DEVASTATE) // Very sturdy.
		set_broken()

/obj/machinery/gravity_generator/blob_act(obj/structure/blob/B)
	if(prob(20))
		set_broken()

/obj/machinery/gravity_generator/zap_act(power, zap_flags)
	. = ..()
	if(zap_flags & ZAP_MACHINE_EXPLOSIVE)
		qdel(src)//like the singulo, tesla deletes it. stops it from exploding over and over

/obj/machinery/gravity_generator/update_icon_state()
	icon_state = "[get_status()]_[sprite_number]"
	return ..()

/obj/machinery/gravity_generator/proc/get_status()
	return "off"

// You aren't allowed to move.
/obj/machinery/gravity_generator/Move()
	. = ..()
	qdel(src)

/obj/machinery/gravity_generator/proc/set_broken()
	obj_break()

/obj/machinery/gravity_generator/proc/set_fix()
	stat &= ~BROKEN

/obj/machinery/gravity_generator/part/Destroy()
	if(main_part)
		qdel(main_part)
	set_broken()
	return ..()

//
// Part generator which is mostly there for looks
//

/obj/machinery/gravity_generator/part
	var/obj/machinery/gravity_generator/main/main_part = null

/obj/machinery/gravity_generator/part/attackby(obj/item/I, mob/user, params)
	return main_part.attackby(I, user)

/obj/machinery/gravity_generator/part/get_status()
	return main_part?.get_status()

/obj/machinery/gravity_generator/part/attack_hand(mob/user, list/modifiers)
	return main_part.attack_hand(user, modifiers)

/obj/machinery/gravity_generator/part/set_broken()
	..()
	if(main_part && !(main_part.stat & BROKEN))
		main_part.set_broken()

/// Used to eat args
/obj/machinery/gravity_generator/part/proc/on_update_icon(obj/machinery/gravity_generator/source, updates, updated)
	SIGNAL_HANDLER
	return update_appearance(updates)

//
// Generator which spawns with the station.
//

/obj/machinery/gravity_generator/main/station/Initialize(mapload)
	. = ..()
	setup_parts()
	middle.add_overlay("activated")
	update_list()

//
// Generator an admin can spawn
//
/obj/machinery/gravity_generator/main/station/admin
	use_power = NO_POWER_USE

//
// Main Generator with the main code
//

/obj/machinery/gravity_generator/main
	icon_state = "on_8"
	idle_power_usage = 0
	active_power_usage = 3000
	power_channel = ENVIRON
	sprite_number = 8
	use_power = IDLE_POWER_USE
	interaction_flags_machine = INTERACT_MACHINE_ALLOW_SILICON | INTERACT_MACHINE_OFFLINE
	var/on = TRUE
	var/breaker = TRUE
	var/list/parts = list()
	var/obj/middle = null
	var/charging_state = POWER_IDLE
	var/charge_count = 100
	var/current_overlay = null
	var/broken_state = 0
	var/setting = 1 //Gravity value when on

/obj/machinery/gravity_generator/main/Destroy() // If we somehow get deleted, remove all of our other parts.
	investigate_log("was destroyed!", INVESTIGATE_GRAVITY)
	on = FALSE
	update_list()
	for(var/obj/machinery/gravity_generator/part/O in parts)
		O.main_part = null
		if(!QDESTROYING(O))
			qdel(O)
	return ..()

/obj/machinery/gravity_generator/main/proc/setup_parts()
	var/turf/our_turf = get_turf(src)
	// 9x9 block obtained from the bottom middle of the block
	var/list/spawn_turfs = block(locate(our_turf.x - 1, our_turf.y + 2, our_turf.z), locate(our_turf.x + 1, our_turf.y, our_turf.z))
	var/count = 10
	for(var/turf/T in spawn_turfs)
		count--
		if(T == our_turf) // Skip our turf.
			continue
		var/obj/machinery/gravity_generator/part/part = new(T)
		if(count == 5) // Middle
			middle = part
		if(count <= 3) // Their sprite is the top part of the generator
			part.density= 0
			part.layer = WALL_OBJ_LAYER
		part.sprite_number = count
		part.main_part = src
		parts += part
		part.update_appearance()
		part.RegisterSignal(src, COMSIG_ATOM_UPDATED_ICON, /obj/machinery/gravity_generator/part/proc/on_update_icon)

/obj/machinery/gravity_generator/main/proc/connected_parts()
	return parts.len == 8

/obj/machinery/gravity_generator/main/set_broken()
	..()
	for(var/obj/machinery/gravity_generator/M in parts)
		if(!(M.stat & BROKEN))
			M.set_broken()
	middle.cut_overlays()
	charge_count = 0
	breaker = FALSE
	set_power()
	set_state(0)
	investigate_log("has broken down.", INVESTIGATE_GRAVITY)

/obj/machinery/gravity_generator/main/set_fix()
	..()
	for(var/obj/machinery/gravity_generator/M in parts)
		if(M.stat & BROKEN)
			M.set_fix()
	broken_state = FALSE
	update_appearance()
	set_power()

// Interaction

// Fixing the gravity generator.
/obj/machinery/gravity_generator/main/attackby(obj/item/I, mob/user, params)
	switch(broken_state)
		if(GRAV_NEEDS_SCREWDRIVER)
			if(I.tool_behaviour == TOOL_SCREWDRIVER)
				to_chat(user, span_notice("You secure the screws of the framework."))
				I.play_tool_sound(src)
				broken_state++
				update_appearance()
				return
		if(GRAV_NEEDS_WELDING)
			if(I.tool_behaviour == TOOL_WELDER)
				if(I.use_tool(src, user, 0, volume=50, amount=1))
					to_chat(user, span_notice("You mend the damaged framework."))
					broken_state++
					update_appearance()
				return
		if(GRAV_NEEDS_PLASTEEL)
			if(istype(I, /obj/item/stack/sheet/plasteel))
				var/obj/item/stack/sheet/plasteel/PS = I
				if(PS.get_amount() >= 10)
					PS.use(10)
					to_chat(user, span_notice("You add the plating to the framework."))
					playsound(src.loc, 'sound/machines/click.ogg', 75, TRUE)
					broken_state++
					update_appearance()
				else
					to_chat(user, span_warning("You need 10 sheets of plasteel!"))
				return
		if(GRAV_NEEDS_WRENCH)
			if(I.tool_behaviour == TOOL_WRENCH)
				to_chat(user, span_notice("You secure the plating to the framework."))
				I.play_tool_sound(src)
				set_fix()
				return
	return ..()

/obj/machinery/gravity_generator/main/ui_interact(mob/user, datum/tgui/ui)
	ui = SStgui.try_update_ui(user, src, ui)
	if(!ui)
		ui = new(user, src, "GravityGenerator", name)
		ui.open()

/obj/machinery/gravity_generator/main/ui_data(mob/user)
	var/list/data = list()

	data["breaker"] = breaker
	data["charge_count"] = charge_count
	data["charging_state"] = charging_state
	data["on"] = on
	data["operational"] = (stat & BROKEN) ? FALSE : TRUE

	return data

/obj/machinery/gravity_generator/main/ui_act(action, params)
	. = ..()
	if(.)
		return

	switch(action)
		if("gentoggle")
			breaker = !breaker
			investigate_log("was toggled [breaker ? "<font color='green'>ON</font>" : "<font color='red'>OFF</font>"] by [key_name(usr)].", INVESTIGATE_GRAVITY)
			set_power()
			. = TRUE

// Power and Icon States

/obj/machinery/gravity_generator/main/power_change()
	. = ..()
	investigate_log("has [stat & NOPOWER ? "lost" : "regained"] power.", INVESTIGATE_GRAVITY)
	set_power()

/obj/machinery/gravity_generator/main/get_status()
	if(stat & BROKEN)
		return "fix[min(broken_state, 3)]"
	return on || charging_state != POWER_IDLE ? "on" : "off"

// Set the charging state based on power/breaker.
/obj/machinery/gravity_generator/main/proc/set_power()
	var/new_state = FALSE
	if(stat & (NOPOWER|BROKEN) || !breaker)
		new_state = FALSE
	else if(breaker)
		new_state = TRUE

	charging_state = new_state ? POWER_UP : POWER_DOWN // Startup sequence animation.
	investigate_log("is now [charging_state == POWER_UP ? "charging" : "discharging"].", INVESTIGATE_GRAVITY)
	update_appearance()

// Set the state of the gravity.
/obj/machinery/gravity_generator/main/proc/set_state(new_state)
	charging_state = POWER_IDLE
	on = new_state
	use_power = on ? ACTIVE_POWER_USE : IDLE_POWER_USE
	// Sound the alert if gravity was just enabled or disabled.
	var/alert = FALSE
	if(SSticker.IsRoundInProgress())
		if(on) // If we turned on and the game is live.
			if(gravity_in_level() == FALSE)
				alert = TRUE
				investigate_log("was brought online and is now producing gravity for this level.", INVESTIGATE_GRAVITY)
				message_admins("The gravity generator was brought online [ADMIN_VERBOSEJMP(src)]")
		else
			if(gravity_in_level() == TRUE)
				alert = TRUE
				investigate_log("was brought offline and there is now no gravity for this level.", INVESTIGATE_GRAVITY)
				message_admins("The gravity generator was brought offline with no backup generator. [ADMIN_VERBOSEJMP(src)]")

	update_appearance()
	update_list()
	src.updateUsrDialog()
	if(alert)
		shake_everyone()

// Charge/Discharge and turn on/off gravity when you reach 0/100 percent.
// Also emit radiation and handle the overlays.
/obj/machinery/gravity_generator/main/process()
	if(stat & BROKEN)
		return
	if(charging_state != POWER_IDLE)
		if(charging_state == POWER_UP && charge_count >= 100)
			set_state(1)
		else if(charging_state == POWER_DOWN && charge_count <= 0)
			set_state(0)
		else
			if(charging_state == POWER_UP)
				charge_count += 2
			else if(charging_state == POWER_DOWN)
				charge_count -= 2

			if(charge_count % 4 == 0 && prob(75)) // Let them know it is charging/discharging.
				playsound(src.loc, 'sound/effects/empulse.ogg', 100, TRUE)

			updateDialog()
			if(prob(25)) // To help stop "Your clothes feel warm." spam.
				pulse_radiation()

			var/overlay_state = null
			switch(charge_count)
				if(0 to 20)
					overlay_state = null
				if(21 to 40)
					overlay_state = "startup"
				if(41 to 60)
					overlay_state = "idle"
				if(61 to 80)
					overlay_state = "activating"
				if(81 to 100)
					overlay_state = "activated"

			if(overlay_state != current_overlay)
				if(middle)
					middle.cut_overlays()
					if(overlay_state)
						middle.add_overlay(overlay_state)
					current_overlay = overlay_state


/obj/machinery/gravity_generator/main/proc/pulse_radiation()
	radiation_pulse(src, 200)

// Shake everyone on the z level to let them know that gravity was enagaged/disenagaged.
/obj/machinery/gravity_generator/main/proc/shake_everyone()
	var/turf/T = get_turf(src)
	var/sound/alert_sound = sound('sound/effects/alert.ogg')
	for(var/i in GLOB.mob_list)
		var/mob/M = i
		if(M.z != z && !(SSmapping.level_trait(z, ZTRAITS_STATION) && SSmapping.level_trait(M.z, ZTRAITS_STATION)))
			continue
		M.update_gravity(M.mob_has_gravity())
		if(M.client)
			shake_camera(M, 15, 1)
			M.playsound_local(T, null, 100, 1, 0.5, S = alert_sound)

/obj/machinery/gravity_generator/main/proc/gravity_in_level()
	var/turf/T = get_turf(src)
	if(!T)
		return FALSE
	if(GLOB.gravity_generators["[T.z]"])
		return length(GLOB.gravity_generators["[T.z]"])
	return FALSE

/obj/machinery/gravity_generator/main/proc/update_list()
	var/turf/T = get_turf(src.loc)
	if(T)
		var/list/z_list = list()
		// Multi-Z, station gravity generator generates gravity on all ZTRAIT_STATION z-levels.
		if(SSmapping.level_trait(T.z, ZTRAIT_STATION))
			for(var/z in SSmapping.levels_by_trait(ZTRAIT_STATION))
				z_list += z
		else
			z_list += T.z
		for(var/z in z_list)
			if(!GLOB.gravity_generators["[z]"])
				GLOB.gravity_generators["[z]"] = list()
			if(on)
				GLOB.gravity_generators["[z]"] |= src
			else
				GLOB.gravity_generators["[z]"] -= src

/obj/machinery/gravity_generator/main/proc/change_setting(value)
	if(value != setting)
		setting = value
		shake_everyone()

// Misc

/obj/item/paper/guides/jobs/engi/gravity_gen
	name = "paper- 'Generate your own gravity!'"
	info = {"<h1>Gravity Generator Instructions For Dummies</h1>
	<p>Surprisingly, gravity isn't that hard to make! All you have to do is inject deadly radioactive minerals into a ball of
	energy and you have yourself gravity! You can turn the machine on or off when required but you must remember that the generator
	will EMIT RADIATION when charging or discharging, you can tell it is charging or discharging by the noise it makes, so please WEAR PROTECTIVE CLOTHING.</p>
	<br>
	<h3>It blew up!</h3>
	<p>Don't panic! The gravity generator was designed to be easily repaired. If, somehow, the sturdy framework did not survive then
	please proceed to panic; otherwise follow these steps.</p><ol>
	<li>Secure the screws of the framework with a screwdriver.</li>
	<li>Mend the damaged framework with a welding tool.</li>
	<li>Add additional plasteel plating.</li>
	<li>Secure the additional plating with a wrench.</li></ol>"}