#define SOURCE_PORTAL 1
#define DESTINATION_PORTAL 2

/* Teleportation devices.
 * Contains:
 * Locator
 * Hand-tele
 */

/*
 * Locator
 */
/obj/item/locator
	name = "bluespace locator"
	desc = "Used to track portable teleportation beacons and targets with embedded tracking implants."
	icon = 'icons/obj/devices/tracker.dmi'
	icon_state = "locator"
	var/temp = null
	obj_flags = CONDUCTS_ELECTRICITY
	w_class = WEIGHT_CLASS_SMALL
	inhand_icon_state = "electronic"
	lefthand_file = 'icons/mob/inhands/items/devices_lefthand.dmi'
	righthand_file = 'icons/mob/inhands/items/devices_righthand.dmi'
	throw_speed = 3
	throw_range = 7
	custom_materials = list(/datum/material/iron= SMALL_MATERIAL_AMOUNT * 4)
	var/tracking_range = 35

/obj/item/locator/ui_interact(mob/user, datum/tgui/ui)
	ui = SStgui.try_update_ui(user, src, ui)
	if(!ui)
		ui = new(user, src, "BluespaceLocator", name)
		ui.open()

/obj/item/locator/ui_data(mob/user)
	var/list/data = list()

	data["trackingrange"] = tracking_range;

	// Get our current turf location.
	var/turf/sr = get_turf(src)

	if (sr)
		// Check every teleport beacon.
		var/list/tele_beacons = list()
		for(var/obj/item/beacon/W in GLOB.teleportbeacons)

			// Get the tracking beacon's turf location.
			var/turf/tr = get_turf(W)

			// Make sure it's on a turf and that its Z-level matches the tracker's Z-level
			if (tr && tr.z == sr.z)
				// Get the distance between the beacon's turf and our turf
				var/distance = max(abs(tr.x - sr.x), abs(tr.y - sr.y))

				// If the target is too far away, skip over this beacon.
				if(distance > tracking_range)
					continue

				var/beacon_name

				if(W.renamed)
					beacon_name = W.name
				else
					var/area/A = get_area(W)
					beacon_name = A.name

				var/D = dir2text(get_dir(sr, tr))
				tele_beacons += list(list(name = beacon_name, direction = D, distance = distance))

		data["telebeacons"] = tele_beacons

		var/list/track_implants = list()

		for (var/obj/item/implant/beacon/tracking_beacon in GLOB.tracked_implants)
			if (!tracking_beacon.imp_in || !isliving(tracking_beacon.loc))
				continue
			else
				var/mob/living/living_mob = tracking_beacon.loc
				if (living_mob.stat == DEAD)
					if (living_mob.timeofdeath + tracking_beacon.lifespan_postmortem < world.time)
						continue
			var/turf/tr = get_turf(tracking_beacon)
			var/distance = max(abs(tr.x - sr.x), abs(tr.y - sr.y))

			if(distance > tracking_range)
				continue

			var/D = dir2text(get_dir(sr, tr))
			track_implants += list(list(name = tracking_beacon.imp_in.name, direction = D, distance = distance))
		data["trackimplants"] = track_implants
	return data

#define PORTAL_LOCATION_DANGEROUS "portal_location_dangerous"
#define PORTAL_DANGEROUS_EDGE_LIMIT 8

/*
 * Hand-tele
 */
/obj/item/hand_tele
	name = "hand tele"
	desc = "A portable item using blue-space technology. One of the buttons opens a portal, the other re-opens your last destination."
	icon = 'icons/obj/devices/tracker.dmi'
	icon_state = "hand_tele"
	inhand_icon_state = "electronic"
	worn_icon_state = "electronic"
	lefthand_file = 'icons/mob/inhands/items/devices_lefthand.dmi'
	righthand_file = 'icons/mob/inhands/items/devices_righthand.dmi'
	throwforce = 0
	w_class = WEIGHT_CLASS_SMALL
	throw_speed = 3
	throw_range = 5
	custom_materials = list(/datum/material/iron= SHEET_MATERIAL_AMOUNT * 5)
	armor_type = /datum/armor/item_hand_tele
	resistance_flags = INDESTRUCTIBLE | LAVA_PROOF | FIRE_PROOF | ACID_PROOF
	var/list/active_portal_pairs
	var/max_portal_pairs = 3

	/**
	 * Represents the last place we teleported to, for making quick portals.
	 * Can be in the following states:
	 * - null, meaning either this hand tele hasn't been used yet, or the last place it was portalled to was removed.
	 * - PORTAL_LOCATION_DANGEROUS, meaning the last place it teleported to was the "None (Dangerous)" location.
	 * - A weakref to a /obj/machinery/computer/teleporter, meaning the last place it teleported to was a pre-setup location.
	*/
	var/last_portal_location

/datum/armor/item_hand_tele
	bomb = 30
	fire = 100
	acid = 100

/obj/item/hand_tele/Initialize(mapload)
	. = ..()
	active_portal_pairs = list()

/obj/item/hand_tele/pre_attack(atom/target, mob/user, params)
	if(try_dispel_portal(target, user))
		return TRUE
	return ..()

/obj/item/hand_tele/proc/try_dispel_portal(atom/target, mob/user)
	if(is_parent_of_portal(target))
		qdel(target)
		to_chat(user, span_notice("You dispel [target] with \the [src]!"))
		return TRUE
	return FALSE

/obj/item/hand_tele/afterattack(atom/target, mob/user)
	try_dispel_portal(target, user)
	. = ..()

/obj/item/hand_tele/pre_attack_secondary(atom/target, mob/user, proximity_flag, click_parameters)
	var/portal_location = last_portal_location

	if (isweakref(portal_location))
		var/datum/weakref/last_portal_location_ref = last_portal_location
		portal_location = last_portal_location_ref.resolve()

	if (isnull(portal_location))
		to_chat(user, span_warning("[src] flashes briefly. No target is locked in."))
		return SECONDARY_ATTACK_CANCEL_ATTACK_CHAIN

	try_create_portal_to(user, portal_location)

	return SECONDARY_ATTACK_CANCEL_ATTACK_CHAIN

/obj/item/hand_tele/attack_self(mob/user)
	if (!can_teleport_notifies(user))
		return

	var/list/locations = list()
	for(var/obj/machinery/computer/teleporter/computer as anything in SSmachines.get_machines_by_type_and_subtypes(/obj/machinery/computer/teleporter))
		var/atom/target = computer.target_ref?.resolve()
		if(!target)
			computer.target_ref = null
			continue
		var/area/computer_area = get_area(target)
		if(!computer_area || (computer_area.area_flags & NOTELEPORT))
			continue
		if(computer.power_station?.teleporter_hub && computer.power_station.engaged)
			locations["[get_area(target)] (Active)"] = computer
		else
			locations["[get_area(target)] (Inactive)"] = computer

	locations["None (Dangerous)"] = PORTAL_LOCATION_DANGEROUS

	var/teleport_location_key = tgui_input_list(user, "Teleporter to lock on", "Hand Teleporter", sort_list(locations))
	if (isnull(teleport_location_key))
		return
	if(user.get_active_held_item() != src || user.incapacitated())
		return

	// Not always a datum, but needed for IS_WEAKREF_OF to cast properly.
	var/datum/teleport_location = locations[teleport_location_key]
	if (!try_create_portal_to(user, teleport_location))
		return

	if (teleport_location == PORTAL_LOCATION_DANGEROUS)
		last_portal_location = PORTAL_LOCATION_DANGEROUS
	else if (!IS_WEAKREF_OF(teleport_location, last_portal_location))
		if (isweakref(teleport_location))
			var/datum/weakref/about_to_replace_location_ref = last_portal_location
			var/obj/machinery/computer/teleporter/about_to_replace_location = about_to_replace_location_ref.resolve()
			if (about_to_replace_location)
				UnregisterSignal(about_to_replace_location, COMSIG_TELEPORTER_NEW_TARGET)

		RegisterSignal(teleport_location, COMSIG_TELEPORTER_NEW_TARGET, PROC_REF(on_teleporter_new_target))

		last_portal_location = WEAKREF(teleport_location)

/// Takes either PORTAL_LOCATION_DANGEROUS or an /obj/machinery/computer/teleport/computer.
/obj/item/hand_tele/proc/try_create_portal_to(mob/user, teleport_location)
	if (length(active_portal_pairs) >= max_portal_pairs)
		user.show_message(span_notice("[src] is recharging!"))
		return

	var/atom/teleport_target

	if (teleport_location == PORTAL_LOCATION_DANGEROUS)
		var/list/dangerous_turfs = list()
		for(var/turf/dangerous_turf in urange(10, orange=1))
			if(dangerous_turf.x > world.maxx - PORTAL_DANGEROUS_EDGE_LIMIT || dangerous_turf.x < PORTAL_DANGEROUS_EDGE_LIMIT)
				continue //putting them at the edge is dumb
			if(dangerous_turf.y > world.maxy - PORTAL_DANGEROUS_EDGE_LIMIT || dangerous_turf.y < PORTAL_DANGEROUS_EDGE_LIMIT)
				continue
			var/area/dangerous_area = dangerous_turf.loc
			if(dangerous_area.area_flags & NOTELEPORT)
				continue
			dangerous_turfs += dangerous_turf

		teleport_target = pick(dangerous_turfs)
	else
		var/obj/machinery/computer/teleporter/computer = teleport_location
		var/atom/target = computer.target_ref?.resolve()
		if(!target)
			computer.target_ref = null
		teleport_target = target

	if (teleport_target == null)
		to_chat(user, span_notice("[src] vibrates, then stops. Maybe you should try something else."))
		return

	var/area/teleport_area = get_area(teleport_target)
	if (teleport_area.area_flags & NOTELEPORT)
		to_chat(user, span_notice("[src] is malfunctioning."))
		return

	if (!can_teleport_notifies(user))
		return

	var/list/obj/effect/portal/created = create_portal_pair(get_turf(user), get_teleport_turf(get_turf(teleport_target)), 300, 1, null)
	if(LAZYLEN(created) != 2)
		return

	var/obj/effect/portal/portal1 = created[1]
	var/obj/effect/portal/portal2 = created[2]

	RegisterSignal(portal1, COMSIG_QDELETING, PROC_REF(on_portal_destroy))
	RegisterSignal(portal2, COMSIG_QDELETING, PROC_REF(on_portal_destroy))

	try_move_adjacent(portal1, user.dir)
	active_portal_pairs[portal1] = portal2

	investigate_log("was used by [key_name(user)] at [AREACOORD(user)] to create a portal pair with destinations [AREACOORD(portal1)] and [AREACOORD(portal2)].", INVESTIGATE_PORTAL)
	add_fingerprint(user)

	user.show_message(span_notice("Locked in."), MSG_AUDIBLE)

	return TRUE

/obj/item/hand_tele/proc/can_teleport_notifies(mob/user)
	var/turf/current_location = get_turf(user)
	var/area/current_area = current_location.loc
	if (!current_location || (current_area.area_flags & NOTELEPORT) || is_away_level(current_location.z) || !isturf(user.loc))
		to_chat(user, span_notice("[src] is malfunctioning."))
		return FALSE

	return TRUE

/obj/item/hand_tele/proc/on_teleporter_new_target(datum/source)
	SIGNAL_HANDLER

	if (IS_WEAKREF_OF(source, last_portal_location))
		last_portal_location = null
		UnregisterSignal(source, COMSIG_TELEPORTER_NEW_TARGET)

/obj/item/hand_tele/proc/on_portal_destroy(obj/effect/portal/P)
	SIGNAL_HANDLER

	active_portal_pairs -= P //If this portal pair is made by us it'll be erased along with the other portal by the portal.

/obj/item/hand_tele/proc/is_parent_of_portal(obj/effect/portal/P)
	if(!istype(P))
		return FALSE
	if(active_portal_pairs[P])
		return SOURCE_PORTAL
	for(var/i in active_portal_pairs)
		if(active_portal_pairs[i] == P)
			return DESTINATION_PORTAL
	return FALSE

/obj/item/hand_tele/suicide_act(mob/living/user)
	if(iscarbon(user))
		user.visible_message(span_suicide("[user] is creating a weak portal and sticking [user.p_their()] head through! It looks like [user.p_theyre()] trying to commit suicide!"))
		var/mob/living/carbon/itemUser = user
		var/obj/item/bodypart/head/head = itemUser.get_bodypart(BODY_ZONE_HEAD)
		if(head)
			head.drop_limb()
			var/list/safeLevels = SSmapping.levels_by_any_trait(list(ZTRAIT_SPACE_RUINS, ZTRAIT_LAVA_RUINS, ZTRAIT_STATION, ZTRAIT_MINING))
			head.forceMove(locate(rand(1, world.maxx), rand(1, world.maxy), pick(safeLevels)))
			itemUser.visible_message(span_suicide("The portal snaps closed taking [user]'s head with it!"))
		else
			itemUser.visible_message(span_suicide("[user] looks even further depressed as they realize they do not have a head...and suddenly dies of shame!"))
		return BRUTELOSS

/obj/item/syndicate_teleporter
	name = "experimental teleporter"
	desc = "A reverse-engineered version of the Nanotrasen handheld teleporter. Lacks the advanced safety features of its counterpart. A three-headed serpent can be seen on the back."
	icon = 'icons/obj/devices/tracker.dmi'
	icon_state = "syndi-tele"
	throwforce = 5
	w_class = WEIGHT_CLASS_SMALL
	throw_speed = 4
	throw_range = 10
	obj_flags = CONDUCTS_ELECTRICITY
	inhand_icon_state = "electronic"
	lefthand_file = 'icons/mob/inhands/items/devices_lefthand.dmi'
	righthand_file = 'icons/mob/inhands/items/devices_righthand.dmi'
	//Uses of the device left
	var/charges = 4
	//The maximum number of stored uses
	var/max_charges = 4
	///Minimum distance to teleport user forward
	var/minimum_teleport_distance = 4
	///Maximum distance to teleport user forward
	var/maximum_teleport_distance = 8
	//How far the emergency teleport checks for a safe position
	var/parallel_teleport_distance = 3

/obj/item/syndicate_teleporter/Initialize(mapload)
	. = ..()
	START_PROCESSING(SSobj, src)

/obj/item/syndicate_teleporter/Destroy(force)
	STOP_PROCESSING(SSobj, src)
	return ..()

/obj/item/syndicate_teleporter/examine(mob/user)
	. = ..()
	. += span_notice("[src] has <b>[charges]</b> out of [max_charges] charges left.")

/obj/item/syndicate_teleporter/attack_self(mob/user)
	. = ..()
	if(.)
		return
	attempt_teleport(user = user, triggered_by_emp = FALSE)
	return TRUE

/obj/item/syndicate_teleporter/process(seconds_per_tick, times_fired)
	if(SPT_PROB(10, seconds_per_tick) && charges < max_charges)
		charges++
		if(ishuman(loc))
			var/mob/living/carbon/human/holder = loc
			balloon_alert(holder, "teleporter beeps")
		playsound(src, 'sound/machines/twobeep.ogg', 10, TRUE, extrarange = SILENCED_SOUND_EXTRARANGE, falloff_distance = 0)

/obj/item/syndicate_teleporter/emp_act(severity)
	. = ..()
	if(!prob(50/severity))
		return
	var/teleported_something = FALSE
	if(ishuman(loc))
		var/mob/living/carbon/human/holder = loc
		balloon_alert(holder, "teleporter buzzes!")
		attempt_teleport(user = holder, triggered_by_emp = TRUE)
	else
		var/turf/teleport_turf = get_turf(src)
		for(var/mob/living/mob_on_same_tile in teleport_turf)
			if(!teleported_something)
				teleported_something = TRUE
			attempt_teleport(user = mob_on_same_tile, triggered_by_emp = TRUE, not_holding_tele = TRUE)
		if(!teleported_something)
			visible_message(span_danger("[src] blinks out of existence!"))
			do_sparks(2, 1, src)
			qdel(src)

/**
 * Tries to teleport the user forward based on random number between min/max teleport distance vars.
 * If destination is closed turf, try to save user from gibbing via a panic teleport.
 * Wearing bag of holding or triggering teleport via EMP removes panic teleport, higher chance of being gibbed.
 * Mobs on same tile as destination get telefragged.
 **/
/obj/item/syndicate_teleporter/proc/attempt_teleport(mob/user, triggered_by_emp = FALSE, not_holding_tele = FALSE)
	if(!charges && !triggered_by_emp)
		balloon_alert(user, "recharging!")
		return

	var/turf/current_location = get_turf(user)

	if(malfunctioning(user, current_location))
		if(not_holding_tele)
			return
		balloon_alert(user, "malfunctioning!")
		return

	var/teleport_distance = rand(minimum_teleport_distance, maximum_teleport_distance)
	var/turf/destination = get_teleport_loc(current_location, user, teleport_distance)
	var/bagholdingcheck = FALSE
	if(iscarbon(user))
		var/mob/living/carbon/teleporting_guy = user
		if(locate(/obj/item/storage/backpack/holding) in teleporting_guy.get_all_gear())
			bagholdingcheck = TRUE

	if(isclosedturf(destination))
		if(!triggered_by_emp && !bagholdingcheck)
			panic_teleport(user, destination) //We're in a wall, engage emergency parallel teleport.
		else
			if(bagholdingcheck && !not_holding_tele)
				to_chat(user, span_warning("The bluespace interface on your bag of holding interferes with the teleport!"))
			get_fragged(user, destination, not_holding_tele) //EMP teleported you into a wall? Wearing a BoH? You're dead.
	else
		telefrag(destination, user)
		do_teleport(user, destination, channel = TELEPORT_CHANNEL_FREE)
		charges = max(charges - 1, 0)
		new /obj/effect/temp_visual/teleport_abductor/syndi_teleporter(current_location)
		new /obj/effect/temp_visual/teleport_abductor/syndi_teleporter(destination)
		make_bloods(current_location, destination, user)
		playsound(current_location, SFX_SPARKS, 50, 1, SHORT_RANGE_SOUND_EXTRARANGE)
		playsound(destination, 'sound/effects/phasein.ogg', 25, 1, SHORT_RANGE_SOUND_EXTRARANGE)
		playsound(destination, SFX_SPARKS, 50, 1, SHORT_RANGE_SOUND_EXTRARANGE)

/obj/item/syndicate_teleporter/proc/malfunctioning(mob/guy_teleporting, turf/current_location)
	var/area/current_area = get_area(current_location)
	if(!current_location)
		return TRUE
	if(current_area.area_flags & NOTELEPORT)
		return TRUE
	if(is_away_level(current_location.z))
		return TRUE
	if(is_centcom_level(current_location.z))
		return TRUE
	if(is_reserved_level(current_location.z))
		return TRUE
	if(!isturf(guy_teleporting.loc))
		return TRUE
	return FALSE

/**
 * Checks parallel_teleport_distance amount of tiles parallel to user's teleport destination.
 * If no valid closed turfs found, gib user.
 **/
/obj/item/syndicate_teleporter/proc/panic_teleport(mob/user, turf/destination)
	var/turf/mobloc = get_turf(user)
	var/turf/emergency_destination = get_teleport_loc(destination, user, distance = 0, closed_turf_check = TRUE, errorx = parallel_teleport_distance)

	if(emergency_destination)
		telefrag(emergency_destination, user)
		do_teleport(user, emergency_destination, channel = TELEPORT_CHANNEL_FREE)
		charges = max(charges - 1, 0)
		new /obj/effect/temp_visual/teleport_abductor/syndi_teleporter(mobloc)
		new /obj/effect/temp_visual/teleport_abductor/syndi_teleporter(emergency_destination)
		balloon_alert(user, "emergency teleport triggered!")
		if (!HAS_TRAIT(user, TRAIT_NOBLOOD))
			make_bloods(mobloc, emergency_destination, user)
		playsound(mobloc, SFX_SPARKS, 50, 1, SHORT_RANGE_SOUND_EXTRARANGE)
		playsound(emergency_destination, 'sound/effects/phasein.ogg', 25, 1, SHORT_RANGE_SOUND_EXTRARANGE)
		playsound(emergency_destination, SFX_SPARKS, 50, 1, SHORT_RANGE_SOUND_EXTRARANGE)
	else //We tried to save. We failed. Death time.
		get_fragged(user, destination)

///Force move victim to destination, explode destination, drop all victim's items, gib them
/obj/item/syndicate_teleporter/proc/get_fragged(mob/living/victim, turf/destination, not_holding_tele = FALSE)
	var/turf/mobloc = get_turf(victim)
	victim.forceMove(destination)
	new /obj/effect/temp_visual/teleport_abductor/syndi_teleporter(mobloc)
	new /obj/effect/temp_visual/teleport_abductor/syndi_teleporter(destination)
	playsound(mobloc, SFX_SPARKS, 50, TRUE, SHORT_RANGE_SOUND_EXTRARANGE)
	playsound(destination, SFX_SPARKS, 50, TRUE, SHORT_RANGE_SOUND_EXTRARANGE)
	playsound(destination, "sound/magic/disintegrate.ogg", 50, TRUE, SHORT_RANGE_SOUND_EXTRARANGE)
	if(!not_holding_tele)
		to_chat(victim, span_userdanger("You teleport into [destination], [src] tries to save you, but..."))
	else
		to_chat(victim, span_userdanger("You teleport into [destination]."))
	destination.ex_act(EXPLODE_HEAVY)
	victim.unequip_everything()
	victim.investigate_log("has been gibbed by [src].", INVESTIGATE_DEATHS)
	victim.gib(DROP_ALL_REMAINS)

///Damage and stun all mobs in fragging_location turf, called after a teleport
/obj/item/syndicate_teleporter/proc/telefrag(turf/fragging_location, mob/user) // Don't let this gib. Never let this gib.
	for(var/mob/living/victim in fragging_location)//Hit everything in the turf
		victim.apply_damage(20, BRUTE)
		victim.Paralyze(6 SECONDS)
		to_chat(victim, span_warning("[user] teleports into you, knocking you to the floor with the bluespace wave!"))

///Bleed and make blood splatters at tele start and end points
/obj/item/syndicate_teleporter/proc/make_bloods(turf/old_location, turf/new_location, mob/living/user)
	user.add_splatter_floor(old_location)
	user.add_splatter_floor(new_location)
	if(!iscarbon(user))
		return
	var/mob/living/carbon/carbon_user = user
	carbon_user.bleed(10)


/obj/item/paper/syndicate_teleporter
	name = "Teleporter Guide"
	default_raw_text = {"
		<b>Instructions on your new prototype teleporter:</b><br>
		<br>
		This teleporter will teleport the user 4-8 meters in the direction they are facing.<br>
		<br>
		It has 4 charges, and will recharge over time randomly. No, sticking the teleporter into an APC, microwave, or electrified airlock will not make it charge faster.<br>
		<br>
		<b>Warning:</b> Teleporting into walls will activate a failsafe teleport parallel up to 3 meters, but the user will be ripped apart if it fails to find a safe location.<br>
		<br>
		Do not expose the teleporter to electromagnetic pulses. Unwanted malfunctions may occur.
		<br>
		Final word of caution: the technology involved is experimental in nature. Although many years of research have allowed us to prevent leaving your organs behind, it simply cannot account for all of the liquid in your body.
		"}

/obj/item/storage/box/syndie_kit/syndicate_teleporter
	name = "syndicate teleporter kit"

/obj/item/storage/box/syndie_kit/syndicate_teleporter/PopulateContents()
	new /obj/item/syndicate_teleporter(src)
	new /obj/item/paper/syndicate_teleporter(src)

/obj/effect/temp_visual/teleport_abductor/syndi_teleporter
	duration = 5

#undef PORTAL_LOCATION_DANGEROUS
#undef PORTAL_DANGEROUS_EDGE_LIMIT

#undef SOURCE_PORTAL
#undef DESTINATION_PORTAL