Yogstation/code/datums/components/chasm.dm

// Used by /turf/open/chasm and subtypes to implement the "dropping" mechanic
/datum/component/chasm
	var/turf/target_turf
	var/obj/effect/abstract/chasm_storage/storage
	var/fall_message = "GAH! Ah... where are you?"
	var/oblivion_message = "You stumble and stare into the abyss before you. It stares back, and you fall into the enveloping dark."

	var/static/list/falling_atoms = list() // Atoms currently falling into chasms
	var/static/list/forbidden_types = typecacheof(list(
		/obj/singularity,
		/obj/docking_port,
		/obj/structure/lattice,
		/obj/structure/stone_tile,
		/obj/projectile,
		/obj/effect/projectile,
		/obj/effect/portal,
		/obj/effect/abstract,
		/obj/effect/hotspot,
		/obj/effect/landmark,
		/obj/effect/temp_visual,
		/obj/effect/light_emitter/tendril,
		/obj/effect/collapse,
		/obj/effect/particle_effect/ion_trails,
		/obj/effect/dummy/phased_mob,
		/obj/effect/dummy/crawling //yogs
		))

/datum/component/chasm/Initialize(turf/target, mapload)
	if(!isturf(parent))
		return COMPONENT_INCOMPATIBLE
	RegisterSignal(parent, SIGNAL_ADDTRAIT(TRAIT_CHASM_STOPPED), PROC_REF(on_chasm_stopped))
	RegisterSignal(parent, SIGNAL_REMOVETRAIT(TRAIT_CHASM_STOPPED), PROC_REF(on_chasm_no_longer_stopped))
	target_turf = target
	RegisterSignal(parent, COMSIG_ATOM_ABSTRACT_ENTERED, PROC_REF(entered))
	RegisterSignal(parent, COMSIG_ATOM_ABSTRACT_EXITED, PROC_REF(exited))
	RegisterSignal(parent, COMSIG_ATOM_AFTER_SUCCESSFUL_INITIALIZED_ON, PROC_REF(initialized_on))
	RegisterSignal(parent, COMSIG_ATOM_INTERCEPT_TELEPORTING, PROC_REF(block_teleport))
	RegisterSignal(parent, COMSIG_ATOM_ATTACKBY, PROC_REF(fish))
	//allow catwalks to give the turf the CHASM_STOPPED trait before dropping stuff when the turf is changed.
	//otherwise don't do anything because turfs and areas are initialized before movables.
	if(!mapload)
		addtimer(CALLBACK(src, PROC_REF(drop_stuff)), 0)
	START_PROCESSING(SSobj, src) // process on create, in case stuff is still there

/datum/component/chasm/proc/Entered(datum/source, atom/movable/AM)
	START_PROCESSING(SSobj, src)
	drop_stuff(AM)

/datum/component/chasm/process()
	if (!drop_stuff())
		STOP_PROCESSING(SSobj, src)

/datum/component/chasm/UnregisterFromParent()
	storage = null

/datum/component/chasm/proc/entered(datum/source, atom/movable/arrived, atom/old_loc, list/atom/old_locs)
	SIGNAL_HANDLER
	drop_stuff()

/datum/component/chasm/proc/exited(datum/source, atom/movable/exited)
	SIGNAL_HANDLER
	UnregisterSignal(exited, list(COMSIG_MOVETYPE_FLAG_DISABLED, COMSIG_LIVING_SET_BUCKLED, COMSIG_MOVABLE_THROW_LANDED))

/datum/component/chasm/proc/initialized_on(datum/source, atom/movable/movable, mapload)
	SIGNAL_HANDLER
	drop_stuff(movable)

/datum/component/chasm/proc/block_teleport()
	return COMPONENT_BLOCK_TELEPORT

/datum/component/chasm/proc/on_chasm_stopped(datum/source)
	SIGNAL_HANDLER
	UnregisterSignal(source, list(COMSIG_ATOM_ENTERED, COMSIG_ATOM_EXITED, COMSIG_ATOM_AFTER_SUCCESSFUL_INITIALIZED_ON))
	for(var/atom/movable/movable as anything in source)
		UnregisterSignal(movable, list(COMSIG_MOVETYPE_FLAG_DISABLED, COMSIG_LIVING_SET_BUCKLED, COMSIG_MOVABLE_THROW_LANDED))

/datum/component/chasm/proc/on_chasm_no_longer_stopped(datum/source)
	SIGNAL_HANDLER
	RegisterSignal(parent, COMSIG_ATOM_ENTERED, PROC_REF(entered))
	RegisterSignal(parent, COMSIG_ATOM_EXITED, PROC_REF(exited))
	RegisterSignal(parent, COMSIG_ATOM_AFTER_SUCCESSFUL_INITIALIZED_ON, PROC_REF(initialized_on))
	drop_stuff()

#define CHASM_NOT_DROPPING 0
#define CHASM_DROPPING 1
///Doesn't drop the movable, but registers a few signals to try again if the conditions change.
#define CHASM_REGISTER_SIGNALS 2

/datum/component/chasm/proc/drop_stuff(atom/movable/dropped_thing)
	if(HAS_TRAIT(parent, TRAIT_CHASM_STOPPED))
		return
	var/atom/atom_parent = parent
	var/to_check = dropped_thing ? list(dropped_thing) : atom_parent.contents
	for (var/atom/movable/thing as anything in to_check)
		var/dropping = droppable(thing)
		switch(dropping)
			if(CHASM_DROPPING)
				INVOKE_ASYNC(src, PROC_REF(drop), thing)
			if(CHASM_REGISTER_SIGNALS)
				RegisterSignals(thing, list(COMSIG_MOVETYPE_FLAG_DISABLED, COMSIG_LIVING_SET_BUCKLED, COMSIG_MOVABLE_THROW_LANDED), PROC_REF(drop_stuff), TRUE)

/datum/component/chasm/proc/droppable(atom/movable/dropped_thing)
	var/datum/weakref/falling_ref = WEAKREF(dropped_thing)
	// avoid an infinite loop, but allow falling a large distance
	if(falling_atoms[falling_ref] && falling_atoms[falling_ref] > 30)
		return CHASM_NOT_DROPPING
	if(is_type_in_typecache(dropped_thing, forbidden_types) || (!isliving(dropped_thing) && !isobj(dropped_thing)))
		return CHASM_NOT_DROPPING
	if(dropped_thing.throwing || (dropped_thing.movement_type & MOVETYPES_NOT_TOUCHING_GROUND))
		return CHASM_REGISTER_SIGNALS

	//Flies right over the chasm
	if(ismob(dropped_thing))
		var/mob/M = dropped_thing
		if(M.buckled) //middle statement to prevent infinite loops just in case!
			var/mob/buckled_to = M.buckled
			if((!ismob(M.buckled) || (buckled_to.buckled != M)) && !droppable(M.buckled))
				return CHASM_REGISTER_SIGNALS
		if(ishuman(dropped_thing))
			var/mob/living/carbon/human/victim = dropped_thing
			for(var/obj/item/wormhole_jaunter/jaunter in victim.get_all_contents())
				var/turf/chasm = get_turf(victim)
				var/fall_into_chasm = jaunter.chasm_react(victim)
				if(!fall_into_chasm)
					chasm.visible_message(span_boldwarning("[victim] falls into the [chasm]!")) //To freak out any bystanders
				return fall_into_chasm ? CHASM_DROPPING : CHASM_NOT_DROPPING
	return CHASM_DROPPING

#undef CHASM_NOT_DROPPING
#undef CHASM_DROPPING
#undef CHASM_REGISTER_SIGNALS

/datum/component/chasm/proc/drop(atom/movable/dropped_thing)
	var/datum/weakref/falling_ref = WEAKREF(dropped_thing)
	//Make sure the item is still there after our sleep
	if(!dropped_thing || !falling_ref?.resolve())
		falling_atoms -= falling_ref
		return
	falling_atoms[falling_ref] = (falling_atoms[falling_ref] || 0) + 1
	var/turf/below_turf = target_turf
	var/atom/parent = src.parent

	if(falling_atoms[falling_ref] > 1)
		return // We're already handling this

	if(below_turf)
		if(HAS_TRAIT(dropped_thing, TRAIT_CHASM_DESTROYED))
			qdel(dropped_thing)
			return

		// send to the turf below
		var/turf/above_turf = get_turf(dropped_thing)
		dropped_thing.visible_message(span_boldwarning("[dropped_thing] falls into [parent]!"), span_userdanger("[fall_message]"))
		below_turf.visible_message(span_boldwarning("[dropped_thing] falls from above!"))
		dropped_thing.forceMove(below_turf)
		below_turf.zImpact(dropped_thing, abs(above_turf.z - below_turf.z), get_turf(dropped_thing), FALL_NO_MESSAGE)
		falling_atoms -= falling_ref
		return

	// send to oblivion
	dropped_thing.visible_message(span_boldwarning("[dropped_thing] falls into [parent]!"), span_userdanger("[oblivion_message]"))
	if (isliving(dropped_thing))
		var/mob/living/falling_mob = dropped_thing
		ADD_TRAIT(falling_mob, TRAIT_NO_TRANSFORM, REF(src))
		falling_mob.Paralyze(20 SECONDS)

	var/oldtransform = dropped_thing.transform
	var/oldcolor = dropped_thing.color
	var/oldalpha = dropped_thing.alpha
	var/oldoffset = dropped_thing.pixel_y

	animate(dropped_thing, transform = matrix() - matrix(), alpha = 0, color = rgb(0, 0, 0), time = 10)
	for(var/i in 1 to 5)
		//Make sure the item is still there after our sleep
		if(!dropped_thing || QDELETED(dropped_thing))
			return
		dropped_thing.pixel_y--
		sleep(0.2 SECONDS)

	//Make sure the item is still there after our sleep
	if(!dropped_thing || QDELETED(dropped_thing))
		return

	if(HAS_TRAIT(dropped_thing, TRAIT_CHASM_DESTROYED))
		qdel(dropped_thing)
		return

	if(!storage)
		storage = (locate() in parent) || new(parent)

	if(storage.contains(dropped_thing))
		return

	dropped_thing.alpha = oldalpha
	dropped_thing.color = oldcolor
	dropped_thing.transform = oldtransform
	dropped_thing.pixel_y = oldoffset

	if(!dropped_thing.forceMove(storage))
		parent.visible_message(span_boldwarning("[parent] spits out [dropped_thing]!"))
		dropped_thing.throw_at(get_edge_target_turf(parent, pick(GLOB.alldirs)), rand(1, 10), rand(1, 10))

	else if(isliving(dropped_thing))
		var/mob/living/fallen_mob = dropped_thing
		REMOVE_TRAIT(fallen_mob, TRAIT_NO_TRANSFORM, REF(src))
		if (fallen_mob.stat != DEAD)
			fallen_mob.investigate_log("has died from falling into a chasm.", INVESTIGATE_DEATHS)
			fallen_mob.death(TRUE)
			fallen_mob.adjustBruteLoss(300)

	falling_atoms -= falling_ref

/**
 * Called when something has left the chasm depths storage.
 * Arguments
 *
 * * source - Chasm object holder.
 * * gone - Item which has just left the chasm contents.
 */
/datum/component/chasm/proc/left_chasm(atom/source, atom/movable/gone)
	SIGNAL_HANDLER
	UnregisterSignal(gone, COMSIG_LIVING_REVIVE)

///Global list needed to let fishermen with a rescue hook fish fallen mobs from any place
GLOBAL_LIST_EMPTY(chasm_fallen_mobs)

/**
 * An abstract object which is basically just a bag that the chasm puts people inside
 */
/obj/effect/abstract/chasm_storage
	name = "chasm depths"
	desc = "The bottom of a hole. You shouldn't be able to interact with this."
	anchored = TRUE
	mouse_opacity = MOUSE_OPACITY_TRANSPARENT

/obj/effect/abstract/chasm_storage/Initialize(mapload)
	. = ..()
	ADD_TRAIT(src, TRAIT_SECLUDED_LOCATION, INNATE_TRAIT)

/obj/effect/abstract/chasm_storage/Entered(atom/movable/arrived)
	. = ..()
	if(isliving(arrived))
		RegisterSignal(arrived, COMSIG_LIVING_REVIVE, PROC_REF(on_revive))
		GLOB.chasm_fallen_mobs += arrived

/obj/effect/abstract/chasm_storage/Exited(atom/movable/gone)
	. = ..()
	if(isliving(gone))
		UnregisterSignal(gone, COMSIG_LIVING_REVIVE)
		GLOB.chasm_fallen_mobs -= gone

#define CHASM_TRAIT "chasm trait"
/**
 * Called if something comes back to life inside the pit. Expected sources are badmins and changelings.
 * Ethereals should take enough damage to be smashed and not revive.
 * Arguments
 * escapee - Lucky guy who just came back to life at the bottom of a hole.
 */
/obj/effect/abstract/chasm_storage/proc/on_revive(mob/living/escapee)
	SIGNAL_HANDLER
	var/turf/turf = get_turf(src)
	if(turf.GetComponent(/datum/component/chasm))
		turf.visible_message(span_boldwarning("After a long climb, [escapee] leaps out of [turf]!"))
	else
		playsound(turf, 'sound/effects/bang.ogg', 50, TRUE)
		turf.visible_message(span_boldwarning("[escapee] busts through [turf], leaping out of the chasm below"))
		turf.ScrapeAway(2, flags = CHANGETURF_INHERIT_AIR)
	ADD_TRAIT(escapee, TRAIT_MOVE_FLYING, CHASM_TRAIT) //Otherwise they instantly fall back in
	escapee.forceMove(turf)
	escapee.throw_at(get_edge_target_turf(turf, pick(GLOB.alldirs)), rand(1, 10), rand(1, 10))
	REMOVE_TRAIT(escapee, TRAIT_MOVE_FLYING, CHASM_TRAIT)
	escapee.Paralyze(20 SECONDS, TRUE)
	UnregisterSignal(escapee, COMSIG_LIVING_REVIVE)

#undef CHASM_TRAIT

/datum/component/chasm/proc/fish(datum/source, obj/item/I, mob/user, params)
	if(!istype(I,/obj/item/fishingrod))
		return
	var/obj/item/fishingrod/rod = I
	if(!HAS_TRAIT(rod, TRAIT_WIELDED))
		to_chat(user, span_warning("You need to wield the rod in both hands before you can fish in the chasm!"))
		return
	if(do_after(user, 3 SECONDS, parent))
		if(!HAS_TRAIT(rod, TRAIT_WIELDED))
			return

		var/list/fishing_contents = list()
		for(var/turf/T in range(3, src.parent))
			if(ischasm(T))
				fishing_contents += T.get_all_contents()

		if(!length(fishing_contents))
			to_chat(user, span_warning("There's nothing here!"))
			return
		var/found = FALSE
		for(var/mob/M in fishing_contents) //since only mobs can fall in here this really isnt needed but on the off chance something naughty happens..
			M.forceMove(get_turf(user))
			UnregisterSignal(M, COMSIG_LIVING_REVIVE)
			found = TRUE
			break //only one mob rather than all
		if(found)
			to_chat(user, span_warning("You reel in something!"))
		else
			to_chat(user, span_warning("There's nothing here!"))
	return