/**
 * Note that we can stack explosive implants and thus increase the payload's devastation radius. (https://github.com/tgstation/tgstation/pull/50674)
 * That's why the three devastation values for the microbomb implant are balanced around in such a way
 * that buying one macrobomb equals to buying 10 microbombs and stacking them.
 */

#define MICROBOMB_DELAY 0.7 SECONDS

#define MICROBOMB_EXPLOSION_LIGHT 2
#define MICROBOMB_EXPLOSION_HEAVY 0.8
#define MICROBOMB_EXPLOSION_DEVASTATE 0.4

/obj/item/implant/explosive
	name = "microbomb implant"
	desc = "And boom goes the weasel."
	icon_state = "explosive"
	actions_types = list(/datum/action/item_action/explosive_implant) //Explosive implant action is always available.
	///Whether the implant's explosion sequence has been activated or not
	var/active = FALSE
	///The final countdown (delay before we explode)
	var/delay = MICROBOMB_DELAY
	///If the delay is equal or lower to MICROBOMB_DELAY (0.7 sec), the explosion will be instantaneous.
	var/instant_explosion = TRUE
	///Radius of weak devastation explosive impact
	var/explosion_light = MICROBOMB_EXPLOSION_LIGHT
	///Radius of medium devastation explosive impact
	var/explosion_heavy = MICROBOMB_EXPLOSION_HEAVY
	///Radius of heavy devastation explosive impact
	var/explosion_devastate = MICROBOMB_EXPLOSION_DEVASTATE
	///Whether the confirmation UI popup is active or not
	var/popup = FALSE
	///Do we rapidly increase the beeping speed as it gets closer to detonating?
	var/panic_beep_sound = FALSE
	///Do we disable paralysis upon activation
	var/no_paralyze = FALSE
	///Do we override other explosive implants?
	var/master_implant = FALSE
	///Will this implant notify ghosts when activated?
	var/notify_ghosts = TRUE
	///Do we tell people when they activated it?
	var/announce_activation = TRUE

	implant_info = "Activates upon death or encoded signal. Triggers an electrically-detonated microexplosive. \
		Can sync with other microbombs to increase explosive yield, but this makes detonation non-instant."

	implant_lore = "The Robust Corp RX-78 Employee Management Implant is an electrically-detonated microexplosive, \
		designed to motivate employees (for organizations with questionable ethics) and/or prevent recovery of \
		equipment and/or evidence (for non-state actors). \
		The microexplosive arms upon cessation of vital signs or manual activation. \
		Upon arming, attempts to sync with any other detected microexplosives for increased detonation yield; \
		the handshake process between microbombs, however, takes a bit, and only gets longer as more microbombs are detected."

/obj/item/implant/explosive/proc/on_death(datum/source, gibbed)
	SIGNAL_HANDLER

	// There may be other signals that want to handle mob's death
	// and the process of activating destroys the body, so let the other
	// signal handlers at least finish. Also, the "delayed explosion"
	// uses sleeps, which is bad for signal handlers to do.
	INVOKE_ASYNC(src, PROC_REF(activate), "death")

/obj/item/implant/explosive/activate(cause)
	. = ..()
	if(!cause || !imp_in || active)
		return FALSE
	if(cause == "action_button")
		if(popup)
			return FALSE
		popup = TRUE
		var/response = tgui_alert(imp_in, "Are you sure you want to activate your [name]? This will cause you to explode!", "[name] Confirmation", list("Yes", "No"))
		popup = FALSE
		if(response != "Yes")
			return FALSE
	if(cause == "death" && HAS_TRAIT(imp_in, TRAIT_PREVENT_IMPLANT_AUTO_EXPLOSION))
		return FALSE
	if(announce_activation)
		to_chat(imp_in, span_notice("You activate your [name]."))
	active = TRUE
	var/turf/boomturf = get_turf(imp_in)
	message_admins("[ADMIN_LOOKUPFLW(imp_in)] has activated their [name] at [ADMIN_VERBOSEJMP(boomturf)], with cause of [cause].")
	//If the delay is shorter or equal to the default delay, just blow up already jeez
	if(delay <= MICROBOMB_DELAY && instant_explosion)
		explode()
		return
	timed_explosion()

/obj/item/implant/explosive/implant(mob/living/target, mob/user, silent = FALSE, force = FALSE)
	for(var/target_implant in target.implants)
		if(istype(target_implant, /obj/item/implant/explosive)) //we don't use our own type here, because macrobombs inherit this proc and need to be able to upgrade microbombs
			var/obj/item/implant/explosive/other_implant = target_implant
			if(other_implant.master_implant && master_implant) //we cant have two master implants at once
				target.balloon_alert(user, "cannot fit implant!")
				return FALSE
			if(master_implant)
				merge_implants(src, other_implant)
			else
				merge_implants(other_implant, src)
				return TRUE

	. = ..()
	if(.)
		RegisterSignal(target, COMSIG_LIVING_DEATH, PROC_REF(on_death))

/obj/item/implant/explosive/removed(mob/target, silent = FALSE, special = FALSE)
	. = ..()
	if(.)
		UnregisterSignal(target, COMSIG_LIVING_DEATH)

/**
 * Merges two explosive implants together, adding the stats of the latter to the former before qdeling the latter implant.
 * kept_implant = the implant that is kept
 * stat_implant = the implant which has its stats added to kept_implant, before being deleted.
 */
/obj/item/implant/explosive/proc/merge_implants(obj/item/implant/explosive/kept_implant, obj/item/implant/explosive/stat_implant)
	kept_implant.explosion_devastate += stat_implant.explosion_devastate
	kept_implant.explosion_heavy += stat_implant.explosion_heavy
	kept_implant.explosion_light += stat_implant.explosion_light
	kept_implant.delay = min(kept_implant.delay + stat_implant.delay, 30 SECONDS)
	qdel(stat_implant)

/**
 * Explosive activation sequence for implants with a delay longer than 0.7 seconds.
 * Make the implantee beep a few times, keel over and explode. Usually to a devastating effect.
 */
/obj/item/implant/explosive/proc/timed_explosion()
	if (isnull(imp_in))
		visible_message(span_warning("[src] starts beeping ominously!"))
	else
		imp_in.visible_message(span_warning("[imp_in] starts beeping ominously!"))
		if(notify_ghosts)
			notify_ghosts(
				"[imp_in.real_name] is about to detonate their explosive implant!",
				source = src,
				header = "Tick Tick Tick...",
				notify_flags = NOTIFY_CATEGORY_NOFLASH,
				ghost_sound = 'sound/machines/warning-buzzer.ogg',
				notify_volume = 75,
			)

	playsound(loc, 'sound/items/timer.ogg', 30, FALSE)
	if(!panic_beep_sound)
		sleep(delay * 0.25)
	if(imp_in && !imp_in.stat && !no_paralyze)
		imp_in.visible_message(span_warning("[imp_in] doubles over in pain!"))
		imp_in.Paralyze(14 SECONDS)

	if(!panic_beep_sound)
		for(var/index in 1 to 3) // Total of 4 bomb beeps, and we've already beeped once
			//for extra spice
			var/beep_volume = 30 + (5 * index)
			playsound(loc, 'sound/items/timer.ogg', beep_volume, vary = FALSE)
			sleep(delay * 0.25)
		explode()
	else
		addtimer(CALLBACK(src, PROC_REF(explode)), delay)
		while(delay > 1) //so we dont accidentally enter an infinite sleep
			var/beep_volume = 35
			playsound(loc, 'sound/items/timer.ogg', beep_volume, vary = FALSE)
			sleep(delay * 0.2)
			delay -= delay * 0.2
			beep_volume += 5


///When called, just explodes
/obj/item/implant/explosive/proc/explode(atom/override_explode_target = null)
	explosion_devastate = floor(explosion_devastate)
	explosion_heavy = floor(explosion_heavy)
	explosion_light = floor(explosion_light)
	explosion(override_explode_target || src, devastation_range = explosion_devastate, heavy_impact_range = explosion_heavy, light_impact_range = explosion_light, flame_range = explosion_light, flash_range = explosion_light, explosion_cause = src)
	var/mob/living/kill_mob = isliving(override_explode_target) ? override_explode_target : imp_in
	if(!isnull(kill_mob))
		kill_mob.investigate_log("has been gibbed by an explosive implant.", INVESTIGATE_DEATHS)
		kill_mob.gib(DROP_ORGANS|DROP_BODYPARTS)
	qdel(src)

///Macrobomb has the strength and delay of 10 microbombs
/obj/item/implant/explosive/macro
	name = "macrobomb implant"
	desc = "And boom goes the weasel. And everything else nearby."
	icon_state = "explosive"
	delay = 10 * MICROBOMB_DELAY
	explosion_light = 10 * MICROBOMB_EXPLOSION_LIGHT
	explosion_heavy = 10 * MICROBOMB_EXPLOSION_HEAVY
	explosion_devastate = 10 * MICROBOMB_EXPLOSION_DEVASTATE
	implant_lore = "The Robust Corp RX-78/M Employee Management Implant is an electrically-detonated explosive, \
		designed to maximize the prevention of recovery of equipment and/or evidence by virtue of being ten microbombs all connected to one implant. \
		Unfortunately, the handshake sequence between microbombs remains an issue. \
		The microexplosives arm upon cessation of vital signs or manual activation. \
		Upon arming, attempts to sync with any other detected microexplosives for increased detonation yield; \
		the handshake process between microbombs, however, takes a bit, and only gets longer as more microbombs are detected."

///Microbomb which prevents you from going into critical condition but also explodes after a timer when you reach critical condition in the first place.
/obj/item/implant/explosive/deniability
	name = "tactical deniability implant"
	desc = "An enhanced version of the microbomb that directly plugs into the brain. No downsides, promise!"
	delay = 10 SECONDS
	panic_beep_sound = TRUE
	no_paralyze = TRUE
	master_implant = TRUE

	implant_info = parent_type::implant_info + "While implanted, prevents unconsciousness from excessive trauma. \
		Does not prevent death from excessive trauma, nor being stunned. \
		Also delays detonation of other implanted microbombs by ten seconds."

	implant_lore = "The Robust Corp RX-78/T Tactical Deniability Implant is an electrically-detonated microexplosive and \
		paired neural override lattice, designed to prevent recovery of equipment and/or evidence for non-state actors, \
		and prevent the reception of pain signals upon excessive trauma (colloquially, \"entering critical condition\"). \
		The microexplosive arms upon cessation of vital signs or manual activation. \
		Upon arming, attempts to sync with any other detected microexplosives for increased detonation yield; \
		the handshake process between microbombs, however, takes a bit, and only gets longer as more microbombs are detected. \
		The tactical deniability implant introduces a ten-second delay by itself in order to allow operators one last hurrah before death."

/obj/item/implant/explosive/deniability/implant(mob/living/target, mob/user, silent = FALSE, force = FALSE)
	. = ..()
	if(.)
		RegisterSignal(target, COMSIG_LIVING_HEALTH_UPDATE, PROC_REF(check_health))
		target.add_traits(list(TRAIT_NOSOFTCRIT, TRAIT_NOHARDCRIT), IMPLANT_TRAIT)

/obj/item/implant/explosive/deniability/removed(mob/target, silent = FALSE, special = FALSE)
	. = ..()
	if(.)
		UnregisterSignal(target, COMSIG_LIVING_HEALTH_UPDATE)
		target.remove_traits(list(TRAIT_NOSOFTCRIT, TRAIT_NOHARDCRIT), IMPLANT_TRAIT)

/obj/item/implant/explosive/deniability/proc/check_health(mob/living/source)
	SIGNAL_HANDLER

	if(source.health < source.crit_threshold)
		INVOKE_ASYNC(src, PROC_REF(activate), "deniability")

/obj/item/implant/explosive/deathmatch
	name = "deathmatch microbomb implant"
	delay = 0.5 SECONDS
	actions_types = null
	instant_explosion = FALSE
	notify_ghosts = FALSE

/obj/item/implanter/explosive
	name = "implanter (microbomb)"
	imp_type = /obj/item/implant/explosive

/obj/item/implantcase/explosive
	name = "implant case - 'Explosive'"
	desc = "A glass case containing an explosive implant."
	imp_type = /obj/item/implant/explosive

/obj/item/implanter/explosive_macro
	name = "implanter (macrobomb)"
	imp_type = /obj/item/implant/explosive/macro

/obj/item/implanter/tactical_deniability
	name = "implanter (tactical deniability)"
	imp_type = /obj/item/implant/explosive/deniability

/datum/action/item_action/explosive_implant
	check_flags = NONE
	name = "Activate Explosive Implant"

#undef MICROBOMB_DELAY
#undef MICROBOMB_EXPLOSION_LIGHT
#undef MICROBOMB_EXPLOSION_HEAVY
#undef MICROBOMB_EXPLOSION_DEVASTATE