shrapnel is no longer rng + u can pick what to grab (#6712)

## About The Pull Request

shrapnel is no longer rng + u can pick what to grab. theres also now a
proper proc for removing something surgically.

## Why It's Good For The Game

no reason for rng in ideal circumstances. u already get penalized for
improper tools so like why have more rng. also a needed proc for
slightly less shitcodedness.

## Changelog

:cl:
add: shrapnel / etc removal now goes through a surgically_remove proc.
qol: shrapnel removal is no longer rng
qol: shrapnel removal now lets u pick what item to remove
/:cl:

code/game/objects/items/weapons/implants/implant.dm

@@ -92,6 +92,10 @@
 	else
 		..()
 
+/obj/item/implant/surgically_remove(mob/living/carbon/human/target, obj/item/organ/external/chest/removing_from)
+	. = ..()
+	imp_in = null
+	implanted = 0
 //////////////////////////////
 //	Tracking Implant
 //////////////////////////////

code/modules/mob/living/simple_mob/subtypes/animal/borer/borer.dm

@@ -51,7 +51,6 @@
 	var/roundstart = FALSE						// If true, spawning won't try to pull a ghost.
 	var/used_dominate							// world.time when the dominate power was last used.
 
-
 /mob/living/simple_mob/animal/borer/roundstart
 	roundstart = TRUE
 
@@ -267,3 +266,9 @@
 			continue
 		else if(M.stat == DEAD && M.get_preference_toggle(/datum/game_preference_toggle/observer/ghost_ears))
 			to_chat(M, "[src.true_name] whispers to [host], \"[message]\"")
+
+/mob/living/simple_mob/animal/borer/proc/surgically_remove(mob/living/carbon/human/target, obj/item/organ/external/chest/removing_from)
+	if(controlling)
+		target.release_control()
+	detatch()
+	leave_host()

code/modules/resleeving/mirror.dm

@@ -81,6 +81,10 @@
 				forceMove(MT)
 				MT.imp = src
 
+/obj/item/implant/mirror/surgically_remove(mob/living/carbon/human/target, obj/item/organ/external/chest/removing_from)
+	. = ..()
+	target.mirror = null
+
 /obj/item/implant/mirror/positronic
 	name = "Synthetic Mirror"
 	desc = "An altered form of the common mirror designed to work with synthetic brains."

code/modules/surgery/implant.dm

@@ -158,6 +158,15 @@
 //					IMPLANT/ITEM REMOVAL SURGERY
 //////////////////////////////////////////////////////////////////
 
+/obj/item/proc/surgically_remove(mob/living/carbon/human/target, obj/item/organ/external/chest/removing_from)
+	removing_from.implants -= src
+
+	target.update_hud_sec_implants()
+
+	loc = get_turf(target)
+	add_blood(target)
+	update_icon()
+
 /datum/surgery_step/cavity/implant_removal
 	allowed_tools = list(
 		/obj/item/surgical/hemostat = 100,	\
@@ -190,49 +199,19 @@
 /datum/surgery_step/cavity/implant_removal/end_step(mob/living/user, mob/living/carbon/human/target, target_zone, obj/item/tool)
 	var/obj/item/organ/external/chest/affected = target.get_organ(target_zone)
 
-	var/find_prob = 0
-
 	if (affected.implants.len)
 
-		var/obj/item/obj = pick(affected.implants)
-
-		if(istype(obj,/obj/item/implant))
-			var/obj/item/implant/imp = obj
-			if (imp.islegal())
-				find_prob +=60
-			else
-				find_prob +=40
-		else
-			find_prob +=50
-
-		if (prob(find_prob))
-			user.visible_message("<font color=#4F49AF>[user] takes something out of incision on [target]'s [affected.name] with \the [tool]!</font>", \
-			"<font color=#4F49AF>You take [obj] out of incision on [target]'s [affected.name]s with \the [tool]!</font>" )
-			affected.implants -= obj
-
-			target.update_hud_sec_implants()
-
-			//Handle possessive brain borers.
-			if(istype(obj,/mob/living/simple_mob/animal/borer))
-				var/mob/living/simple_mob/animal/borer/worm = obj
-				if(worm.controlling)
-					target.release_control()
-				worm.detatch()
-				worm.leave_host()
-			else
-				obj.loc = get_turf(target)
-				obj.add_blood(target)
-				obj.update_icon()
-				if(istype(obj,/obj/item/implant))
-					var/obj/item/implant/imp = obj
-					imp.imp_in = null
-					imp.implanted = 0
-					if(istype(obj, /obj/item/implant/mirror))
-						target.mirror = null
-				else if(istype(tool,/obj/item/nif)){var/obj/item/nif/N = tool;N.unimplant(target)}
-		else
-			user.visible_message("<font color=#4F49AF>[user] removes \the [tool] from [target]'s [affected.name].</font>", \
-			"<font color=#4F49AF>There's something inside [target]'s [affected.name], but you just missed it this time.</font>" )
+		var/obj/item/obj = input("What do you want to extract?") in affected.implants
+
+		user.visible_message("<font color=#4F49AF>[user] takes something out of incision on [target]'s [affected.name] with \the [tool]!</font>", \
+		"<font color=#4F49AF>You take [obj] out of incision on [target]'s [affected.name]s with \the [tool]!</font>" )
+
+		obj.surgically_remove(target, affected)
+
+		if(istype(tool, /obj/item/nif))
+			var/obj/item/nif/N = tool
+			N.unimplant(target)
+
 	else
 		user.visible_message("<font color=#4F49AF>[user] could not find anything inside [target]'s [affected.name], and pulls \the [tool] out.</font>", \
 		"<font color=#4F49AF>You could not find anything inside [target]'s [affected.name].</font>" )