[MIRROR] Changeling Blood Test (#11353)

Co-authored-by: Will <7099514+Willburd@users.noreply.github.com>

code/modules/food/food.dm

@@ -38,6 +38,10 @@
 		src.pixel_x = rand(-6.0, 6) //Randomizes postion
 		src.pixel_y = rand(-6.0, 6)
 
+/obj/item/reagent_containers/food/attackby(obj/item/W, mob/user)
+	. = ..()
+	attempt_changeling_test(W,user)
+
 /obj/item/reagent_containers/food/afterattack(atom/A, mob/user, proximity, params)
 	if((center_of_mass_x || center_of_mass_y) && proximity && params && istype(A, /obj/structure/table))
 		//Places the item on a grid

code/modules/mob/living/carbon/human/species/species.dm

@@ -249,6 +249,7 @@
 	var/rad_levels = NORMAL_RADIATION_RESISTANCE		//For handle_mutations_and_radiation
 	var/rad_removal_mod = 1
 
+	var/ambulant_blood = FALSE								// Force changeling blood effects
 
 	var/rarity_value = 1									// Relative rarity/collector value for this species.
 	var/economic_modifier = 2								// How much money this species makes

code/modules/mob/living/carbon/human/species/station/traits/negative_genes.dm

@@ -197,3 +197,15 @@
 
 	sdisability=SPINE
 	activation_message="Your legs shake..."
+
+/datum/trait/negative/ambulant_blood
+	name = "Ambulant Blood"
+	desc = "Your blood reacts to hostile stimulation such as burning when seperated from your body, as if it was its own creature. You WILL be mistaken for a changeling, you may want to document this in your medical records."
+	var_changes = list("ambulant_blood" = TRUE)
+	cost = -1
+
+	is_genetrait = TRUE
+	hidden = FALSE
+	activity_bounds = DNA_HARDER_BOUNDS // Shouldn't be easy for genetics to find this
+
+	activation_message="You feel like there are spiders in your veins..."

code/modules/organs/blood.dm

@@ -50,6 +50,7 @@ var/const/CE_STABLE_THRESHOLD = 0.5
 			if(isSynthetic())
 				B.data["species"] = "synthetic"
 
+			B.data["changeling"] = (!isnull(mind) && is_changeling(mind)) || species?.ambulant_blood
 			B.color = B.data["blood_colour"]
 			B.name = B.data["blood_name"]
 
@@ -295,6 +296,7 @@ var/const/CE_STABLE_THRESHOLD = 0.5
 		B.data["resistances"] |= GetResistances()
 	B.data["blood_DNA"] = copytext(src.dna.unique_enzymes,1,0)
 	B.data["blood_type"] = copytext(src.dna.b_type,1,0)
+	B.data["changeling"] = (!isnull(mind) && is_changeling(mind)) || species?.ambulant_blood
 
 	// Putting this here due to return shenanigans.
 	if(ishuman(src))

code/modules/reagents/machinery/chem_master.dm

@@ -159,6 +159,7 @@
 						var/datum/reagent/blood/B = R
 						result["blood_type"] = B.data["blood_type"]
 						result["blood_dna"] = B.data["blood_DNA"]
+						result["changeling"] = B.data["changeling"]
 
 					arguments["analysis"] = result
 					tgui_modal_message(src, id, "", null, arguments)

code/modules/reagents/machinery/dispenser/reagent_tank.dm

@@ -543,5 +543,5 @@
 
 /obj/structure/reagent_dispensers/bloodbarrel/Initialize(mapload)
 	. = ..()
-	reagents.add_reagent(REAGENT_ID_BLOOD, 1000, list("donor"=null,"viruses"=null,"blood_DNA"=null,"blood_type"="O-","resistances"=null,"trace_chem"=null))
+	reagents.add_reagent(REAGENT_ID_BLOOD, 1000, list("donor"=null,"viruses"=null,"blood_DNA"=null,"blood_type"="O-","resistances"=null,"trace_chem"=null,"changeling"=FALSE))
 	AddElement(/datum/element/climbable)

code/modules/reagents/reagent_containers/_reagent_containers.dm

@@ -164,3 +164,10 @@
 	EXTRAPOLATOR_ACT_SET(., EXTRAPOLATOR_ACT_PRIORITY_ISOLATE)
 	var/datum/reagent/blood/blood = reagents.get_reagent(REAGENT_ID_BLOOD)
 	EXTRAPOLATOR_ACT_ADD_DISEASES(., blood?.get_diseases())
+
+/obj/item/reagent_containers/proc/attempt_changeling_test(var/obj/item/W,var/mob/user)
+	if(is_open_container() && W.is_hot())
+		var/datum/reagent/blood/B = reagents.get_reagent("blood")
+		if(B)
+			balloon_alert(user, "\The [W] burns the blood in \the [src].")
+			B.changling_blood_test(reagents)

code/modules/reagents/reagent_containers/blood_pack.dm

@@ -36,7 +36,7 @@
 	if(blood_type != null)
 		label_text = "[blood_type]"
 		update_iv_label()
-		reagents.add_reagent(reag_id, 200, list("donor"=null,"viruses"=null,"blood_DNA"=null,"blood_type"=blood_type,"resistances"=null,"trace_chem"=null))
+		reagents.add_reagent(reag_id, 200, list("donor"=null,"viruses"=null,"blood_DNA"=null,"blood_type"=blood_type,"resistances"=null,"trace_chem"=null,"changeling"=FALSE))
 		update_icon()
 
 /obj/item/reagent_containers/blood/on_reagent_change()

code/modules/reagents/reagent_containers/glass.dm

@@ -168,6 +168,7 @@
 	if(W && W.w_class <= w_class && (flags & OPENCONTAINER) && user.a_intent != I_HELP)
 		balloon_alert(user, "[W] dipped into \the [src].")
 		reagents.touch_obj(W, reagents.total_volume)
+	attempt_changeling_test(W,user)
 
 /obj/item/reagent_containers/glass/proc/update_name_label()
 	if(label_text == "")

code/modules/reagents/reagent_containers/virology.dm

@@ -1,7 +1,7 @@
 /obj/item/reagent_containers/glass/beaker/vial/culture
 	name = "virus culture"
 	desc = "A bottle with a virus culture"
-	var/list/data = list("donor" = null, "viruses" = null, "blood_DNA" = null, "blood_type" = null, "resistances" = null, "trace_chems" = null)
+	var/list/data = list("donor" = null, "viruses" = null, "blood_DNA" = null, "blood_type" = null, "resistances" = null, "trace_chems" = null, "changeling"=FALSE)
 	var/list/diseases = list()
 
 /obj/item/reagent_containers/glass/beaker/vial/culture/cold

code/modules/reagents/reagents/core.dm

@@ -1,5 +1,5 @@
 /datum/reagent/blood
-	data = new/list("donor" = null, "viruses" = null, "species" = SPECIES_HUMAN, "blood_DNA" = null, "blood_type" = null, "blood_colour" = "#A10808", "resistances" = null, "trace_chem" = null, REAGENT_ID_ANTIBODIES = list())
+	data = new/list("donor" = null, "viruses" = null, "species" = SPECIES_HUMAN, "blood_DNA" = null, "blood_type" = null, "blood_colour" = "#A10808", "resistances" = null, "trace_chem" = null, REAGENT_ID_ANTIBODIES = list(), "changeling" = FALSE)
 	name = REAGENT_BLOOD
 	id = REAGENT_ID_BLOOD
 	description = "Blood."
@@ -113,6 +113,9 @@
 	if(!data || !newdata)
 		return
 
+	if(newdata["species"] != "synthetic" && (data["changeling"] || newdata["changeling"]))
+		data["changeling"] = TRUE // Spread to other samples as an antag tactic
+
 	if(data["viruses"] || newdata["viruses"])
 		var/list/mix1 = data["viruses"]
 		var/list/mix2 = newdata["viruses"]
@@ -170,12 +173,23 @@
 
 			if(!H.isSynthetic() && data["species"] == "synthetic")	// Remember not to inject oil into your veins, it's bad for you.
 				H.reagents.add_reagent(REAGENT_ID_TOXIN, removed * 1.5)
-
 			return
 
 	M.inject_blood(src, volume * volume_mod)
 	remove_self(volume)
 
+/datum/reagent/blood/proc/changling_blood_test(var/datum/reagents/holder)
+	if(data["changeling"])
+		var/location = get_turf(holder.my_atom)
+		holder.my_atom.visible_message(span_danger("The blood in \the [holder.my_atom] screams and leaps out!"))
+		if(istype(holder.my_atom,/obj/item/reagent_containers/glass))
+			holder.splash(location, holder.total_volume)
+		holder.clear_reagents() // lets be sure it's all gone if it was in something weird instead
+		playsound(holder.my_atom, 'sound/effects/splat.ogg', 50, 1)
+		playsound(holder.my_atom, 'sound/voice/hiss6.ogg', 50, 1)
+		return TRUE
+	return FALSE
+
 /datum/reagent/blood/proc/get_diseases()
 	. = list()
 	if(data && data["viruses"])