Add near/vis checks, log on event spawn failure

code/__HELPERS/game.dm

@@ -517,14 +517,16 @@ proc/pollCandidates(Question, be_special_type, antag_age_check = FALSE, poll_tim
   * Returns a list of vents that can be used as a potential spawn if they meet the criteria set by the arguments
   *
   * Will not include parent-less vents to the returned list.
-  * Only returns vents in the main station
   * Arguments:
   * * unwelded_only - Whether the list should only include vents that are unwelded
+  * * exclude_mobs_nearby - Whether to exclude vents that are near living mobs regardless of visibility
+  * * nearby_mobs_range - The range at which to look for living mobs around the vent for the above argument
+  * * exclude_visible_by_mobs - Whether to exclude vents that are visible to any living mob
   * * min_network_size - The minimum length (non-inclusive) of the vent's parent network. A smaller number means vents in small networks (Security, Virology) will appear in the list
   * * station_levels_only - Whether to only consider vents that are in a Z-level with a STATION_LEVEL trait
   * * z_level - The Z-level number to look for vents in. Defaults to all
   */
-/proc/get_valid_vent_spawns(unwelded_only = TRUE, min_network_size = 50, station_levels_only = TRUE, z_level = 0)
+/proc/get_valid_vent_spawns(unwelded_only = TRUE, exclude_mobs_nearby = FALSE, nearby_mobs_range = world.view, exclude_visible_by_mobs = FALSE, min_network_size = 50, station_levels_only = TRUE, z_level = 0)
 	ASSERT(min_network_size >= 0)
 	ASSERT(z_level >= 0)
 
@@ -542,6 +544,24 @@ proc/pollCandidates(Question, be_special_type, antag_age_check = FALSE, poll_tim
 			continue
 		if(unwelded_only && vent.welded)
 			continue
+		if(exclude_mobs_nearby)
+			var/turf/T = get_turf(vent)
+			var/mobs_nearby = FALSE
+			for(var/mob/living/M in orange(nearby_mobs_range, T))
+				if(!M.is_dead())
+					mobs_nearby = TRUE
+					break
+			if(mobs_nearby)
+				continue
+		if(exclude_visible_by_mobs)
+			var/turf/T = get_turf(vent)
+			var/visible_by_mobs = FALSE
+			for(var/mob/living/M in viewers(world.view, T))
+				if(!M.is_dead())
+					visible_by_mobs = TRUE
+					break
+			if(visible_by_mobs)
+				continue
 		if(!vent.parent) // This seems to have been an issue in the past, so this is here until it's definitely fixed
 			log_debug("get_valid_vent_spawns(), vent has no parent: [vent], qdeled: [QDELETED(vent)], loc: [vent.loc]")
 			continue

code/game/gamemodes/miniantags/borer/borer_event.dm

@@ -13,6 +13,10 @@
 /datum/event/borer_infestation/announce()
 	if(successSpawn)
 		GLOB.command_announcement.Announce("Unidentified lifesigns detected coming aboard [station_name()]. Secure any exterior access, including ducting and ventilation.", "Lifesign Alert", new_sound = 'sound/AI/aliens.ogg')
+	else
+		var/text = "Warning: Could not spawn any mobs for event Borer Infestation"
+		message_admins(text)
+		log_adminwarn(text)
 
 /datum/event/borer_infestation/start()
 	var/list/vents = get_valid_vent_spawns()

code/modules/events/alien_infestation.dm

@@ -11,6 +11,10 @@
 /datum/event/alien_infestation/announce()
 	if(successSpawn)
 		GLOB.event_announcement.Announce("Unidentified lifesigns detected coming aboard [station_name()]. Secure any exterior access, including ducting and ventilation.", "Lifesign Alert", new_sound = 'sound/AI/aliens.ogg')
+	else
+		var/text = "Warning: Could not spawn any mobs for event Alien Infestation"
+		message_admins(text)
+		log_adminwarn(text)
 
 /datum/event/alien_infestation/start()
 	var/list/vents = get_valid_vent_spawns()

code/modules/events/blob.dm

@@ -6,6 +6,10 @@
 /datum/event/blob/announce()
 	if(successSpawn)
 		GLOB.event_announcement.Announce("Confirmed outbreak of level 5 biohazard aboard [station_name()]. All personnel must contain the outbreak.", "Biohazard Alert", 'sound/AI/outbreak5.ogg')
+	else
+		var/text = "Warning: Could not spawn any mobs for event Blob"
+		message_admins(text)
+		log_adminwarn(text)
 
 /datum/event/blob/start()
 	processing = FALSE //so it won't fire again in next tick

code/modules/events/spider_infestation.dm

@@ -13,6 +13,10 @@ GLOBAL_VAR_INIT(sent_spiders_to_station, 0)
 /datum/event/spider_infestation/announce()
 	if(successSpawn)
 		GLOB.event_announcement.Announce("Unidentified lifesigns detected coming aboard [station_name()]. Secure any exterior access, including ducting and ventilation.", "Lifesign Alert", new_sound = 'sound/AI/aliens.ogg')
+	else
+		var/text = "Warning: Could not spawn any mobs for event Spider Infestation"
+		message_admins(text)
+		log_adminwarn(text)
 
 /datum/event/spider_infestation/start()
 	var/list/vents = get_valid_vent_spawns()

code/modules/events/spider_terror.dm

@@ -11,9 +11,13 @@
 /datum/event/spider_terror/announce()
 	if(successSpawn)
 		GLOB.command_announcement.Announce("Confirmed outbreak of level 3 biohazard aboard [station_name()]. All personnel must contain the outbreak.", "Biohazard Alert", 'sound/effects/siren-spooky.ogg')
+	else
+		var/text = "Warning: Could not spawn any mobs for event Terror Spiders"
+		message_admins(text)
+		log_adminwarn(text)
 
 /datum/event/spider_terror/start()
-	var/list/vents = get_valid_vent_spawns()
+	var/list/vents = get_valid_vent_spawns(exclude_visible_by_mobs = TRUE)
 	var/spider_type
 	var/infestation_type = pick(1, 2, 3, 4, 5)
 	switch(infestation_type)
@@ -33,18 +37,8 @@
 			spider_type = /mob/living/simple_animal/hostile/poison/terror_spider/princess
 			spawncount = 2
 	while(spawncount && length(vents))
-		var/obj/vent = pick(vents)
-		// If the vent we picked has any living mob nearby, just remove it from the list, loop again, and pick something else.
-		var/turf/T = get_turf(vent)
-		var/hostiles_present = FALSE
-		for(var/mob/living/L in viewers(T))
-			if(L.stat != DEAD)
-				hostiles_present = TRUE
-				break
-
-		vents -= vent
-		if(!hostiles_present)
-			new spider_type(vent.loc)
-			spawncount--
-			successSpawn = TRUE
+		var/obj/vent = pick_n_take(vents)
+		new spider_type(vent.loc)
+		spawncount--
+		successSpawn = TRUE