Emergency Response Team Housekeeping (shiptest-ss13#2744)

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## About The Pull Request
This PR introduces a system to limit special roles picked in ERTs, which
can be toggled in the settings screen, and sorts out the antagonist
datums into factional files.

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## Why It's Good For The Game

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This could happen to you.

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## Changelog

:cl:
code: ERT antag datums are now sorted into factional files
admin: ERTs can have limited special roles
/:cl:

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---------

Signed-off-by: meem <[email protected]>
Co-authored-by: Mark Suckerberg <[email protected]>

code/datums/ert.dm

@@ -12,7 +12,9 @@
 	var/polldesc
 	/// If TRUE, gives the team members "[role] [random last name]" style names
 	var/random_names = FALSE
-	/// If TRUE, the admin who created the response team will be spawned in the briefing room in their preferred briefing outfit (assuming they're a ghost)
+	/// If TRUE, special slots (that are not the leader) will use a predefined limit
+	var/limit_slots = FALSE
+	/// If TRUE, the admin who created the response team will be spawned in the briefing room (or in the shuttle) in their preferred briefing outfit (assuming they're a ghost)
 	var/spawn_admin = FALSE
 	/// If TRUE, we try and pick one of the most experienced players who volunteered to fill the leader slot
 	var/leader_experience = TRUE
@@ -51,7 +53,7 @@
 
 /datum/ert/marine
 	leader_role = /datum/antagonist/ert/marine
-	roles = list(/datum/antagonist/ert/marine/security, /datum/antagonist/ert/marine/engineer, /datum/antagonist/ert/marine/medic)
+	roles = list(/datum/antagonist/ert/marine/security, /datum/antagonist/ert/marine/engineer = 1, /datum/antagonist/ert/marine/medic = 1)
 	rename_team = "Marine Squad"
 	polldesc = "an 'elite' Nanotrasen Strike Team"
 	opendoors = FALSE
@@ -102,7 +104,7 @@
 	teamsize = 4
 	opendoors = FALSE
 	leader_role = /datum/antagonist/ert/lp/lieutenant
-	roles = list(/datum/antagonist/ert/lp, /datum/antagonist/ert/lp/medic, /datum/antagonist/ert/lp/engineer)
+	roles = list(/datum/antagonist/ert/lp, /datum/antagonist/ert/lp/medic = 1, /datum/antagonist/ert/lp/engineer = 1)
 	rename_team = "Loss Prevention Team"
 	polldesc = "a Nanotrasen loss prevention team"
 
@@ -195,7 +197,7 @@
 
 /datum/ert/syndicate/gorlex
 	leader_role = /datum/antagonist/ert/syndicate/gorlex/leader
-	roles = list(/datum/antagonist/ert/syndicate/gorlex, /datum/antagonist/ert/syndicate/gorlex/pointman, /datum/antagonist/ert/syndicate/gorlex/medic, /datum/antagonist/ert/syndicate/gorlex/sniper)
+	roles = list(/datum/antagonist/ert/syndicate/gorlex, /datum/antagonist/ert/syndicate/gorlex/pointman = 1, /datum/antagonist/ert/syndicate/gorlex/medic = 1, /datum/antagonist/ert/syndicate/gorlex/sniper = 1)
 	mission = "Serve the interests of the 2nd Battlegroup."
 	rename_team = "2nd Battlegroup Squad"
 	polldesc = "a loyalist Gorlex squad"

code/modules/admin/verbs/one_click_antag.dm

@@ -223,6 +223,7 @@
 	.["mainsettings"]["open_armory"]["value"] = newtemplate.opendoors ? "Yes" : "No"
 	.["mainsettings"]["leader_experience"]["value"] = newtemplate.leader_experience ? "Yes" : "No"
 	.["mainsettings"]["random_names"]["value"] = newtemplate.random_names ? "Yes" : "No"
+	.["mainsettings"]["limit_slots"]["value"] = newtemplate.limit_slots ? "Yes" : "No"
 	.["mainsettings"]["spawn_admin"]["value"] = newtemplate.spawn_admin ? "Yes" : "No"
 	.["mainsettings"]["use_custom_shuttle"]["value"] = newtemplate.use_custom_shuttle ? "Yes" : "No"
 	.["mainsettings"]["spawn_at_outpost"]["value"] = newtemplate.spawn_at_outpost ? "Yes" : "No"
@@ -293,6 +294,7 @@
 		"open_armory" = list("desc" = "Open armory doors", "type" = "boolean", "value" = "[(ertemplate.opendoors ? "Yes" : "No")]"),
 		"leader_experience" = list("desc" = "Pick an experienced leader", "type" = "boolean", "value" = "[(ertemplate.leader_experience ? "Yes" : "No")]"),
 		"random_names" = list("desc" = "Randomize names", "type" = "boolean", "value" = "[(ertemplate.random_names ? "Yes" : "No")]"),
+		"limit_slots" = list("desc" = "Limit special roles", "type" = "boolean", "value" = "[(ertemplate.limit_slots ? "Yes" : "No")]"),
 		"spawn_admin" = list("desc" = "Spawn yourself as briefing officer", "type" = "boolean", "value" = "[(ertemplate.spawn_admin ? "Yes" : "No")]"),
 		"use_custom_shuttle" = list("desc" = "Use the ERT's custom shuttle (if it has one)", "type" = "boolean", "value" = "[(ertemplate.use_custom_shuttle ? "Yes" : "No")]"),
 		"spawn_at_outpost" = list("desc" = "Spawn the ERT/Dock the ERT at the Outpost", "type" = "boolean", "value" = "[(ertemplate.spawn_at_outpost ? "Yes" : "No")]"),
@@ -317,10 +319,11 @@
 		ertemplate.teamsize = prefs["teamsize"]["value"]
 		ertemplate.mission = prefs["mission"]["value"]
 		ertemplate.polldesc = prefs["polldesc"]["value"]
-		ertemplate.enforce_human = prefs["enforce_human"]["value"] == "Yes" // these next 7 are effectively toggles
+		ertemplate.enforce_human = prefs["enforce_human"]["value"] == "Yes" // these next 8 are effectively toggles
 		ertemplate.opendoors = prefs["open_armory"]["value"] == "Yes"
 		ertemplate.leader_experience = prefs["leader_experience"]["value"] == "Yes"
 		ertemplate.random_names = prefs["random_names"]["value"] == "Yes"
+		ertemplate.limit_slots = prefs["limit_slots"]["value"] == "Yes"
 		ertemplate.spawn_admin = prefs["spawn_admin"]["value"] == "Yes"
 		ertemplate.use_custom_shuttle = prefs["use_custom_shuttle"]["value"] == "Yes"
 		ertemplate.spawn_at_outpost = prefs["spawn_at_outpost"]["value"] == "Yes"
@@ -459,6 +462,23 @@
 				ert_antag = new ertemplate.leader_role ()
 				earmarked_leader = null
 				leader_spawned = TRUE
+			else if(ertemplate.limit_slots)
+				// pick a role from the role list
+				var/rolepick
+				rolepick = pick(ertemplate.roles)
+				var/count = ertemplate.roles[rolepick]
+				// is it a special role (does it have a number value)? if not, tough luck, spawn
+				if(!isnum(count))
+					ert_antag = rolepick
+					ert_antag = new ert_antag
+				// pick another if the count is 0
+				else if(!count)
+					continue
+				// pick it and decrease the count by one
+				else
+					count =- 1
+					ert_antag = rolepick
+					ert_antag = new ert_antag
 			else
 				ert_antag = ertemplate.roles[WRAP(numagents,1,length(ertemplate.roles) + 1)]
 				ert_antag = new ert_antag