Stops shotgun juggling for real this time (#4402)

# About the pull request

Alright, so this should close up most of the ways around the delays when
running around with multiple shotguns. At this point, we just don't want
people using multiple shotguns.

Double barrel shotguns are likely coming back after this is merged with
a slight nerf.

# Explain why it's good for the game

The CC/damage potential of multiple shotguns spitfiring rounds is too
much. We've already been down this argument before though. This PR just
closes up the gaps.

# Testing Photographs and Procedure
<details>
<summary>Screenshots & Videos</summary>

Put screenshots and videos here with an empty line between the
screenshots and the `<details>` tags.

</details>


# Changelog

:cl: Morrow
fix: Fixed a few ways around fire group delays
/:cl:

code/modules/projectiles/gun.dm

@@ -503,8 +503,7 @@ As sniper rifles have both and weapon mods can change them as well. ..() deals w
 
 	var/delay_left = (last_fired + fire_delay + additional_fire_group_delay) - world.time
 	if(fire_delay_group && delay_left > 0)
-		for(var/group in fire_delay_group)
-			LAZYSET(user.fire_delay_next_fire, group, world.time + delay_left)
+		LAZYSET(user.fire_delay_next_fire, src, world.time + delay_left)
 
 	if(slot in list(WEAR_L_HAND, WEAR_R_HAND))
 		set_gun_user(user)
@@ -523,8 +522,7 @@ As sniper rifles have both and weapon mods can change them as well. ..() deals w
 
 	var/delay_left = (last_fired + fire_delay + additional_fire_group_delay) - world.time
 	if(fire_delay_group && delay_left > 0)
-		for(var/group in fire_delay_group)
-			LAZYSET(user.fire_delay_next_fire, group, world.time + delay_left)
+		LAZYSET(user.fire_delay_next_fire, src, world.time + delay_left)
 
 	unwield(user)
 	set_gun_user(null)
@@ -1111,27 +1109,20 @@ and you're good to go.
 		if(PB_burst_bullets_fired) //Has a burst been carried over from a PB?
 			PB_burst_bullets_fired = 0 //Don't need this anymore. The torch is passed.
 
-	//Dual wielding. Do we have a gun in the other hand, is it loaded, and is it the same category?
+	//Dual wielding. Do we have a gun in the other hand and is it the same category?
+	var/obj/item/weapon/gun/akimbo = user.get_inactive_hand()
 	if(!reflex && !dual_wield && user)
-		var/obj/item/weapon/gun/akimbo = user.get_inactive_hand()
 		if(istype(akimbo) && akimbo.gun_category == gun_category && !(akimbo.flags_gun_features & GUN_WIELDED_FIRING_ONLY))
-			/*Does the offhand weapon have a loaded selected attachable gun or ammo? This doesn't necessarily mean the offhand gun can be *fired*,
-			an unpumped shotgun or opened double-barrel or a revolver with a spun cylinder would pass it, but it's less indiscrimate than it used to be.*/
-			if(akimbo.active_attachable?.current_rounds || akimbo.has_ammunition())
-				dual_wield = TRUE //increases recoil, increases scatter, and reduces accuracy.
-				if(user?.client?.prefs?.toggle_prefs & TOGGLE_ALTERNATING_DUAL_WIELD)
-					user.swap_hand()
-				else
-					akimbo.Fire(target,user,params, 0, TRUE)
+			dual_wield = TRUE //increases recoil, increases scatter, and reduces accuracy.
 
-	var/fire_return = handle_fire(target, user, params, reflex, dual_wield, check_for_attachment_fire)
+	var/fire_return = handle_fire(target, user, params, reflex, dual_wield, check_for_attachment_fire, akimbo)
 	if(!fire_return)
 		return fire_return
 
 	flags_gun_features &= ~GUN_BURST_FIRING // We always want to turn off bursting when we're done, mainly for when we break early mid-burstfire.
 	return AUTOFIRE_CONTINUE
 
-/obj/item/weapon/gun/proc/handle_fire(atom/target, mob/living/user, params, reflex = FALSE, dual_wield, check_for_attachment_fire)
+/obj/item/weapon/gun/proc/handle_fire(atom/target, mob/living/user, params, reflex = FALSE, dual_wield, check_for_attachment_fire, akimbo)
 	var/turf/curloc = get_turf(user) //In case the target or we are expired.
 	var/turf/targloc = get_turf(target)
 
@@ -1210,11 +1201,20 @@ and you're good to go.
 			active_attachable.last_fired = world.time
 		else
 			last_fired = world.time
+			var/delay_left = (last_fired + fire_delay + additional_fire_group_delay) - world.time
+			if(fire_delay_group && delay_left > 0)
+				LAZYSET(user.fire_delay_next_fire, src, world.time + delay_left)
 		SEND_SIGNAL(user, COMSIG_MOB_FIRED_GUN, src)
 		. = TRUE
 
 		shots_fired++
 
+		if(dual_wield)
+			if(user?.client?.prefs?.toggle_prefs & TOGGLE_ALTERNATING_DUAL_WIELD)
+				user.swap_hand()
+			else
+				INVOKE_ASYNC(akimbo, PROC_REF(Fire), target, user, params, 0, TRUE)
+
 	else
 		return TRUE
 
@@ -1240,7 +1240,7 @@ and you're good to go.
 		return TRUE
 
 
-/obj/item/weapon/gun/attack(mob/living/attacked_mob, mob/living/user)
+/obj/item/weapon/gun/attack(mob/living/attacked_mob, mob/living/user, dual_wield)
 	if(active_attachable && (active_attachable.flags_attach_features & ATTACH_MELEE)) //this is expected to do something in melee.
 		active_attachable.last_fired = world.time
 		active_attachable.fire_attachment(attacked_mob, src, user)
@@ -1352,6 +1352,11 @@ and you're good to go.
 		else
 			active_attachable.activate_attachment(src, null, TRUE)//No way.
 
+	//Dual wielding. Do we have a gun in the other hand and is it the same category?
+	var/obj/item/weapon/gun/akimbo = user.get_inactive_hand()
+	if(!dual_wield && user)
+		if(istype(akimbo) && akimbo.gun_category == gun_category && !(akimbo.flags_gun_features & GUN_WIELDED_FIRING_ONLY))
+			dual_wield = TRUE //increases recoil, increases scatter, and reduces accuracy.
 
 	var/bullets_to_fire = 1
 
@@ -1394,7 +1399,7 @@ and you're good to go.
 				SPAN_WARNING("You fire [src] point blank at [attacked_mob]!"), null, null, CHAT_TYPE_WEAPON_USE)
 
 		user.track_shot(initial(name))
-		apply_bullet_effects(projectile_to_fire, user, bullets_fired) //We add any damage effects that we need.
+		apply_bullet_effects(projectile_to_fire, user, bullets_fired, dual_wield) //We add any damage effects that we need.
 
 		SEND_SIGNAL(projectile_to_fire, COMSIG_BULLET_USER_EFFECTS, user)
 		SEND_SIGNAL(user, COMSIG_BULLET_DIRECT_HIT, attacked_mob)
@@ -1436,9 +1441,18 @@ and you're good to go.
 			active_attachable.last_fired = world.time
 		else
 			last_fired = world.time
+			var/delay_left = (last_fired + fire_delay + additional_fire_group_delay) - world.time
+			if(fire_delay_group && delay_left > 0)
+				LAZYSET(user.fire_delay_next_fire, src, world.time + delay_left)
 
 		SEND_SIGNAL(user, COMSIG_MOB_FIRED_GUN, src)
 
+		if(dual_wield)
+			if(user?.client?.prefs?.toggle_prefs & TOGGLE_ALTERNATING_DUAL_WIELD)
+				user.swap_hand()
+			else
+				INVOKE_ASYNC(akimbo, PROC_REF(attack), attacked_mob, user, TRUE)
+
 		if(EXECUTION_CHECK) //Continue execution if on the correct intent. Accounts for change via the earlier do_after
 			user.visible_message(SPAN_DANGER("[user] has executed [attacked_mob] with [src]!"), SPAN_DANGER("You have executed [attacked_mob] with [src]!"), message_flags = CHAT_TYPE_WEAPON_USE)
 			attacked_mob.death()
@@ -1548,9 +1562,20 @@ not all weapons use normal magazines etc. load_into_chamber() itself is designed
 
 		if(fire_delay_group)
 			for(var/group in fire_delay_group)
-				var/group_next_fire = LAZYACCESS(user.fire_delay_next_fire, group)
-				if(!isnull(group_next_fire) && world.time < group_next_fire)
-					return
+				for(var/obj/item/weapon/gun/cycled_gun in user.fire_delay_next_fire)
+					if(cycled_gun == src)
+						continue
+
+					for(var/cycled_gun_group in cycled_gun.fire_delay_group)
+						if(group != cycled_gun_group)
+							continue
+
+						if(user.fire_delay_next_fire[cycled_gun] < world.time)
+							user.fire_delay_next_fire -= cycled_gun
+							continue
+
+						return
+
 	return TRUE
 
 /obj/item/weapon/gun/proc/click_empty(mob/user)

code/modules/projectiles/guns/shotguns.dm

@@ -515,6 +515,7 @@ can cause issues with ammo types getting mixed up during the burst.
 	burst_delay = 0 //So doubleshotty can doubleshot
 	has_open_icon = TRUE
 	civilian_usable_override = TRUE // Come on. It's THE survivor shotgun.
+	additional_fire_group_delay = 1.5 SECONDS
 
 /obj/item/weapon/gun/shotgun/double/set_gun_attachment_offsets()
 	attachable_offset = list("muzzle_x" = 32, "muzzle_y" = 19,"rail_x" = 11, "rail_y" = 20, "under_x" = 15, "under_y" = 14, "stock_x" = 13, "stock_y" = 14)
@@ -761,7 +762,6 @@ can cause issues with ammo types getting mixed up during the burst.
 	reload_sound = 'sound/weapons/handling/gun_mou_reload.ogg'//unique shell insert
 	flags_equip_slot = SLOT_BACK
 	flags_gun_features = GUN_CAN_POINTBLANK|GUN_INTERNAL_MAG
-	additional_fire_group_delay = 1.5 SECONDS
 	current_mag = /obj/item/ammo_magazine/internal/shotgun/double/mou53 //Take care, she comes loaded!
 	attachable_allowed = list(
 		/obj/item/attachable/bayonet,