ctf_classes: Implement cooldown after class change (#637)

Defaults to a 30s cooldown. Players with ctf_admin priv are exempt from this restriction.

mods/ctf/ctf_classes/api.lua

@@ -78,6 +78,8 @@ function ctf_classes.set(player, new_name)
 	meta:set_string("ctf_classes:class", new_name)
 	ctf_classes.update(player)
 
+	ctf_classes.set_cooldown(player:get_player_name())
+
 	if old_name == nil or old_name ~= new_name then
 		local old = old_name and ctf_classes.__classes[old_name]
 		for i=1, #registered_on_changed do
@@ -150,10 +152,34 @@ function ctf_classes.can_change(player)
 		return true
 	end
 
-	local flag_pos = get_flag_pos(player)
-	if not flag_pos then
-		return false
+	if ctf_classes.get_cooldown(player:get_player_name()) then
+		return false, "You need to wait to change classes again!"
 	end
 
-	return sqdist(player:get_pos(), flag_pos) < 25
+	local flag_pos = get_flag_pos(player)
+	if flag_pos then
+		return sqdist(player:get_pos(), flag_pos) < 25,
+			"Move closer to the flag to change classes!"
+	end
+
+	return false, "Flag does not exist!"
 end
+
+-- Cooldown time to prevent consumables abuse by changing to a class and back
+local COOLDOWN_TIME = 30
+local cooldown = {}
+
+function ctf_classes.get_cooldown(name)
+	return cooldown[name]
+end
+
+function ctf_classes.set_cooldown(name)
+	cooldown[name] = true
+	minetest.after(COOLDOWN_TIME, function()
+		cooldown[name] = nil
+	end)
+end
+
+minetest.register_on_dieplayer(function(player)
+	cooldown[player:get_player_name()] = nil
+end)

mods/ctf/ctf_classes/flags.lua

@@ -24,7 +24,12 @@ local function on_punch(pos, node, player, ...)
 end
 
 local function show(_, _, player)
+	local can_change, reason = ctf_classes.can_change(player)
+	if not can_change then
+		minetest.chat_send_player(player:get_player_name(), reason)
+	else
 		ctf_classes.show_gui(player:get_player_name(), player)
+	end
 end
 
 ctf_flag.on_rightclick = show

mods/ctf/ctf_classes/gui.lua

@@ -1,16 +1,11 @@
 function ctf_classes.show_gui(name, player)
 	player = player or minetest.get_player_by_name(name)
 	assert(player.get_player_name)
-	if not ctf_classes.can_change(player) then
-		minetest.chat_send_player(name, "Move closer to your flag to change classes!")
-		return
-	end
 
 	local fs = {
 		"size[", #ctf_classes.__classes_ordered * 3 , ",3.4]"
 	}
 
-
 	local x = 0
 	local y = 0
 	for _, class in pairs(ctf_classes.__classes_ordered) do
@@ -79,9 +74,10 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 		return false
 	end
 
-	if not ctf_classes.can_change(player) then
-		minetest.chat_send_player(player:get_player_name(),
-				"Move closer to the flag to change classes!")
+	local can_change, reason = ctf_classes.can_change(player)
+	if not can_change then
+		minetest.chat_send_player(player:get_player_name(), reason)
+		return
 	end
 
 	for name in pairs(ctf_classes.__classes) do

mods/ctf/ctf_classes/init.lua

@@ -15,8 +15,9 @@ dofile(minetest.get_modpath("ctf_classes") .. "/classes.lua")
 minetest.register_on_joinplayer(function(player)
 	ctf_classes.update(player)
 
-	if minetest.check_player_privs(player, { interact = true }) then
-		ctf_classes.show_gui(player:get_player_name())
+	if ctf_classes.can_change(player) and
+			minetest.check_player_privs(player, { interact = true }) then
+		ctf_classes.show_gui(player:get_player_name(), player)
 	end
 end)
 
@@ -27,8 +28,9 @@ minetest.register_chatcommand("class", {
 			return false, "You must be online to do this!"
 		end
 
-		if not ctf_classes.can_change(player) then
-			return false, "Move closer to your flag to change classes!"
+		local can_change, reason = ctf_classes.can_change(player)
+		if not can_change then
+			return false, reason
 		end
 
 		local cname = params:trim()