add semaphore for temporary status updates

lua/main.lua

@@ -1112,3 +1112,96 @@ function wesnoth.wml_actions.set_wrath_intensity(cfg)
 	end
 	wesnoth.units.to_map(unit)
 end
+
+-- [unit_status_semaphore]
+--
+-- first call with action=incr will save original value and set status
+-- last call with action=decr (count=0) will restore original value
+--
+-- unit.variables.statuses.foo.original_value, where foo is a status like 'unhealable' - stores original value to restore when all custom actions are done messing with this status
+-- unit.variables.statuses.foo.count  - counts the number of custom actions that currently need this status set
+function wesnoth.wml_actions.unit_status_semaphore(cfg)
+	local debug = cfg.debug or false
+	if debug and not debug then print("shut up luacheck") end
+	local unit_id = cfg.id or wml.error("[unit_status_semaphore]: missing required id=")
+	local status = cfg.status or wml.error("[unit_status_semaphore]: missing required status=")
+	local action = cfg.action or wml.error("[unit_status_semaphore]: missing required action=")
+
+	local unit = wesnoth.units.get(unit_id).__cfg
+	local vars = wml.get_child(unit, "variables")
+	local statuses = wml.get_child(vars, "statuses")
+	local current = {}
+	local had_current = false
+	if statuses ~= nil then
+		current = wml.get_child(statuses, status)
+		if current == nil then
+			current = {}
+		else
+			had_current = true
+		end
+	end
+	if action == "clear" then -- just clear, do not reset to original value
+		if statuses ~= nil then
+			if status == "all" then
+				wml.remove_child(vars, "statuses")
+			else
+				wml.remove_child(statuses, status)
+				if #statuses == 0 then wml.remove_child(vars, "statuses") end
+			end
+		end
+	elseif action == "reset" then  -- clear and reset to original value
+		if statuses == nil then
+			wml.error("[unit_status_semaphore]: reset failed to find any original values")
+		else
+			if status == "all" then
+				for s in wml.child_range(vars, "statuses") do
+					wml.get_child(unit, "status")[s] = current.original_value
+					wml.remove_child(statuses, s)
+				end
+			else
+				if current == nil then
+					wml.error(string.format("[unit_status_semaphore]: reset failed to find original value for %s",status))
+				else
+					wml.get_child(unit, "status")[status] = current.original_value
+					wml.remove_child(statuses, status)
+				end
+			end
+			if #statuses == 0 then wml.remove_child(vars, "statuses") end
+		end
+	elseif action == "get_count" then
+		local variable = cfg.variable or wml.error("[unit_status_semaphore]: get_count requires variable=")
+		wml.variables[variable] = current.count
+	elseif action == "get_original" then
+		local variable = cfg.variable or wml.error("[unit_status_semaphore]: get_original requires variable=")
+                wml.variables[variable] = current.original_value
+	elseif action == "incr" then
+		if current == nil or current.count == nil or current.count == 0 then
+			current.count = 1
+			current.original_value = wml.get_child(unit, "status")[status]
+			wml.get_child(unit, "status")[status] = true
+		else
+			current.count = current.count + 1
+		end
+		if statuses == nil then
+			statuses = {}
+			table.insert(statuses, { status, current } )
+			table.insert(vars, { "statuses", statuses } )
+		else
+			if not had_current then table.insert(statuses, { status, current } ) end
+		end
+	elseif action == "decr" then
+		if statuses == nil or current == nil or current.count == nil or current.count == 0 then
+			wml.error("[unit_status_semaphore]: Cannot decrement nil/0 value")
+		else
+			current.count = current.count - 1
+			if current.count == 0 then
+				wml.get_child(unit, "status")[status] = current.original_value
+				wml.remove_child(statuses, status)
+				if #statuses == 0 then wml.remove_child(vars, "statuses") end
+			end
+		end
+	else
+		wml.error(string.format("[unit_status_semaphore]: Unknown action: %s", action))
+	end
+	wesnoth.units.to_map(unit)
+end