Another attempt using the tick handler ... but I have to shelve this …

…for now since I know of no way to reliably tell which locomotive is moving forwards and visa versa.

control.lua

@@ -2,23 +2,24 @@
 
 local movingstate = {
 	[defines.train_state.on_the_path] = true,
-	[defines.train_state.path_lost] = true,
+	[defines.train_state.path_lost] = false,
 	[defines.train_state.no_schedule] = false,
 	[defines.train_state.no_path] = false,
 	[defines.train_state.arrive_signal] = true,
-	[defines.train_state.wait_signal] = false,
+	[defines.train_state.wait_signal] = true,
 	[defines.train_state.arrive_station] = true,
 	[defines.train_state.wait_station] = false,
 	[defines.train_state.manual_control_stop] = false,
 	[defines.train_state.manual_control] = false,
 }
 
 local function rotate(loco)
-	loco.disconnect_rolling_stock(defines.rail_direction.back)
-	loco.disconnect_rolling_stock(defines.rail_direction.front)
+	local back = loco.disconnect_rolling_stock(defines.rail_direction.back)
+	local front = loco.disconnect_rolling_stock(defines.rail_direction.front)
 	local ret = loco.rotate()
-	loco.connect_rolling_stock(defines.rail_direction.back)
-	loco.connect_rolling_stock(defines.rail_direction.front)
+	-- @todo: Check if this needs to be inversed due to rotate or not?
+	if back then loco.connect_rolling_stock(defines.rail_direction.back) end
+	if front then loco.connect_rolling_stock(defines.rail_direction.front) end
 	return ret
 end
 
@@ -28,9 +29,7 @@ script.on_init(function()
 end)
 
 script.on_event(defines.events.on_train_created, function (event)
-	global.movingstate = global.movingstate or {}
-	global.lastmode = global.lastmode or {}
-	if event.old_train_id_1 then -- We can ignore the second one since the first old id is the one that gets its stuff copied.
+	if event.old_train_id_1 then -- We can ignore old_train_id_2 since the first old id is the one that gets its stuff copied.
 		-- Train changed
 		global.movingstate[event.train.id] = global.movingstate[event.old_train_id_1]
 		global.movingstate[event.old_train_id_1] = nil
@@ -44,6 +43,50 @@ script.on_event(defines.events.on_train_created, function (event)
 	end
 end)
 
+script.on_nth_tick(10, function()
+	local trains = game.surfaces[1].get_trains()
+	for _,train in pairs(trains) do
+		local moving = train.speed ~= 0 --@todo: Maybe see slow moving as stopped as well?
+		if moving ~= global.movingstate[train.id] then
+			global.movingstate[train.id] = moving
+			global.lastmode[train.id] = train.manual_mode
+			if moving then
+				-- figure out which locos are facing the wrong way
+				-- I currently know of no way to reliably tell which locomotives are moving forward and visa versa.
+				game.print("f: " .. train.front_stock.unit_number .. " b: " .. train.back_stock.unit_number)
+				for _,w in pairs(train.locomotives) do
+					for k,v in pairs(w) do
+						game.print(k .. ":" .. v.unit_number .. ": " .. v.orientation)
+					end
+				end
+				for _,v in pairs(train.carriages) do
+					if v.type == "locomotive" then
+						game.print(v.unit_number .. ": " .. v.orientation)
+					end
+				end
+			else
+				for _, loco in pairs(train.locomotives.back_movers) do
+					if global[loco.unit_number] then
+						rotate(loco)
+						global[loco.unit_number] = nil
+						train = loco.train
+					end
+				end
+				for _, loco in pairs(train.locomotives.front_movers) do
+					if global[loco.unit_number] then
+						rotate(loco)
+						global[loco.unit_number] = nil
+						train = loco.train
+					end
+				end
+				train.manual_mode = global.lastmode[train.id]
+			end
+		end
+	end
+end)
+
+-- @todo: I may have to do this stuff in on-tick and just check train speed/direction then
+--[[
 script.on_event(defines.events.on_train_changed_state, function(event)
 	local train = event.train
 	if train.state == defines.train_state.manual_control or train.state == defines.train_state.manual_control_stop then
@@ -52,11 +95,14 @@ script.on_event(defines.events.on_train_changed_state, function(event)
 	if event.old_state == defines.train_state.manual_control or event.old_state == defines.train_state.manual_control_stop then
 		return
 	end
+	game.print("f:" .. train.front_stock.unit_number)
+	game.print("b:" .. train.back_stock.unit_number)
 	if movingstate[train.state] ~= global.movingstate[train.id] then
 		global.movingstate[train.id] = movingstate[train.state]
 		global.lastmode[train.id] = train.manual_mode
 		if movingstate[train.state] then
 			for _, loco in pairs(train.locomotives.back_movers) do
+				game.print("l" .. loco.unit_number .. ":" .. serpent.line(loco.train.riding_state))
 				global[loco.unit_number] = rotate(loco)
 				train = loco.train
 			end
@@ -79,4 +125,5 @@ script.on_event(defines.events.on_train_changed_state, function(event)
 			train.manual_mode = global.lastmode[train.id]
 		end
 	end
-end)
+end)
+--]]