core: more info returned by find_route(), stop if trains appear in the wrong place

core.lua

@@ -343,8 +343,12 @@ F.core.train_enter = function(place, dir, train)
 	train.place = S.places[place]
 	train.dir = dir
 
-	if train.desired_state == nil or
-		(train.desired_state == "routed" and train.desired_place == place and train.desired_dir == dir) then
+	if not is_entry then
+		F.core.expect_train(train)
+	end
+
+	if train.desired == nil or
+		(train.desired.state == "routed" and train.desired.place == place and train.desired.dir == dir) then
 			local dest = F.core.train_find_next_destination(train)
 			if dest == nil then
 				if is_entry then
@@ -353,25 +357,29 @@ F.core.train_enter = function(place, dir, train)
 					table.insert(flags, "rejecting")
 				else
 					table.insert(flags, "parking")
-					train.desired_state = "parked"
-					train.desired_place = place
-					train.desired_dir = dir
+					train.desired = {
+						["state"] = "parked",
+						["place"] = place,
+						["dir"] = dir,
+					}
 					local msg = "Parking train "..F.util.dump(train.id).." at "..F.util.dump(place).."→"..F.util.dump(dir).."."
 					F.util.debug(msg)
 					print(msg)
 				end
 			else
-				train.desired_state = "routed"
-				train.desired_place = dest.place.fullname
-				train.desired_dir = dest.dir
+				train.desired = {
+					["state"] = "routed",
+					["place"] = dest.place.fullname,
+					["dir"] = dest.dir,
+				}
 				table.insert(S.tasks, {["type"] = "route", ["train"] = train, ["dest"] = dest})
 				payload.new_task = "route"
 			end
-	elseif (train.desired_state == "routed" or train.desired_state == "parked") and (train.desired_place ~= place or train.desired_dir ~= dir) then
-		F.core.validate_place_dir_combo(train.desired_place, train.desired_dir)
+	elseif (train.desired.state == "routed" or train.desired.state == "parked") and (train.desired.place ~= place or train.desired.dir ~= dir) then
+		F.core.validate_place_dir_combo(train.desired.place, train.desired.dir)
 		table.insert(S.tasks, {["type"] = "route", ["train"] = train, ["dest"] = {
-			["place"] = S.places[train.desired_place],
-			["dir"] = train.desired_dir,
+			["place"] = S.places[train.desired.place],
+			["dir"] = train.desired.dir,
 		}})
 		payload.new_task = "route"
 	end
@@ -406,6 +414,14 @@ F.core.train_exit = function(place, dir, train)
 		F.util.debug(msg)
 		assert(false, msg)
 	end
+	-- use the original object
+	train = S.trains[train.id]
+	-- save current place and dir
+	train.place = S.places[place]
+	train.dir = dir
+
+	F.core.expect_train(train)
+
 	F.util.debug("Train "..F.util.dump(train.id).." exited via "..F.util.dump(place).."→"..F.util.dump(dir))
 	train.place = nil
 	train.dir = nil
@@ -430,9 +446,11 @@ F.core.reject_train = function(train)
 	if S.caches.interfaces[train.place.fullname] ~= nil and S.caches.interfaces[train.place.fullname][train.dir] ~= nil then
 		local interface = S.caches.interfaces[train.place.fullname][train.dir].interface
 		if interface.exit ~= nil then
-			train.desired_state = "routed"
-			train.desired_place = interface.exit.place.fullname
-			train.desired_dir = interface.exit.dir
+			train.desired = {
+				["state"] = "routed",
+				["place"] = interface.exit.place.fullname,
+				["dir"] = interface.exit.dir,
+			}
 			table.insert(S.tasks, {["type"] = "route", ["train"] = train, ["dest"] = interface.exit})
 			return
 		end
@@ -443,6 +461,24 @@ F.core.reject_train = function(train)
 	assert(false, msg)
 end
 
+F.core.expect_train = function(train, dest)
+	if dest == nil then
+		dest = train.expected
+	end
+	local place
+	if type(dest.place) == "string" then
+		place = train.place.fullname == dest.place
+	else
+		place = train.place.fullname == dest.place.fullname
+	end
+	if not (place and train.dir == dest.dir) then
+		atc_send("BB")
+		local msg = "Train "..F.util.dump(train.id).." wrongly appeared at "..F.util.dump(train.place.name).."→"..F.util.dump(train.dir).."!"
+		F.util.debug(msg)
+		assert(false, msg)
+	end
+end
+
 F.core.train_find_next_destination = function(train)
 	-- TODO: lookup where we expect the train to go next
 	return nil
@@ -554,7 +590,13 @@ print("NEW PHASE - TODO: "..F.util.dump(a))]]--
 							end
 							-- merge with already found options
 							for _,v in ipairs(routes) do
-								result_found.routes[v[1]] = costs[min[2]] + v[2]
+								result_found.routes[v[1]] = {
+									["name"] = v[1],
+									["cost"] = costs[min[2]] + v[2],
+									["individual_cost"] = v[2],
+									["place"] = dest.place,
+									["dir"] = dest.dir,
+								}
 							end
 print("find_route() intermediary result: "..F.util.dump(result_found))
 						else
@@ -592,6 +634,9 @@ print("find_route() intermediary result: "..F.util.dump(result_found))
 end
 
 F.core.do_route = function(dest, train)
+	if train ~= S.trains[train.id] then
+		train = S.trains[train.id]
+	end
 	local flags = {"do_route"}
 	local payload = {["dest"] = dest, ["train"] = train}
 
@@ -611,17 +656,25 @@ F.core.do_route = function(dest, train)
 		end
 		if can_set_route(pos, result.best_route) then
 			set_route(pos, result.best_route)
+			train.expected = {
+				["place"] = result.routes[result.best_route].place.fullname,
+				["dir"] = result.routes[result.best_route].dir,
+			}
 		else
 			local options = {}
-			for k,v in pairs(result.routes) do
-				table.insert(options, {k,v})
+			for name,v in pairs(result.routes) do
+				table.insert(options, v)
 			end
-			table.sort(options, function(a,b) return a[2] < b[2] end)
+			table.sort(options, function(a,b) return a.cost < b.cost end)
 			local success = false
 			for _,v in ipairs(options) do
-				if v[1] ~= result.best_route and can_set_route(pos, v[1]) then
-					set_route(pos, v[1])
+				if v.name ~= result.best_route and can_set_route(pos, v.name) then
+					set_route(pos, v.name)
 					success = true
+					train.expected = {
+						["place"] = v.place.fullname,
+						["dir"] = v.dir,
+					}
 				end
 			end
 			if not success then