leg-aware capacity and wagon sharing

apps/edr-freight-web/backoffice/src/components/trainScheduling/compositionEditor/InteractiveTrainConsist.tsx

@@ -26,6 +26,8 @@ type DragState = { sourceWagonId: string } | null;
 interface InteractiveTrainConsistProps {
   wagons: Wagon[];
   locomotive: Locomotive | null | undefined;
+  /** Full locomotive set (built trains, ≥2). Takes precedence over `locomotive`. */
+  locomotives?: NonNullable<TrainScheduleDetail["trainSet"]>["locomotives"] | null;
   /** Resolve the customer/company name for a booking id (joined from schedule bookings). */
   getCompany: (bookingId: string | undefined) => string | null;
   selectedWagonId: string | null;
@@ -557,6 +559,7 @@ function WagonCar({
 export const InteractiveTrainConsist = ({
   wagons,
   locomotive,
+  locomotives,
   getCompany,
   selectedWagonId,
   onSelectWagon,
@@ -565,6 +568,7 @@ export const InteractiveTrainConsist = ({
   onMoveLoad,
 }: InteractiveTrainConsistProps) => {
   const [drag, setDrag] = useState<DragState>(null);
+  const locos = locomotives?.length ? locomotives : locomotive ? [locomotive] : [];
   return (
     <Box
       style={{
@@ -589,7 +593,12 @@ export const InteractiveTrainConsist = ({
       ) : null}
 
       <Group gap={0} wrap="nowrap" align="flex-start" style={{ minWidth: "min-content" }}>
-        {locomotive ? <LocomotiveCar locomotive={locomotive} /> : null}
+        {locos.map((loco, i) => (
+          <Group key={loco.code ?? i} gap={0} wrap="nowrap" align="flex-start">
+            {i > 0 ? <Coupler /> : null}
+            <LocomotiveCar locomotive={loco} />
+          </Group>
+        ))}
         {wagons.length === 0 ? (
           <Text size="sm" c="dimmed" pl="md" pt="lg">
             No wagons assigned
@@ -599,7 +608,7 @@ export const InteractiveTrainConsist = ({
             const bookingId = wagon.allocations?.[0]?.bookingId;
             return (
               <Group key={wagon.id} gap={0} wrap="nowrap" align="flex-start">
-                {i > 0 || locomotive ? <Coupler /> : null}
+                {i > 0 || locos.length ? <Coupler /> : null}
                 <WagonCar
                   wagon={wagon}
                   company={getCompany(bookingId)}

apps/edr-freight-web/backoffice/src/components/trainScheduling/compositionEditor/TrainConsistView.tsx

@@ -135,13 +135,27 @@ export const TrainConsistView = ({
   const weightUsed = cargoUsed + tareUsed;
   const lengthUsed = wagons.reduce((sum, w) => sum + (w.lengthMeters ?? 0), 0);
 
+  // Weakest locomotive caps the set — same rule the allocation engine applies.
+  const locos = trainSet?.locomotives?.length
+    ? trainSet.locomotives
+    : trainSet?.locomotive
+      ? [trainSet.locomotive]
+      : [];
+  const weightMax = locos.length
+    ? Math.min(...locos.map((l) => l.maxPullWeightTons))
+    : null;
+  const lengthCaps = locos
+    .map((l) => l.maxTrainLengthMeters)
+    .filter((v): v is number => v != null);
+  const lengthMax = lengthCaps.length ? Math.min(...lengthCaps) : null;
+
   return (
     <Stack gap="md" style={{ width: "100%" }}>
       <TrainStatsBar
         weightUsed={weightUsed}
-        weightMax={trainSet?.locomotive?.maxPullWeightTons ?? null}
+        weightMax={weightMax}
         lengthUsed={lengthUsed}
-        lengthMax={trainSet?.locomotive?.maxTrainLengthMeters ?? null}
+        lengthMax={lengthMax}
         wagonCount={loadedCount}
         wagonMax={maxWagons}
       />
@@ -202,6 +216,7 @@ export const TrainConsistView = ({
           <InteractiveTrainConsist
             wagons={wagons}
             locomotive={trainSet?.locomotive}
+            locomotives={trainSet?.locomotives}
             getCompany={(bookingId) => (bookingId ? companyByBooking.get(bookingId) ?? null : null)}
             selectedWagonId={selectedWagonId}
             onSelectWagon={(w) => setSelectedWagonId((prev) => (prev === w.id ? null : w.id))}