solve priorty issue

apps/edr-freight-web/backoffice/src/components/trainScheduling/batchForecast.ts

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+import type {
+  BatchBoardBookingDetail,
+  BatchBoardScheduleDetail,
+} from "@/types/trainScheduling";
+
+/**
+ * Client-side forecast of what the batch engine WOULD select if it ran right now.
+ *
+ * The real selection only happens once the document-review window closes and staff
+ * hit "run batch". Before that, operations can only see the *current* per-booking
+ * state (READY / SELECTED / …). This module simulates the engine's greedy fill so
+ * the board can show the likely winners + waiting list live, during OPEN and
+ * DOC_REVIEW, before anything is committed.
+ *
+ * It mirrors the engine (booking-batch.service): rank government-first, then
+ * priority score desc, then oldest booked; greedily board each booking while it
+ * fits ALL THREE capacity axes at once — wagon slots, max pull weight (tons), and
+ * train length (metres). The first booking that busts any axis, and everyone after
+ * it, drops to the waiting list. Purely a projection; the server stays the source
+ * of truth for the real run.
+ */
+
+export interface ForecastLimits {
+  /** Wagon-slot cap (schedule.maxWagons), or null if unknown. */
+  maxWagons: number | null;
+  /** Locomotive max pull weight in tons, or null. */
+  maxWeightTons: number | null;
+  /** Max train length in metres, or null. */
+  maxLengthMeters: number | null;
+}
+
+/** Which capacity axis stopped a booking from boarding (for the "why not" hint). */
+export type BlockingAxis = "wagons" | "weight" | "length";
+
+export interface ForecastRow {
+  booking: BatchBoardBookingDetail;
+  /** 1-based rank across the whole eligible pool. */
+  rank: number;
+  /** True → boards in the simulated batch; false → simulated waiting list. */
+  selected: boolean;
+  /** Cumulative wagons/weight/length AFTER this booking (only when selected). */
+  cumulativeWagons: number;
+  cumulativeWeightTons: number;
+  cumulativeLengthMeters: number;
+  /** If not selected, the first axis that would have overflowed. */
+  blockedBy: BlockingAxis | null;
+}
+
+export interface ForecastResult {
+  rows: ForecastRow[];
+  selected: ForecastRow[];
+  waiting: ForecastRow[];
+  /** Bookings excluded from the sim entirely (expired / no signed contract). */
+  ineligible: BatchBoardBookingDetail[];
+  limits: ForecastLimits;
+  /** Totals of the simulated batch. */
+  usedWagons: number;
+  usedWeightTons: number;
+  usedLengthMeters: number;
+  /** True once any axis is at/over its cap — train is "full" in the sim. */
+  full: boolean;
+}
+
+/** Engine rank order: government first, then priority desc, then oldest booked. */
+export function rankBookings(
+  bookings: BatchBoardBookingDetail[],
+): BatchBoardBookingDetail[] {
+  const time = (b: BatchBoardBookingDetail) =>
+    b.fullyExecutedAt
+      ? new Date(b.fullyExecutedAt).getTime()
+      : Number.MAX_SAFE_INTEGER;
+  return [...bookings].sort((a, b) => {
+    if (a.isGovernment !== b.isGovernment) return a.isGovernment ? -1 : 1;
+    if (b.priorityScore !== a.priorityScore)
+      return b.priorityScore - a.priorityScore;
+    return time(a) - time(b);
+  });
+}
+
+/**
+ * A booking can compete in the batch only once its contract is signed. Expired
+ * bookings and pending-contract bookings never board, so they're pulled out of the
+ * sim (surfaced separately so they don't vanish from the board).
+ */
+function isEligible(b: BatchBoardBookingDetail): boolean {
+  return b.state !== "EXPIRED" && b.state !== "PENDING_CONTRACT";
+}
+
+const round2 = (n: number) => Math.round(n * 100) / 100;
+
+/** Would adding `add` to `used` exceed `cap`? (cap null ⇒ axis unconstrained.) */
+function overflows(used: number, add: number, cap: number | null): boolean {
+  return cap != null && used + add > cap;
+}
+
+export function simulateBatch(
+  bookings: BatchBoardBookingDetail[],
+  limits: ForecastLimits,
+): ForecastResult {
+  const ranked = rankBookings(bookings);
+  const eligible = ranked.filter(isEligible);
+  const ineligible = ranked.filter((b) => !isEligible(b));
+
+  const rows: ForecastRow[] = [];
+  let wagons = 0;
+  let weight = 0;
+  let length = 0;
+  // Once the train is full we stop boarding, but keep ranking the rest as waiting.
+  let full = false;
+
+  eligible.forEach((booking, i) => {
+    let blockedBy: BlockingAxis | null = null;
+    if (!full) {
+      if (overflows(wagons, booking.wagons, limits.maxWagons))
+        blockedBy = "wagons";
+      else if (overflows(weight, booking.weightTons, limits.maxWeightTons))
+        blockedBy = "weight";
+      else if (overflows(length, booking.lengthMeters, limits.maxLengthMeters))
+        blockedBy = "length";
+    }
+    // Strict fill: the first booking that doesn't fit closes the train, so lower-
+    // priority bookings can't leapfrog it even if they'd individually fit. Matches
+    // the engine's greedy pass.
+    const selected = !full && blockedBy === null;
+    if (selected) {
+      wagons += booking.wagons;
+      weight = round2(weight + booking.weightTons);
+      length = round2(length + booking.lengthMeters);
+    } else {
+      full = true;
+    }
+    rows.push({
+      booking,
+      rank: i + 1,
+      selected,
+      cumulativeWagons: selected ? wagons : 0,
+      cumulativeWeightTons: selected ? weight : 0,
+      cumulativeLengthMeters: selected ? length : 0,
+      blockedBy: selected ? null : (blockedBy ?? firstBindingAxis(limits)),
+    });
+  });
+
+  return {
+    rows,
+    selected: rows.filter((r) => r.selected),
+    waiting: rows.filter((r) => !r.selected),
+    ineligible,
+    limits,
+    usedWagons: wagons,
+    usedWeightTons: weight,
+    usedLengthMeters: length,
+    full,
+  };
+}
+
+/** When the train closed on an earlier booking, name the tightest axis for the hint. */
+function firstBindingAxis(limits: ForecastLimits): BlockingAxis {
+  if (limits.maxWagons != null) return "wagons";
+  if (limits.maxWeightTons != null) return "weight";
+  return "length";
+}
+
+/** Pull the three capacity caps off the board detail response. */
+export function limitsFromDetail(
+  data: BatchBoardScheduleDetail,
+): ForecastLimits {
+  return {
+    maxWagons: data.capacity.maxWagons ?? null,
+    maxWeightTons:
+      data.capacity.maxWeightTons ??
+      data.locomotive?.maxPullWeightTons ??
+      null,
+    maxLengthMeters:
+      data.capacity.maxLengthMeters ??
+      data.locomotive?.maxTrainLengthMeters ??
+      null,
+  };
+}
+
+/**
+ * The forecast is meaningful before the batch is committed — i.e. while bookings
+ * are still being taken or reviewed. Once the engine has run (PAYMENT onward) the
+ * real per-booking state is the truth, so we stop showing the projection.
+ */
+export function forecastIsLive(
+  phase: BatchBoardScheduleDetail["windowPhase"],
+): boolean {
+  return phase === "PRE_WINDOW" || phase === "OPEN" || phase === "DOC_REVIEW";
+}