From 2ba6721200765a91f10fe646ad1f1fc732af32c1 Mon Sep 17 00:00:00 2001
From: fireshaper <rory54@gmail.com>
Date: Sat, 3 Oct 2026 15:10:31 -0400
Subject: [PATCH] Step 10B.8: deadhead any idle ship to a discovered location

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 DECISIONS.md                   |   6 ++
 apps/web/src/screens/Fleet.tsx | 122 ++++++++++++++++++++++++---------
 apps/web/test/fleet.test.tsx   |  72 +++++++++++++++----
 memory-bank/progress.md        |   2 +-
 4 files changed, 156 insertions(+), 46 deletions(-)

diff --git a/DECISIONS.md b/DECISIONS.md
index 48c785d..719e0cb 100644
--- a/DECISIONS.md
+++ b/DECISIONS.md
@@ -656,3 +656,9 @@ Implementation decisions not spelled out in `memory-bank/implementation-plan.md`
 - **The selector is a wrapping row of location buttons (`aria-pressed`), not a `<select>`**, because each entry carries an idle-ship badge; a native option cannot hold one. Locations without idle ships show no badge.
 - **The URL is the source of truth for the selection** (`?location=`, replacing `?bay=`), so "Find work here" and the map link work even when Contracts is already open. An undiscovered or unknown id falls back to the default.
 - **A hint shows when no idle ship is at the selected location**, pointing to deadheading from the Fleet. The old "no bays yet" message is gone: every player can see Earth's market.
+
+## Step 10B.8
+
+- **The picker runs `validateReposition` per destination**, so the client and server agree on what is possible. Fuel is `tripFuelCost` and time is `tripRealMs` with zero cargo, the same inputs the sim's reposition record uses.
+- **The action shows on every idle ship, crewed or not.** An uncrewed ship's options are all disabled with "No pilot assigned", which tells the player what to fix rather than hiding the action.
+- **Disabled destinations still show fuel and time**, so the player can see how far off they are.
diff --git a/apps/web/src/screens/Fleet.tsx b/apps/web/src/screens/Fleet.tsx
index 4e775a7..770320a 100644
--- a/apps/web/src/screens/Fleet.tsx
+++ b/apps/web/src/screens/Fleet.tsx
@@ -1,16 +1,24 @@
+import { content } from "@deadhead/content";
 import type { Dispatch, Ship } from "@deadhead/schema";
-import { dispatchProgress } from "@deadhead/sim";
+import {
+  dispatchProgress,
+  realToGame,
+  tripFuelCost,
+  validateReposition,
+  type RepositionFailure,
+} from "@deadhead/sim";
 import { useState } from "react";
 import { Link } from "react-router";
 import { useClock } from "../clock/clock";
 import { Countdown } from "../components/Countdown";
-import { locationName, shipModelName } from "../format";
+import { formatCredits, formatDuration, locationName, shipModelName } from "../format";
+import { location, shipModel, tripRealMs } from "../game";
 import { errorMessage, useGameAction, useLoadedPlayer } from "../state/actions";
 
-/** All ships, their pilots and flights; idle ships at a bay can reposition (Step 9.6). */
+/** All ships, their pilots and flights; any idle ship can deadhead (Steps 9.6, 10B.8). */
 export function Fleet() {
   const state = useLoadedPlayer();
-  const [repositioning, setRepositioning] = useState<Ship | null>(null);
+  const [deadheading, setDeadheading] = useState<Ship | null>(null);
 
   return (
     <section className="space-y-3 p-4">
@@ -31,20 +39,12 @@ export function Fleet() {
               ship={ship}
               dispatch={state.activeDispatches.find((d) => d.id === ship.dispatchId)}
               pilotName={state.pilots.find((p) => p.id === ship.pilotId)?.name ?? null}
-              canReposition={
-                ship.status === "idle" &&
-                ship.pilotId !== null &&
-                state.bays.some((b) => b.locationId === ship.locationId) &&
-                state.bays.length > 1
-              }
-              onReposition={() => setRepositioning(ship)}
+              onDeadhead={() => setDeadheading(ship)}
             />
           ))}
         </ul>
       )}
-      {repositioning && (
-        <RepositionPicker ship={repositioning} onClose={() => setRepositioning(null)} />
-      )}
+      {deadheading && <DeadheadPicker ship={deadheading} onClose={() => setDeadheading(null)} />}
     </section>
   );
 }
@@ -53,8 +53,7 @@ function ShipRow(props: {
   ship: Ship;
   dispatch: Dispatch | undefined;
   pilotName: string | null;
-  canReposition: boolean;
-  onReposition: () => void;
+  onDeadhead: () => void;
 }) {
   const { ship, dispatch, pilotName } = props;
   const now = useClock((s) => s.now);
@@ -98,57 +97,114 @@ function ShipRow(props: {
           Find work here
         </Link>
       )}
-      {props.canReposition && (
+      {ship.status === "idle" && (
         <button
           type="button"
-          onClick={props.onReposition}
+          onClick={props.onDeadhead}
           className="mt-2 rounded-md border border-slate-700 px-3 py-1 text-sm"
         >
-          Reposition
+          Deadhead (fly empty)
         </button>
       )}
     </li>
   );
 }
 
-/** Choose another bay to fly an idle ship to, empty (fuel only). */
-function RepositionPicker({ ship, onClose }: { ship: Ship; onClose: () => void }) {
+/** Why a deadhead destination is unavailable, in plain words. */
+const DEADHEAD_REASONS: Partial<Record<RepositionFailure, string>> = {
+  "cannot-land": "Can't land there",
+  "out-of-range": "Out of range",
+  "insufficient-credits": "Not enough credits for fuel",
+  "pilot-not-idle": "Pilot is flying",
+  "pilot-not-assigned": "No pilot assigned",
+};
+
+/**
+ * Fly an idle ship empty to any other discovered location, paying fuel only
+ * (CR-002). The sim decides which destinations are possible, as the server will.
+ */
+function DeadheadPicker({ ship, onClose }: { ship: Ship; onClose: () => void }) {
   const state = useLoadedPlayer();
+  const now = useClock((s) => s.now);
   const reposition = useGameAction("createDispatch");
-  const destinations = state.bays.filter((b) => b.locationId !== ship.locationId);
+  const model = shipModel(ship.modelId);
+  const origin = ship.locationId!;
+  const pilot = state.pilots.find((p) => p.assignedShipId === ship.id) ?? null;
+  const discovered = state.locations.filter((l) => l.discovered).map((l) => l.id);
+  const discoveredIds = new Set(discovered);
+  const gameNow = realToGame(now, content.config);
+
+  const options = discovered
+    .filter((id) => id !== origin)
+    .map((id) => {
+      const check = validateReposition(
+        {
+          ship: { id: ship.id, modelId: ship.modelId, locationId: origin, inFlight: false },
+          pilot: {
+            id: pilot?.id ?? "",
+            isAvatar: pilot?.isAvatar ?? false,
+            assignedShipId: pilot ? ship.id : null,
+            inFlight: pilot?.status === "in-flight",
+            skills: pilot?.skills ?? {},
+          },
+          destinationId: id,
+          discoveredIds,
+          credits: state.company.credits,
+          now,
+        },
+        content,
+      );
+      return {
+        id,
+        problem: check.ok ? null : (DEADHEAD_REASONS[check.reason] ?? check.reason),
+        fuelCost: tripFuelCost(model, location(origin), location(id), gameNow),
+        tripMs: tripRealMs(model, origin, id, 0, now),
+      };
+    });
 
   return (
     <div className="fixed inset-0 z-20 flex items-end justify-center bg-black/60 sm:items-center">
       <div
         role="dialog"
         aria-modal="true"
-        aria-labelledby="reposition-title"
+        aria-labelledby="deadhead-title"
         className="w-full max-w-md rounded-t-xl border border-slate-700 bg-slate-900 p-4 sm:rounded-xl"
       >
-        <h2 id="reposition-title" className="text-lg font-semibold">
-          Reposition {ship.name}
+        <h2 id="deadhead-title" className="text-lg font-semibold">
+          Deadhead {ship.name}
         </h2>
-        <p className="text-sm text-slate-400">Fly empty to another bay. You pay fuel only.</p>
+        <p className="text-sm text-slate-400">
+          Fly empty from {locationName(origin)} to another place you know. You pay fuel only.
+        </p>
         <ul className="mt-3 space-y-2">
-          {destinations.map((bay) => (
-            <li key={bay.id}>
+          {options.map((option) => (
+            <li key={option.id}>
               <button
                 type="button"
-                disabled={reposition.isPending}
+                aria-label={locationName(option.id)}
+                disabled={option.problem !== null || reposition.isPending}
                 onClick={() =>
                   reposition.mutate(
                     {
                       kind: "reposition",
                       shipId: ship.id,
-                      pilotId: ship.pilotId!,
-                      destinationId: bay.locationId,
+                      pilotId: pilot!.id,
+                      destinationId: option.id,
                     },
                     { onSuccess: onClose },
                   )
                 }
-                className="w-full rounded-lg border border-slate-700 p-3 text-left"
+                className="w-full rounded-lg border border-slate-700 p-3 text-left disabled:opacity-50"
               >
-                {locationName(bay.locationId)}
+                <span className="flex items-baseline justify-between gap-2">
+                  <span className="font-medium">{locationName(option.id)}</span>
+                  <span className="text-sm tabular-nums text-slate-300">
+                    {formatCredits(option.fuelCost)} fuel · {formatDuration(option.tripMs)}
+                  </span>
+                </span>
+                {option.problem && (
+                  <span className="mt-1 block text-sm text-red-400">{option.problem}</span>
+                )}
               </button>
             </li>
           ))}
diff --git a/apps/web/test/fleet.test.tsx b/apps/web/test/fleet.test.tsx
index 8df2196..ff5e7fb 100644
--- a/apps/web/test/fleet.test.tsx
+++ b/apps/web/test/fleet.test.tsx
@@ -1,9 +1,11 @@
+import { content } from "@deadhead/content";
 import type { Dispatch, PlayerState, Ship } from "@deadhead/schema";
-import { dispatchProgress } from "@deadhead/sim";
+import { createRepositionRecord, dispatchProgress } from "@deadhead/sim";
 import { act, screen, waitFor, within } from "@testing-library/react";
 import userEvent from "@testing-library/user-event";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { useClock } from "../src/clock/clock";
+import { formatCredits, formatDuration } from "../src/format";
 import { fakeApi, renderApp, samplePlayerState } from "./render";
 
 const NOW = Date.parse("2100-01-01T00:00:00Z");
@@ -106,33 +108,79 @@ describe("fleet screen", () => {
     expect(idle).toHaveTextContent("Captain");
   });
 
-  it("repositions to a destination chosen from the player's other bays only", async () => {
-    const api = fakeApi({ getPlayerState: () => fleetState() });
+  /** A crewed Courier idle at the Moon with no Moon bay; Mars discovered but out of range. */
+  const atMoon = () =>
+    fleetState({
+      bays: [{ id: "b1", locationId: "earth" }],
+      locations: [
+        { id: "earth", discovered: true },
+        { id: "moon", discovered: true },
+        { id: "mars", discovered: true },
+        { id: "ceres-station", discovered: false },
+        { id: "jupiter-cloud-platform", discovered: false },
+      ],
+      company: { id: "c", name: "D", credits: 10_000, loanBalance: 0 },
+      ships: [
+        ship({ id: "s-idle", name: "Dusty Mule", locationId: "moon", pilotId: "avatar" }),
+        fleetState().ships[1]!,
+      ],
+    });
+
+  it("lets an idle ship with no bay where it is deadhead to a discovered location", async () => {
+    const api = fakeApi({ getPlayerState: atMoon });
     renderApp(api, "/fleet");
     const idle = (await screen.findByText("Dusty Mule")).closest("li")!;
-    await userEvent.click(within(idle).getByRole("button", { name: "Reposition" }));
+    await userEvent.click(within(idle).getByRole("button", { name: "Deadhead (fly empty)" }));
 
-    const picker = screen.getByRole("dialog", { name: "Reposition Dusty Mule" });
+    const picker = screen.getByRole("dialog", { name: "Deadhead Dusty Mule" });
     const options = within(picker)
       .getAllByRole("button")
-      .map((b) => b.textContent)
-      .filter((t) => t !== "Cancel");
-    expect(options).toEqual(["Moon", "Mars"]);
+      .map((b) => b.getAttribute("aria-label"))
+      .filter((label) => label !== null);
+    expect(options).toEqual(["Earth", "Mars"]);
 
-    await userEvent.click(within(picker).getByRole("button", { name: "Moon" }));
+    const mars = within(picker).getByRole("button", { name: "Mars" });
+    expect(mars).toBeDisabled();
+    expect(mars).toHaveTextContent("Out of range");
+
+    const earth = within(picker).getByRole("button", { name: "Earth" });
+    const record = createRepositionRecord(
+      {
+        id: "r",
+        ship: { id: "s-idle", modelId: "courier", locationId: "moon", inFlight: false },
+        pilot: {
+          id: "avatar",
+          isAvatar: true,
+          assignedShipId: "s-idle",
+          inFlight: false,
+          skills: {},
+        },
+        destinationId: "earth",
+        now: NOW,
+        worldSeed: 1,
+      },
+      content,
+    );
+    expect(earth).toBeEnabled();
+    expect(earth).toHaveTextContent(`${formatCredits(record.fuelCost)} fuel`);
+    expect(earth).toHaveTextContent(formatDuration(record.arrivalAt - record.departureAt));
+
+    await userEvent.click(earth);
     await waitFor(() =>
       expect(api.call).toHaveBeenCalledWith("createDispatch", {
         kind: "reposition",
         shipId: "s-idle",
         pilotId: "avatar",
-        destinationId: "moon",
+        destinationId: "earth",
       }),
     );
   });
 
-  it("does not offer reposition to in-flight ships", async () => {
+  it("does not offer a deadhead to in-flight ships", async () => {
     renderApp(fakeApi({ getPlayerState: () => fleetState() }), "/fleet");
     const flying = (await screen.findByText("Slow Ox")).closest("li")!;
-    expect(within(flying).queryByRole("button", { name: "Reposition" })).not.toBeInTheDocument();
+    expect(
+      within(flying).queryByRole("button", { name: "Deadhead (fly empty)" }),
+    ).not.toBeInTheDocument();
   });
 });
diff --git a/memory-bank/progress.md b/memory-bank/progress.md
index 246b49b..a2ab2e8 100644
--- a/memory-bank/progress.md
+++ b/memory-bank/progress.md
@@ -141,6 +141,6 @@ Spec: `memory-bank/change-requests/CR-002-open-markets.md`. New decisions record
 - [x] **Step 10B.5 — Server: no more stranded ships.** Contract and deadhead dispatch never consulted bays after 10B.2/10B.4; this step proves it. `stranded.test.ts` covers the original bug: a Courier delivers Earth→Moon with no Moon bay, takes a Moon→Earth job from the Moon board and lands at Earth; separately it deadheads Moon→Earth. The Step 6.11 test now deadheads to the Moon without a Moon bay.
 - [x] **Step 10B.6 — Server: ship delivery to a bay.** `buyShip` takes `{ modelId, bayId }`; the ship appears idle and uncrewed at that bay's location. Missing `bayId` is `400 validation-error`; a bay the player does not own is `404 not-found` with nothing changed. The Market sends the first bay's id until the 10B.9 picker. Test helpers return `earthBayId`.
 - [x] **Step 10B.7 — Client: Contracts screen by location.** `LocationBoards` (was `BayBoards`) shows a Location button group of every discovered location with an idle-ship count badge, defaulting to the most recently arrived idle ship's location (else Earth); `?location=` selects one (map link and Fleet's new "Find work here"). API: `Ship.lastArrivalAt`. Tests: `location-boards.test.tsx`, `last-arrival.test.ts`.
-- [ ] Step 10B.8 — Client: deadhead action
+- [x] **Step 10B.8 — Client: deadhead action.** Fleet's "Reposition" is now "Deadhead (fly empty)" on every idle ship. The picker lists discovered locations except the ship's own, each with sim fuel cost and trip time; destinations the sim rejects (out of range, can't land, fuel, no pilot) are disabled with the reason. Test: `fleet.test.tsx`.
 - [ ] Step 10B.9 — Client: bays as HQs
 - [ ] Step 10B.10 — Plan amendments and regression