Step 3.14: add reposition dispatch

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

DECISIONS.md

@@ -151,3 +151,10 @@ Implementation decisions not spelled out in `memory-bank/implementation-plan.md`
 - **Arrival** = departure + travel time in game ms ÷ compression, rounded to whole real milliseconds.
 - **`fuelCost` is what the player pays:** 0 for tutorial runs.
 - **`expectedPayout` is the contract payout** before pilot pay; resolution deducts pilot pay.
+
+## Step 3.14
+
+- **A reposition needs a player bay at the destination**, checked against `bayLocationIds`. Bays exist only at discovered locations, so this also guarantees the destination is discovered.
+- **Reposition check order:** ship idle → pilot idle → pilot assigned → not already there → bay at destination → landing → range → fuel credits. There are no skill checks (decision 0.5.24). Tutorial loaners cannot reposition.
+- **Contract and reposition records share one builder**; a reposition has `contract: null` and `expectedPayout: 0`.
+- **"Zero XP" is enforced at resolution** (Step 3.17), because the record has no XP field. That step's tests cover it.

memory-bank/progress.md

@@ -32,7 +32,7 @@
 - [x] **Step 3.11 — Pilot eligibility.** `src/pilot.ts`: `checkPilotEligibility(skills, contract)` returns `ok` or `cargo-skill-too-low` / `long-haul-too-low`.
 - [x] **Step 3.12 — Dispatch validation.** `src/dispatch.ts`: `ShipState`, `PilotState`, `validateDispatch` (first failing reason, plan order), `tripFuelCost` (rounded). One test per failure reason plus tutorial cases.
 - [x] **Step 3.13 — Dispatch record creation.** `createDispatchRecord` in `src/dispatch.ts`: `DispatchRecord` with arrival from travel time, fuel cost, departure distance, a `tutorial` flag and a per-dispatch seed.
-- [ ] Step 3.14 — Reposition dispatch
+- [x] **Step 3.14 — Reposition dispatch.** `validateReposition` and `createRepositionRecord` in `src/dispatch.ts`: empty flight to a player bay, range/landing/fuel only, zero payout. Zero XP is covered by resolution (Step 3.17).
 - [ ] Step 3.15 — In-flight position and progress
 - [ ] Step 3.16 — XP and leveling
 - [ ] Step 3.17 — Dispatch resolution

packages/sim/src/dispatch.ts

@@ -137,13 +137,25 @@ export interface RecordInput {
   worldSeed: Seed;
 }
 
-/** Turns an already-validated dispatch into its record. Same inputs give the same record. */
-export function createDispatchRecord(input: RecordInput, content: SimContent): DispatchRecord {
-  const { id, ship, pilot, contract, tutorial, now, worldSeed } = input;
+function buildRecord(
+  args: {
+    id: string;
+    ship: ShipState;
+    pilot: PilotState;
+    contract: Contract | null;
+    originId: string;
+    destinationId: string;
+    tutorial: boolean;
+    now: RealTime;
+    worldSeed: Seed;
+  },
+  content: SimContent,
+): DispatchRecord {
+  const { id, ship, pilot, contract, tutorial, now, worldSeed } = args;
   const { config } = content;
   const model = findShipModel(ship.modelId, content);
-  const origin = findLocation(contract.originId, content);
-  const destination = findLocation(contract.destinationId, content);
+  const origin = findLocation(args.originId, content);
+  const destination = findLocation(args.destinationId, content);
   const departure = realToGame(now, config);
   const distance = routeDistance(origin, destination, departure);
   const travelGameMs = travelTimeGameHours(model, distance) * MS_PER_HOUR;
@@ -160,7 +172,88 @@ export function createDispatchRecord(input: RecordInput, content: SimContent): D
     arrivalAt: now + Math.round(travelGameMs / config.timeCompression),
     distanceMillionKm: distance,
     fuelCost: tutorial ? 0 : tripFuelCost(model, origin, destination, departure),
-    expectedPayout: contract.payout,
+    expectedPayout: contract?.payout ?? 0,
     seed: deriveSeed(worldSeed, `dispatch:${id}`),
   };
 }
+
+/** Turns an already-validated dispatch into its record. Same inputs give the same record. */
+export function createDispatchRecord(input: RecordInput, content: SimContent): DispatchRecord {
+  const { contract } = input;
+  return buildRecord(
+    { ...input, originId: contract.originId, destinationId: contract.destinationId },
+    content,
+  );
+}
+
+export interface RepositionProposal {
+  ship: ShipState;
+  pilot: PilotState;
+  destinationId: string;
+  /** Locations where the player has a bay (bays exist only at discovered locations). */
+  bayLocationIds: ReadonlySet<string>;
+  credits: number;
+  now: RealTime;
+}
+
+export type RepositionFailure =
+  | "ship-not-idle"
+  | "pilot-not-idle"
+  | "pilot-not-assigned"
+  | "already-there"
+  | "no-bay-at-destination"
+  | "cannot-land"
+  | "out-of-range"
+  | "insufficient-credits";
+
+export type RepositionCheck = { ok: true } | { ok: false; reason: RepositionFailure };
+
+/**
+ * Validates an empty flight to one of the player's bays. Only range and landing
+ * apply; no skills are needed (decision 0.5.24).
+ */
+export function validateReposition(
+  proposal: RepositionProposal,
+  content: SimContent,
+): RepositionCheck {
+  const { ship, pilot, destinationId, bayLocationIds, credits, now } = proposal;
+  const failWith = (reason: RepositionFailure): RepositionCheck => ({ ok: false, reason });
+
+  if (ship.inFlight) return failWith("ship-not-idle");
+  if (pilot.inFlight) return failWith("pilot-not-idle");
+  if (pilot.assignedShipId !== ship.id) return failWith("pilot-not-assigned");
+  if (destinationId === ship.locationId) return failWith("already-there");
+  if (!bayLocationIds.has(destinationId)) return failWith("no-bay-at-destination");
+
+  const model = findShipModel(ship.modelId, content);
+  const origin = findLocation(ship.locationId, content);
+  const destination = findLocation(destinationId, content);
+  const departure = realToGame(now, content.config);
+  const route = checkRoute(model, origin, destination, departure);
+  if (!route.ok) return failWith(route.reason);
+
+  if (credits < tripFuelCost(model, origin, destination, departure)) {
+    return failWith("insufficient-credits");
+  }
+  return { ok: true };
+}
+
+export interface RepositionRecordInput {
+  id: string;
+  ship: ShipState;
+  pilot: PilotState;
+  destinationId: string;
+  now: RealTime;
+  worldSeed: Seed;
+}
+
+/** Record for a validated reposition: no contract, fuel only, zero payout. */
+export function createRepositionRecord(
+  input: RepositionRecordInput,
+  content: SimContent,
+): DispatchRecord {
+  return buildRecord(
+    { ...input, contract: null, originId: input.ship.locationId, tutorial: false },
+    content,
+  );
+}

packages/sim/test/reposition.test.ts

@@ -0,0 +1,70 @@
+import { content } from "@deadhead/content";
+import { describe, expect, it } from "vitest";
+import {
+  createRepositionRecord,
+  validateReposition,
+  type PilotState,
+  type RepositionProposal,
+  type ShipState,
+} from "../src/index";
+
+const now = Date.parse("2100-01-01T00:30:00Z");
+const ship: ShipState = { id: "s1", modelId: "courier", locationId: "earth", inFlight: false };
+const pilot: PilotState = {
+  id: "p1",
+  isAvatar: false,
+  assignedShipId: "s1",
+  inFlight: false,
+  skills: {},
+};
+const valid: RepositionProposal = {
+  ship,
+  pilot,
+  destinationId: "moon",
+  bayLocationIds: new Set(["earth", "moon"]),
+  credits: 10_000,
+  now,
+};
+
+const reason = (proposal: RepositionProposal) => {
+  const result = validateReposition(proposal, content);
+  return result.ok ? "valid" : result.reason;
+};
+
+describe("reposition", () => {
+  it("accepts an empty flight to a bay in range, with no skills needed", () => {
+    expect(reason(valid)).toBe("valid");
+  });
+
+  it("fails validation when the destination has no player bay", () => {
+    expect(reason({ ...valid, bayLocationIds: new Set(["earth"]) })).toBe("no-bay-at-destination");
+  });
+
+  it("still applies range and fuel checks", () => {
+    expect(
+      reason({ ...valid, destinationId: "mars", bayLocationIds: new Set(["earth", "mars"]) }),
+    ).toBe("out-of-range");
+    expect(reason({ ...valid, credits: 0 })).toBe("insufficient-credits");
+  });
+
+  it("rejects flying to where the ship already is, or with a busy or unassigned crew", () => {
+    expect(reason({ ...valid, destinationId: "earth" })).toBe("already-there");
+    expect(reason({ ...valid, ship: { ...ship, inFlight: true } })).toBe("ship-not-idle");
+    expect(reason({ ...valid, pilot: { ...pilot, inFlight: true } })).toBe("pilot-not-idle");
+    expect(reason({ ...valid, pilot: { ...pilot, assignedShipId: null } })).toBe(
+      "pilot-not-assigned",
+    );
+  });
+
+  it("creates a record with no contract, zero payout and a fuel charge", () => {
+    const record = createRepositionRecord(
+      { id: "r1", ship, pilot, destinationId: "moon", now, worldSeed: 7 },
+      content,
+    );
+    expect(record.contract).toBeNull();
+    expect(record.expectedPayout).toBe(0);
+    expect(record.fuelCost).toBeGreaterThan(0);
+    expect([record.originId, record.destinationId]).toEqual(["earth", "moon"]);
+    expect(record.arrivalAt).toBeGreaterThan(record.departureAt);
+  });
+});