import fs from 'node:fs/promises';
import os from 'node:os';
import path from 'node:path';
import { eq } from 'drizzle-orm';
import { afterAll, beforeAll, describe, expect, it, vi } from 'vitest';
import { openGameDb } from '@/lib/db/client';
import * as schema from '@/lib/db/schema';
import { loadAirportsGeoJson } from '@/lib/airports';
import { haversineKm, initialBearingDeg } from '@/lib/geo';
import { weatherFor } from '@/lib/weather';
import { FUEL_DISCOUNT_PER_REP, FUEL_PRICE_PER_L, MAX_FUEL_DISCOUNT, PLANE_TYPES, REPAIR_DURATION_MS, repRate, WEAR_PER_KM } from '@/lib/game/catalog';
import { SPECIALS } from '@/lib/game/specials';
import { MARKET_TARGET_OPEN_PACKAGES, mulberry32 } from '@/lib/game/seed';
import { arrivalTimeFor, fuelAtWeighted, requiredFuelFor, windBurnFactor } from './movement';
import {
  clampTimeScale,
  deliverPackages,
  expirePackages,
  finishRepairs,
  MAX_TICK_ELAPSED_MS,
  MAX_TIME_SCALE,
  MIN_TIME_SCALE,
  reputationGainFor,
  spawnCoveragePackages,
  spawnOpenPackages,
  tickOnce,
} from './engine';

// Engine tests run against throwaway DB files (openGameDb) with fake timers so
// Date.now() — the only wall-clock input to a tick — is fully controlled. The
// public tickNow()/applyTimeControls() wrappers (singleton + lock) are covered
// by app/api/sim/route.test.ts and the e2e suite.

let dir: string;
const T0 = 1_750_000_000_000; // seed moment / fake "now" at DB open

beforeAll(async () => {
  vi.useFakeTimers();
  vi.setSystemTime(T0);
  dir = await fs.mkdtemp(path.join(os.tmpdir(), 'flight-sim-'));
});

afterAll(async () => {
  vi.useRealTimers();
  await fs.rm(dir, { recursive: true, force: true });
});

async function freshDb(name: string) {
  vi.setSystemTime(T0); // each throwaway DB is seeded at the same fake "now"
  return openGameDb(path.join(dir, name));
}

describe('tickOnce — clock advance', () => {
  it('advances the clock by elapsed real ms × timeScale', async () => {
    const inst = await freshDb('scale.db');
    vi.setSystemTime(T0 + 1_000); // one real second later
    await inst.db.update(schema.simState).set({ timeScale: 5 });

    const sim = await tickOnce(inst);

    expect(sim.clockMs).toBe(T0 + 5_000); // 1 s × 5
    expect(sim.lastRealTickMs).toBe(T0 + 1_000);
  });

  it('freezes the clock while paused but keeps tracking real time', async () => {
    const inst = await freshDb('pause.db');
    await inst.db.update(schema.simState).set({ paused: true, timeScale: 60 });

    vi.setSystemTime(T0 + 3_600_000); // an hour of real pause
    let sim = await tickOnce(inst);
    expect(sim.clockMs).toBe(T0); // frozen — no advance at all
    expect(sim.lastRealTickMs).toBe(T0 + 3_600_000);

    // Unpause: resumes from where it stopped, with NO catch-up for the pause.
    await inst.db.update(schema.simState).set({ paused: false });
    vi.setSystemTime(T0 + 3_600_500);
    sim = await tickOnce(inst);
    expect(sim.clockMs).toBe(T0 + 500 * 60); // only the 500 ms since unpausing × 60
  });

  it('clamps long absences: a 1-hour gap advances at most MAX_TICK_ELAPSED_MS × scale', async () => {
    const inst = await freshDb('clamp.db');
    vi.setSystemTime(T0 + 3_600_000); // server sat idle for an hour

    const sim = await tickOnce(inst); // timeScale is the seeded 1

    expect(sim.clockMs).toBe(T0 + MAX_TICK_ELAPSED_MS); // exactly one clamped tick, not a fast-forward
    vi.setSystemTime(T0); // reset for later tests in this file
  });

  it('does not advance when two ticks land in the same millisecond', async () => {
    const inst = await freshDb('same-ms.db');
    vi.setSystemTime(T0 + 1_000);
    const a = await tickOnce(inst);
    const b = await tickOnce(inst); // no real time passed since `a`
    expect(b.clockMs).toBe(a.clockMs);
  });
});

describe('expirePackages', () => {
  it('flips open AND loaded packages past their deadline; terminal statuses never expire', async () => {
    const inst = await freshDb('expiry.db');
    const clock = T0 + 100_000;

    await inst.db.insert(schema.packages).values([
      { id: 'p-open-past', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock - 1, status: 'open', planeId: null, createdSimTime: T0 },
      { id: 'p-open-future', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock + 1, status: 'open', planeId: null, createdSimTime: T0 },
      { id: 'p-loaded-past', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock - 1, status: 'loaded', planeId: 'plane-starter', createdSimTime: T0 },
      { id: 'p-delivered-past', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock - 1, status: 'delivered', planeId: null, createdSimTime: T0 },
      { id: 'p-abandoned-past', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock - 1, status: 'abandoned', planeId: null, createdSimTime: T0 },
      { id: 'p-ignored-past', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: clock - 1, status: 'ignored', planeId: null, createdSimTime: T0 },
    ]);

    const n = await expirePackages(inst, clock);
    expect(n).toBe(2); // the open and the loaded one

    const byId = new Map((await inst.db.select().from(schema.packages)).map((p) => [p.id, p.status]));
    expect(byId.get('p-open-past')).toBe('expired');
    expect(byId.get('p-open-future')).toBe('open'); // deadline not reached yet
    expect(byId.get('p-loaded-past')).toBe('expired'); // v0.12.0: loaded packages expire too (keep their slot)
    expect(byId.get('p-delivered-past')).toBe('delivered'); // terminal — never flips
    expect(byId.get('p-abandoned-past')).toBe('abandoned'); // terminal — never flips
    expect(byId.get('p-ignored-past')).toBe('ignored'); // v0.29.0 (ISS-047 part B) — terminal, never flips
  });

  it('a deadline exactly at the clock counts as expired', async () => {
    const inst = await freshDb('expiry-edge.db');
    await inst.db.insert(schema.packages).values({
      id: 'p-edge', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1,
      deadlineSimTime: T0 + 50_000, status: 'open', planeId: null, createdSimTime: T0,
    });
    expect(await expirePackages(inst, T0 + 50_000)).toBe(1); // <= is inclusive
  });
});

describe('deliverPackages (v0.12.0 arrival delivery)', () => {
  const FROM = 'EDDF';
  const TO = 'LEMD';

  async function setupFlight(name: string) {
    const inst = await freshDb(name);
    const fc = await loadAirportsGeoJson();
    const from = fc.features.find((f) => f.properties.icao === FROM)!.properties;
    const to = fc.features.find((f) => f.properties.icao === TO)!.properties;
    const km = haversineKm(from.lat, from.lon, to.lat, to.lon);
    const type = PLANE_TYPES.atr72;

    // A manual flight (v0.12.0 fly): plane flying with dest_icao set and its fuel
    // frozen at departure — no contract involved anymore.
    await inst.db.update(schema.planes)
      .set({ status: 'flying', destIcao: TO, departureSimTime: T0, fuel: type.maxFuel })
      .where(eq(schema.planes.id, 'plane-starter'));

    return { inst, from, to, km, type };
  }

  it('does nothing before the arrival time', async () => {
    const { inst, km, type } = await setupFlight('deliver-early.db');
    const accountBefore = (await inst.db.select().from(schema.account))[0]!;

    const clock = T0 + travelMs(km, type.speedKmh) - 1; // one ms before arrival
    expect(await deliverPackages(inst, clock)).toBe(0);

    const plane = (await inst.db.select().from(schema.planes))[0];
    const account = (await inst.db.select().from(schema.account))[0]!;
    expect(plane.status).toBe('flying');
    expect(account.cash).toBe(accountBefore.cash); // no award before landing
  });

  it('delivers in-deadline cargo, unbinds expired cargo for free, keeps other-dest cargo bound', async () => {
    const { inst, from, to, km, type } = await setupFlight('deliver-mixed.db');
    const accountBefore = (await inst.db.select().from(schema.account))[0]!;

    // Three packages on the plane: one in-deadline for TO, one expired for TO,
    // one loaded for a DIFFERENT airport (stays bound for a later leg).
    await inst.db.insert(schema.packages).values([
      { id: 'p-pay', originIcao: FROM, destIcao: TO, reward: 5_000, cargoType: 'Passengers', cargoCount: 60, deadlineSimTime: T0 + 24 * 3_600_000, status: 'loaded', planeId: 'plane-starter', createdSimTime: T0 },
      { id: 'p-late', originIcao: FROM, destIcao: TO, reward: 7_000, cargoType: 'Mail', cargoCount: 10, deadlineSimTime: T0 + 3_600_000, status: 'expired', planeId: 'plane-starter', createdSimTime: T0 },
      { id: 'p-elsewhere', originIcao: FROM, destIcao: 'EHAM', reward: 9_000, cargoType: 'Mail', cargoCount: 10, deadlineSimTime: T0 + 24 * 3_600_000, status: 'loaded', planeId: 'plane-starter', createdSimTime: T0 },
    ]);

    const clock = T0 + travelMs(km, type.speedKmh); // exactly at arrival
    expect(await deliverPackages(inst, clock)).toBe(1);

    const plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.status).toBe('available');
    expect(plane.locationIcao).toBe(TO);
    expect(plane.lat).toBe(to.lat);
    expect(plane.lon).toBe(to.lon);
    // Remaining fuel per the v0.16.0 weight-proportional burn model (closed form), wind-adjusted
    // (v0.36.0) by the departure airport's weather vs the route heading.
    const w = weatherFor(FROM);
    const f = windBurnFactor(w.windKt, w.windDirDeg, initialBearingDeg(from.lat, from.lon, to.lat, to.lon));
    expect(plane.fuel).toBeCloseTo(fuelAtWeighted(type.maxFuel, type.burnPerKm * f, type.emptyWeightKg, type.maxFuel, km, 1), 6);
    expect(plane.departureSimTime).toBeNull();
    expect(plane.destIcao).toBeNull(); // flight context cleared on landing

    const byId = new Map((await inst.db.select().from(schema.packages)).map((p) => [p.id, p]));
    expect(byId.get('p-pay')!.status).toBe('delivered');
    expect(byId.get('p-late')!.status).toBe('expired'); // still expired — just unbound…
    expect(byId.get('p-late')!.planeId).toBeNull(); // …slot freed, no reward
    expect(byId.get('p-elsewhere')!.status).toBe('loaded'); // not this airport's cargo…
    expect(byId.get('p-elsewhere')!.planeId).toBe('plane-starter'); // …stays bound for the next leg

    const account = (await inst.db.select().from(schema.account))[0]!;
    expect(account.cash).toBeCloseTo(accountBefore.cash + 5_000, 9); // ONLY p-pay paid out
    expect(account.reputation).toBeCloseTo(
      Math.round((accountBefore.reputation + reputationGainFor(km)) * 100) / 100,
      9,
    );

    // A later tick must not award again — the plane is no longer 'flying'.
    expect(await deliverPackages(inst, clock + 3_600_000)).toBe(0);
    const accountAfter = (await inst.db.select().from(schema.account))[0]!;
    expect(accountAfter.cash).toBe(account.cash);
    expect(accountAfter.reputation).toBe(account.reputation);
  });

  it('delivers every in-deadline package for the arrival airport with per-package rewards', async () => {
    const { inst, km } = await setupFlight('deliver-multi.db');
    const accountBefore = (await inst.db.select().from(schema.account))[0]!;

    await inst.db.insert(schema.packages).values([
      { id: 'p-a', originIcao: FROM, destIcao: TO, reward: 1_000, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: T0 + 24 * 3_600_000, status: 'loaded', planeId: 'plane-starter', createdSimTime: T0 },
      { id: 'p-b', originIcao: FROM, destIcao: TO, reward: 2_500, cargoType: 'Mail', cargoCount: 1, deadlineSimTime: T0 + 24 * 3_600_000, status: 'loaded', planeId: 'plane-starter', createdSimTime: T0 },
    ]);

    const clock = T0 + travelMs(km, PLANE_TYPES.atr72.speedKmh);
    expect(await deliverPackages(inst, clock)).toBe(1);

    const account = (await inst.db.select().from(schema.account))[0]!;
    expect(account.cash).toBeCloseTo(accountBefore.cash + 3_500, 9); // both rewards
    expect(account.reputation).toBeCloseTo(
      Math.round((accountBefore.reputation + reputationGainFor(km) * 2) * 100) / 100,
      9,
    ); // rep per delivered package
  });

  it('adds the registry rep bonus for a special package at delivery (v0.37.0)', async () => {
    const { inst, km } = await setupFlight('deliver-special.db');
    const accountBefore = (await inst.db.select().from(schema.account))[0]!;

    await inst.db.insert(schema.packages).values([
      { id: 'p-prio', originIcao: FROM, destIcao: TO, reward: 5_000, cargoType: 'Mail', cargoCount: 10, special: 'priority', deadlineSimTime: T0 + 24 * 3_600_000, status: 'loaded', planeId: 'plane-starter', createdSimTime: T0 },
    ]);

    const clock = T0 + travelMs(km, PLANE_TYPES.atr72.speedKmh); // exactly at arrival
    expect(await deliverPackages(inst, clock)).toBe(1);

    const account = (await inst.db.select().from(schema.account))[0]!;
    expect(account.cash).toBeCloseTo(accountBefore.cash + 5_000, 9);
    // Distance-based gain + the registry rep bonus — double-rounded like every other award.
    expect(account.reputation).toBeCloseTo(
      Math.round((accountBefore.reputation + reputationGainFor(km) + SPECIALS.priority.repBonus) * 100) / 100,
      9,
    );
  });

  it('leaves planes without route info alone', async () => {
    const inst = await freshDb('deliver-noroute.db');
    // Flying plane whose dest_icao is missing — defensive skip, no crash.
    await inst.db.update(schema.planes)
      .set({ status: 'flying', departureSimTime: T0 });
    expect(await deliverPackages(inst, T0 + 3_600_000)).toBe(0);
  });

  // --- Auto-chain on landing (v0.25.0, ISS-043) ---

  it('auto-chains to the next queued leg when fuel covers it', async () => {
    const { inst, from, to, km, type } = await setupFlight('chain-ok.db'); // full tank EDDF→LEMD
    const fc = await loadAirportsGeoJson();
    const nextP = fc.features.find((f) => f.properties.icao === 'EHAM')!.properties;
    const nextKm = haversineKm(to.lat, to.lon, nextP.lat, nextP.lon);

    // Precondition sanity: a full-tank departure leaves enough for the LEMD→EHAM hop — both legs
    // wind-adjusted (v0.36.0) exactly as deliverPackages computes them.
    const wFrom = weatherFor(FROM);
    const fOut = windBurnFactor(wFrom.windKt, wFrom.windDirDeg, initialBearingDeg(from.lat, from.lon, to.lat, to.lon));
    const landedFuel = fuelAtWeighted(type.maxFuel, type.burnPerKm * fOut, type.emptyWeightKg, type.maxFuel, km, 1);
    const wTo = weatherFor(TO); // the chained leg departs from the arrival airport
    const fNext = windBurnFactor(wTo.windKt, wTo.windDirDeg, initialBearingDeg(to.lat, to.lon, nextP.lat, nextP.lon));
    expect(requiredFuelFor(type.burnPerKm * fNext, type.emptyWeightKg, type.maxFuel, nextKm)).toBeLessThanOrEqual(landedFuel);

    await inst.db.update(schema.planes)
      .set({ queue: JSON.stringify(['EHAM', 'EDDV']) })
      .where(eq(schema.planes.id, 'plane-starter'));

    const clock = T0 + travelMs(km, type.speedKmh); // exactly at arrival
    expect(await deliverPackages(inst, clock)).toBe(1);

    const plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.status).toBe('flying'); // chained — still airborne, no ground stop
    expect(plane.destIcao).toBe('EHAM'); // first queued leg is now the active one
    expect(plane.departureSimTime).toBe(clock); // departed at the arrival instant…
    expect(plane.locationIcao).toBe(TO); // …from the airport just landed at
    expect(plane.lat).toBe(to.lat);
    expect(plane.lon).toBe(to.lon);
    expect(JSON.parse(plane.queue)).toEqual(['EDDV']); // first leg consumed, rest kept in order
  });

  it('auto-refuels a short tank and chains the next queued leg when cash allows (ISS-082)', async () => {
    const { inst, from, to, km, type } = await setupFlight('chain-autorefuel.db');

    // Depart with exactly the wind-adjusted fuel for EDDF→LEMD (v0.36.0) → lands empty; the LEMD→EHAM hop needs a top-up.
    const w = weatherFor(FROM);
    const f = windBurnFactor(w.windKt, w.windDirDeg, initialBearingDeg(from.lat, from.lon, to.lat, to.lon));
    const depFuel = requiredFuelFor(type.burnPerKm * f, type.emptyWeightKg, type.maxFuel, km);
    await inst.db.update(schema.planes)
      .set({ fuel: depFuel, queue: JSON.stringify(['EHAM']) })
      .where(eq(schema.planes.id, 'plane-starter'));

    const accountBefore = (await inst.db.select().from(schema.account))[0]!; // seeded €20k — the top-up is affordable
    const clock = T0 + travelMs(km, type.speedKmh); // exactly at arrival
    expect(await deliverPackages(inst, clock)).toBe(1);

    // Expected top-up from the SAME helpers the engine uses: landed fuel (≈ 0), wind-adjusted
    // requirement for LEMD→EHAM, ×1.5 margin capped at tank capacity.
    const fc = await loadAirportsGeoJson();
    const nextP = fc.features.find((x) => x.properties.icao === 'EHAM')!.properties;
    const landedFuel = fuelAtWeighted(depFuel, type.burnPerKm * f, type.emptyWeightKg, type.maxFuel, km, 1);
    expect(landedFuel).toBeCloseTo(0, 6); // sanity: arrived empty — the top-up path is what ran
    const wTo = weatherFor(TO); // the chained leg departs from the arrival airport
    const fNext = windBurnFactor(wTo.windKt, wTo.windDirDeg, initialBearingDeg(to.lat, to.lon, nextP.lat, nextP.lon));
    const nextRequiredL = requiredFuelFor(
      type.burnPerKm * fNext,
      type.emptyWeightKg,
      type.maxFuel,
      haversineKm(to.lat, to.lon, nextP.lat, nextP.lon),
    );
    const target = Math.min(type.maxFuel, Math.max(landedFuel, nextRequiredL * 1.5));
    const liters = Math.max(0, target - landedFuel);
    expect(liters).toBeGreaterThan(0); // the hop genuinely needs more than what's left
    const rate = repRate(accountBefore.reputation, FUEL_DISCOUNT_PER_REP, MAX_FUEL_DISCOUNT);
    const expectedCost = Math.round(liters * FUEL_PRICE_PER_L * (1 - rate) * 100) / 100;

    const plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.status).toBe('flying'); // chained — the top-up funded it…
    expect(plane.destIcao).toBe('EHAM');
    expect(plane.departureSimTime).toBe(clock);
    expect(JSON.parse(plane.queue)).toEqual([]); // …leg consumed, rest kept in order
    expect(plane.fuel).toBeCloseTo(target, 6); // …departing with the post-top-up level

    const account = (await inst.db.select().from(schema.account))[0]!;
    expect(account.cash).toBeCloseTo(accountBefore.cash - expectedCost, 9); // exactly the rep-discounted cost
  });

  it('grounds with the queue intact when cash cannot cover the auto top-up (ISS-082)', async () => {
    const { inst, from, to, km, type } = await setupFlight('chain-nofuel-poor.db');

    // Same empty-tank landing as above, but the account is broke — the top-up is unaffordable.
    const w = weatherFor(FROM);
    const f = windBurnFactor(w.windKt, w.windDirDeg, initialBearingDeg(from.lat, from.lon, to.lat, to.lon));
    const depFuel = requiredFuelFor(type.burnPerKm * f, type.emptyWeightKg, type.maxFuel, km);
    await inst.db.update(schema.planes)
      .set({ fuel: depFuel, queue: JSON.stringify(['EHAM']) })
      .where(eq(schema.planes.id, 'plane-starter'));
    await inst.db.update(schema.account).set({ cash: 0 });

    const clock = T0 + travelMs(km, type.speedKmh); // exactly at arrival
    expect(await deliverPackages(inst, clock)).toBe(1);

    const plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.status).toBe('available'); // grounded safely…
    expect(plane.destIcao).toBeNull();
    expect(plane.departureSimTime).toBeNull();
    expect(JSON.parse(plane.queue)).toEqual(['EHAM']); // …queue kept for a later dispatch
    const landedFuel = fuelAtWeighted(depFuel, type.burnPerKm * f, type.emptyWeightKg, type.maxFuel, km, 1);
    expect(plane.fuel).toBeCloseTo(landedFuel, 6); // no top-up happened — the tank is untouched
    expect((await inst.db.select().from(schema.account))[0]!.cash).toBe(0);
  });

  it('grounds as before when the queue is empty', async () => {
    const { inst, km } = await setupFlight('chain-empty.db'); // seeded default queue '[]'

    expect(await deliverPackages(inst, T0 + travelMs(km, PLANE_TYPES.atr72.speedKmh))).toBe(1);

    const plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.status).toBe('available'); // unchanged landing behavior…
    expect(JSON.parse(plane.queue)).toEqual([]); // …and the queue stays empty
  });

  it('grounds with the queue intact when the next leg does not fit even a full tank (v0.46.0 backstop)', async () => {
    const { inst, to, km, type } = await setupFlight('chain-nofit.db'); // full tank EDDF→LEMD
    const fc = await loadAirportsGeoJson();
    const farP = fc.features.find((f) => f.properties.icao === 'FGSL')!.properties; // ~4267 km from LEMD — beyond ATR range

    // Precondition sanity: the LEMD→FGSL hop genuinely does not fit a full tank (wind-adjusted,
    // exactly as deliverPackages computes it) — so no top-up could ever make it flyable.
    const wTo = weatherFor(TO);
    const fNext = windBurnFactor(wTo.windKt, wTo.windDirDeg, initialBearingDeg(to.lat, to.lon, farP.lat, farP.lon));
    const nextRequiredL = requiredFuelFor(
      type.burnPerKm * fNext,
      type.emptyWeightKg,
      type.maxFuel,
      haversineKm(to.lat, to.lon, farP.lat, farP.lon),
    );
    expect(nextRequiredL).toBeGreaterThan(type.maxFuel);

    await inst.db.update(schema.planes)
      .set({ queue: JSON.stringify(['FGSL']) })
      .where(eq(schema.planes.id, 'plane-starter'));

    const clock = T0 + travelMs(km, type.speedKmh); // exactly at arrival
    expect(await deliverPackages(inst, clock)).toBe(1);

    const plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.status).toBe('available'); // grounded — the unflyable leg was NOT chained…
    expect(plane.destIcao).toBeNull();
    expect(JSON.parse(plane.queue)).toEqual(['FGSL']); // …queue kept intact for a later dispatch
  });

  it('drops a queued leg to the arrival airport without flying — defensive guard for legacy rows (v0.46.0)', async () => {
    const { inst, km, type } = await setupFlight('chain-selfleg.db'); // full tank EDDF→LEMD
    // Legacy state: queue[0] is the airport we are about to land at — pre-v0.46.0 this chained a
    // zero-distance self-hop (the phantom hop). The guard drops it and grounds instead.
    await inst.db.update(schema.planes)
      .set({ queue: JSON.stringify(['LEMD', 'EHAM']) })
      .where(eq(schema.planes.id, 'plane-starter'));

    expect(await deliverPackages(inst, T0 + travelMs(km, type.speedKmh))).toBe(1);

    const plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.status).toBe('available'); // grounded — the self-leg was dropped, not flown…
    expect(plane.destIcao).toBeNull();
    expect(JSON.parse(plane.queue)).toEqual(['EHAM']); // …the rest of the queue kept for a later dispatch
  });
});

describe('wear on landed legs (v0.39.0, ISS-069)', () => {
  const FROM = 'EDDF';
  const TO = 'LEMD';

  // Starter flying EDDF→LEMD with a full tank — same shape as the deliverPackages setup above.
  async function setupFlight(name: string) {
    const inst = await freshDb(name);
    const fc = await loadAirportsGeoJson();
    const from = fc.features.find((f) => f.properties.icao === FROM)!.properties;
    const to = fc.features.find((f) => f.properties.icao === TO)!.properties;
    const km = haversineKm(from.lat, from.lon, to.lat, to.lon);
    const type = PLANE_TYPES.atr72;

    await inst.db.update(schema.planes)
      .set({ status: 'flying', destIcao: TO, departureSimTime: T0, fuel: type.maxFuel })
      .where(eq(schema.planes.id, 'plane-starter'));

    return { inst, from, to, km, type };
  }

  it('drops health by exactly WEAR_PER_KM × km on a landed leg', async () => {
    const { inst, km } = await setupFlight('wear-leg.db');

    expect(await deliverPackages(inst, T0 + travelMs(km, PLANE_TYPES.atr72.speedKmh))).toBe(1);

    const plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.health).toBeCloseTo(100 - WEAR_PER_KM * km, 9); // one mid-range hop ≈ −0.98 health (v0.43.0, ISS-085)
  });

  it('clamps at 0 across multiple legs', async () => {
    const { inst, from, to, km, type } = await setupFlight('wear-clamp.db');
    // Start below one leg's wear so the first landing clamps…
    await inst.db.update(schema.planes)
      .set({ health: WEAR_PER_KM * km / 2 })
      .where(eq(schema.planes.id, 'plane-starter'));

    expect(await deliverPackages(inst, T0 + travelMs(km, type.speedKmh))).toBe(1);
    let plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.health).toBe(0); // clamped — never negative…

    // …and a second leg keeps it pinned at 0.
    const eham = (await loadAirportsGeoJson()).features.find((f) => f.properties.icao === 'EHAM')!.properties;
    const nextKm = haversineKm(to.lat, to.lon, eham.lat, eham.lon);
    await inst.db.update(schema.planes)
      .set({ status: 'flying', destIcao: 'EHAM', departureSimTime: T0 + travelMs(km, type.speedKmh), fuel: type.maxFuel })
      .where(eq(schema.planes.id, 'plane-starter'));

    expect(await deliverPackages(inst, T0 + travelMs(km, type.speedKmh) + travelMs(nextKm, type.speedKmh))).toBe(1);
    plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.health).toBe(0); // still clamped after the second leg
  });

  it('a plane that lands broken does NOT chain — grounded with the queue intact (v0.45.0, ISS-089)', async () => {
    const { inst, km, type } = await setupFlight('wear-broken-nochain.db'); // full tank EDDF→LEMD
    // Start below one leg's wear so this landing clamps health to 0 — a full-tank departure leaves
    // enough fuel for the queued LEMD→EHAM hop (same precondition as chain-ok), so ONLY the broken
    // guard can explain why it doesn't chain.
    await inst.db.update(schema.planes)
      .set({ health: WEAR_PER_KM * km / 2, queue: JSON.stringify(['EHAM']) })
      .where(eq(schema.planes.id, 'plane-starter'));

    expect(await deliverPackages(inst, T0 + travelMs(km, type.speedKmh))).toBe(1);

    const plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.health).toBe(0); // broken by this landing's wear…
    expect(plane.status).toBe('available'); // …grounded — the chain was skipped despite enough fuel…
    expect(plane.destIcao).toBeNull();
    expect(JSON.parse(plane.queue)).toEqual(['EHAM']); // …queue kept intact for a later dispatch
  });
});

describe('finishRepairs (v0.39.0, ISS-069)', () => {
  it('flips repairing planes back to available once the gate passes, clearing the gate', async () => {
    const inst = await freshDb('repair-finish.db');
    await inst.db.update(schema.planes)
      .set({ status: 'repairing', repairUntilSimTime: T0 + 5_000 })
      .where(eq(schema.planes.id, 'plane-starter'));

    expect(await finishRepairs(inst, T0 + 4_999)).toBe(0); // gate not reached yet…
    let plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.status).toBe('repairing');

    expect(await finishRepairs(inst, T0 + 5_000)).toBe(1); // <= is inclusive at the clock
    plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.status).toBe('available');
    expect(plane.repairUntilSimTime ?? null).toBeNull(); // gate cleared
  });

  it('runs inside tickOnce even when nothing landed: a past gate flips the plane back', async () => {
    const inst = await freshDb('repair-tick.db');
    await inst.db.update(schema.planes)
      .set({ status: 'repairing', repairUntilSimTime: T0 + 1_500 })
      .where(eq(schema.planes.id, 'plane-starter'));

    vi.setSystemTime(T0 + 2_000); // one clamped tick at scale 1 → clock T0+2000 ≥ gate; nothing is flying
    await tickOnce(inst);

    const plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.status).toBe('available');
    expect(plane.repairUntilSimTime ?? null).toBeNull();
  });

  it('heals gradually along round(f × 100) while repairing; lands exactly on 100 + available at the gate (v0.45.0, ISS-089)', async () => {
    const inst = await freshDb('repair-curve.db');
    // Repair started at T0 with health 42 — the gate is what repairPlane stores: start + duration.
    const gate = T0 + REPAIR_DURATION_MS;
    await inst.db.update(schema.planes)
      .set({ status: 'repairing', health: 42, repairUntilSimTime: gate })
      .where(eq(schema.planes.id, 'plane-starter'));

    // Mid-repair (f = 0.5): the curve (round(50)) is above the start value → health climbs to 50…
    expect(await finishRepairs(inst, T0 + REPAIR_DURATION_MS / 2)).toBe(0); // …but no flip before the gate…
    let plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.status).toBe('repairing');
    expect(plane.health).toBe(50);

    // …and it never DROPS below the start value: at f = 0.2 the curve (20) is below 42, so health stays put.
    const inst2 = await freshDb('repair-curve-floor.db');
    await inst2.db.update(schema.planes)
      .set({ status: 'repairing', health: 42, repairUntilSimTime: gate })
      .where(eq(schema.planes.id, 'plane-starter'));
    expect(await finishRepairs(inst2, T0 + REPAIR_DURATION_MS / 5)).toBe(0);
    const plane2 = (await inst2.db.select().from(schema.planes))[0];
    expect(plane2.health).toBe(42); // max(p.health, round(f × 100)) — the start value is the floor

    // At the gate: exactly 100 and back in service.
    expect(await finishRepairs(inst, gate)).toBe(1);
    plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.status).toBe('available');
    expect(plane.health).toBe(100);
    expect(plane.repairUntilSimTime ?? null).toBeNull();
  });
});

describe('slow to 1× when a landing leaves any plane on the ground (ISS-057)', () => {
  const FROM = 'EDDF';
  const TO = 'LEMD';

  // Starter flying EDDF→LEMD with departureSimTime set so its arrival is EXACTLY T0 —
  // any advancing tick past T0 finalizes it. timeScale is the value under test;
  // lastSelectedTimeScale mirrors what a manual POST /api/sim would have stored.
  async function setupLanding(name: string, timeScale: number) {
    const inst = await freshDb(name);
    const fc = await loadAirportsGeoJson();
    const from = fc.features.find((f) => f.properties.icao === FROM)!.properties;
    const to = fc.features.find((f) => f.properties.icao === TO)!.properties;
    const km = haversineKm(from.lat, from.lon, to.lat, to.lon);
    const type = PLANE_TYPES.atr72;

    await inst.db.update(schema.simState).set({ timeScale, lastSelectedTimeScale: timeScale });
    await inst.db.update(schema.planes)
      .set({ status: 'flying', destIcao: TO, departureSimTime: T0 - travelMs(km, type.speedKmh), fuel: type.maxFuel })
      .where(eq(schema.planes.id, 'plane-starter'));

    return { inst, from, km, type };
  }

  it('last plane lands → sim slows to 1× WITHOUT pausing; lastSelectedTimeScale is preserved', async () => {
    const { inst } = await setupLanding('slow-last.db', 1000);
    vi.setSystemTime(T0 + 2_000); // one full clamped tick at scale 1000 → clock T0+2e6 ≥ arrival (T0)

    const sim = await tickOnce(inst);

    expect(sim.paused).toBe(false); // no pause anymore — ISS-057 replaces it with a slow-down…
    expect((await inst.db.select().from(schema.simState))[0].paused).toBe(false); // …persisted on the row…
    expect(sim.timeScale).toBe(1); // …slowed to the floor…
    expect(sim.lastSelectedTimeScale).toBe(1000); // …with the last manual speed kept for resume
    expect((await inst.db.select().from(schema.planes))[0].status).toBe('available'); // landing itself unchanged
  });

  it('a landing while another plane is still flying → slows to 1× (any plane on ground)', async () => {
    const { inst, from, type } = await setupLanding('slow-other.db', 1000);
    // A second plane on the same route departing at T0 — arrives far after this tick's clock.
    await inst.db.insert(schema.planes).values({
      id: 'p-b', model: 'atr72', status: 'flying', fuel: type.maxFuel, maxFuel: type.maxFuel,
      locationIcao: FROM, destIcao: TO, lat: from.lat, lon: from.lon, departureSimTime: T0,
    });

    vi.setSystemTime(T0 + 2_000);
    const sim = await tickOnce(inst);

    expect(sim.paused).toBe(false);
    expect(sim.timeScale).toBe(1); // the just-landed starter is on ground → slow (literal issue reading)
    const byId = new Map((await inst.db.select().from(schema.planes)).map((p) => [p.id, p.status]));
    expect(byId.get('plane-starter')).toBe('available'); // the starter did land…
    expect(byId.get('p-b')).toBe('flying'); // …but the fleet is not idle — still slowed
  });

  it('already at 1× → stays 1 (no-op slow)', async () => {
    const { inst } = await setupLanding('slow-one.db', 1);
    vi.setSystemTime(T0 + 2_000); // one tick at scale 1 advances 2e3 game ms — past the T0 arrival

    const sim = await tickOnce(inst);

    expect(sim.paused).toBe(false);
    expect(sim.timeScale).toBe(1);
    expect((await inst.db.select().from(schema.planes))[0].status).toBe('available');
  });

  it('a chained plane does NOT slow the sim (nothing is grounded)', async () => {
    const { inst } = await setupLanding('slow-chain.db', 1000); // full tank, arrival exactly T0
    // A queued next hop with plenty of fuel → chains on landing instead of grounding.
    await inst.db.update(schema.planes)
      .set({ queue: JSON.stringify(['EDDV']) })
      .where(eq(schema.planes.id, 'plane-starter'));

    vi.setSystemTime(T0 + 2_000); // one full clamped tick at scale 1000 → clock T0+2e6 ≥ arrival (T0)
    const sim = await tickOnce(inst);

    expect(sim.paused).toBe(false);
    expect(sim.timeScale).toBe(1000); // still flying after the chain, nothing grounded — no slow…
    const plane = (await inst.db.select().from(schema.planes))[0];
    expect(plane.status).toBe('flying'); // …the fresh select in tickOnce counts it as airborne
    expect(plane.destIcao).toBe('EDDV');
  });

  it('manually-paused sim is untouched by ticks (no landing processed while paused)', async () => {
    const inst = await freshDb('slow-paused.db');
    // The fleet is fully grounded (the seeded starter) — a paused tick must not touch the
    // controls even though "any plane on ground" holds: the trigger requires a landing this tick.
    await inst.db.update(schema.simState).set({ timeScale: 1000, lastSelectedTimeScale: 1000, paused: true });

    vi.setSystemTime(T0 + 5_000);
    const sim = await tickOnce(inst);

    expect(sim.paused).toBe(true); // no landing processed while paused → trigger never fires
    expect(sim.timeScale).toBe(1000);
    expect(sim.lastSelectedTimeScale).toBe(1000);
    expect((await inst.db.select().from(schema.planes))[0].status).toBe('available');
  });
});

describe('spawnOpenPackages', () => {
  it('tops the market up to MARKET_TARGET_OPEN_PACKAGES using the shared seed builder', async () => {
    const inst = await freshDb('spawn.db');
    const clock = T0 + 123_456;

    // Leave exactly 3 open packages (the rest of the seeded set is "done").
    const all = await inst.db.select().from(schema.packages);
    for (const p of all.slice(3)) {
      await inst.db.update(schema.packages).set({ status: 'delivered' }).where(eq(schema.packages.id, p.id));
    }

    const needed = await spawnOpenPackages(inst, clock, mulberry32(7));
    expect(needed).toBe(MARKET_TARGET_OPEN_PACKAGES - 3);

    const openRows = (await inst.db.select().from(schema.packages)).filter((p) => p.status === 'open');
    expect(openRows.length).toBe(MARKET_TARGET_OPEN_PACKAGES);

    const fc = await loadAirportsGeoJson();
    const icaoSet = new Set(fc.features.map((f) => f.properties.icao));
    for (const p of openRows.slice(3)) { // the spawned ones
      expect(p.createdSimTime).toBe(clock); // created at game time, not real time
      expect(icaoSet.has(p.originIcao)).toBe(true);
      expect(icaoSet.has(p.destIcao)).toBe(true);
      expect(p.originIcao).not.toBe(p.destIcao);
      expect(p.planeId).toBeNull();
      // Same deadline window as the seed: now + 6–72h game time — scaled by any special status (v0.37.0).
      const scale = p.special ? SPECIALS[p.special]?.deadlineScale ?? 1 : 1;
      expect(p.deadlineSimTime).toBeGreaterThan(clock + 6 * 3_600_000 * scale - 1);
      expect(p.deadlineSimTime).toBeLessThanOrEqual(clock + 72 * 3_600_000 * scale);
    }

    // Already at target → nothing more to spawn.
    expect(await spawnOpenPackages(inst, clock, mulberry32(7))).toBe(0);
  });

  it('is deterministic for an injected RNG (spawn matches the seed builder)', async () => {
    const a = await freshDb('spawn-a.db');
    const b = await freshDb('spawn-b.db');
    const clock = T0 + 999;

    // Wipe all packages in both so both spawn from zero with the same RNG.
    for (const inst of [a, b]) {
      const rows = await inst.db.select().from(schema.packages);
      for (const r of rows) {
        await inst.db.delete(schema.packages).where(eq(schema.packages.id, r.id));
      }
    }

    expect(await spawnOpenPackages(a, clock, mulberry32(42))).toBe(MARKET_TARGET_OPEN_PACKAGES);
    expect(await spawnOpenPackages(b, clock, mulberry32(42))).toBe(MARKET_TARGET_OPEN_PACKAGES);

    const strip = (rows: schema.PackageRow[]) =>
      rows.filter((p) => p.status === 'open').map(({ id: _id, ...rest }) => JSON.stringify(rest)).sort();
    expect(strip(await a.db.select().from(schema.packages))).toEqual(
      strip(await b.db.select().from(schema.packages)),
    );
  });
});

describe('spawnCoveragePackages (v0.8.0 spawn coverage rule)', () => {
  // The seeded starter plane is grounded at EDDF with no seeded package from
  // there, so a fresh DB always has exactly one uncovered airport: EDDF.

  it('spawns an open package originating at the airport of each uncovered grounded plane', async () => {
    const inst = await freshDb('coverage.db');
    const clock = T0 + 5_000;

    // Wipe all seeded packages so coverage is the only source of new ones.
    for (const p of await inst.db.select().from(schema.packages)) {
      await inst.db.delete(schema.packages).where(eq(schema.packages.id, p.id));
    }

    const n = await spawnCoveragePackages(inst, clock, mulberry32(7));
    expect(n).toBe(1); // only EDDF is uncovered (single grounded plane)

    const openRows = (await inst.db.select().from(schema.packages)).filter((p) => p.status === 'open');
    expect(openRows.length).toBe(1);
    expect(openRows[0].originIcao).toBe('EDDF'); // origin forced to the plane's airport
    expect(openRows[0].createdSimTime).toBe(clock);
  });

  it('does nothing when every grounded airport already has an open package', async () => {
    const inst = await freshDb('coverage-covered.db');
    for (const p of await inst.db.select().from(schema.packages)) {
      await inst.db.delete(schema.packages).where(eq(schema.packages.id, p.id));
    }
    // One open package from EDDF covers the starter plane's airport.
    await inst.db.insert(schema.packages).values({
      id: 'p-cover', originIcao: 'EDDF', destIcao: 'LEMD', reward: 1, cargoType: 'Mail', cargoCount: 1,
      deadlineSimTime: T0 + 3_600_000, status: 'open', planeId: null, createdSimTime: T0,
    });

    expect(await spawnCoveragePackages(inst, T0 + 5_000, mulberry32(7))).toBe(0);
    expect((await inst.db.select().from(schema.packages)).length).toBe(1); // nothing added
  });

  it('spawns one package per uncovered airport when planes sit at several airports', async () => {
    const inst = await freshDb('coverage-multi.db');
    for (const p of await inst.db.select().from(schema.packages)) {
      await inst.db.delete(schema.packages).where(eq(schema.packages.id, p.id));
    }
    // A second grounded plane at LEMD; two planes sharing EDDF must not double-spawn.
    await inst.db.insert(schema.planes).values([
      { id: 'p-2', model: 'atr72', status: 'available', fuel: 100, maxFuel: 6300, locationIcao: 'LEMD', destIcao: null, lat: 40.4, lon: -3.6, departureSimTime: null },
      { id: 'p-3', model: 'atr72', status: 'available', fuel: 100, maxFuel: 6300, locationIcao: 'EDDF', destIcao: null, lat: 50.03, lon: 8.57, departureSimTime: null },
    ]);

    const n = await spawnCoveragePackages(inst, T0 + 5_000, mulberry32(7));
    expect(n).toBe(2); // EDDF (×2 planes → one package) and LEMD

    const origins = (await inst.db.select().from(schema.packages))
      .filter((p) => p.status === 'open')
      .map((p) => p.originIcao)
      .sort();
    expect(origins).toEqual(['EDDF', 'LEMD']);
  });

  it('ignores flying planes — they cannot take new work until they land', async () => {
    const inst = await freshDb('coverage-flying.db');
    for (const p of await inst.db.select().from(schema.packages)) {
      await inst.db.delete(schema.packages).where(eq(schema.packages.id, p.id));
    }
    await inst.db.update(schema.planes)
      .set({ status: 'flying', departureSimTime: T0, destIcao: 'LEMD' })
      .where(eq(schema.planes.id, 'plane-starter'));

    expect(await spawnCoveragePackages(inst, T0 + 5_000, mulberry32(7))).toBe(0); // no grounded planes
  });

  it('runs inside tickOnce: a fresh DB gains an EDDF-origin package after one advancing tick', async () => {
    const inst = await freshDb('coverage-tick.db');
    vi.setSystemTime(T0 + 1_000); // one real second → advanceMs > 0 at scale 1

    await tickOnce(inst);

    const fromEdff = (await inst.db.select().from(schema.packages)).filter(
      (p) => p.status === 'open' && p.originIcao === 'EDDF',
    );
    expect(fromEdff.length).toBeGreaterThanOrEqual(1); // coverage held through the full tick pipeline
  });
});

describe('clampTimeScale — v0.14.0 ladder bounds [1, 1000]', () => {
  it('clamps below-minimum values to MIN_TIME_SCALE', () => {
    expect(clampTimeScale(0)).toBe(MIN_TIME_SCALE);
    expect(clampTimeScale(-5)).toBe(MIN_TIME_SCALE);
    expect(clampTimeScale(0.1)).toBe(MIN_TIME_SCALE);
  });

  it('clamps above-maximum values to MAX_TIME_SCALE', () => {
    expect(clampTimeScale(1001)).toBe(MAX_TIME_SCALE);
    expect(clampTimeScale(2000)).toBe(MAX_TIME_SCALE);
    expect(clampTimeScale(Number.MAX_SAFE_INTEGER)).toBe(MAX_TIME_SCALE);
  });

  it('passes in-range values through unclamped — ladder and off-ladder alike', () => {
    for (const s of [1, 2, 5, 10, 25, 50, 100, 250, 500, 1000]) {
      expect(clampTimeScale(s)).toBe(s); // the full v0.14.0 slider ladder
    }
    expect(clampTimeScale(37)).toBe(37); // off-ladder but in range (e.g. a legacy value)
  });

  it('keeps the endpoints exact', () => {
    expect(clampTimeScale(MIN_TIME_SCALE)).toBe(MIN_TIME_SCALE);
    expect(clampTimeScale(MAX_TIME_SCALE)).toBe(MAX_TIME_SCALE);
  });
});

// Local helper mirroring lib/sim/movement.ts (kept private there on purpose — the
// engine composes arrivalTimeFor; tests just need the duration for fixtures).
function travelMs(km: number, speedKmh: number): number {
  return (km / speedKmh) * 3_600_000;
}