import { describe, expect, it } from 'vitest';
import { haversineKm } from '@/lib/geo';
import { PLANE_TYPES, STARTER_MODEL } from './catalog';
import {
  BASE_REWARD,
  buildSeed,
  CONTRACT_COUNT_MAX,
  CONTRACT_COUNT_MIN,
  generateContract,
  HUB_ICAO,
  mulberry32,
  REWARD_PER_KM,
  rewardForDistanceKm,
  STARTING_CASH,
  STARTING_REPUTATION,
  type SeedAirport,
} from './seed';

const NOW = 1_750_000_000_000;

// Small fixed fixture — includes the hub (EDDF Frankfurt) so the happy path is covered.
const AIRPORTS: SeedAirport[] = [
  { icao: 'EDDF', name: 'Frankfurt Main', lat: 50.0333, lon: 8.5706 },
  { icao: 'EHAM', name: 'Amsterdam Schiphol', lat: 52.31, lon: 4.76 },
  { icao: 'EGLL', name: 'London Heathrow', lat: 51.47, lon: -0.454 },
  { icao: 'LEBC', name: 'Madrid Barajas', lat: 40.47, lon: -3.56 },
  { icao: 'LIRF', name: 'Rome Fiumicino', lat: 41.8, lon: 12.25 },
];

const seedWith = (rngSeed: number, airports: SeedAirport[] = AIRPORTS) =>
  buildSeed({ airports, rng: mulberry32(rngSeed), nowMs: NOW });

describe('buildSeed', () => {
  it('grounds the starter plane full of fuel at the hub airport', () => {
    const seed = seedWith(42);
    const type = PLANE_TYPES[STARTER_MODEL];
    expect(seed.plane).toEqual({
      id: 'plane-starter',
      model: STARTER_MODEL,
      status: 'available',
      fuel: type.maxFuel,
      maxFuel: type.maxFuel,
      locationIcao: HUB_ICAO,
      contractId: null,
      lat: 50.0333,
      lon: 8.5706,
    });
  });

  it('falls back to the first airport when the hub ICAO is missing', () => {
    const seed = buildSeed({ airports: AIRPORTS.slice(1), rng: mulberry32(42), nowMs: NOW });
    expect(seed.plane.locationIcao).toBe(AIRPORTS[1].icao);
  });

  it('seeds 8–12 open contracts between distinct fixture airports', () => {
    const seed = seedWith(42);
    expect(seed.contracts.length).toBeGreaterThanOrEqual(CONTRACT_COUNT_MIN);
    expect(seed.contracts.length).toBeLessThanOrEqual(CONTRACT_COUNT_MAX);

    const icaoSet = new Set(AIRPORTS.map((a) => a.icao));
    for (const c of seed.contracts) {
      expect(icaoSet.has(c.originIcao)).toBe(true);
      expect(icaoSet.has(c.destIcao)).toBe(true);
      expect(c.originIcao).not.toBe(c.destIcao);
      expect(c.status).toBe('open');
      expect(c.planeId).toBeNull();
      expect(c.createdSimTime).toBe(NOW);
    }
    expect(new Set(seed.contracts.map((c) => c.id)).size).toBe(seed.contracts.length);
  });

  it('scales reward by haversine distance: round(500 + 2.5 * km)', () => {
    const seed = seedWith(42);
    for (const c of seed.contracts) {
      const o = AIRPORTS.find((a) => a.icao === c.originIcao)!;
      const d = AIRPORTS.find((a) => a.icao === c.destIcao)!;
      expect(c.reward).toBe(Math.round(BASE_REWARD + REWARD_PER_KM * haversineKm(o.lat, o.lon, d.lat, d.lon)));
    }
  });

  it('sets deadlines inside the 6–72h game-time window after now', () => {
    const seed = seedWith(42);
    for (const c of seed.contracts) {
      expect(c.deadlineSimTime).toBeGreaterThan(NOW + 6 * 3_600_000 - 1);
      expect(c.deadlineSimTime).toBeLessThanOrEqual(NOW + 72 * 3_600_000);
    }
  });

  it('seeds the starting account and sim state', () => {
    const seed = seedWith(42);
    expect(seed.account).toEqual({ cash: STARTING_CASH, reputation: STARTING_REPUTATION });
    // lastRealTickMs starts at the seed moment so the first tick-on-read advances ~0.
    expect(seed.simState).toEqual({ clockMs: NOW, timeScale: 1, paused: false, lastRealTickMs: NOW });
  });

  it('is fully deterministic for a fixed RNG and inputs', () => {
    expect(seedWith(42)).toEqual(seedWith(42));
  });

  it('produces different contracts for a different RNG seed', () => {
    expect(seedWith(1).contracts).not.toEqual(seedWith(2).contracts);
  });

  it('rejects an airport list too small to form a route', () => {
    expect(() => buildSeed({ airports: AIRPORTS.slice(0, 1), rng: mulberry32(42), nowMs: NOW })).toThrow();
  });

  it('rewardForDistanceKm applies the documented formula', () => {
    expect(rewardForDistanceKm(0)).toBe(BASE_REWARD);
    expect(rewardForDistanceKm(1000)).toBe(Math.round(BASE_REWARD + REWARD_PER_KM * 1000));
  });
});

describe('generateContract (shared seed/spawn builder)', () => {
  it('builds an open contract between distinct fixture airports with the reward formula', () => {
    const c = generateContract({ id: 'c-x', airports: AIRPORTS, rng: mulberry32(42), nowMs: NOW });

    expect(c.id).toBe('c-x');
    expect(c.status).toBe('open');
    expect(c.planeId).toBeNull();
    expect(c.createdSimTime).toBe(NOW);
    const icaoSet = new Set(AIRPORTS.map((a) => a.icao));
    expect(icaoSet.has(c.originIcao)).toBe(true);
    expect(icaoSet.has(c.destIcao)).toBe(true);
    expect(c.originIcao).not.toBe(c.destIcao);

    const o = AIRPORTS.find((a) => a.icao === c.originIcao)!;
    const d = AIRPORTS.find((a) => a.icao === c.destIcao)!;
    expect(c.reward).toBe(Math.round(BASE_REWARD + REWARD_PER_KM * haversineKm(o.lat, o.lon, d.lat, d.lon)));

    // Same 6–72h game-time deadline window as the seed.
    expect(c.deadlineSimTime).toBeGreaterThan(NOW + 6 * 3_600_000 - 1);
    expect(c.deadlineSimTime).toBeLessThanOrEqual(NOW + 72 * 3_600_000);
  });

  it('is deterministic for a fixed RNG and honors the id/nowMs inputs', () => {
    const a = generateContract({ id: 'c-1', airports: AIRPORTS, rng: mulberry32(7), nowMs: NOW });
    const b = generateContract({ id: 'c-1', airports: AIRPORTS, rng: mulberry32(7), nowMs: NOW });
    expect(a).toEqual(b);

    const c = generateContract({ id: 'c-2', airports: AIRPORTS, rng: mulberry32(8), nowMs: NOW + 1000 });
    expect(c.id).toBe('c-2');
    expect(c.createdSimTime).toBe(NOW + 1000);
    expect(c.deadlineSimTime).not.toBe(a.deadlineSimTime); // different RNG/now → different contract
  });

  it('deadlineOffsetMs pins the deadline to now + offset (e2e expiry hook)', () => {
    const c = generateContract({ id: 'c-hook', airports: AIRPORTS, rng: mulberry32(1), nowMs: NOW, deadlineOffsetMs: 10_000 });
    expect(c.deadlineSimTime).toBe(NOW + 10_000);
  });

  it('buildSeed contracts are exactly the shared builder output (spawn matches seed)', () => {
    const rngA = mulberry32(42);
    const count = CONTRACT_COUNT_MIN + Math.floor(rngA() * (CONTRACT_COUNT_MAX - CONTRACT_COUNT_MIN + 1));
    const expected: string[] = [];
    for (let i = 0; i < count; i++) {
      expected.push(JSON.stringify(generateContract({ id: `contract-${i + 1}`, airports: AIRPORTS, rng: rngA, nowMs: NOW })));
    }
    const seed = buildSeed({ airports: AIRPORTS, rng: mulberry32(42), nowMs: NOW });
    expect(seed.contracts.map((c) => JSON.stringify(c))).toEqual(expected);
  });

  it('rejects an airport list too small to form a route', () => {
    expect(() => generateContract({ id: 'c-x', airports: AIRPORTS.slice(0, 1), rng: mulberry32(42), nowMs: NOW })).toThrow();
  });

  describe('forced endpoints (v0.8.0 spawn coverage + test hook)', () => {
    it('originIcao forces the origin; dest stays random but distinct', () => {
      const c = generateContract({ id: 'c-o', airports: AIRPORTS, rng: mulberry32(42), nowMs: NOW, originIcao: 'EDDF' });
      expect(c.originIcao).toBe('EDDF');
      expect(c.destIcao).not.toBe('EDDF');

      const o = AIRPORTS.find((a) => a.icao === c.originIcao)!;
      const d = AIRPORTS.find((a) => a.icao === c.destIcao)!;
      expect(c.reward).toBe(Math.round(BASE_REWARD + REWARD_PER_KM * haversineKm(o.lat, o.lon, d.lat, d.lon)));
    });

    it('destIcao forces the destination; origin stays random but distinct', () => {
      const c = generateContract({ id: 'c-d', airports: AIRPORTS, rng: mulberry32(42), nowMs: NOW, destIcao: 'LEBC' });
      expect(c.destIcao).toBe('LEBC');
      expect(c.originIcao).not.toBe('LEBC');
    });

    it('both forced → the exact requested route with the distance-based reward', () => {
      const c = generateContract({ id: 'c-b', airports: AIRPORTS, rng: mulberry32(42), nowMs: NOW, originIcao: 'EDDF', destIcao: 'EHAM' });
      expect(c.originIcao).toBe('EDDF');
      expect(c.destIcao).toBe('EHAM');

      const o = AIRPORTS[0]; // EDDF
      const d = AIRPORTS[1]; // EHAM
      expect(c.reward).toBe(Math.round(BASE_REWARD + REWARD_PER_KM * haversineKm(o.lat, o.lon, d.lat, d.lon)));
    });

    it('is deterministic for a fixed RNG with forced endpoints', () => {
      const a = generateContract({ id: 'c-1', airports: AIRPORTS, rng: mulberry32(7), nowMs: NOW, originIcao: 'EDDF' });
      const b = generateContract({ id: 'c-1', airports: AIRPORTS, rng: mulberry32(7), nowMs: NOW, originIcao: 'EDDF' });
      expect(a).toEqual(b);
    });

    it('throws on an unknown forced ICAO or identical endpoints', () => {
      expect(() => generateContract({ id: 'c-x', airports: AIRPORTS, rng: mulberry32(1), nowMs: NOW, originIcao: 'XXXX' })).toThrow(/unknown origin/);
      expect(() => generateContract({ id: 'c-x', airports: AIRPORTS, rng: mulberry32(1), nowMs: NOW, destIcao: 'XXXX' })).toThrow(/unknown destination/);
      expect(() => generateContract({ id: 'c-x', airports: AIRPORTS, rng: mulberry32(1), nowMs: NOW, originIcao: 'EDDF', destIcao: 'EDDF' })).toThrow(/must differ/);
    });

    it('omitting both endpoints keeps the pre-v0.8.0 RNG call order (byte-identical output)', () => {
      // Same seed as a historical unforced call → same contract, proving forced
      // endpoints consume no extra RNG draws when absent.
      const a = generateContract({ id: 'c-x', airports: AIRPORTS, rng: mulberry32(42), nowMs: NOW });
      const b = generateContract({ id: 'c-x', airports: AIRPORTS, rng: mulberry32(42), nowMs: NOW, originIcao: undefined, destIcao: undefined });
      expect(a).toEqual(b);
    });
  });
});