import { describe, it, expect } from 'vitest';
import { InMemoryStateStore } from '../src/store.js';
import type { UniverseSnapshot } from '@kerbal-rt/shared-types';

function makeSnapshot(ut: number, vesselId = 'v-1'): UniverseSnapshot {
  return {
    ut,
    capturedAt: new Date().toISOString(),
    activeVesselId: vesselId,
    bodies: [
      {
        id: 'kerbin',
        name: 'Kerbin',
        kind: 'planet',
        parentId: 'kerbol',
        radius: 600_000,
        sphereOfInfluence: 84_159_286,
        gravitationalParameter: 3.5316e12,
        rotationPeriod: 21_600,
        axialTilt: 0,
        orbit: {
          semiMajorAxis: 13_599_840_256,
          eccentricity: 0,
          inclination: 0,
          longitudeOfAscendingNode: 0,
          argumentOfPeriapsis: 0,
          meanAnomalyAtEpoch: 0,
          epoch: 0,
        },
      },
    ],
    vessels: [
      {
        id: vesselId,
        name: 'Test',
        type: 'Probe',
        owner: 'KASA',
        situation: 'ORBITING',
        status: 'ACTIVE',
        orbit: {
          semiMajorAxis: 7e6,
          eccentricity: 0,
          inclination: 0,
          longitudeOfAscendingNode: 0,
          argumentOfPeriapsis: 0,
          meanAnomalyAtEpoch: 0,
          epoch: 0,
        },
        referenceBodyId: 'kerbin',
        createdAt: '2026-01-01T00:00:00Z',
        retiredAt: null,
      },
    ],
    groundStations: [],
  };
}

describe('InMemoryStateStore', () => {
  it('starts empty', async () => {
    const store = new InMemoryStateStore();
    expect(await store.latestSnapshot()).toBeNull();
    expect(await store.listVessels()).toEqual([]);
  });

  it('stores and returns snapshots', async () => {
    const store = new InMemoryStateStore();
    await store.applySnapshot(makeSnapshot(100));
    const snap = await store.latestSnapshot();
    expect(snap).not.toBeNull();
    expect(snap!.ut).toBe(100);
  });

  it('looks up vessels by id', async () => {
    const store = new InMemoryStateStore();
    await store.applySnapshot(makeSnapshot(1, 'kasa-1'));
    const v = await store.getVessel('kasa-1');
    expect(v?.name).toBe('Test');
    expect(await store.getVessel('missing')).toBeNull();
  });

  it('overwrites on subsequent snapshots', async () => {
    const store = new InMemoryStateStore();
    await store.applySnapshot(makeSnapshot(1));
    await store.applySnapshot(makeSnapshot(2));
    expect((await store.latestSnapshot())!.ut).toBe(2);
  });

  it('notifies subscribers when a snapshot is applied', async () => {
    const store = new InMemoryStateStore();
    const seen: number[] = [];
    const unsub = await store.subscribe((snap) => seen.push(snap.ut));

    await store.applySnapshot(makeSnapshot(1));
    // allow microtask to flush
    await new Promise((r) => setTimeout(r, 10));
    await store.applySnapshot(makeSnapshot(2));
    await new Promise((r) => setTimeout(r, 10));

    expect(seen).toEqual([1, 2]);

    await unsub();
    await store.applySnapshot(makeSnapshot(3));
    await new Promise((r) => setTimeout(r, 10));
    expect(seen).toEqual([1, 2]); // unsub'd
  });
});