import { describe, expect, it } from 'vitest';

import {
  archiveFileName,
  backupIdTime,
  dumpFileName,
  expiredSets,
  listSets,
  newBackupId,
} from './backup-set.js';

const DAY = 24 * 60 * 60 * 1000;

function setFiles(id: string): string[] {
  return [dumpFileName(id), archiveFileName(id)];
}

describe('backup ids', () => {
  it('round-trips through the id format', () => {
    const now = new Date('2026-07-11T03:00:00Z');
    const id = newBackupId(now);
    expect(id).toBe('20260711-030000');
    expect(backupIdTime(id)?.toISOString()).toBe(now.toISOString());
  });

  it('rejects malformed ids', () => {
    expect(backupIdTime('not-a-backup')).toBeNull();
    expect(backupIdTime('20260711')).toBeNull();
  });
});

describe('listSets', () => {
  it('groups files by id and flags completeness', () => {
    const sets = listSets([
      'status.json',
      'db-20260701-030000.dump.partial',
      ...setFiles('20260710-030000'),
      'db-20260711-030000.dump',
    ]);
    expect(sets.map((set) => set.id)).toEqual(['20260710-030000', '20260711-030000']);
    expect(sets[0]?.complete).toBe(true);
    expect(sets[1]?.complete).toBe(false);
  });
});

describe('expiredSets', () => {
  const now = new Date('2026-07-31T04:00:00Z');

  it('removes only sets past retention', () => {
    const fresh = newBackupId(new Date(now.getTime() - 2 * DAY));
    const old = newBackupId(new Date(now.getTime() - 10 * DAY));
    const newest = newBackupId(new Date(now.getTime() - 1 * DAY));
    const sets = listSets([...setFiles(old), ...setFiles(fresh), ...setFiles(newest)]);

    const expired = expiredSets(sets, now, 7);
    expect(expired.map((set) => set.id)).toEqual([old]);
  });

  it('never removes the newest complete set, even when expired', () => {
    const older = newBackupId(new Date(now.getTime() - 40 * DAY));
    const newestComplete = newBackupId(new Date(now.getTime() - 20 * DAY));
    // A newer but incomplete set (crashed run) must not shield the complete one.
    const newerIncomplete = newBackupId(new Date(now.getTime() - 9 * DAY));
    const sets = listSets([
      ...setFiles(older),
      ...setFiles(newestComplete),
      dumpFileName(newerIncomplete),
    ]);

    const expired = expiredSets(sets, now, 7);
    expect(expired.map((set) => set.id)).toEqual([older, newerIncomplete]);
  });
});