import { describe, expect, test } from 'bun:test';
import type { DbClient } from '../../db/client';
import { auditSchema } from './schema';

const fakeDb = {} as DbClient;

const journalWith = (tags: string[]) => () => ({
  version: '5',
  dialect: 'sqlite',
  entries: tags.map((tag, i) => ({ idx: i, tag, when: 1700000000 + i })),
});

describe('auditSchema', () => {
  test('an unreadable journal is unmeasured, not clean', async () => {
    // Was `expect(result).toEqual([])`. Silence rendered as READY, and pending
    // migrations are the difference between a `.deb` that installed and a
    // `.deb` that works — `apt upgrade` does not run them (celilo#169).
    const result = await auditSchema({
      journal: () => null,
      applied: () => [],
      db: fakeDb,
    });
    expect(result).toHaveLength(1);
    expect(result[0]?.severity).toBe('unmeasured');
    expect(result[0]?.code).toBe('schema_journal_unreadable');
  });

  test('no finding when every journal entry is applied', async () => {
    const result = await auditSchema({
      journal: journalWith(['0000_init', '0001_add_zones']),
      applied: () => ['0000_init', '0001_add_zones'],
      db: fakeDb,
    });
    expect(result).toEqual([]);
  });

  test('blocked finding when migrations are pending', async () => {
    const result = await auditSchema({
      journal: journalWith(['0000_init', '0001_add_zones', '0002_backup_tables']),
      applied: () => ['0000_init'],
      db: fakeDb,
    });

    expect(result).toHaveLength(1);
    expect(result[0]).toMatchObject({
      category: 'schema',
      severity: 'blocked',
      code: 'schema_pending_migrations',
      subject: 'system',
    });
    expect(result[0].message).toContain('2 pending');
    expect(result[0].details).toContain('0001_add_zones');
    expect(result[0].details).toContain('0002_backup_tables');
  });

  test('singular wording for exactly one pending migration', async () => {
    const result = await auditSchema({
      journal: journalWith(['0000_init', '0001_add_zones']),
      applied: () => ['0000_init'],
      db: fakeDb,
    });
    expect(result[0].message).toBe('1 pending DB migration');
  });

  test('treats applied set as a set (order-independent)', async () => {
    const result = await auditSchema({
      journal: journalWith(['0000_init', '0001_add_zones']),
      applied: () => ['0001_add_zones', '0000_init'], // reversed
      db: fakeDb,
    });
    expect(result).toEqual([]);
  });
});