import { describe, expect, it, vi } from 'vitest';
import { comparisonReadPortFrom, type ComparisonReadMethods } from '../../src/comparison/comparison-read-port';

// The engine port shares reads within one repository revision and never serves a read of an older revision.
function repository() {
  return {
    getProject: vi.fn(async () => null),
    listAssessments: vi.fn(async () => []),
    loadAssessmentModel: vi.fn(async (id: string) => ({ id })),
    queryUnifiedResults: vi.fn(async () => ({ results: [] })),
    listPolicyEvaluations: vi.fn(async () => []),
    listGpoBackupInstances: vi.fn(async () => [])
  };
}

describe('Comparison Engine read port', () => {
  it('loads each read once per revision, also for parallel requests of both timeslots', async () => {
    const source = repository();
    const port = comparisonReadPortFrom(source as unknown as ComparisonReadMethods, async () => 1);
    await Promise.all([port.listPolicyEvaluations('p'), port.listPolicyEvaluations('p')]);
    const [a, b] = await Promise.all([port.loadAssessmentModel('a'), port.loadAssessmentModel('a')]);
    await port.loadAssessmentModel('b');
    expect(source.listPolicyEvaluations).toHaveBeenCalledTimes(1);
    expect(source.loadAssessmentModel).toHaveBeenCalledTimes(2);
    expect(a).toBe(b);
  });

  it('reloads after a committed change and does not keep a failed read', async () => {
    const source = repository();
    let revision = 1;
    const port = comparisonReadPortFrom(source as unknown as ComparisonReadMethods, async () => revision);
    await port.loadAssessmentModel('a');
    revision = 2;
    await port.loadAssessmentModel('a');
    expect(source.loadAssessmentModel).toHaveBeenCalledTimes(2);
    source.listGpoBackupInstances.mockRejectedValueOnce(new Error('unavailable'));
    await expect(port.listGpoBackupInstances('p')).rejects.toThrow('unavailable');
    await port.listGpoBackupInstances('p');
    expect(source.listGpoBackupInstances).toHaveBeenCalledTimes(2);
  });
});