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

import { resolveBaseRefForLog } from './service.js';

describe('resolveBaseRefForLog', () => {
  it('returns the local ref unchanged when it exists, even if origin also exists', async () => {
    // Both local 'main' and 'refs/remotes/origin/main' are present.
    // The local ref takes precedence — callers that ask for 'main' get 'main'.
    const checkRef = async (ref) => ref === 'main' || ref === 'refs/remotes/origin/main';
    expect(await resolveBaseRefForLog('main', checkRef)).toBe('main');
  });

  it('falls back to origin/<from> when local ref cannot be resolved but origin can', async () => {
    // Local 'main' is absent (e.g. user never checked it out), but origin/main exists.
    const checkRef = async (ref) => ref === 'refs/remotes/origin/main';
    expect(await resolveBaseRefForLog('main', checkRef)).toBe('origin/main');
  });

  it('returns the original ref when neither local nor origin ref can be resolved', async () => {
    // Neither ref exists; return as-is so git surfaces a meaningful error.
    const checkRef = async () => false;
    expect(await resolveBaseRefForLog('nonexistent-branch', checkRef)).toBe('nonexistent-branch');
  });

  it('returns undefined when from is undefined', async () => {
    const checkRef = async () => true;
    expect(await resolveBaseRefForLog(undefined, checkRef)).toBeUndefined();
  });

  it('returns undefined when from is an empty string', async () => {
    const checkRef = async () => true;
    expect(await resolveBaseRefForLog('', checkRef)).toBeUndefined();
  });

  it('returns undefined when from is a whitespace-only string', async () => {
    const checkRef = async () => true;
    expect(await resolveBaseRefForLog('   ', checkRef)).toBeUndefined();
  });
});