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

import { createDirectoryQueryCanonicalizer } from './proxy.js';

describe('createDirectoryQueryCanonicalizer', () => {
  it('canonicalizes directory query params and preserves other params', async () => {
    const canonicalize = createDirectoryQueryCanonicalizer({
      realpath: async (value) => value === '/link/project' ? '/real/project' : value,
    });

    await expect(canonicalize('/session?foo=1&directory=/link/project&bar=2'))
      .resolves.toBe('/session?foo=1&directory=%2Freal%2Fproject&bar=2');
  });

  it('caches directory realpath lookups', async () => {
    let calls = 0;
    const canonicalize = createDirectoryQueryCanonicalizer({
      realpath: async () => {
        calls += 1;
        return '/real/project';
      },
    });

    await expect(canonicalize('/session?directory=/link/project')).resolves.toBe('/session?directory=%2Freal%2Fproject');
    await expect(canonicalize('/session?directory=/link/project')).resolves.toBe('/session?directory=%2Freal%2Fproject');
    expect(calls).toBe(1);
  });

  it('deduplicates concurrent directory realpath lookups', async () => {
    let calls = 0;
    let release = () => undefined;
    const pending = new Promise((resolve) => {
      release = () => resolve('/real/project');
    });
    const canonicalize = createDirectoryQueryCanonicalizer({
      realpath: async () => {
        calls += 1;
        return pending;
      },
    });

    const first = canonicalize('/session?directory=/link/project');
    const second = canonicalize('/session?directory=/link/project');
    await Promise.resolve();

    expect(calls).toBe(1);
    release();
    await expect(Promise.all([first, second])).resolves.toEqual([
      '/session?directory=%2Freal%2Fproject',
      '/session?directory=%2Freal%2Fproject',
    ]);
  });

  it('falls back to the original URL when realpath fails', async () => {
    const canonicalize = createDirectoryQueryCanonicalizer({
      realpath: async () => {
        throw new Error('missing');
      },
    });

    await expect(canonicalize('/session?foo=1&directory=/missing/project'))
      .resolves.toBe('/session?foo=1&directory=/missing/project');
  });

  it('leaves URLs without directory params unchanged', async () => {
    const canonicalize = createDirectoryQueryCanonicalizer({
      realpath: async () => '/real/project',
    });

    await expect(canonicalize('/session?foo=1')).resolves.toBe('/session?foo=1');
  });
});
