// The API contract, checked against the API.
//
// docs/api-reference.md was hand-written and drifted until it documented
// twenty-three endpoints that answer 404. The document is now generated from
// the router, which fixes the paths; this fixes the prose, by failing when a
// route exists that nothing describes.
//
// It runs here rather than in the unit suite because it needs the whole app
// mounted, and requiring server.js from node:test pulls in the database pool
// and hangs the run — that has happened before in this repo.
const { test, expect } = require('../fixtures');

async function spec(page) {
  const response = await page.request.get('/api/openapi.json');
  expect(response.status(), 'the document should be served to a signed-in user').toBe(200);
  return response.json();
}

test.describe('OpenAPI', () => {
  test('the document describes this deployment, not a remembered one', async ({ authedPage: page }) => {
    const doc = await spec(page);
    expect(doc.openapi).toBe('3.1.0');
    expect(Object.keys(doc.paths).length).toBeGreaterThan(100);
    // Both ways of holding a session are declared.
    expect(Object.keys(doc.components.securitySchemes).sort()).toEqual(['bearer', 'cookie']);
  });

  test('endpoints that exist are in it', async ({ authedPage: page }) => {
    const doc = await spec(page);
    for (const path of ['/api/health', '/api/build', '/api/auth/me', '/api/my-resources']) {
      expect(doc.paths[path], path + ' is missing from the document').toBeTruthy();
    }
    // A path parameter is written the way OpenAPI writes one.
    expect(doc.paths['/api/my-resources/{id}']).toBeTruthy();
    expect(doc.paths['/api/my-resources/:id']).toBeFalsy();
  });

  test('endpoints that were removed are not', async ({ authedPage: page }) => {
    // Learning Hub is gone. The generated document cannot claim otherwise,
    // which is exactly what the hand-written reference did for weeks.
    const doc = await spec(page);
    const stale = Object.keys(doc.paths).filter(p => p.includes('/learning'));
    expect(stale, 'removed endpoints are still described').toEqual([]);
  });

  test('every documented operation is reachable, and none 404s', async ({ authedPage: page }) => {
    const doc = await spec(page);
    const missing = [];
    for (const [path, methods] of Object.entries(doc.paths)) {
      // Only GETs with no path parameter can be probed safely: a POST would
      // change something and a templated path has no real id to try.
      if (!methods.get || path.includes('{')) continue;
      const response = await page.request.get(path, { failOnStatusCode: false });
      if (response.status() === 404) missing.push(path);
    }
    expect(missing, 'documented but answering 404').toEqual([]);
  });

  test('a description is required, so a new endpoint cannot ship unexplained', async ({ authedPage: page }) => {
    // The generator supplies paths and methods; a person supplies meaning. This
    // is the half that rots, so it is the half that is enforced — undescribed
    // operations are listed by name rather than counted, so the failure says
    // what to write.
    const doc = await spec(page);
    const undescribed = [];
    for (const [path, methods] of Object.entries(doc.paths)) {
      for (const [method, operation] of Object.entries(methods)) {
        if (!operation.summary) undescribed.push(method.toUpperCase() + ' ' + path);
      }
    }
    // A ratchet, not a target. 199 of 215 operations have no summary yet —
    // this API was written over a year with no spec at all, and describing all
    // of it in one sitting would produce 199 sentences nobody read. The number
    // is the debt as measured, and it may only go down: adding an endpoint
    // pushes the count above it and fails the build, so the backlog cannot
    // grow while it is being paid off.
    const BUDGET = Number(process.env.OPENAPI_UNDESCRIBED_BUDGET || 199);
    expect(undescribed.length,
      'undescribed operations (add them to src/utils/openapiRoutes.js):\n  ' +
      undescribed.slice(0, 40).join('\n  ')).toBeLessThanOrEqual(BUDGET);
  });
});