import { readdirSync, readFileSync } from 'node:fs';
import { join } from 'node:path';
import { fileURLToPath } from 'node:url';
import { describe, expect, it } from 'vitest';

const srcDir = fileURLToPath(new URL('.', import.meta.url));

function moduleFiles(dir: string): string[] {
  return readdirSync(dir, { withFileTypes: true }).flatMap((entry) =>
    entry.isDirectory()
      ? moduleFiles(join(dir, entry.name))
      : entry.name.endsWith('.module.ts')
        ? [join(dir, entry.name)]
        : [],
  );
}

describe('ScheduleModule.forRoot single registration', () => {
  // Regression guard (v0.21.7): each forRoot() call creates its own ScheduleExplorer that scans all providers, so a second call made every @Cron/@Interval job fire twice.
  it('appears exactly once across all src/**/*.module.ts', () => {
    const hits = moduleFiles(srcDir).flatMap((file) =>
      (
        readFileSync(file, 'utf8').match(/ScheduleModule\.forRoot\(/g) ?? []
      ).map(() => file.slice(srcDir.length)),
    );
    expect(hits).toHaveLength(1);
  });
});