import fs from 'node:fs';
import path from 'node:path';

export interface DashboardAssets {
  directory: string;
  indexFile: string;
}

export type FileExists = (filePath: string) => boolean;

export function resolveDashboardAssets(
  workspaceDirectory: string,
  fileExists: FileExists = fs.existsSync,
): DashboardAssets {
  const reactDirectory = path.join(workspaceDirectory, 'apps', 'dashboard', 'dist');
  const reactIndexFile = path.join(reactDirectory, 'index.html');

  if (fileExists(reactIndexFile)) {
    return {
      directory: reactDirectory,
      indexFile: reactIndexFile,
    };
  }

  throw new Error(
    `React dashboard build is missing at ${reactIndexFile}. Run npm run dashboard:build before starting the web server.`,
  );
}