#!/usr/bin/env node
const { promises: fs } = require('fs');
const path = require('path');

(async () => {
  const nvmPath = process.env.NVM_DIR;

  if (!nvmPath) {
    console.error('Unable to detect nvm path. Exiting.');
    process.exit(1);
  }

  const onlyNpm = {};
  const nothing = {};
  const apps = await fs.readdir(path.resolve(nvmPath, 'versions'));

  for await (const app of apps) {

    const versions = await fs.readdir(path.resolve(nvmPath, 'versions', app));

    for (const version of versions) {
      const packagesPath = [nvmPath, 'versions', app, version, 'lib', 'node_modules'];
      const packages = await fs.readdir(path.resolve(...packagesPath));

      const hasOnlyNpm = packages.length === 1 && packages[0] === 'npm';
      const hasNothing = !packages.length;
      if (hasOnlyNpm) {
        if (!onlyNpm[app]) {
          onlyNpm[app] = [];
        }
        onlyNpm[app].push(version);
        continue;
      } else if (hasNothing) {
        if (!nothing[app]) {
          nothing[app] = [];
        }
        nothing[app].push(version);
        continue;
      }

      console.log([`Node ${version}`, ...packages].join(`\n    - `), '\n');
    }
  }

  if (Object.keys(onlyNpm).length) {
    console.log(`# Only npm:`);
    for (const app in onlyNpm) {
      console.log(`    - ${app}: ${onlyNpm[app].join(', ')}`);
    }
    console.log('');
  }

  if (Object.keys(nothing).length) {
    console.log(`# No package:`);
    for (const app in nothing) {
      console.log(`    - ${app}: ${nothing[app].join(', ')}`);
    }
    console.log('');
  }

  process.exit(0);
})();