/**
 * @noflow
 */

const fs = require('fs');
const path = require('path');
const blacklist = require('metro-bundler/src/blacklist');

module.exports = {
  getBlacklistRE() {
    return blacklist([
      /react\-navigation\/examples\/(?!NavigationPlayground).*/,
      /react\-navigation\/node_modules\/react-native\/(.*)/,
      /react\-navigation\/node_modules\/react\/(.*)/
    ]);
  },
  extraNodeModules: getNodeModulesForDirectory(path.resolve('.')),
};

function getNodeModulesForDirectory(rootPath) {
  const nodeModulePath = path.join(rootPath, 'node_modules');
  const folders = fs.readdirSync(nodeModulePath);
  return folders.reduce((modules, folderName) => {
    const folderPath = path.join(nodeModulePath, folderName);
    if (folderName.startsWith('@')) {
      const scopedModuleFolders = fs.readdirSync(folderPath);
      const scopedModules = scopedModuleFolders.reduce(
        (scopedModules, scopedFolderName) => {
          scopedModules[
            `${folderName}/${scopedFolderName}`
          ] = maybeResolveSymlink(path.join(folderPath, scopedFolderName));
          return scopedModules;
        },
        {}
      );
      return Object.assign({}, modules, scopedModules);
    }
    modules[folderName] = maybeResolveSymlink(folderPath);
    return modules;
  }, {});
}

function maybeResolveSymlink(maybeSymlinkPath) {
  if (fs.lstatSync(maybeSymlinkPath).isSymbolicLink()) {
    const resolved = path.resolve(
      path.dirname(maybeSymlinkPath),
      fs.readlinkSync(maybeSymlinkPath)
    );
    return resolved;
  }
  return maybeSymlinkPath;
}