// Learn more https://docs.expo.io/guides/customizing-metro
const path = require('path')
const {getDefaultConfig} = require('expo/metro-config')
const cfg = getDefaultConfig(__dirname)

if (process.env.ATPROTO_ROOT) {
  const atprotoRoot = path.resolve(process.cwd(), process.env.ATPROTO_ROOT)

  // Watch folders are used as roots for the virtual file system. Any file that
  // needs to be resolved by the metro bundler must be within one of the watch
  // folders. Since we will be resolving dependencies from the atproto packages,
  // we need to add the atproto root to the watch folders so that the
  cfg.watchFolders ||= []
  cfg.watchFolders.push(atprotoRoot)

  const resolveRequest = cfg.resolver.resolveRequest
  cfg.resolver.resolveRequest = (context, moduleName, platform) => {
    // Alias @atproto/* modules to the corresponding package in the atproto root
    if (moduleName.startsWith('@atproto/')) {
      const [, packageName] = moduleName.split('/', 2)
      const packagePath = path.join(atprotoRoot, 'packages', packageName)
      return context.resolveRequest(context, packagePath, platform)
    }

    // Polyfills are added by the build process and are not actual dependencies
    // of the @atproto/* packages. Resolve those from here.
    if (
      moduleName.startsWith('@babel/') &&
      context.originModulePath.startsWith(atprotoRoot)
    ) {
      return {
        type: 'sourceFile',
        filePath: require.resolve(moduleName),
      }
    }

    return (resolveRequest || context.resolveRequest)(
      context,
      moduleName,
      platform,
    )
  }
}

cfg.resolver.sourceExts = process.env.RN_SRC_EXT
  ? process.env.RN_SRC_EXT.split(',').concat(cfg.resolver.sourceExts)
  : cfg.resolver.sourceExts

cfg.transformer.getTransformOptions = async () => ({
  transform: {
    experimentalImportSupport: true,
    inlineRequires: true,
    nonInlinedRequires: [
      // We can remove this option and rely on the default after
      // https://github.com/facebook/metro/pull/1126 is released.
      'React',
      'react',
      'react/jsx-dev-runtime',
      'react/jsx-runtime',
      'react-native',
    ],
  },
})

module.exports = cfg