const { getDefaultConfig, mergeConfig } = require('@react-native/metro-config');
const exclusionList = require('metro-config/private/defaults/exclusionList').default;

/*
 * "Open DevTools" launches React Native DevTools, which is an Electron app
 * spawned from this process with this process's environment. VS Code sets
 * ELECTRON_RUN_AS_NODE=1 for everything its extensions start, so a Metro
 * launched from inside the editor hands that on, and the DevTools app then
 * runs as plain Node, rejects `--frontendUrl` as a "bad option" and exits.
 * Nothing opens and the app shows no error. Metro itself is not Electron, so
 * dropping the variable here costs nothing.
 */
delete process.env.ELECTRON_RUN_AS_NODE;

/**
 * Metro configuration
 * https://reactnative.dev/docs/metro
 *
 * Native build output (android/app/build alone is >2GB after a debug build) is
 * excluded from the file crawl. Without watchman installed Metro walks these
 * directories on startup and never becomes responsive.
 *
 * The same crawl runs on every start, and it walks every file that is not
 * blocked here. @hugeicons/core-free-icons alone ships ~24,000 files — a
 * CommonJS copy, type definitions and a source map for each of ~6,000 icons —
 * out of ~70,000 in node_modules. Metro resolves the icons to `dist/esm/*.js`
 * only, so the rest is skipped. If an icon import ever fails to resolve after
 * a library upgrade, check these two entries first.
 *
 * @type {import('@react-native/metro-config').MetroConfig}
 */
const config = {
  resolver: {
    blockList: exclusionList([
      /\/android\/build\/.*/,
      /\/android\/app\/build\/.*/,
      /\/android\/\.gradle\/.*/,
      /\/android\/\.kotlin\/.*/,
      /\/node_modules\/.*\/android\/build\/.*/,
      /\/\.cxx\/.*/,
      /\/ios\/build\/.*/,
      /\/ios\/Pods\/.*/,
      /\/node_modules\/@hugeicons\/core-free-icons\/dist\/(cjs|types)\/.*/,
      /\/node_modules\/@hugeicons\/core-free-icons\/dist\/esm\/.*\.map$/,
    ]),
  },
};

module.exports = mergeConfig(getDefaultConfig(__dirname), config);