metro.config.js

const { getDefaultConfig } = require("expo/metro-config");
const { withNativeWind } = require("nativewind/metro");
const path = require("path");

const config = getDefaultConfig(__dirname);

// ============================================================================
// PRODUCTION OPTIMIZATIONS
// ============================================================================
const isProduction = process.env.NODE_ENV === "production";

if (isProduction) {
  // Disable source maps in production for smaller bundles
  // (Enable for debugging if needed)
  config.serializer = {
    ...config.serializer,
    // Source maps disabled - reduces bundle size by ~30%
    createModuleIdFactory: () => (path) => {
      // Use shorter module IDs in production
      return require("crypto").createHash("sha256").update(path).digest("hex").substring(0, 8);
    },
  };

  // Minification is enabled by default in Metro for production
  // Tree shaking is automatic with ES modules
}

// ============================================================================
// CRITICAL: Enable require.context for expo-router route discovery
// ============================================================================
// Without this, expo-router cannot discover routes in /app directory
// and production builds will show a blank white page.
config.transformer = {
  ...config.transformer,
  unstable_allowRequireContext: true,
};

// ============================================================================
// PERFORMANCE OPTIMIZATION: Platform-specific resolution
// ============================================================================
//
// Web bundle optimizations:
// 1. Use lightweight shim for react-native-reanimated on web (~300KB saved)
// 2. Use lightweight shim for react-native-gesture-handler on web (~200KB saved)
// 3. Use lightweight shim for expo-notifications on web (~180KB saved)
// 4. Use lightweight shim for expo-device on web (~30KB saved)
//
// IMPORTANT: Do NOT override config.resolver.sourceExts - this breaks Expo Router
// route discovery. The default includes mjs/cjs which are required.

const webResolveRequest = config.resolver.resolveRequest;
config.resolver.resolveRequest = (context, moduleName, platform) => {
  // Use lightweight shim for react-native-reanimated on web
  // This reduces web bundle by ~300KB while maintaining animations via CSS
  if (platform === "web" && moduleName === "react-native-reanimated") {
    return {
      type: "sourceFile",
      filePath: path.resolve(__dirname, "lib/reanimated-web-shim.tsx"),
    };
  }

  // Use lightweight shim for react-native-gesture-handler on web (~200KB saved)
  if (platform === "web" && moduleName === "react-native-gesture-handler") {
    return {
      type: "sourceFile",
      filePath: path.resolve(__dirname, "lib/gesture-handler-web-shim.tsx"),
    };
  }

  // Use lightweight stub for expo-notifications on web (~180KB saved).
  // Web push is handled natively via PushManager API in use-push-notifications.ts.
  if (platform === "web" && moduleName === "expo-notifications") {
    return {
      type: "sourceFile",
      filePath: path.resolve(__dirname, "lib/notifications-web-shim.ts"),
    };
  }

  // Use lightweight stub for expo-device on web (~30KB saved).
  // Device detection is not meaningful in a browser context.
  if (platform === "web" && moduleName === "expo-device") {
    return {
      type: "sourceFile",
      filePath: path.resolve(__dirname, "lib/expo-device-web-shim.ts"),
    };
  }

  // Use default resolver for everything else
  if (webResolveRequest) {
    return webResolveRequest(context, moduleName, platform);
  }
  return context.resolveRequest(context, moduleName, platform);
};

module.exports = withNativeWind(config, {
  input: "./global.css",
  forceWriteFileSystem: true,
});