import {spawnSync} from 'node:child_process';

import fs from 'node:fs';

const shellRoot = new URL('../', import.meta.url);
const outputRoot = new URL('../.expo-export-smoke/', import.meta.url);
const npmCommand = process.platform === 'win32' ? 'npm.cmd' : 'npm';
const platforms = ['android', 'ios'];

function runExpoExport(platform) {
  const outputDir = `.expo-export-smoke/${platform}`;
  const result = spawnSync(
    npmCommand,
    [
      'exec',
      'expo',
      'export',
      '--',
      '--platform',
      platform,
      '--output-dir',
      outputDir,
    ],
    {
      cwd: shellRoot,
      encoding: 'utf8',
      stdio: 'pipe',
    },
  );

  if (result.error) {
    throw new Error(
      `failed to start Expo ${platform} export smoke: ${result.error.message}`,
    );
  }

  if (result.signal) {
    throw new Error(
      `Expo ${platform} export smoke was terminated by signal ${result.signal}`,
    );
  }

  if ((result.status ?? 0) !== 0) {
    process.stdout.write(result.stdout ?? '');
    process.stderr.write(result.stderr ?? '');
    process.exit(result.status ?? 1);
  }
}

function readMetadata(platform) {
  const metadataPath = new URL(`${platform}/metadata.json`, outputRoot);
  if (!fs.existsSync(metadataPath)) {
    throw new Error(`Expo ${platform} export did not produce metadata.json`);
  }

  const metadata = JSON.parse(fs.readFileSync(metadataPath, 'utf8'));
  if (metadata.bundler !== 'metro') {
    throw new Error(`Expo ${platform} export must use the Metro bundler`);
  }

  const bundlePath = metadata.fileMetadata?.[platform]?.bundle;
  if (typeof bundlePath !== 'string' || bundlePath.length === 0) {
    throw new Error(`Expo ${platform} export metadata is missing bundle path`);
  }

  return bundlePath;
}

function assertBundle(platform, bundlePath) {
  const bundleFile = new URL(`${platform}/${bundlePath}`, outputRoot);
  if (!fs.existsSync(bundleFile)) {
    throw new Error(`Expo ${platform} bundle is missing: ${bundlePath}`);
  }

  const stats = fs.statSync(bundleFile);
  if (stats.size < 100_000) {
    throw new Error(`Expo ${platform} bundle is unexpectedly small`);
  }

  if (!bundlePath.includes(`/static/js/${platform}/AppEntry-`)) {
    throw new Error(`Expo ${platform} bundle path does not target AppEntry`);
  }
}

fs.rmSync(outputRoot, {recursive: true, force: true});

try {
  for (const platform of platforms) {
    runExpoExport(platform);
    assertBundle(platform, readMetadata(platform));
  }

  console.log('[mobile-shell:expo-export] OK');
} finally {
  fs.rmSync(outputRoot, {recursive: true, force: true});
}