export function createRollupBundle(config: BundleConfig): Promise<any> {
  const bundleOptions: any = {
    context: 'this',
    external: config.external,
    entry: config.entry,
  };

  const writeOptions = {
    // Keep the moduleId empty because we don't want to force developers to a specific moduleId.
    moduleId: '',
    moduleName: config.moduleName,
    // banner: buildConfig.licenseBanner,
    format: config.format,
    dest: config.dest,
    globals: config.globals,
    sourceMap: true
  };

  // When creating a UMD, we want to exclude tslib from the `external` bundle option so that it
  // is inlined into the bundle.
  if (config.format === 'umd') {
    bundleOptions.plugins = [resolve()];

    if (bundleOptions.external && bundleOptions.external.indexOf('tslib') > -1) {
      bundleOptions.external.splice(bundleOptions.external.indexOf('tslib'), 1);
    }
  }

  return rollup.rollup(bundleOptions).then((bundle: any) => bundle.write(writeOptions));
}

task('release.createUmdBundle', (done: Function) => {
  return rollup({
    entry: DIST_BUILD_UMD_BUNDLE_ENTRYPOINT,
    plugins: [
      nodeResolve({
        module: true,
        jsnext: true,
        main: true
      }),
      commonjs()
    ]
  }).then((bundle) => {
    return bundle.write({
      format: 'umd',
      moduleName: 'ionicBundle',
      dest: `${DIST_BUNDLE_ROOT}/ionic.umd.js`
    });
  });
});

function bundle(inputFile: string, outputFile: string): Promise<any> {
  console.log(`Starting rollup on ${inputFile} ... writing to ${outputFile}`);
  return rollup.rollup({
    entry: inputFile,
    plugins: [
      commonjs(),
      nodeResolve({
        module: true,
        jsnext: true,
        main: true,
        extensions: ['.js']
      })
    ]
  }).then(bundle => {
    return bundle.write({
      format: 'iife',
      dest: outputFile,
    });
  });
}