'use strict';

const ClosureCompiler = require('google-closure-compiler').compiler;

const {promisify} = require('util');

const fs = require('fs');

const tmp = require('tmp');

const writeFileAsync = promisify(fs.writeFile);

function compile(flags) {

  return new Promise((resolve, reject) => {

    const closureCompiler = new ClosureCompiler(flags);

    closureCompiler.run(function (exitCode, stdOut, stdErr) {

      if (!stdErr) {

        resolve(stdOut);

      } else {

        reject(new Error(stdErr));

      }

    });

  });

}

module.exports = function closure(flags = {}) {

  return {

    name: 'scripts/rollup/plugins/closure-plugin',

    async renderChunk(code) {

      const inputFile = tmp.fileSync();

      const tempPath = inputFile.name;

      flags = Object.assign({}, flags, {js: tempPath});

      await writeFileAsync(tempPath, code, 'utf8');

      const compiledCode = await compile(flags);

      inputFile.removeCallback();

      return {code: compiledCode};

    },

  };

};