const fs = require('fs');

var _require = (filePath, required = false) => {
  try {
    console.log(`looking for ${filePath}`);
    if(filePath.endsWith('.json')) {
      return require(filePath);
    } else {
      return JSON.parse(fs.readFileSync(filePath));
    }
  } catch (error) {
    console.log(`cannot find ${filePath}`);
    if(required) {
      console.log(`${filePath} is needed. Exiting.`);
      process.exit(1);
    } else {
      return {};
    }
  }
};

const babelConfFilePath = process.cwd() + '/' + '.babelrc';
const settingPath = '.vscode';
const settingsDirPath = process.cwd() + '/' + settingPath ;
const settingsFilePath = process.cwd() + '/' + settingPath + '/settings.json';
const jsconfigFilePath = process.cwd() + '/' + 'jsconfig.json';

const babelConf = _require(babelConfFilePath, true);
const settings = _require(settingsFilePath);
const jsconfig = _require(jsconfigFilePath);

let alias = {};

if (babelConf.plugins) {
  babelConf.plugins.forEach((elem) => {
    if(elem[0] === 'module-resolver') {
      for (var key in elem[1].alias) {
        alias[key] = elem[1].alias[key];
      }
    }
  });
}

if( Object.keys(alias).length === 0 ) {
  console.log(`no plugin config in ${babelConfFilePath}`);
  process.exit(1);
}

const newSettings = {};
const newJsconfig = {};

// prepare jsconfig.json
newJsconfig.compilerOptions = jsconfig.compilerOptions || {};
newJsconfig.compilerOptions.baseUrl = './';
newJsconfig.compilerOptions.paths = {};
newJsconfig.exclude = jsconfig.exclude || [];
if (newJsconfig.exclude.indexOf('node_modules') === -1) {
  newJsconfig.exclude.push('node_modules');
}

Object.keys(alias).forEach((name) => {
  const value = alias[name];
  const settingsName = name;
  const settingsValue = value.replace('./', '${workspaceRoot}/');
  const JsconfigName = name+'/*';
  let JsconfigValue = value.replace('./','')+'/*';
  if (JsconfigValue === '/*' ) {
    JsconfigValue = '*';
  }
  const JsconfigName2 = name;
  const JsconfigValue2 = value.replace('./','');

  newJsconfig.compilerOptions.paths[JsconfigName] = [JsconfigValue];
  newJsconfig.compilerOptions.paths[JsconfigName2] = [JsconfigValue2];
  newSettings[settingsName] = settingsValue;
});

// prepare vscode/settings.json
settings['path-intellisense.mappings'] = newSettings;
settings['files.exclude'] = settings['files.exclude'] || {};
settings['files.exclude']["jsconfig.json"] = true;

// write settings
if (!fs.existsSync(settingsDirPath)){
  fs.mkdirSync(settingsDirPath);
}
if (fs.existsSync(settingsFilePath)) {
  fs.truncateSync(settingsFilePath, 0);
}
console.log(`writing ${settingsFilePath} ...`);
fs.writeFileSync(settingsFilePath, JSON.stringify(settings, null, 2));

// write jsconfig
if (fs.existsSync(jsconfigFilePath)) {
  fs.truncateSync(jsconfigFilePath, 0);
}
console.log(`writing ${jsconfigFilePath} ...`);
fs.writeFileSync(jsconfigFilePath, JSON.stringify(newJsconfig, null, 2));

console.log('done.');