'use strict';

const fs = require('fs');

const path = require('path');

const paths = require('./paths');

const chalk = require('chalk');

const resolve = require('resolve');

/**

 * Get additional module paths based on the baseUrl of a compilerOptions object.

 *

 * @param {Object} options

 */

function getAdditionalModulePaths(options = {}) {

  const baseUrl = options.baseUrl;

  if (!baseUrl) {

    return '';

  }

  const baseUrlResolved = path.resolve(paths.appPath, baseUrl);

  // We don't need to do anything if `baseUrl` is set to `node_modules`. This is

  // the default behavior.

  if (path.relative(paths.appNodeModules, baseUrlResolved) === '') {

    return null;

  }

  // Allow the user set the `baseUrl` to `appSrc`.

  if (path.relative(paths.appSrc, baseUrlResolved) === '') {

    return [paths.appSrc];

  }

  // If the path is equal to the root directory we ignore it here.

  // We don't want to allow importing from the root directly as source files are

  // not transpiled outside of `src`. We do allow importing them with the

  // absolute path (e.g. `src/Components/Button.js`) but we set that up with

  // an alias.

  if (path.relative(paths.appPath, baseUrlResolved) === '') {

    return null;

  }

  // Otherwise, throw an error.

  throw new Error(

    chalk.red.bold(

      "Your project's `baseUrl` can only be set to `src` or `node_modules`." +

        ' Create React App does not support other values at this time.'

    )

  );

}

/**

 * Get webpack aliases based on the baseUrl of a compilerOptions object.

 *

 * @param {*} options

 */

function getWebpackAliases(options = {}) {

  const baseUrl = options.baseUrl;

  if (!baseUrl) {

    return {};

  }

  const baseUrlResolved = path.resolve(paths.appPath, baseUrl);

  if (path.relative(paths.appPath, baseUrlResolved) === '') {

    return {

      src: paths.appSrc,

    };

  }

}

/**

 * Get jest aliases based on the baseUrl of a compilerOptions object.

 *

 * @param {*} options

 */

function getJestAliases(options = {}) {

  const baseUrl = options.baseUrl;

  if (!baseUrl) {

    return {};

  }

  const baseUrlResolved = path.resolve(paths.appPath, baseUrl);

  if (path.relative(paths.appPath, baseUrlResolved) === '') {

    return {

      '^src/(.*)$': '<rootDir>/src/$1',

    };

  }

}

function getModules() {

  // Check if TypeScript is setup

  const hasTsConfig = fs.existsSync(paths.appTsConfig);

  const hasJsConfig = fs.existsSync(paths.appJsConfig);

  if (hasTsConfig && hasJsConfig) {

    throw new Error(

      'You have both a tsconfig.json and a jsconfig.json. If you are using TypeScript please remove your jsconfig.json file.'

    );

  }

  let config;

  // If there's a tsconfig.json we assume it's a

  // TypeScript project and set up the config

  // based on tsconfig.json

  if (hasTsConfig) {

    const ts = require(

      resolve.sync('typescript', {

        basedir: paths.appNodeModules,

      })

    );

    config = ts.readConfigFile(paths.appTsConfig, ts.sys.readFile).config;

    // Otherwise we'll check if there is jsconfig.json

    // for non TS projects.

  } else if (hasJsConfig) {

    config = require(paths.appJsConfig);

  }

  config = config || {};

  const options = config.compilerOptions || {};

  const additionalModulePaths = getAdditionalModulePaths(options);

  return {

    additionalModulePaths: additionalModulePaths,

    webpackAliases: getWebpackAliases(options),

    jestAliases: getJestAliases(options),

    hasTsConfig,

  };

}

module.exports = getModules();