/**

 * React Static Boilerplate

 * https://github.com/kriasoft/react-static-boilerplate

 *

 * Copyright © 2015-present Kriasoft, LLC. All rights reserved.

 *

 * This source code is licensed under the MIT license found in the

 * LICENSE.txt file in the root directory of this source tree.

 */

const toRegExp = require("path-to-regexp");

function escape(text) {

  return text.replace("'", "\\'").replace("\\", "\\\\");

}

/**

 * Converts application routes from JSON to JavaScript. For example, a route like

 *

 *   {

 *     "path": "/about",

 *     "page": "./pages/about"

 *   }

 *

 * becomes

 *

 *   {

 *     path: '/about',

 *     pattern: /^\\/about(?:\/(?=$))?$/i,

 *     keys: [],

 *     page: './pages/about',

 *     load: function () { return new Promise(resolve => require(['./pages/about'], resolve)); }

 *   }

 */

module.exports = function routesLoader(source) {

  this.cacheable();

  const output = ["[\n"];

  const routes = JSON.parse(source);

  for (const route of routes) {

    const keys = [];

    const pattern = toRegExp(route.path, keys);

    const required =

      route.chunk && route.chunk === "main"

        ? (module) => `Promise.resolve(require('${escape(module)}').default)`

        : (module) => `new Promise(function (resolve, reject) {

        try {

          require.ensure(['${escape(module)}'], function (require) {

            resolve(require('${escape(module)}').default);

          }${typeof route.chunk === "string" ? `, '${escape(route.chunk)}'` : ""});

        } catch (err) {

          reject(err);

        }

      })`;

    output.push("  {\n");

    output.push(`    path: '${escape(route.path)}',\n`);

    output.push(`    pattern: ${pattern.toString()},\n`);

    output.push(`    keys: ${JSON.stringify(keys)},\n`);

    output.push(`    page: '${escape(route.page)}',\n`);

    if (route.data) {

      output.push(`    data: ${JSON.stringify(route.data)},\n`);

    }

    output.push(`    load() {\n      return ${required(route.page)};\n    },\n`);

    output.push("  },\n");

  }

  output.push("]");

  return `module.exports = ${output.join("")};`;

};