/**
   * @fileoverview Implements the Node.js require.resolve algorithm
   * @author Nicholas C. Zakas
   */
  
  "use strict";
  
  //------------------------------------------------------------------------------
  // Requirements
  //------------------------------------------------------------------------------
  
  const Module = require("module");
  
  //------------------------------------------------------------------------------
  // Private
  //------------------------------------------------------------------------------
  
  const DEFAULT_OPTIONS = {
  
      /*
       * module.paths is an array of paths to search for resolving things relative
       * to this file. Module.globalPaths contains all of the special Node.js
       * directories that can also be searched for modules.
       *
       * Need to check for existence of module.paths because Jest seems not to
       * include it. See https://github.com/eslint/eslint/issues/5791.
       */
      lookupPaths: module.paths ? module.paths.concat(Module.globalPaths) : Module.globalPaths.concat()
  };
  
  /**
   * Resolves modules based on a set of options.
   */
  class ModuleResolver {
  
      /**
       * Resolves modules based on a set of options.
       * @param {Object} options The options for resolving modules.
       * @param {string[]} options.lookupPaths An array of paths to include in the
       *      lookup with the highest priority paths coming first.
       */
      constructor(options) {
          this.options = Object.assign({}, DEFAULT_OPTIONS, options || {});
      }
  
      /**
       * Resolves the file location of a given module relative to the configured
       * lookup paths.
       * @param {string} name The module name to resolve.
       * @param {string} extraLookupPath An extra path to look into for the module.
       *      This path is used with the highest priority.
       * @returns {string} The resolved file path for the module.
       * @throws {Error} If the module cannot be resolved.
       */
      resolve(name, extraLookupPath) {
  
          /*
           * First, clone the lookup paths so we're not messing things up for
           * subsequent calls to this function. Then, move the extraLookupPath to the
           * top of the lookup paths list so it will be searched first.
           */
          const lookupPaths = this.options.lookupPaths.concat();
  
          lookupPaths.unshift(extraLookupPath);
  
          /**
           * Module._findPath is an internal method to Node.js, then one they use to
           * lookup file paths when require() is called. So, we are hooking into the
           * exact same logic that Node.js uses.
           */
          const result = Module._findPath(name, lookupPaths);   // eslint-disable-line no-underscore-dangle
  
          if (!result) {
              throw new Error(`Cannot find module '${name}'`);
          }
  
          return result;
      }
  }
  
  //------------------------------------------------------------------------------
  // Public API
  //------------------------------------------------------------------------------
  
  module.exports = ModuleResolver;