'use strict';
                        
                        var fs = require('fs');
                        var path = require('path');
                        
                        var envVar = require('../environment-variables');
                        
                        /**
                         * @class  PublishGithubPages
                         * @module  AutodocsPublish
                         */
                        
                        /**
                         * Initialisation step for Github Pages
                         *
                         * Used to check/ set any Github Pages environment variables
                         *
                         * @method  init
                         * @for  PublishGithubPages
                         */
                        function environmentVariablesGithub() {
                          /**
                           * @property GH_TOKEN
                           * @type String (Environment Variable)
                           * @default None - throws when not set
                           */
                          envVar.require('GH_TOKEN');
                        
                          /**
                           * @property REPO_SLUG
                           * @type String (Environment Variable)
                           * @default None - throws when not set
                           */
                          envVar.require('REPO_SLUG');
                        
                          if (!envVar.exists('GH_USER') ||
                              !envVar.exists('GH_REPO')) {
                            var tokens = process.env.REPO_SLUG.split('/');
                        
                            /**
                             * @property GH_USER
                             * @type String (Environment Variable)
                             * @default First half of `REPO_SLUG`
                             */
                            envVar.default('GH_USER', tokens[0]);
                        
                            /**
                             * @property GH_REPO
                             * @type String (Environment Variable)
                             * @default Second half of `REPO_SLUG`
                             */
                            envVar.default('GH_REPO', tokens[1]);
                        
                            process.env.SCRIPT_DIR = __dirname;
                          }
                        }
                        
                        /**
                         * Performs the required steps for publishing to Github pages
                         *
                         * - runs `npm run generatedocs`
                         * - `git fetch`es the `gh-pages` branch of the project into a throwaway git repository
                         * - copies the documentation generated by the `generatedocs` script into the `gh-pages` branch
                         * - copies any additional files required into the gh-pages branch
                         * - if any files have changed, `git commit`s `git push`es on the `gh-pages` branch
                         *   - this is when the files actually succeed in publishing
                         * - if necessary, cleans up the throwaway git repository
                         *
                         * @method run
                         * @for  PublishGithubPages
                         */
                        function publishGithubPages() {
                          var childProcess = require('child_process');
                          var script = childProcess.spawn(path.join(__dirname, 'github-pages.sh'), [], {
                            stdio: 'inherit',
                          });
                          script.on('close', function(code) {
                            outputUrls();
                            process.exit(code);
                          });
                        }
                        
                        /**
                         * Outputs the base URL and the API URL at which the documentation should be published.
                         *
                         * Uses `CNAME` file based on best guess,
                         * otherwise defaults to `*.github/*`
                         *
                         * @method  outputUrls
                         * @for  PublishGithubPages
                         * @private
                         */
                        function outputUrls() {
                          var CNAME;
                          if (process.env.FLAG_COPY_ASSETS === 'true' &&
                              process.env.DOCUMENT_ASSETS.split(' ').indexOf('CNAME') >= 0) {
                            // Best guess that CNAME file was copied in
                            try {
                              var CNAMEfile = path.join(process.env.PROJECT_DIR, 'CNAME');
                              CNAME = fs.readFileSync(CNAMEfile).toString().trim();
                            }
                            catch (e) {
                              // Do nothing
                            }
                          }
                          CNAME = CNAME || (process.env.GH_USER+'.github.io');
                          var publishDomain = 'http://'+CNAME;
                          var publishUrl = publishDomain+'/'+process.env.GH_REPO;
                          var publishApiUrl = publishUrl+'/'+process.env.DOCUMENT_PUBLISH_FOLDER;
                          console.log('Base URL: '+publishUrl);
                          console.log('API  URL: '+publishApiUrl);
                        }
                        
                        module.exports = {
                          init: environmentVariablesGithub,
                          run: publishGithubPages,
                        };