// # Task automation for Ghost
//
// Run various tasks when developing for and working with Ghost.
//
// **Usage instructions:** can be found in the [Custom Tasks](#custom%20tasks) section or by running `grunt --help`.
//
// **Debug tip:** If you have any problems with any Grunt tasks, try running them with the `--verbose` command
var _              = require('lodash'),
    chalk          = require('chalk'),
    fs             = require('fs-extra'),
    moment         = require('moment'),
    getTopContribs = require('top-gh-contribs'),
    path           = require('path'),
    Promise        = require('bluebird'),
    request        = require('request'),

    escapeChar     = process.platform.match(/^win/) ? '^' : '\\',
    cwd            = process.cwd().replace(/( |\(|\))/g, escapeChar + '$1'),
    buildDirectory = path.resolve(cwd, '.build'),
    distDirectory  = path.resolve(cwd, '.dist'),
    mochaPath      = path.resolve(cwd + '/node_modules/grunt-mocha-cli/node_modules/mocha/bin/mocha'),
    emberPath      = path.resolve(cwd + '/core/client/node_modules/.bin/ember'),

    // ## Build File Patterns
    // A list of files and patterns to include when creating a release zip.
    // This is read from the `.npmignore` file and all patterns are inverted as the `.npmignore`
    // file defines what to ignore, whereas we want to define what to include.
    buildGlob = (function () {
        /*jslint stupid:true */
        return fs.readFileSync('.npmignore', {encoding: 'utf8'}).split('\n').map(function (pattern) {
            if (pattern[0] === '!') {
                return pattern.substr(1);
            }
            return '!' + pattern;
        }).filter(function (pattern) {
            // Remove empty patterns
            return pattern !== '!';
        });
    }()),

    // ## Grunt configuration

    configureGrunt = function (grunt) {
        // #### Load all grunt tasks
        //
        // Find all of the task which start with `grunt-` and load them, rather than explicitly declaring them all
        require('matchdep').filterDev(['grunt-*', '!grunt-cli']).forEach(grunt.loadNpmTasks);

        var cfg = {
            // #### Common paths used by tasks
            paths: {
                build: buildDirectory,
                releaseBuild: path.join(buildDirectory, 'release'),
                dist: distDirectory,
                releaseDist: path.join(distDirectory, 'release')
            },
            // Standard build type, for when we have nightlies again.
            buildType: 'Build',
            // Load package.json so that we can create correctly versioned releases.
            pkg: grunt.file.readJSON('package.json'),

            // ### grunt-contrib-watch
            // Watch files and livereload in the browser during development.
            // See the [grunt dev](#live%20reload) task for how this is used.
            watch: {
                livereload: {
                    files: [
                        'content/themes/casper/assets/css/*.css',
                        'content/themes/casper/assets/js/*.js',
                        'core/client/dist/*.js',
                        'core/client/dist/*.css',
                        'core/built/scripts/*.js'
                    ],
                    options: {
                        livereload: true
                    }
                },
                express: {
                    files:  ['core/server.js', 'core/server/**/*.js'],
                    tasks:  ['express:dev'],
                    options: {
                        // **Note:** Without this option specified express won't be reloaded
                        nospawn: true
                    }
                }
            },

            // ### grunt-express-server
            // Start a Ghost expess server for use in development and testing
            express: {
                options: {
                    script: 'index.js',
                    output: 'Ghost is running'
                },

                dev: {
                    options: {}
                },
                test: {
                    options: {
                        node_env: 'testing'
                    }
                }
            },

            // ### grunt-contrib-jshint
            // Linting rules, run as part of `grunt validate`. See [grunt validate](#validate) and its subtasks for
            // more information.
            jshint: {
                options: {
                    jshintrc: true
                },

                client: [
                    'core/client/**/*.js',
                    '!core/client/node_modules/**/*.js',
                    '!core/client/bower_components/**/*.js',
                    '!core/client/tmp/**/*.js',
                    '!core/client/dist/**/*.js',
                    '!core/client/vendor/**/*.js'
                ],

                server: [
                    '*.js',
                    '!config*.js', // note: i added this, do we want this linted?
                    'core/*.js',
                    'core/server/**/*.js',
                    'core/shared/**/*.js',
                    'core/test/**/*.js',
                    '!core/test/coverage/**',
                    '!core/shared/vendor/**/*.js'
                ]
            },

            jscs: {
                options: {
                    config: true
                },

                client: {
                    options: {
                        esnext: true,
                        disallowObjectController: true
                    },

                    files: {
                        src: [
                            'core/client/**/*.js',
                            '!core/client/node_modules/**/*.js',
                            '!core/client/bower_components/**/*.js',
                            '!core/client/tmp/**/*.js',
                            '!core/client/dist/**/*.js',
                            '!core/client/vendor/**/*.js'
                        ]
                    }
                },

                server: {
                    files: {
                        src: [
                            '*.js',
                            '!config*.js', // note: i added this, do we want this linted?
                            'core/*.js',
                            'core/server/**/*.js',
                            'core/shared/**/*.js',
                            'core/test/**/*.js',
                            '!core/test/coverage/**',
                            '!core/shared/vendor/**/*.js'
                        ]
                    }
                }
            },

            // ### grunt-mocha-cli
            // Configuration for the mocha test runner, used to run unit, integration and route tests as part of
            // `grunt validate`. See [grunt validate](#validate) and its sub tasks for more information.
            mochacli: {
                options: {
                    ui: 'bdd',
                    reporter: grunt.option('reporter') || 'spec',
                    timeout: '15000',
                    save: grunt.option('reporter-output')
                },

                // #### All Unit tests
                unit: {
                    src: [
                        'core/test/unit/**/*_spec.js'
                    ]
                },

                // ##### Groups of unit tests
                server: {
                    src: ['core/test/unit/**/server*_spec.js']
                },

                helpers: {
                    src: ['core/test/unit/server_helpers/*_spec.js']
                },

                middleware: {
                    src: ['core/test/unit/middleware/*_spec.js']
                },

                showdown: {
                    src: ['core/test/unit/**/showdown*_spec.js']
                },

                perm: {
                    src: ['core/test/unit/**/permissions_spec.js']
                },

                migrate: {
                    src: [
                        'core/test/unit/**/export_spec.js',
                        'core/test/unit/**/import_spec.js'
                    ]
                },

                storage: {
                    src: ['core/test/unit/**/storage*_spec.js']
                },

                // #### All Integration tests
                integration: {
                    src: [
                        'core/test/integration/**/model*_spec.js',
                        'core/test/integration/**/api*_spec.js',
                        'core/test/integration/*_spec.js'
                    ]
                },

                // ##### Model integration tests
                model: {
                    src: ['core/test/integration/**/model*_spec.js']
                },

                // ##### API integration tests
                api: {
                    src: ['core/test/integration/**/api*_spec.js']
                },

                // #### All Route tests
                routes: {
                    src: [
                        'core/test/functional/routes/**/*_spec.js'
                    ]
                },

                // #### All Module tests
                module: {
                    src: [
                        'core/test/functional/module/**/*_spec.js'
                    ]
                }
            },

            // ### grunt-mocha-istanbul
            // Configuration for the mocha test coverage generator
            // `grunt coverage`.
            mocha_istanbul: {
                coverage: {
                    // TODO fix the timing/async & cleanup issues with the route and integration tests so that
                    // they can also have coverage generated for them & the order doesn't matter
                    src: ['core/test/integration', 'core/test/unit'],
                    options: {
                        mask: '**/*_spec.js',
                        coverageFolder: 'core/test/coverage',
                        mochaOptions: ['--timeout=15000'],
                        excludes: ['core/client/**']
                    }
                }
            },

            // ### grunt-bg-shell
            // Used to run ember-cli watch in the background
            bgShell: {
                ember: {
                    cmd: emberPath + ' build --watch',
                    execOpts: {
                        cwd: path.resolve(cwd + '/core/client/')
                    },
                    bg: true,
                    stdout: function (out) {
                        grunt.log.writeln(chalk.cyan('Ember-cli::') + out);
                    },
                    stderror: function (error) {
                        grunt.log.error(chalk.red('Ember-cli::' + error));
                    }
                }
            },
            // ### grunt-shell
            // Command line tools where it's easier to run a command directly than configure a grunt plugin
            shell: {
                ember: {
                    command: function (mode) {
                        switch (mode) {
                            case 'init':
                                return 'echo Installing client dependencies... && npm install';

                            case 'prod':
                                return emberPath + ' build --environment=production --silent';

                            case 'dev':
                                return emberPath + ' build';

                            case 'test':
                                return emberPath + ' test --silent';
                        }
                    },
                    options: {
                        execOptions: {
                            cwd: path.resolve(cwd + '/core/client/'),
                            stdout: false
                        }
                    }
                },
                // #### Run bower install
                // Used as part of `grunt init`. See the section on [Building Assets](#building%20assets) for more
                // information.
                bower: {
                    command: path.resolve(cwd + '/node_modules/.bin/bower --allow-root install'),
                    options: {
                        stdout: true,
                        stdin: false
                    }
                },

                test: {
                    command: function (test) {
                        return 'node ' + mochaPath  + ' --timeout=15000 --ui=bdd --reporter=spec core/test/' + test;
                    }
                },

                shrinkwrap: {
                    command: 'npm shrinkwrap'
                }
            },

            // ### grunt-docker
            // Generate documentation from code
            docker: {
                docs: {
                    dest: 'docs',
                    src: ['.'],
                    options: {
                        onlyUpdated: true,
                        exclude: 'node_modules,.git,.tmp,bower_components,content,*built,*test,*doc*,*vendor,' +
                            'config.js,.travis.yml,*.min.css,screen.css',
                        extras: ['fileSearch']
                    }
                }
            },

            // ### grunt-contrib-clean
            // Clean up files as part of other tasks
            clean: {
                built: {
                    src: [
                        'core/built/**',
                        'core/client/dist/**',
                        'core/client/public/assets/img/contributors/**',
                        'core/client/app/templates/-contributors.hbs'
                    ]
                },
                release: {
                    src: ['<%= paths.releaseBuild %>/**']
                },
                test: {
                    src: ['content/data/ghost-test.db']
                },
                tmp: {
                    src: ['.tmp/**']
                },
                dependencies: {
                    src: ['node_modules/**', 'core/client/bower_components/**', 'core/client/node_modules/**']
                }
            },

            // ### grunt-contrib-copy
            // Copy files into their correct locations as part of building assets, or creating release zips
            copy: {
                jquery: {
                    cwd: 'core/client/bower_components/jquery/dist/',
                    src: 'jquery.js',
                    dest: 'core/built/public/',
                    expand: true,
                    nonull: true
                },
                release: {
                    files: [{
                        cwd: 'core/client/bower_components/jquery/dist/',
                        src: 'jquery.js',
                        dest: 'core/built/public/',
                        expand: true
                    }, {
                        expand: true,
                        src: buildGlob,
                        dest: '<%= paths.releaseBuild %>/'
                    }]
                }
            },

            // ### grunt-contrib-compress
            // Zip up files for builds / releases
            compress: {
                release: {
                    options: {
                        archive: '<%= paths.releaseDist %>/Ghost-<%= pkg.version %>.zip'
                    },
                    expand: true,
                    cwd: '<%= paths.releaseBuild %>/',
                    src: ['**']
                }
            },

            // ### grunt-contrib-uglify
            // Minify concatenated javascript files ready for production
            uglify: {
                prod: {
                    options: {
                        sourceMap: false
                    },
                    files: {
                        'core/built/public/jquery.min.js': 'core/built/public/jquery.js'
                    }
                },
                release: {
                    options: {
                        sourceMap: false
                    },
                    files: {
                        'core/built/public/jquery.min.js': 'core/built/public/jquery.js'
                    }
                }
            },

            // ### grunt-update-submodules
            // Grunt task to update git submodules
            update_submodules: {
                default: {
                    options: {
                        params: '--init'
                    }
                }
            }
        };

        // Load the configuration
        grunt.initConfig(cfg);

        // ## Utilities
        //
        // ### Spawn Casper.js
        // Custom test runner for our Casper.js functional tests
        // This really ought to be refactored into a separate grunt task module
        grunt.registerTask('spawnCasperJS', function (target) {
            target = _.contains(['client', 'setup'], target) ? target + '/' : undefined;

            var done = this.async(),
                options = ['host', 'noPort', 'port', 'email', 'password'],
                args = ['test']
                    .concat(grunt.option('target') || target || ['client/'])
                    .concat(['--includes=base.js', '--log-level=debug', '--port=2369']);

            // Forward parameters from grunt to casperjs
            _.each(options, function processOption(option) {
                if (grunt.option(option)) {
                    args.push('--' + option + '=' + grunt.option(option));
                }
            });

            if (grunt.option('fail-fast')) {
                args.push('--fail-fast');
            }

            // Show concise logs in Travis as ours are getting too long
            if (grunt.option('concise') || process.env.TRAVIS) {
                args.push('--concise');
            } else {
                args.push('--verbose');
            }

            grunt.util.spawn({
                cmd: 'casperjs',
                args: args,
                opts: {
                    cwd: path.resolve('core/test/functional'),
                    stdio: 'inherit'
                }
            }, function (error, result, code) {
                /*jshint unused:false*/
                if (error) {
                    grunt.fail.fatal(result.stdout);
                }
                grunt.log.writeln(result.stdout);
                done();
            });
        });

        // # Custom Tasks

        // Ghost has a number of useful tasks that we use every day in development. Tasks marked as *Utility* are used
        // by grunt to perform current actions, but isn't useful to developers.
        //
        // Skip ahead to the section on:
        //
        // * [Building assets](#building%20assets):
        //     `grunt init`, `grunt` & `grunt prod` or live reload with `grunt dev`
        // * [Testing](#testing):
        //     `grunt validate`, the `grunt test-*` sub-tasks or generate a coverage report with `grunt coverage`.

        // ### Help
        // Run `grunt help` on the commandline to get a print out of the available tasks and details of
        // what each one does along with any available options. This is an alias for `grunt --help`
        grunt.registerTask('help',
            'Outputs help information if you type `grunt help` instead of `grunt --help`',
            function () {
                console.log('Type `grunt --help` to get the details of available grunt tasks, ' +
                    'or alternatively visit https://github.com/TryGhost/Ghost/wiki/Grunt-Toolkit');
            });

        // ### Documentation
        // Run `grunt docs` to generate annotated source code using the documentation described in the code comments.
        grunt.registerTask('docs', 'Generate Docs', ['docker']);

        // ## Testing

        // Ghost has an extensive set of test suites. The following section documents the various types of tests
        // and how to run them.
        //
        // TLDR; run `grunt validate`

        // #### Set Test Env *(Utility Task)*
        // Set the NODE_ENV to 'testing' unless the environment is already set to TRAVIS.
        // This ensures that the tests get run under the correct environment, using the correct database, and
        // that they work as expected. Trying to run tests with no ENV set will throw an error to do with `client`.
        grunt.registerTask('setTestEnv',
            'Use "testing" Ghost config; unless we are running on travis (then show queries for debugging)',
            function () {
                process.env.NODE_ENV = process.env.TRAVIS ? process.env.NODE_ENV : 'testing';
                cfg.express.test.options.node_env = process.env.NODE_ENV;
            });

        // #### Ensure Config *(Utility Task)*
        // Make sure that we have a `config.js` file when running tests
        // Ghost requires a `config.js` file to specify the database settings etc. Ghost comes with an example file:
        // `config.example.js` which is copied and renamed to `config.js` by the bootstrap process
        grunt.registerTask('ensureConfig', function () {
            var config = require('./core/server/config'),
                done = this.async();
            config.load().then(function () {
                done();
            }).catch(function (err) {
                grunt.fail.fatal(err.stack);
            });
        });

        // #### Reset Database to "New" state *(Utility Task)*
        // Drops all database tables and then runs the migration process to put the database
        // in a "new" state.
        grunt.registerTask('cleanDatabase', function () {
            var done = this.async(),
                models    = require('./core/server/models'),
                migration = require('./core/server/data/migration');

            migration.reset().then(function () {
                return models.init();
            }).then(function () {
                return migration.init();
            }).then(function () {
                done();
            }).catch(function (err) {
                grunt.fail.fatal(err.stack);
            });
        });

        grunt.registerTask('test', function (test) {
            if (!test) {
                grunt.log.write('no test provided');
            }

            grunt.task.run('test-setup', 'shell:test:' + test);
        });

        // ### Validate
        // **Main testing task**
        //
        // `grunt validate` will build, lint and test your local Ghost codebase.
        //
        // `grunt validate` is one of the most important and useful grunt tasks that we have available to use. It
        // manages the build of your environment and then calls `grunt test`
        //
        // `grunt validate` is called by `npm test` and is used by Travis.
        grunt.registerTask('validate', 'Run tests and lint code',
            ['init', 'lint', 'test-all']);

        // ### Test-All
        // **Main testing task**
        //
        // `grunt test-all` will lint and test your pre-built local Ghost codebase.
        //
        // `grunt test-all` runs jshint and jscs as well as all 6 test suites. See the individual sub tasks below for
        // details of each of the test suites.
        //
        grunt.registerTask('test-all', 'Run tests and lint code',
            ['test-routes', 'test-module', 'test-unit', 'test-integration', 'shell:ember:test', 'test-functional']);

        // ### Lint
        //
        // `grunt lint` will run the linter and the code style checker so you can make sure your code is pretty
        grunt.registerTask('lint', 'Run the code style checks and linter',
            ['jshint', 'jscs']
        );

        // ### test-setup *(utility)(
        // `grunt test-setup` will run all the setup tasks required for running tests
        grunt.registerTask('test-setup', 'Setup ready to run tests',
            ['clean:test', 'setTestEnv', 'ensureConfig']
        );

        // ### Unit Tests *(sub task)*
        // `grunt test-unit` will run just the unit tests
        //
        // Provided you already have a `config.js` file, you can run individual sections from
        // [mochacli](#grunt-mocha-cli) by running:
        //
        // `NODE_ENV=testing grunt mochacli:section`
        //
        // If you need to run an individual unit test file, you can do so, providing you have mocha installed globally
        // by using a command in the form:
        //
        // `NODE_ENV=testing mocha --timeout=15000 --ui=bdd --reporter=spec core/test/unit/config_spec.js`
        //
        // Unit tests are run with [mocha](http://mochajs.org/) using
        // [should](https://github.com/visionmedia/should.js) to describe the tests in a highly readable style.
        // Unit tests do **not** touch the database.
        // A coverage report can be generated for these tests using the `grunt test-coverage` task.
        grunt.registerTask('test-unit', 'Run unit tests (mocha)',
            ['test-setup', 'mochacli:unit']
        );

        // ### Integration tests *(sub task)*
        // `grunt test-integration` will run just the integration tests
        //
        // Provided you already have a `config.js` file, you can run just the model integration tests by running:
        //
        // `NODE_ENV=testing grunt mochacli:model`
        //
        // Or just the api integration tests by running:
        //
        // `NODE_ENV=testing grunt mochacli:api`
        //
        // Integration tests are run with [mocha](http://mochajs.org/) using
        // [should](https://github.com/visionmedia/should.js) to describe the tests in a highly readable style.
        // Integration tests are different to the unit tests because they make requests to the database.
        //
        // If you need to run an individual integration test file you can do so, providing you have mocha installed
        // globally, by using a command in the form (replace path to api_tags_spec.js with the test file you want to
        // run):
        //
        // `NODE_ENV=testing mocha --timeout=15000 --ui=bdd --reporter=spec core/test/integration/api/api_tags_spec.js`
        //
        // Their purpose is to test that both the api and models behave as expected when the database layer is involved.
        // These tests are run against sqlite3, mysql and pg on travis and ensure that differences between the databases
        // don't cause bugs. At present, pg often fails and is not officially supported.
        //
        // A coverage report can be generated for these tests using the `grunt test-coverage` task.
        grunt.registerTask('test-integration', 'Run integration tests (mocha + db access)',
            ['test-setup', 'mochacli:integration']
        );

        // ### Route tests *(sub task)*
        // `grunt test-routes` will run just the route tests
        //
        // If you need to run an individual route test file, you can do so, providing you have a `config.js` file and
        // mocha installed globally by using a command in the form:
        //
        // `NODE_ENV=testing mocha --timeout=15000 --ui=bdd --reporter=spec core/test/functional/routes/admin_spec.js`
        //
        // Route tests are run with [mocha](http://mochajs.org/) using
        // [should](https://github.com/visionmedia/should.js) and [supertest](https://github.com/visionmedia/supertest)
        // to describe and create the tests.
        //
        // Supertest enables us to describe requests that we want to make, and also describe the response we expect to
        // receive back. It works directly with express, so we don't have to run a server to run the tests.
        //
        // The purpose of the route tests is to ensure that all of the routes (pages, and API requests) in Ghost
        // are working as expected, including checking the headers and status codes received. It is very easy and
        // quick to test many permutations of routes / urls in the system.
        grunt.registerTask('test-routes', 'Run functional route tests (mocha)',
            ['test-setup', 'mochacli:routes']
        );

        // ### Module tests *(sub task)*
        // `grunt test-module` will run just the module tests
        //
        // The purpose of the module tests is to ensure that Ghost can be used as an npm module and exposes all
        // required methods to interact with it.
        grunt.registerTask('test-module', 'Run functional module tests (mocha)',
            ['test-setup', 'mochacli:module']
        );

        // ### Ember unit tests *(sub task)*
        // `grunt testem` will run just the ember unit tests
        grunt.registerTask('test-ember', 'Run the ember unit tests',
            ['test-setup', 'shell:ember:test']
        );

        // ### Functional tests *(sub task)*
        // `grunt test-functional` will run just the functional tests
        //
        // You can use the `--target` argument to run any individual test file, or the admin or frontend tests:
        //
        // `grunt test-functional --target=client/editor_test.js` - run just the editor tests
        //
        // `grunt test-functional --target=client/` - run all of the tests in the client directory
        //
        // Functional tests are run with [phantom.js](http://phantomjs.org/) and defined using the testing api from
        // [casper.js](http://docs.casperjs.org/en/latest/testing.html).
        //
        // An express server is started with the testing environment set, and then a headless phantom.js browser is
        // used to make requests to that server. The Casper.js API then allows us to describe the elements and
        // interactions we expect to appear on the page.
        //
        // The purpose of the functional tests is to ensure that Ghost is working as is expected from a user perspective
        // including buttons and other important interactions in the admin UI.
        grunt.registerTask('test-functional', 'Run functional interface tests (CasperJS)',
            ['test-setup', 'cleanDatabase', 'express:test', 'spawnCasperJS', 'express:test:stop', 'test-functional-setup']
        );

        // ### Functional tests for the setup process
        // `grunt test-functional-setup will run just the functional tests for the setup page.
        //
        // Setup only works with a brand new database, so it needs to run isolated from the rest of
        // the functional tests.
        grunt.registerTask('test-functional-setup', 'Run functional tests for setup',
            ['test-setup', 'cleanDatabase', 'express:test', 'spawnCasperJS:setup', 'express:test:stop']
        );

        // ### Coverage
        // `grunt coverage` will generate a report for the Unit Tests.
        //
        // This is not currently done as part of CI or any build, but is a tool we have available to keep an eye on how
        // well the unit and integration tests are covering the code base.
        // Ghost does not have a minimum coverage level - we're more interested in ensuring important and useful areas
        // of the codebase are covered, than that the whole codebase is covered to a particular level.
        //
        // Key areas for coverage are: helpers and theme elements, apps / GDK, the api and model layers.

        grunt.registerTask('coverage', 'Generate unit and integration (mocha) tests coverage report',
            ['test-setup', 'mocha_istanbul:coverage']
        );

        // #### Master Warning *(Utility Task)*
        // Warns git users not ot use the `master` branch in production.
        // `master` is an unstable branch and shouldn't be used in production as you run the risk of ending up with a
        // database in an unrecoverable state. Instead there is a branch called `stable` which is the equivalent of the
        // release zip for git users.
        grunt.registerTask('master-warn',
            'Outputs a warning to runners of grunt prod, that master shouldn\'t be used for live blogs',
            function () {
                console.log('>', chalk.red('Always two there are, no more, no less. A master and a'),
                        chalk.bold.red('stable') + chalk.red('.'));
                console.log('Use the', chalk.bold('stable'), 'branch for live blogs.', chalk.bold('Never'), 'master!');
            });

        // ### Build About Page *(Utility Task)*
        // Builds the github contributors partial template used on the Settings/About page,
        // and downloads the avatar for each of the users.
        // Run by any task that compiles the ember assets or manually via `grunt buildAboutPage`.
        // Change which version you're working against by setting the "releaseTag" below.
        //
        // Only builds if the contributors template does not exist.
        // To force a build regardless, supply the --force option.
        //     `grunt buildAboutPage --force`
        grunt.registerTask('buildAboutPage', 'Compile assets for the About Ghost page', function () {
            var done = this.async(),
                templatePath = 'core/client/app/templates/-contributors.hbs',
                imagePath = 'core/client/public/assets/img/contributors/',
                ninetyDaysAgo = Date.now() - (1000 * 60 * 60 * 24 * 90),
                oauthKey = process.env.GITHUB_OAUTH_KEY;

            if (fs.existsSync(templatePath) && !grunt.option('force')) {
                grunt.log.writeln('Contributors template already exists.');
                grunt.log.writeln(chalk.bold('Skipped'));
                return done();
            }

            grunt.verbose.writeln('Downloading release and contributor information from GitHub');

            return Promise.join(
                Promise.promisify(fs.mkdirs)(imagePath),
                getTopContribs({
                    user: 'tryghost',
                    repo: 'ghost',
                    oauthKey: oauthKey,
                    releaseDate: ninetyDaysAgo,
                    count: 20,
                    retry: true
                })
            ).then(function (results) {
                var contributors = results[1],
                    contributorTemplate = '<li>\n    <a href="<%githubUrl%>" title="<%name%>">\n' +
                    '        <img src="{{gh-path "admin" "/img/contributors"}}/<%name%>" alt="<%name%>">\n' +
                    '    </a>\n</li>',

                    downloadImagePromise = function (url, name) {
                        return new Promise(function (resolve, reject) {
                            request(url)
                            .pipe(fs.createWriteStream(imagePath + name))
                            .on('close', resolve)
                            .on('error', reject);
                        });
                    };

                grunt.verbose.writeln('Creating contributors template.');
                grunt.file.write(templatePath,
                    // Map contributors to the template.
                    _.map(contributors, function (contributor) {
                        return contributorTemplate
                            .replace(/<%githubUrl%>/g, contributor.githubUrl)
                            .replace(/<%name%>/g, contributor.name);
                    }).join('\n')
                );

                grunt.verbose.writeln('Downloading images for top contributors');
                return Promise.all(_.map(contributors, function (contributor) {
                    return downloadImagePromise(contributor.avatarUrl + '&s=60', contributor.name);
                }));
            }).then(done).catch(function (error) {
                grunt.log.error(error);

                if (error.http_status) {
                    grunt.log.writeln('GitHub API request returned status: ' + error.http_status);
                }

                if (error.ratelimit_limit) {
                    grunt.log.writeln('Rate limit data: limit: %d, remaining: %d, reset: %s', error.ratelimit_limit, error.ratelimit_remaining, moment.unix(error.ratelimit_reset).fromNow());
                }

                done(false);
            });
        });

        // ## Building assets
        //
        // Ghost's GitHub repository contains the un-built source code for Ghost. If you're looking for the already
        // built release zips, you can get these from the [release page](https://github.com/TryGhost/Ghost/releases) on
        // GitHub or from https://ghost.org/download. These zip files are created using the [grunt release](#release)
        // task.
        //
        // If you want to work on Ghost core, or you want to use the source files from GitHub, then you have to build
        // the Ghost assets in order to make them work.
        //
        // There are a number of grunt tasks available to help with this. Firstly after fetching an updated version of
        // the Ghost codebase, after running `npm install`, you will need to run [grunt init](#init%20assets).
        //
        // For production blogs you will need to run [grunt prod](#production%20assets).
        //
        // For updating assets during development, the tasks [grunt](#default%20asset%20build) and
        // [grunt dev](#live%20reload) are available.

        // ### Init assets
        // `grunt init` - will run an initial asset build for you
        //
        // Grunt init runs `bower install` as well as the standard asset build tasks which occur when you run just
        // `grunt`. This fetches the latest client side dependencies, and moves them into their proper homes.
        //
        // This task is very important, and should always be run and when fetching down an updated code base just after
        // running `npm install`.
        //
        // `bower` does have some quirks, such as not running as root. If you have problems please try running
        // `grunt init --verbose` to see if there are any errors.
        grunt.registerTask('init', 'Prepare the project for development',
            ['shell:ember:init', 'shell:bower', 'update_submodules', 'assets', 'default']);

        // ### Basic Asset Building
        // Builds and moves necessary client assets. Prod additionally builds the ember app.
        grunt.registerTask('assets', 'Basic asset building & moving',
            ['clean:tmp', 'buildAboutPage', 'copy:jquery']);

        // ### Default asset build
        // `grunt` - default grunt task
        //
        // Build assets and dev version of the admin app.
        grunt.registerTask('default', 'Build JS & templates for development',
            ['shell:ember:dev']);

        // ### Production assets
        // `grunt prod` - will build the minified assets used in production.
        //
        // It is otherwise the same as running `grunt`, but is only used when running Ghost in the `production` env.
        grunt.registerTask('prod', 'Build JS & templates for production',
            ['shell:ember:prod', 'uglify:prod', 'master-warn']);

        // ### Live reload
        // `grunt dev` - build assets on the fly whilst developing
        //
        // If you want Ghost to live reload for you whilst you're developing, you can do this by running `grunt dev`.
        // This works hand-in-hand with the [livereload](http://livereload.com/) chrome extension.
        //
        // `grunt dev` manages starting an express server and restarting the server whenever core files change (which
        // require a server restart for the changes to take effect) and also manage reloading the browser whenever
        // frontend code changes.
        //
        // Note that the current implementation of watch only works with casper, not other themes.
        grunt.registerTask('dev', 'Dev Mode; watch files and restart server on changes',
           ['bgShell:ember', 'express:dev', 'watch']);

        // ### Release
        // Run `grunt release` to create a Ghost release zip file.
        // Uses the files specified by `.npmignore` to know what should and should not be included.
        // Runs the asset generation tasks for both development and production so that the release can be used in
        // either environment, and packages all the files up into a zip.
        grunt.registerTask('release',
            'Release task - creates a final built zip\n' +
            ' - Do our standard build steps \n' +
            ' - Copy files to release-folder/#/#{version} directory\n' +
            ' - Clean out unnecessary files (travis, .git*, etc)\n' +
            ' - Zip files in release-folder to dist-folder/#{version} directory',
            ['init', 'shell:ember:prod', 'uglify:release', 'clean:release',  'shell:shrinkwrap', 'copy:release', 'compress:release']);
    };

// Export the configuration
module.exports = configureGrunt;