Rough in new preflight steps. There is still much that is missing; th…

…is shows general structure only.

drush

@@ -29,15 +29,16 @@
  *   - Return status code
  */
 
+$loader = false;
 if (file_exists($path = __DIR__ . '/vendor/autoload.php')
     || file_exists($path = __DIR__ . '/../autoload.php')
     || file_exists($path = __DIR__ . '/../../autoload.php')
 ) {
-    include_once($path);
+    $loader = include_once($path);
 } else {
     throw new \Exception('Could not locate autoload.php');
 }
 
-$preflight = new \Drush\Drush\Preflight();
-$status_code = $preflight->run();
+$preflight = new \Drush\Boot\Preflight($loader, dirname($path));
+$status_code = $preflight->run($_SERVER['argv']);
 exit($status_code);

src/Boot/Preflight.php

@@ -0,0 +1,224 @@
+<?php
+namespace Drush\Boot;
+
+use Composer\Autoload\ClassLoader;
+use Webmozart\PathUtil\Path;
+
+use Symfony\Component\Console\Input\ArgvInput;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Input\StringInput;
+use Symfony\Component\Console\Output\OutputInterface;
+
+/**
+ * Prepare to bootstrap Drupal
+ *
+ * - Determine the site to use
+ * - Set up the DI container
+ * - Start the bootstrap process
+ */
+class Preflight
+{
+    /**
+     * @var ClassLoader $loader The class loader returned from autoload.php.
+     */
+    protected $loader;
+
+    /**
+     * @var $vendorPath The path to the 'vendor' directory
+     */
+    protected $vendorPath;
+
+    public function __construct(ClassLoader $loader, $vendorPath)
+    {
+        $this->loader = $loader;
+        $this->vendorPath = $vendorPath;
+    }
+
+    public function run($argv)
+    {
+        $home = Path::getHomeDirectory();
+        $drushBasePath = dirname(dirname(__DIR__));
+
+        // Define legacy constants, and include legacy files that Drush still needs
+        $this->includeLegacyCode($drushBasePath);
+        $this->defineLegacyConstants($drushBasePath);
+        $this->setTerminationHandlers();
+
+        // Preprocess the args, removing any @sitealias that may be present
+        $argProcessor = new PreprocessArgs($argv);
+
+        // Load configuration and aliases from defined global locations
+        // where such things are found.
+        // TODO: Support --local to turn off global configuration locations.
+        $configLocater = new ConfigLocater();
+        $configLocater->addUserConfig($argProcessor->configPath(), $home);
+        $configLocater->addDrushConfig($drushBasePath);
+        $configLocater->addAliasConfig($argProcessor->alias(), $argProcessor->aliasPath(), $home);
+
+        // Determine the local Drupal site targeted, if any
+        // TODO: We should probably pass cwd into the bootstrap manager as a parameter.
+        Drush::bootstrapManager()->locateRoot($argProcessor->selectedSite());
+
+        // Include the Composer autoload for Drupal (if different)
+
+        // Extend configuration and alias files to include files in target Drupal site.
+        $configLocater->addSiteConfig(Drush::bootstrapManager()->getRoot());
+
+        // Create the Symfony Application et. al.
+        $input = new ArgvInput($argProcessor->args());
+        $output = new \Symfony\Component\Console\Output\ConsoleOutput();
+        $application = new \Symfony\Component\Console\Application('Drush Commandline Tool', Drush::getVersion());
+
+        // Set up the DI container
+        $container = $this->initDependencyInjectionContainer($application, $configLocater->config(), $input, $output);
+
+        // Run the Symfony Application
+        // Predispatch: call a remote Drush command if applicable (via a 'pre-init' hook)
+        // Bootstrap: bootstrap site to the level requested by the command (via a 'post-init' hook)
+        $status = $application->run($input, $output);
+
+        return $status;
+    }
+
+    /**
+     * Define legacy constants.
+     */
+    protected function defineLegacyConstants($drushBasePath)
+    {
+        define('DRUSH_REQUEST_TIME', microtime(TRUE));
+        define('DRUSH_BASE_PATH', $drushBasePath);
+
+        /*
+         * @deprecated. Use Drush::getVersion().
+         */
+        define('DRUSH_VERSION', Drush::getVersion());
+
+        /*
+         * @deprecated. Use Drush::getMajorVersion().
+         */
+        define('DRUSH_MAJOR_VERSION', Drush::getMajorVersion());
+
+        /*
+         * @deprecated. Use Drush::getMinorVersion().
+         */
+        define('DRUSH_MINOR_VERSION', Drush::getMinorVersion());
+
+        /*
+         * @deprecated. Do not use
+         */
+        drush_set_context('argc', $GLOBALS['argc']);
+        drush_set_context('argv', $GLOBALS['argv']);
+        drush_set_context('DRUSH_VENDOR_PATH', $this->vendorPath);
+        drush_set_context('DRUSH_CLASSLOADER', $this->loader);
+    }
+
+    /**
+     * Include old code. It is an aspirational goal to remove or refactor
+     * all of this into more modular, class-based code.
+     */
+    protected function includeLegacyCode($drushBasePath)
+    {
+        require_once $drushBasePath . '/includes/preflight.inc';
+        require_once $drushBasePath . '/includes/bootstrap.inc';
+        require_once $drushBasePath . '/includes/environment.inc';
+        require_once $drushBasePath . '/includes/annotationcommand_adapter.inc';
+        require_once $drushBasePath . '/includes/command.inc';
+        require_once $drushBasePath . '/includes/drush.inc';
+        require_once $drushBasePath . '/includes/backend.inc';
+        require_once $drushBasePath . '/includes/batch.inc';
+        require_once $drushBasePath . '/includes/context.inc';
+        require_once $drushBasePath . '/includes/sitealias.inc';
+        require_once $drushBasePath . '/includes/exec.inc';
+        require_once $drushBasePath . '/includes/drupal.inc';
+        require_once $drushBasePath . '/includes/output.inc';
+        require_once $drushBasePath . '/includes/cache.inc';
+        require_once $drushBasePath . '/includes/filesystem.inc';
+        require_once $drushBasePath . '/includes/legacy.inc';
+    }
+
+    /**
+     * Make sure we are notified on exit, and when bad things happen.
+     */
+    protected function setTerminationHandlers()
+    {
+        // Set an error handler and a shutdown function
+        set_error_handler('drush_error_handler');
+        register_shutdown_function('drush_shutdown');
+    }
+
+    /**
+     * Set up our dependency injection container.
+     *
+     * The Drupal6 boot service is needed in order to show the D6 deprecation message.
+     */
+    protected function initDependencyInjectionContainer($application, $config, $input = null, $output = null)
+    {
+        // Create default input and output objects if they were not provided
+        if (!$input) {
+            $input = new StringInput('');
+        }
+        if (!$output) {
+            $output = new \Symfony\Component\Console\Output\ConsoleOutput();
+        }
+        // Set up our dependency injection container.
+        $container = new \League\Container\Container();
+
+        \Robo\Robo::configureContainer($container, $application, $config, $input, $output);
+        $container->add('container', $container);
+
+        // Override Robo's logger with our own
+        $container->share('logger', 'Drush\Log\Logger')
+          ->withArgument('output')
+          ->withMethodCall('setLogOutputStyler', ['logStyler']);
+
+        // Override Robo's formatter manager with our own
+        // @todo not sure that we'll use this. Maybe remove it.
+        $container->share('formatterManager', \Drush\Formatters\DrushFormatterManager::class)
+            ->withMethodCall('addDefaultFormatters', [])
+            ->withMethodCall('addDefaultSimplifiers', []);
+
+        // Add some of our own objects to the container
+        $container->share('bootstrap.default', 'Drush\Boot\EmptyBoot');
+        $container->share('bootstrap.drupal6', 'Drush\Boot\DrupalBoot6');
+        $container->share('bootstrap.drupal7', 'Drush\Boot\DrupalBoot7');
+        $container->share('bootstrap.drupal8', 'Drush\Boot\DrupalBoot8');
+        $container->share('bootstrap.manager', 'Drush\Boot\BootstrapManager')
+          ->withArgument('bootstrap.default');
+        $container->extend('bootstrap.manager')
+          ->withMethodCall('add', ['bootstrap.drupal6'])
+          ->withMethodCall('add', ['bootstrap.drupal7'])
+          ->withMethodCall('add', ['bootstrap.drupal8']);
+
+        // Robo does not manage the command discovery object in the container,
+        // but we will register and configure one for our use.
+        $container->share('commandDiscovery', 'Consolidation\AnnotatedCommand\CommandFileDiscovery')
+          ->withMethodCall('addSearchLocation', ['CommandFiles'])
+          ->withMethodCall('setSearchPattern', ['#.*(Commands|CommandFile).php$#']);
+
+        // Store the container in the \Drush object
+        Drush::setContainer($container);
+        \Robo\Robo::setContainer($container);
+
+        // Add our own callback to the hook manager
+        $hookManager = $container->get('hookManager');
+        $hookManager->addOutputExtractor(new \Drush\Backend\BackendResultSetter());
+        // @todo: do we need both backend result setters? The one below should be removed at some point.
+        $hookManager->add('annotatedcomand_adapter_backend_result', HookManager::EXTRACT_OUTPUT);
+
+        // Install our command cache into the command factory
+        // TODO: Create class-based implementation of our cache management functions.
+        $cacheBackend = _drush_cache_get_object('factory');
+        $commandCacheDataStore = new CommandCache($cacheBackend);
+
+        $factory = $container->get('commandFactory');
+        $factory->setIncludeAllPublicMethods(false);
+        $factory->setDataStore($commandCacheDataStore);
+
+        // It is necessary to set the dispatcher when using configureContainer
+        $eventDispatcher = $container->get('eventDispatcher');
+        $eventDispatcher->addSubscriber(new \Drush\Command\GlobalOptionsEventListener());
+        $application->setDispatcher($eventDispatcher);
+
+        return $container;
+    }
+}

src/Boot/PreprocessArgs.php

@@ -0,0 +1,42 @@
+<?php
+namespace Drush\Boot;
+
+/**
+ * Preprocess commandline arguments
+ *
+ * If we are still going to support --php and --php-options flags, then
+ * we need to remove those here as well (or add them to the Symfony
+ * application).
+ */
+class PreprocessArgs
+{
+        public function __construct($argv)
+        {
+
+        }
+
+        public function args()
+        {
+            return [];
+        }
+
+        public function alias()
+        {
+            return false;
+        }
+
+        public function selectedSite()
+        {
+            return false;
+        }
+
+        public function configPath()
+        {
+            return false;
+        }
+
+        public function aliasPath()
+        {
+            return false;
+        }
+}

src/Config/ConfigLocater.php

@@ -0,0 +1,43 @@
+<?php
+namespace Drush\Config;
+
+use Webmozart\PathUtil\Path;
+
+/**
+ * Locate configuration files
+ */
+class ConfigLocater
+{
+    public function __construct()
+    {
+    }
+
+    public function config()
+    {
+        $roboConfig = new \Robo\Config(); // TODO: make a global Drush config class derived from \Robo\Config. Then use $drushConfig here instead of $roboConfig
+        return $roboConfig;
+    }
+
+    public function addUserConfig($configPath, $home)
+    {
+
+    }
+
+    public function addDrushConfig($drushProjectDir)
+    {
+
+    }
+
+    public function addAliasConfig($alias, $aliasPath, $home)
+    {
+
+    }
+
+    public function addSiteConfig($siteRoot)
+    {
+        // There might not be a site
+        if (!$siteRoot) {
+            return;
+        }
+    }
+}