Initial version of InitCommand

This command allows a user to create a basic composer.json
definition easily.  The idea is to create a command similar
to the `npm init` command.

This version only has `name` and `description` support.
Additional fields will be added such as `require`, `authors`,
`version`, etc.

src/Composer/Command/Helper/DialogHelper.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace Composer\Command\Helper;
+
+use Symfony\Component\Console\Helper\DialogHelper as BaseDialogHelper;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class DialogHelper extends BaseDialogHelper
+{
+    public function writeSection(OutputInterface $output, $text, $style = 'bg=blue;fg=white')
+    {
+        $output->writeln(array(
+            '',
+            $this->getHelperSet()->get('formatter')->formatBlock($text, $style, true),
+            '',
+        ));
+    }
+
+    public function getQuestion($question, $default, $sep = ':')
+    {
+        return $default ? sprintf('<info>%s</info> [<comment>%s</comment>]%s ', $question, $default, $sep) : sprintf('<info>%s</info>%s ', $question, $sep);
+    }
+}

src/Composer/Command/InitCommand.php

@@ -0,0 +1,126 @@
+<?php
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) Nils Adermann <naderman@naderman.de>
+ *     Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer\Command;
+
+use Composer\Json\JsonFile;
+use Composer\Command\Helper\DialogHelper;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+
+
+if (!defined('JSON_PRETTY_PRINT')) {
+    define('JSON_PRETTY_PRINT', 128);
+}
+
+/**
+ * @author Justin Rainbow <justin.rainbow@gmail.com>
+ */
+class InitCommand extends Command
+{
+    protected function configure()
+    {
+        $this
+            ->setName('init')
+            ->setDescription('Creates a basic composer.json file in current directory.')
+            ->setDefinition(array(
+                new InputOption('name', null, InputOption::VALUE_NONE, 'Name of the package'),
+                new InputOption('description', null, InputOption::VALUE_NONE, 'Description of package'),
+                // new InputOption('version', null, InputOption::VALUE_NONE, 'Version of package'),
+                new InputOption('homepage', null, InputOption::VALUE_NONE, 'Homepage of package'),
+            ))
+            ->setHelp(<<<EOT
+The <info>install</info> command reads the composer.json file from the
+current directory, processes it, and downloads and installs all the
+libraries and dependencies outlined in that file.
+
+<info>php composer.phar install</info>
+
+EOT
+            )
+        ;
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output)
+    {
+        $dialog = $this->getDialogHelper();
+
+        $options = array_filter(array_intersect_key($input->getOptions(), array_flip(array('name','description'))));
+
+        $file = new JsonFile("composer.json");
+
+        $indentSize = 2;
+        $lines = array();
+
+        foreach ($options as $key => $value) {
+            $lines[] = sprintf('%s%s: %s', str_repeat(' ', $indentSize), json_encode($key), json_encode($value));
+        }
+
+        $json = "{\n" . implode(",\n", $lines) . "\n}\n";
+
+        if ($input->isInteractive()) {
+            $output->writeln(array(
+                '',
+                $json,
+                ''
+            ));
+            if (!$dialog->askConfirmation($output, $dialog->getQuestion('Do you confirm generation', 'yes', '?'), true)) {
+                $output->writeln('<error>Command aborted</error>');
+
+                return 1;
+            }
+        }
+
+        $file->write($options);
+    }
+
+    protected function interact(InputInterface $input, OutputInterface $output)
+    {
+        $dialog = $this->getDialogHelper();
+        $dialog->writeSection($output, 'Welcome to the Composer config generator');
+
+        // namespace
+        $output->writeln(array(
+            '',
+            'This command will guide you through creating your composer.json config.',
+            '',
+        ));
+
+        $cwd = realpath(".");
+
+        $name = $input->getOption('name') ?: basename($cwd);
+        $name = $dialog->ask(
+            $output,
+            $dialog->getQuestion('Package name', $name),
+            $name
+        );
+        $input->setOption('name', $name);
+
+        $description = $input->getOption('description') ?: false;
+        $description = $dialog->ask(
+            $output,
+            $dialog->getQuestion('Description', $description)
+        );
+        $input->setOption('description', $description);
+    }
+
+    protected function getDialogHelper()
+    {
+        $dialog = $this->getHelperSet()->get('dialog');
+        if (!$dialog || get_class($dialog) !== 'Composer\Command\Helper\DialogHelper') {
+            $this->getHelperSet()->set($dialog = new DialogHelper());
+        }
+
+        return $dialog;
+    }
+}

src/Composer/Console/Application.php

@@ -104,6 +104,7 @@ class Application extends BaseApplication
     {
         $this->add(new Command\AboutCommand());
         $this->add(new Command\DependsCommand());
+        $this->add(new Command\InitCommand());
         $this->add(new Command\InstallCommand());
         $this->add(new Command\UpdateCommand());
         $this->add(new Command\SearchCommand());