composer/src/Composer/Command/SuggestsCommand.php

<?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\Repository\PlatformRepository;
use Symfony\Component\Console\Input\InputArgument;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Input\InputOption;
use Symfony\Component\Console\Output\OutputInterface;

class SuggestsCommand extends BaseCommand
{
    protected function configure()
    {
        $this
            ->setName('suggests')
            ->setDescription('Shows package suggestions.')
            ->setDefinition(array(
                new InputOption('by-package', null, InputOption::VALUE_NONE, 'Groups output by suggesting package'),
                new InputOption('by-suggestion', null, InputOption::VALUE_NONE, 'Groups output by suggested package'),
                new InputOption('no-dev', null, InputOption::VALUE_NONE, 'Exclude suggestions from require-dev packages'),
                new InputArgument('packages', InputArgument::IS_ARRAY | InputArgument::OPTIONAL, 'Packages that you want to list suggestions from.'),
            ))
            ->setHelp(
                <<<EOT

The <info>%command.name%</info> command shows a sorted list of suggested packages.

Enabling <info>-v</info> implies <info>--by-package --by-suggestion</info>, showing both lists.

Read more at https://getcomposer.org/doc/03-cli.md#suggests
EOT
            )
        ;
    }

    protected function execute(InputInterface $input, OutputInterface $output)
    {
        $lock = $this->getComposer()->getLocker()->getLockData();

        if (empty($lock)) {
            throw new \RuntimeException('Lockfile seems to be empty?');
        }

        $packages = $lock['packages'];

        if (!$input->getOption('no-dev')) {
            $packages += $lock['packages-dev'];
        }

        $filter = $input->getArgument('packages');

        // First assemble lookup list of packages that are installed, replaced or provided
        $installed = array();
        foreach ($packages as $package) {
            $installed[] = $package['name'];

            if (!empty($package['provide'])) {
                $installed = array_merge($installed, array_keys($package['provide']));
            }

            if (!empty($package['replace'])) {
                $installed = array_merge($installed, array_keys($package['replace']));
            }
        }

        // Undub and sort the install list into a sorted lookup array
        $installed = array_flip($installed);
        ksort($installed);

        // Init platform repo
        $platform = new PlatformRepository(array(), $this->getComposer()->getConfig()->get('platform') ?: array());

        // Next gather all suggestions that are not in that list
        $suggesters = array();
        $suggested = array();
        foreach ($packages as $package) {
            $packageName = $package['name'];
            if ((!empty($filter) && !in_array($packageName, $filter)) || empty($package['suggest'])) {
                continue;
            }
            foreach ($package['suggest'] as $suggestion => $reason) {
                if (false === strpos('/', $suggestion) && null !== $platform->findPackage($suggestion, '*')) {
                    continue;
                }
                if (!isset($installed[$suggestion])) {
                    $suggesters[$packageName][$suggestion] = $reason;
                    $suggested[$suggestion][$packageName] = $reason;
                }
            }
        }
        ksort($suggesters);
        ksort($suggested);

        // Determine output mode
        $mode = 0;
        $io = $this->getIO();
        if ($input->getOption('by-package') || $io->isVerbose()) {
            $mode |= 1;
        }
        if ($input->getOption('by-suggestion')) {
            $mode |= 2;
        }

        // Simple mode
        if ($mode === 0) {
            foreach (array_keys($suggested) as $suggestion) {
                $io->write(sprintf('<info>%s</info>', $suggestion));
            }

            return 0;
        }

        // Grouped by package
        if ($mode & 1) {
            foreach ($suggesters as $suggester => $suggestions) {
                $io->write(sprintf('<comment>%s</comment> suggests:', $suggester));

                foreach ($suggestions as $suggestion => $reason) {
                    $io->write(sprintf(' - <info>%s</info>: %s', $suggestion, $reason ?: '*'));
                }
                $io->write('');
            }
        }

        // Grouped by suggestion
        if ($mode & 2) {
            // Improve readability in full mode
            if ($mode & 1) {
                $io->write(str_repeat('-', 78));
            }
            foreach ($suggested as $suggestion => $suggesters) {
                $io->write(sprintf('<comment>%s</comment> is suggested by:', $suggestion));

                foreach ($suggesters as $suggester => $reason) {
                    $io->write(sprintf(' - <info>%s</info>: %s', $suggester, $reason ?: '*'));
                }
                $io->write('');
            }
        }

        return 0;
    }
}