class Composer

class Composer {
    
    /**
     * Update metapackages whenever composer.lock is updated.
     *
     * @param \Composer\Script\Event $event
     *   The Composer event.
     */
    public static function generateMetapackages(Event $event) : void {
        $generator = new PackageGenerator();
        $generator->generate($event->getIO(), getcwd());
    }
    
    /**
     * Update component packages whenever composer.lock is updated.
     *
     * @param \Composer\Script\Event $event
     *   The Composer event.
     */
    public static function generateComponentPackages(Event $event) : void {
        $generator = new ComponentGenerator();
        $generator->generate($event, getcwd());
    }
    
    /**
     * Set the version of Drupal; used in release process and by the test suite.
     *
     * @param string $root
     *   Path to root of drupal/drupal repository.
     * @param string $version
     *   Semver version to set Drupal's version to.
     *
     * @throws \UnexpectedValueException
     */
    public static function setDrupalVersion(string $root, string $version) : void {
        // We use VersionParser::normalize to validate that $version is valid.
        // It will throw an exception if it is not.
        $versionParser = new VersionParser();
        $versionParser->normalize($version);
        // Rewrite Drupal.php with the provided version string.
        $drupal_static_path = "{$root}/core/lib/Drupal.php";
        $drupal_static_source = file_get_contents($drupal_static_path);
        $drupal_static_source = preg_replace('#const VERSION = [^;]*#', "const VERSION = '{$version}'", $drupal_static_source);
        file_put_contents($drupal_static_path, $drupal_static_source);
        // Update the template project stability to match the version we set.
        static::setTemplateProjectStability($root, $version);
    }
    
    /**
     * Set the stability of the template projects to match the Drupal version.
     *
     * @param string $root
     *   Path to root of drupal/drupal repository.
     * @param string $version
     *   Semver version that Drupal was set to.
     */
    protected static function setTemplateProjectStability(string $root, string $version) : void {
        $stability = VersionParser::parseStability($version);
        $templateProjectPaths = static::composerSubprojectPaths($root, 'Template');
        foreach ($templateProjectPaths as $path) {
            $dir = dirname($path);
            exec("composer --working-dir={$dir} config minimum-stability {$stability}", $output, $status);
            if ($status) {
                throw new \Exception('Could not set minimum-stability for template project ' . basename($dir));
            }
        }
    }
    
    /**
     * Ensure that the minimum required version of Composer is running.
     *
     * Throw an exception if Composer is too old.
     */
    public static function ensureComposerVersion() : void {
        $composerVersion = method_exists(ComposerApp::class, 'getVersion') ? ComposerApp::getVersion() : ComposerApp::VERSION;
        if (Comparator::lessThan($composerVersion, '1.9.0')) {
            throw new \RuntimeException("Drupal core development requires Composer 1.9.0, but Composer {$composerVersion} is installed. Please run 'composer self-update'.");
        }
    }
    
    /**
     * Return the branch name the current Drupal version is associated with.
     *
     * @return string
     *   A branch name, e.g. 8.9.x or 9.0.x.
     */
    public static function drupalVersionBranch() : string {
        return preg_replace('#\\.[0-9]+-dev#', '.x-dev', \Drupal::VERSION);
    }
    
    /**
     * Return the list of subprojects of a given type.
     *
     * @param string $root
     *   Path to root of drupal/drupal repository.
     * @param string $subprojectType
     *   Type of subproject - one of Metapackage, Plugin, or Template
     *
     * @return \Symfony\Component\Finder\Finder
     */
    public static function composerSubprojectPaths(string $root, string $subprojectType) : Finder {
        return Finder::create()->files()
            ->name('composer.json')
            ->in("{$root}/composer/{$subprojectType}");
    }

}