class InstallConfigurator

final class InstallConfigurator {
    
    /**
     * The list of modules to install.
     *
     * This list is sorted an includes any module dependencies of the provided
     * extensions.
     *
     * @var string[]
     */
    public readonly array $modules;
    
    /**
     * The list of themes to install.
     *
     * This list is sorted an includes any theme dependencies of the provided
     * extensions.
     *
     * @var string[]
     */
    public readonly array $themes;
    
    /**
     * @param string[] $extensions
     *   A list of extensions for a recipe to install.
     * @param \Drupal\Core\Extension\ModuleExtensionList $module_list
     *   The module list service.
     * @param \Drupal\Core\Extension\ThemeExtensionList $theme_list
     *   The theme list service.
     */
    public function __construct(array $extensions, ModuleExtensionList $module_list, ThemeExtensionList $theme_list) {
        assert(Inspector::assertAllStrings($extensions), 'Extension names must be strings.');
        $extensions = array_map(fn($extension) => Dependency::createFromString($extension)->getName(), $extensions);
        $extensions = array_combine($extensions, $extensions);
        $module_data = $module_list->reset()
            ->getList();
        $theme_data = $theme_list->reset()
            ->getList();
        $modules = array_intersect_key($extensions, $module_data);
        $themes = array_intersect_key($extensions, $theme_data);
        $missing_extensions = array_diff($extensions, $modules, $themes);
        // Add theme module dependencies.
        foreach ($themes as $theme => $value) {
            $modules = array_merge($modules, array_keys($theme_data[$theme]->module_dependencies));
        }
        // Add modules that other modules depend on.
        foreach ($modules as $module) {
            if ($module_data[$module]->requires) {
                $modules = array_merge($modules, array_keys($module_data[$module]->requires));
            }
        }
        // Remove all modules that have been installed already.
        $modules = array_diff(array_unique($modules), array_keys($module_list->getAllInstalledInfo()));
        $modules = array_combine($modules, $modules);
        // Create a sortable list of modules.
        foreach ($modules as $name => $value) {
            if (isset($module_data[$name])) {
                $modules[$name] = $module_data[$name]->sort;
            }
            else {
                $missing_extensions[$name] = $name;
            }
        }
        // Add any missing base themes to the list of themes to install.
        foreach ($themes as $theme => $value) {
            // $theme_data[$theme]->requires contains both theme and module
            // dependencies keyed by the extension machine names.
            // $theme_data[$theme]->module_dependencies contains only the module
            // dependencies keyed by the module extension machine name. Therefore,
            // we can find the theme dependencies by finding array keys for
            // 'requires' that are not in $module_dependencies.
            $theme_dependencies = array_diff_key($theme_data[$theme]->requires, $theme_data[$theme]->module_dependencies);
            $themes = array_merge($themes, array_keys($theme_dependencies));
        }
        // Remove all themes that have been installed already.
        $themes = array_diff(array_unique($themes), array_keys($theme_list->getAllInstalledInfo()));
        $themes = array_combine($themes, $themes);
        // Create a sortable list of themes.
        foreach ($themes as $name => $value) {
            if (isset($theme_data[$name])) {
                $themes[$name] = $theme_data[$name]->sort;
            }
            else {
                $missing_extensions[$name] = $name;
            }
        }
        if (!empty($missing_extensions)) {
            throw new RecipeMissingExtensionsException(array_values($missing_extensions));
        }
        arsort($modules);
        arsort($themes);
        $this->modules = array_keys($modules);
        $this->themes = array_keys($themes);
    }

}