class PgsqlRequirements

class PgsqlRequirements implements InstallRequirementsInterface {
    
    /**
     * {@inheritdoc}
     */
    public static function getRequirements() : array {
        $requirements = [];
        // Test with PostgreSQL databases for the status of the pg_trgm extension.
        if (Database::isActiveConnection()) {
            $connection = Database::getConnection();
            // Set the requirement just for postgres.
            if ($connection->driver() == 'pgsql') {
                $requirements['pgsql_extension_pg_trgm'] = [
                    'severity' => REQUIREMENT_OK,
                    'title' => t('PostgreSQL pg_trgm extension'),
                    'value' => t('Available'),
                    'description' => t('The pg_trgm PostgreSQL extension is present.'),
                ];
                // If the extension is not available, set the requirement error.
                if (!$connection->schema()
                    ->extensionExists('pg_trgm')) {
                    $requirements['pgsql_extension_pg_trgm']['severity'] = REQUIREMENT_ERROR;
                    $requirements['pgsql_extension_pg_trgm']['value'] = t('Not created');
                    $requirements['pgsql_extension_pg_trgm']['description'] = t('The <a href=":pg_trgm">pg_trgm</a> PostgreSQL extension is not present. The extension is required by Drupal to improve performance when using PostgreSQL. See <a href=":requirements">Drupal database server requirements</a> for more information.', [
                        ':pg_trgm' => 'https://www.postgresql.org/docs/current/pgtrgm.html',
                        ':requirements' => 'https://www.drupal.org/docs/system-requirements/database-server-requirements',
                    ]);
                }
            }
        }
        return $requirements;
    }

}