class CodeExporter

final class CodeExporter {
    public function constants(Snapshot $snapshot) : string {
        $result = '';
        foreach ($snapshot->constants() as $name => $value) {
            $result .= sprintf('if (!defined(\'%s\')) define(\'%s\', %s);' . "\n", $name, $name, $this->exportVariable($value));
        }
        return $result;
    }
    public function globalVariables(Snapshot $snapshot) : string {
        $result = <<<'EOT'
call_user_func(
    function ()
    {
        foreach (array_keys($GLOBALS) as $key) {
            unset($GLOBALS[$key]);
        }
    }
);


EOT;
        foreach ($snapshot->globalVariables() as $name => $value) {
            $result .= sprintf('$GLOBALS[%s] = %s;' . PHP_EOL, $this->exportVariable($name), $this->exportVariable($value));
        }
        return $result;
    }
    public function iniSettings(Snapshot $snapshot) : string {
        $result = '';
        foreach ($snapshot->iniSettings() as $key => $value) {
            $result .= sprintf('@ini_set(%s, %s);' . "\n", $this->exportVariable($key), $this->exportVariable($value));
        }
        return $result;
    }
    private function exportVariable(mixed $variable) : string {
        if (is_scalar($variable) || null === $variable || is_array($variable) && $this->arrayOnlyContainsScalars($variable)) {
            return var_export($variable, true);
        }
        return 'unserialize(' . var_export(serialize($variable), true) . ')';
    }
    private function arrayOnlyContainsScalars(array $array) : bool {
        $result = true;
        foreach ($array as $element) {
            if (is_array($element)) {
                $result = $this->arrayOnlyContainsScalars($element);
            }
            elseif (!is_scalar($element) && null !== $element) {
                $result = false;
            }
            if ($result === false) {
                break;
            }
        }
        return $result;
    }

}