class TextPart

class TextPart extends AbstractPart {
    private const DEFAULT_ENCODERS = [
        'quoted-printable',
        'base64',
        '8bit',
    ];
    
    /** @internal */
    protected Headers $_headers;
    private static array $encoders = [];
    
    /** @var resource|string|File */
    private $body;
    private ?string $charset;
    private string $subtype;
    private ?string $disposition = null;
    private ?string $name = null;
    private string $encoding;
    private ?bool $seekable = null;
    
    /**
     * @param resource|string|File $body Use a File instance to defer loading the file until rendering
     */
    public function __construct($body, ?string $charset = 'utf-8', string $subtype = 'plain', ?string $encoding = null) {
        parent::__construct();
        if (!\is_string($body) && !\is_resource($body) && !$body instanceof File) {
            throw new \TypeError(\sprintf('The body of "%s" must be a string, a resource, or an instance of "%s" (got "%s").', self::class, File::class, get_debug_type($body)));
        }
        if ($body instanceof File) {
            $path = $body->getPath();
            if (is_file($path) && !is_readable($path) || is_dir($path)) {
                throw new InvalidArgumentException(\sprintf('Path "%s" is not readable.', $path));
            }
        }
        $this->body = $body;
        $this->charset = $charset;
        $this->subtype = $subtype;
        $this->seekable = \is_resource($body) ? stream_get_meta_data($body)['seekable'] && 0 === fseek($body, 0, \SEEK_CUR) : null;
        if (null === $encoding) {
            $this->encoding = $this->chooseEncoding();
        }
        else {
            if (!\in_array($encoding, self::DEFAULT_ENCODERS, true) && !\array_key_exists($encoding, self::$encoders)) {
                throw new InvalidArgumentException(\sprintf('The encoding must be one of "%s" ("%s" given).', implode('", "', array_unique(array_merge(self::DEFAULT_ENCODERS, array_keys(self::$encoders)))), $encoding));
            }
            $this->encoding = $encoding;
        }
    }
    public function getMediaType() : string {
        return 'text';
    }
    public function getMediaSubtype() : string {
        return $this->subtype;
    }
    
    /**
     * @param string $disposition one of attachment, inline, or form-data
     *
     * @return $this
     */
    public function setDisposition(string $disposition) : static {
        $this->disposition = $disposition;
        return $this;
    }
    
    /**
     * @return ?string null or one of attachment, inline, or form-data
     */
    public function getDisposition() : ?string {
        return $this->disposition;
    }
    
    /**
     * Sets the name of the file (used by FormDataPart).
     *
     * @return $this
     */
    public function setName(string $name) : static {
        $this->name = $name;
        return $this;
    }
    
    /**
     * Gets the name of the file.
     */
    public function getName() : ?string {
        return $this->name;
    }
    public function getBody() : string {
        if ($this->body instanceof File) {
            if (false === ($ret = @file_get_contents($this->body
                ->getPath()))) {
                throw new InvalidArgumentException(error_get_last()['message']);
            }
            return $ret;
        }
        if (null === $this->seekable) {
            return $this->body;
        }
        if ($this->seekable) {
            rewind($this->body);
        }
        return stream_get_contents($this->body) ?: '';
    }
    public function bodyToString() : string {
        return $this->getEncoder()
            ->encodeString($this->getBody(), $this->charset);
    }
    public function bodyToIterable() : iterable {
        if ($this->body instanceof File) {
            $path = $this->body
                ->getPath();
            if (false === ($handle = @fopen($path, 'r', false))) {
                throw new InvalidArgumentException(\sprintf('Unable to open path "%s".', $path));
            }
            yield from $this->getEncoder()
                ->encodeByteStream($handle);
        }
        elseif (null !== $this->seekable) {
            if ($this->seekable) {
                rewind($this->body);
            }
            yield from $this->getEncoder()
                ->encodeByteStream($this->body);
        }
        else {
            (yield $this->getEncoder()
                ->encodeString($this->body));
        }
    }
    public function getPreparedHeaders() : Headers {
        $headers = parent::getPreparedHeaders();
        $headers->setHeaderBody('Parameterized', 'Content-Type', $this->getMediaType() . '/' . $this->getMediaSubtype());
        if ($this->charset) {
            $headers->setHeaderParameter('Content-Type', 'charset', $this->charset);
        }
        if ($this->name && 'form-data' !== $this->disposition) {
            $headers->setHeaderParameter('Content-Type', 'name', $this->name);
        }
        $headers->setHeaderBody('Text', 'Content-Transfer-Encoding', $this->encoding);
        if (!$headers->has('Content-Disposition') && null !== $this->disposition) {
            $headers->setHeaderBody('Parameterized', 'Content-Disposition', $this->disposition);
            if ($this->name) {
                $headers->setHeaderParameter('Content-Disposition', 'name', $this->name);
            }
        }
        return $headers;
    }
    public function asDebugString() : string {
        $str = parent::asDebugString();
        if (null !== $this->charset) {
            $str .= ' charset: ' . $this->charset;
        }
        if (null !== $this->disposition) {
            $str .= ' disposition: ' . $this->disposition;
        }
        return $str;
    }
    private function getEncoder() : ContentEncoderInterface {
        if ('8bit' === $this->encoding) {
            return self::$encoders[$this->encoding] ??= new EightBitContentEncoder();
        }
        if ('quoted-printable' === $this->encoding) {
            return self::$encoders[$this->encoding] ??= new QpContentEncoder();
        }
        if ('base64' === $this->encoding) {
            return self::$encoders[$this->encoding] ??= new Base64ContentEncoder();
        }
        return self::$encoders[$this->encoding];
    }
    public static function addEncoder(ContentEncoderInterface $encoder) : void {
        if (\in_array($encoder->getName(), self::DEFAULT_ENCODERS, true)) {
            throw new InvalidArgumentException('You are not allowed to change the default encoders ("quoted-printable", "base64", and "8bit").');
        }
        self::$encoders[$encoder->getName()] = $encoder;
    }
    private function chooseEncoding() : string {
        if (null === $this->charset) {
            return 'base64';
        }
        return 'quoted-printable';
    }
    public function __sleep() : array {
        // convert resources to strings for serialization
        if (null !== $this->seekable) {
            $this->body = $this->getBody();
            $this->seekable = null;
        }
        $this->_headers = $this->getHeaders();
        return [
            '_headers',
            'body',
            'charset',
            'subtype',
            'disposition',
            'name',
            'encoding',
        ];
    }
    public function __wakeup() : void {
        $r = new \ReflectionProperty(AbstractPart::class, 'headers');
        $r->setValue($this, $this->_headers);
        unset($this->_headers);
    }

}