kodedphp / http

<?php

/*

 * This file is part of the Koded package.

 *

 * (c) Mihail Binev <[email protected]>

 *

 * Please view the LICENSE distributed with this source code

 * for the full copyright and license information.

 *

 */

namespace Koded\Http;

use Exception;

use Generator;

use Psr\Http\Message\StreamInterface;

use ReflectionFunction;

use RuntimeException;

use Throwable;

use function fclose;

use function feof;

use function fopen;

use function fread;

use function fseek;

use function fwrite;

use function mb_strlen;

class CallableStream implements StreamInterface

{

    private $callable;

    private int $position = 0;

    private bool $isGenerator;

    public function __construct(callable $callable)

    {

        $this->callable    = $callable;

        $this->isGenerator = (new ReflectionFunction($this->callable))

            ->isGenerator();

    }

    public function __destruct()

    {

        $this->close();

    }

    public function __toString(): string

    {

        try {

            return $this->getContents();

        } catch (RuntimeException) {

            return '';

        }

    }

    public function close(): void

    {

        $this->detach();

    }

    public function detach()

    {

        $this->callable = null;

        $this->position = 0;

    }

    public function getSize(): ?int

    {

        return null;

    }

    public function tell(): int

    {

        return $this->position;

    }

    public function eof(): bool

    {

        return null === $this->callable;

    }

    public function seek($offset, $whence = SEEK_SET): void

    {

        throw new RuntimeException('Cannot seek in CallableStream');

    }

    public function rewind(): void

    {

        throw new RuntimeException('Cannot rewind the CallableStream');

    }

    public function write($string): int

    {

        throw new RuntimeException('Cannot write to CallableStream');

    }

    public function read($length): string

    {

        $content = '';

        if (null === $this->callable) {

            return $content;

        }

        try {

            foreach ($this->reader($length) as $chunk) {

                $content        .= $chunk;

                $this->position += mb_strlen($chunk);

            }

        } catch (Exception $e) {

            throw new RuntimeException($e->getMessage(), $e->getCode(), $e);

        } finally {

            $this->callable = null;

        }

        return $content;

    }

    public function getContents(): string

    {

        return $this->read(65536); // 64KB

    }

    public function getMetadata($key = null): ?array

    {

        return $key ? null : [];

    }

    public function isSeekable(): bool

    {

        return false;

    }

    public function isWritable(): bool

    {

        return false;

    }

    public function isReadable(): bool

    {

        return true;

    }

    /**

     * @param int $length

     *

     * @return Generator

     * @throws RuntimeException

     */

    private function reader(int $length): Generator

    {

        if ($this->isGenerator) {

            yield from ($this->callable)();

        } elseif ($resource = fopen('php://temp', 'r+')) {

            try {

                fwrite($resource, ($this->callable)());

            } catch (Throwable $e) {

                throw new RuntimeException('Cannot write to stream', 0, $e);

            }

            fseek($resource, 0);

            while (false === feof($resource)) {

                yield fread($resource, $length);

            }

            fclose($resource);

        }

    }

}