Stream.php

<?php

/*
 * This file is part of the Koded package.
 *
 * (c) Mihail Binev <mihail@kodeart.com>
 *
 * Please view the LICENSE distributed with this source code
 * for the full copyright and license information.
 *
 */

namespace Koded\Http;

use Koded\Http\Interfaces\HttpStatus;
use Psr\Http\Message\StreamInterface;


class Stream implements StreamInterface
{
    protected const MODES = [
        'w+'  => 1,
        'r+'  => 1,
        'x+'  => 1,
        'c+'  => 1,
        'a+'  => 1,
        'w+b' => 1,
        'r+b' => 1,
        'x+b' => 1,
        'c+b' => 1,
        'w+t' => 1,
        'r+t' => 1,
        'x+t' => 1,
        'c+t' => 1
    ];

    /** @var resource The underlying stream resource */
    protected $stream;
    protected string $mode   = 'w+b';
    protected bool $seekable = false;

    public function __construct($stream)
    {
        if (false === \is_resource($stream) || 'stream' !== \get_resource_type($stream)) {
            throw new \RuntimeException(
                'The provided resource is not a valid stream resource, ' . \gettype($stream) . ' given.',
                HttpStatus::UNPROCESSABLE_ENTITY
            );
        }
        $metadata       = \stream_get_meta_data($stream);
        $this->mode     = $metadata['mode'] ?? 'w+b';
        $this->seekable = $metadata['seekable'] ?? false;
        $this->stream   = $stream;
    }

    public function __destruct()
    {
        $this->close();
    }

    public function __toString(): string
    {
        try {
            $this->seek(0);
            return $this->getContents();
        } catch (\Throwable) {
            return '';
        }
    }

    public function close(): void
    {
        if ($this->stream) {
            \fclose($this->stream);
            $this->detach();
        }
    }

    public function detach()
    {
        if (empty($this->stream)) {
            return null;
        }
        $resource       = $this->stream;
        $this->mode     = 'w+b';
        $this->stream   = null;
        $this->seekable = false;
        return $resource;
    }

    public function getSize(): ?int
    {
        if (empty($this->stream)) {
            return null;
        }
        return \fstat($this->stream)['size'] ?? null;
    }

    public function tell(): int
    {
        if (false === $position = \ftell($this->stream)) {
            throw new \RuntimeException('Failed to find the position of the file pointer');
        }
        return $position;
    }

    public function eof(): bool
    {
        return \feof($this->stream);
    }

    public function seek($offset, $whence = SEEK_SET): void
    {
        if (0 !== @\fseek($this->stream, $offset, $whence)) {
            throw new \RuntimeException('Failed to seek to file pointer');
        }
    }

    public function rewind(): void
    {
        if (false === $this->seekable) {
            throw new \RuntimeException('The stream is not seekable');
        }
        $this->seek(0);
    }

    public function write($string): int
    {
        if (false === $this->isWritable()) {
            throw new \RuntimeException('The stream is not writable');
        }
        if (false === $bytes = \fwrite($this->stream, $string)) {
            throw new \RuntimeException('Failed to write data to the stream');
        }
        return $bytes;
    }

    public function read($length): string
    {
        if (false === $this->isReadable()) {
            throw new \RuntimeException('The stream is not readable');
        }
        if (empty($length)) {
            return '';
        }
        if (false === $data = \fread($this->stream, $length)) {
            throw new \RuntimeException('Failed to read the data from stream');
        }
        return $data;
    }

    public function getContents(): string
    {
        if (false === $content = \stream_get_contents($this->stream)) {
            throw new \RuntimeException('Unable to read the stream content');
        }
        return $content;
    }

    public function getMetadata($key = null)
    {
        $metadata = \stream_get_meta_data($this->stream);
        if (null === $key) {
            return $metadata;
        }
        return $metadata[$key] ?? null;
    }

    public function isSeekable(): bool
    {
        return $this->seekable;
    }

    public function isReadable(): bool
    {
        return isset((self::MODES + ['r' => 1, 'rb' => 1, 'rt' => 1])[$this->mode]);
    }

    public function isWritable(): bool
    {
        return isset((self::MODES + ['w' => 1, 'rw' => 1, 'a' => 1, 'wb' => 1])[$this->mode]);
    }
}