<?php
namespace GuzzleHttp\Stream;

/**
* PHP stream implementation
*/
class Stream implements StreamInterface
{
private $stream;
private $size;
private $seekable;
private $readable;
private $writable;
private $uri;
private $customMetadata;

/** @var array Hash of readable and writable stream types */
private static $readWriteHash = [
'read' => [
'r' => true, 'w+' => true, 'r+' => true, 'x+' => true, 'c+' => true,
'rb' => true, 'w+b' => true, 'r+b' => true, 'x+b' => true,
'c+b' => true, 'rt' => true, 'w+t' => true, 'r+t' => true,
'x+t' => true, 'c+t' => true, 'a+' => true,
],
'write' => [
'w' => true, 'w+' => true, 'rw' => true, 'r+' => true, 'x+' => true,
'c+' => true, 'wb' => true, 'w+b' => true, 'r+b' => true,
'x+b' => true, 'c+b' => true, 'w+t' => true, 'r+t' => true,
'x+t' => true, 'c+t' => true, 'a' => true, 'a+' => true,
],
];

/**
* Create a new stream based on the input type.
*
* This factory accepts the same associative array of options as described
* in the constructor.
*
* @param resource|string|StreamInterface $resource Entity body data
* @param array $options Additional options
*
* @return Stream
* @throws \InvalidArgumentException if the $resource arg is not valid.
*/
public static function factory($resource = '', array $options = [])
{
$type = gettype($resource);

if ($type == 'string') {
$stream = fopen('php://temp', 'r+');
if ($resource !== '') {
fwrite($stream, $resource);
fseek($stream, 0);
}
return new self($stream, $options);
}

if ($type == 'resource') {
return new self($resource, $options);
}

if ($resource instanceof StreamInterface) {
return $resource;
}

if ($type == 'object' && method_exists($resource, '__toString')) {
return self::factory((string) $resource, $options);
}

if (is_callable($resource)) {
return new PumpStream($resource, $options);
}

if ($resource instanceof \Iterator) {
return new PumpStream(function () use ($resource) {
if (!$resource->valid()) {
return false;
}
$result = $resource->current();
$resource->next();
return $result;
}, $options);
}

throw new \InvalidArgumentException('Invalid resource type: ' . $type);
}

/**
* This constructor accepts an associative array of options.
*
* - size: (int) If a read stream would otherwise have an indeterminate
* size, but the size is known due to foreknownledge, then you can
* provide that size, in bytes.
* - metadata: (array) Any additional metadata to return when the metadata
* of the stream is accessed.
*
* @param resource $stream Stream resource to wrap.
* @param array $options Associative array of options.
*
* @throws \InvalidArgumentException if the stream is not a stream resource
*/
public function __construct($stream, $options = [])
{
if (!is_resource($stream)) {
throw new \InvalidArgumentException('Stream must be a resource');
}

if (isset($options['size'])) {
$this->size = $options['size'];
}

$this->customMetadata = isset($options['metadata'])
? $options['metadata']
: [];

$this->attach($stream);
}

/**
* Closes the stream when the destructed
*/
public function __destruct()
{
$this->close();
}

public function __toString()
{
if (!$this->stream) {
return '';
}

$this->seek(0);

return (string) stream_get_contents($this->stream);
}

public function getContents()
{
return $this->stream ? stream_get_contents($this->stream) : '';
}

public function close()
{
if (is_resource($this->stream)) {
fclose($this->stream);
}

$this->detach();
}

public function detach()
{
$result = $this->stream;
$this->stream = $this->size = $this->uri = null;
$this->readable = $this->writable = $this->seekable = false;

return $result;
}

public function attach($stream)
{
$this->stream = $stream;
$meta = stream_get_meta_data($this->stream);
$this->seekable = $meta['seekable'];
$this->readable = isset(self::$readWriteHash['read'][$meta['mode']]);
$this->writable = isset(self::$readWriteHash['write'][$meta['mode']]);
$this->uri = $this->getMetadata('uri');
}

public function getSize()
{
if ($this->size !== null) {
return $this->size;
}

if (!$this->stream) {
return null;
}

// Clear the stat cache if the stream has a URI
if ($this->uri) {
clearstatcache(true, $this->uri);
}

$stats = fstat($this->stream);
if (isset($stats['size'])) {
$this->size = $stats['size'];
return $this->size;
}

return null;
}

public function isReadable()
{
return $this->readable;
}

public function isWritable()
{
return $this->writable;
}

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

public function eof()
{
return !$this->stream || feof($this->stream);
}

public function tell()
{
return $this->stream ? ftell($this->stream) : false;
}

public function setSize($size)
{
$this->size = $size;

return $this;
}

public function seek($offset, $whence = SEEK_SET)
{
return $this->seekable
? fseek($this->stream, $offset, $whence) === 0
: false;
}

public function read($length)
{
return $this->readable ? fread($this->stream, $length) : false;
}

public function write($string)
{
// We can't know the size after writing anything
$this->size = null;

return $this->writable ? fwrite($this->stream, $string) : false;
}

public function getMetadata($key = null)
{
if (!$this->stream) {
return $key ? null : [];
} elseif (!$key) {
return $this->customMetadata + stream_get_meta_data($this->stream);
} elseif (isset($this->customMetadata[$key])) {
return $this->customMetadata[$key];
}

$meta = stream_get_meta_data($this->stream);

return isset($meta[$key]) ? $meta[$key] : null;
}
}