<?php

namespace GuzzleHttp\Psr7;

use Psr\Http\Message\StreamInterface;

/**
* Trait implementing functionality common to requests and responses.
*/
trait MessageTrait
{
/** @var array Map of all registered headers, as original name => array of values */
private $headers = [];

/** @var array Map of lowercase header name => original name at registration */
private $headerNames = [];

/** @var string */
private $protocol = '1.1';

/** @var StreamInterface|null */
private $stream;

public function getProtocolVersion()
{
return $this->protocol;
}

public function withProtocolVersion($version)
{
if ($this->protocol === $version) {
return $this;
}

$new = clone $this;
$new->protocol = $version;
return $new;
}

public function getHeaders()
{
return $this->headers;
}

public function hasHeader($header)
{
return isset($this->headerNames[strtolower($header)]);
}

public function getHeader($header)
{
$header = strtolower($header);

if (!isset($this->headerNames[$header])) {
return [];
}

$header = $this->headerNames[$header];

return $this->headers[$header];
}

public function getHeaderLine($header)
{
return implode(', ', $this->getHeader($header));
}

public function withHeader($header, $value)
{
$this->assertHeader($header);
$value = $this->normalizeHeaderValue($value);
$normalized = strtolower($header);

$new = clone $this;
if (isset($new->headerNames[$normalized])) {
unset($new->headers[$new->headerNames[$normalized]]);
}
$new->headerNames[$normalized] = $header;
$new->headers[$header] = $value;

return $new;
}

public function withAddedHeader($header, $value)
{
$this->assertHeader($header);
$value = $this->normalizeHeaderValue($value);
$normalized = strtolower($header);

$new = clone $this;
if (isset($new->headerNames[$normalized])) {
$header = $this->headerNames[$normalized];
$new->headers[$header] = array_merge($this->headers[$header], $value);
} else {
$new->headerNames[$normalized] = $header;
$new->headers[$header] = $value;
}

return $new;
}

public function withoutHeader($header)
{
$normalized = strtolower($header);

if (!isset($this->headerNames[$normalized])) {
return $this;
}

$header = $this->headerNames[$normalized];

$new = clone $this;
unset($new->headers[$header], $new->headerNames[$normalized]);

return $new;
}

public function getBody()
{
if (!$this->stream) {
$this->stream = Utils::streamFor('');
}

return $this->stream;
}

public function withBody(StreamInterface $body)
{
if ($body === $this->stream) {
return $this;
}

$new = clone $this;
$new->stream = $body;
return $new;
}

private function setHeaders(array $headers)
{
$this->headerNames = $this->headers = [];
foreach ($headers as $header => $value) {
if (is_int($header)) {
// Numeric array keys are converted to int by PHP but having a header name '123' is not forbidden by the spec
// and also allowed in withHeader(). So we need to cast it to string again for the following assertion to pass.
$header = (string) $header;
}
$this->assertHeader($header);
$value = $this->normalizeHeaderValue($value);
$normalized = strtolower($header);
if (isset($this->headerNames[$normalized])) {
$header = $this->headerNames[$normalized];
$this->headers[$header] = array_merge($this->headers[$header], $value);
} else {
$this->headerNames[$normalized] = $header;
$this->headers[$header] = $value;
}
}
}

/**
* @param mixed $value
*
* @return string[]
*/
private function normalizeHeaderValue($value)
{
if (!is_array($value)) {
return $this->trimAndValidateHeaderValues([$value]);
}

if (count($value) === 0) {
throw new \InvalidArgumentException('Header value can not be an empty array.');
}

return $this->trimAndValidateHeaderValues($value);
}

/**
* Trims whitespace from the header values.
*
* Spaces and tabs ought to be excluded by parsers when extracting the field value from a header field.
*
* header-field = field-name ":" OWS field-value OWS
* OWS = *( SP / HTAB )
*
* @param mixed[] $values Header values
*
* @return string[] Trimmed header values
*
* @see https://tools.ietf.org/html/rfc7230#section-3.2.4
*/
private function trimAndValidateHeaderValues(array $values)
{
return array_map(function ($value) {
if (!is_scalar($value) && null !== $value) {
throw new \InvalidArgumentException(sprintf(
'Header value must be scalar or null but %s provided.',
is_object($value) ? get_class($value) : gettype($value)
));
}

$trimmed = trim((string) $value, " \t");
$this->assertValue($trimmed);

return $trimmed;
}, array_values($values));
}

/**
* @see https://tools.ietf.org/html/rfc7230#section-3.2
*
* @param mixed $header
*
* @return void
*/
private function assertHeader($header)
{
if (!is_string($header)) {
throw new \InvalidArgumentException(sprintf(
'Header name must be a string but %s provided.',
is_object($header) ? get_class($header) : gettype($header)
));
}

if ($header === '') {
throw new \InvalidArgumentException('Header name can not be empty.');
}

if (! preg_match('/^[a-zA-Z0-9\'`#$%&*+.^_|~!-]+$/D', $header)) {
throw new \InvalidArgumentException(
sprintf('"%s" is not valid header name.', $header)
);
}
}

/**
* @param string $value
*
* @return void
*
* @see https://tools.ietf.org/html/rfc7230#section-3.2
*
* field-value = *( field-content / obs-fold )
* field-content = field-vchar [ 1*( SP / HTAB ) field-vchar ]
* field-vchar = VCHAR / obs-text
* VCHAR = %x21-7E
* obs-text = %x80-FF
* obs-fold = CRLF 1*( SP / HTAB )
*/
private function assertValue($value)
{
// The regular expression intentionally does not support the obs-fold production, because as
// per RFC 7230#3.2.4:
//
// A sender MUST NOT generate a message that includes
// line folding (i.e., that has any field-value that contains a match to
// the obs-fold rule) unless the message is intended for packaging
// within the message/http media type.
//
// Clients must not send a request with line folding and a server sending folded headers is
// likely very rare. Line folding is a fairly obscure feature of HTTP/1.1 and thus not accepting
// folding is not likely to break any legitimate use case.
if (! preg_match('/^[\x20\x09\x21-\x7E\x80-\xFF]*$/D', $value)) {
throw new \InvalidArgumentException(
sprintf('"%s" is not valid header value.', $value)
);
}
}
}