<?php

/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <fabien@symfony.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/

namespace Symfony\Component\Mime\Header;

use Symfony\Component\Mime\Encoder\Rfc2231Encoder;

/**
* @author Chris Corbyn
*/
final class ParameterizedHeader extends UnstructuredHeader
{
/**
* RFC 2231's definition of a token.
*
* @var string
*/
public const TOKEN_REGEX = '(?:[\x21\x23-\x27\x2A\x2B\x2D\x2E\x30-\x39\x41-\x5A\x5E-\x7E]+)';

private $encoder;
private $parameters = [];

public function __construct(string $name, string $value, array $parameters = [])
{
parent::__construct($name, $value);

foreach ($parameters as $k => $v) {
$this->setParameter($k, $v);
}

if ('content-type' !== strtolower($name)) {
$this->encoder = new Rfc2231Encoder();
}
}

public function setParameter(string $parameter, ?string $value)
{
$this->setParameters(array_merge($this->getParameters(), [$parameter => $value]));
}

public function getParameter(string $parameter): string
{
return $this->getParameters()[$parameter] ?? '';
}

/**
* @param string[] $parameters
*/
public function setParameters(array $parameters)
{
$this->parameters = $parameters;
}

/**
* @return string[]
*/
public function getParameters(): array
{
return $this->parameters;
}

public function getBodyAsString(): string
{
$body = parent::getBodyAsString();
foreach ($this->parameters as $name => $value) {
if (null !== $value) {
$body .= '; '.$this->createParameter($name, $value);
}
}

return $body;
}

/**
* Generate a list of all tokens in the final header.
*
* This doesn't need to be overridden in theory, but it is for implementation
* reasons to prevent potential breakage of attributes.
*/
protected function toTokens(?string $string = null): array
{
$tokens = parent::toTokens(parent::getBodyAsString());

// Try creating any parameters
foreach ($this->parameters as $name => $value) {
if (null !== $value) {
// Add the semi-colon separator
$tokens[\count($tokens) - 1] .= ';';
$tokens = array_merge($tokens, $this->generateTokenLines(' '.$this->createParameter($name, $value)));
}
}

return $tokens;
}

/**
* Render an RFC 2047 compliant header parameter from the $name and $value.
*/
private function createParameter(string $name, string $value): string
{
$origValue = $value;

$encoded = false;
// Allow room for parameter name, indices, "=" and DQUOTEs
$maxValueLength = $this->getMaxLineLength() - \strlen($name.'=*N"";') - 1;
$firstLineOffset = 0;

// If it's not already a valid parameter value...
if (!preg_match('/^'.self::TOKEN_REGEX.'$/D', $value)) {
// TODO: text, or something else??
// ... and it's not ascii
if (!preg_match('/^[\x00-\x08\x0B\x0C\x0E-\x7F]*$/D', $value)) {
$encoded = true;
// Allow space for the indices, charset and language
$maxValueLength = $this->getMaxLineLength() - \strlen($name.'*N*="";') - 1;
$firstLineOffset = \strlen($this->getCharset()."'".$this->getLanguage()."'");
}

if (\in_array($name, ['name', 'filename'], true) && 'form-data' === $this->getValue() && 'content-disposition' === strtolower($this->getName()) && preg_match('//u', $value)) {
// WHATWG HTML living standard 4.10.21.8 2 specifies:
// For field names and filenames for file fields, the result of the
// encoding in the previous bullet point must be escaped by replacing
// any 0x0A (LF) bytes with the byte sequence `%0A`, 0x0D (CR) with `%0D`
// and 0x22 (") with `%22`.
// The user agent must not perform any other escapes.
$value = str_replace(['"', "\r", "\n"], ['%22', '%0D', '%0A'], $value);

if (\strlen($value) <= $maxValueLength) {
return $name.'="'.$value.'"';
}

$value = $origValue;
}
}

// Encode if we need to
if ($encoded || \strlen($value) > $maxValueLength) {
if (null !== $this->encoder) {
$value = $this->encoder->encodeString($origValue, $this->getCharset(), $firstLineOffset, $maxValueLength);
} else {
// We have to go against RFC 2183/2231 in some areas for interoperability
$value = $this->getTokenAsEncodedWord($origValue);
$encoded = false;
}
}

$valueLines = $this->encoder ? explode("\r\n", $value) : [$value];

// Need to add indices
if (\count($valueLines) > 1) {
$paramLines = [];
foreach ($valueLines as $i => $line) {
$paramLines[] = $name.'*'.$i.$this->getEndOfParameterValue($line, true, 0 === $i);
}

return implode(";\r\n ", $paramLines);
} else {
return $name.$this->getEndOfParameterValue($valueLines[0], $encoded, true);
}
}

/**
* Returns the parameter value from the "=" and beyond.
*
* @param string $value to append
*/
private function getEndOfParameterValue(string $value, bool $encoded = false, bool $firstLine = false): string
{
$forceHttpQuoting = 'form-data' === $this->getValue() && 'content-disposition' === strtolower($this->getName());
if ($forceHttpQuoting || !preg_match('/^'.self::TOKEN_REGEX.'$/D', $value)) {
$value = '"'.$value.'"';
}
$prepend = '=';
if ($encoded) {
$prepend = '*=';
if ($firstLine) {
$prepend = '*='.$this->getCharset()."'".$this->getLanguage()."'";
}
}

return $prepend.$value;
}
}