<?php

namespace GuzzleHttp\Psr7;

final class Header
{
/**
* Parse an array of header values containing ";" separated data into an
* array of associative arrays representing the header key value pair data
* of the header. When a parameter does not contain a value, but just
* contains a key, this function will inject a key with a '' string value.
*
* @param string|array $header Header to parse into components.
*
* @return array Returns the parsed header values.
*/
public static function parse($header)
{
static $trimmed = "\"' \n\t\r";
$params = $matches = [];

foreach (self::normalize($header) as $val) {
$part = [];
foreach (preg_split('/;(?=([^"]*"[^"]*")*[^"]*$)/', $val) as $kvp) {
if (preg_match_all('/<[^>]+>|[^=]+/', $kvp, $matches)) {
$m = $matches[0];
if (isset($m[1])) {
$part[trim($m[0], $trimmed)] = trim($m[1], $trimmed);
} else {
$part[] = trim($m[0], $trimmed);
}
}
}
if ($part) {
$params[] = $part;
}
}

return $params;
}

/**
* Converts an array of header values that may contain comma separated
* headers into an array of headers with no comma separated values.
*
* @param string|array $header Header to normalize.
*
* @return array Returns the normalized header field values.
*/
public static function normalize($header)
{
if (!is_array($header)) {
return array_map('trim', explode(',', $header));
}

$result = [];
foreach ($header as $value) {
foreach ((array) $value as $v) {
if (strpos($v, ',') === false) {
$result[] = $v;
continue;
}
foreach (preg_split('/,(?=([^"]*"[^"]*")*[^"]*$)/', $v) as $vv) {
$result[] = trim($vv);
}
}
}

return $result;
}
}