Yiisoft\Http\HeaderValueHelper

Complexity

Total Complexity

39

Size/Duplication

Total Lines	254
Duplicated Lines	0 %

Test Coverage

Coverage

98.8%

Importance

Changes	1
Bugs	0	Features	0

4 Methods

Rating	Name	Duplication	Size	Complexity
A	getValueAndParameters()	0	20	4
B	getSortedValueAndParameters()	0	47	10
C	getSortedAcceptTypes()	0	55	16
B	getParameters()	0	49	9

<?php

declare(strict_types=1);

namespace Yiisoft\Http;

use InvalidArgumentException;

use function array_shift;
use function asort;
use function count;
use function explode;
use function implode;
use function is_array;
use function is_string;
use function mb_strtolower;
use function mb_strpos;
use function mb_substr;
use function preg_match;
use function preg_split;
use function preg_replace;
use function preg_replace_callback;
use function reset;
use function rtrim;
use function strtolower;
use function strpos;
use function substr;
use function trim;
use function usort;

/**
 * HeaderValueHelper parses the header value parameters.
 */
final class HeaderValueHelper
{
    /**
     * @link https://www.rfc-editor.org/rfc/rfc2616.html#section-2.2
     * token = 1*<any CHAR except CTLs or separators>
     */
    private const PATTERN_TOKEN = '(?:(?:[^()<>@,;:\\"\/[\\]?={} \t\x7f]|[\x00-\x1f])+)';

    /**
     * @link https://www.rfc-editor.org/rfc/rfc2616.html#section-3.6
     * attribute = token
     */
    private const PATTERN_ATTRIBUTE = self::PATTERN_TOKEN;

    /**
     * @link https://www.rfc-editor.org/rfc/rfc2616.html#section-2.2
     * quoted-string  = ( <"> *(qdtext | quoted-pair ) <"> )
     * qdtext         = <any TEXT except <">>
     * quoted-pair    = "\" CHAR
     */
    private const PATTERN_QUOTED_STRING = '(?:"(?:(?:\\\\.)+|[^\\"]+)*")';

    /**
     * @link https://www.rfc-editor.org/rfc/rfc2616.html#section-3.6
     * value = token | quoted-string
     */
    private const PATTERN_VALUE = '(?:' . self::PATTERN_QUOTED_STRING . '|' . self::PATTERN_TOKEN . ')';

    /**
     * Explodes a header value to value and parameters (eg. text/html;q=2;version=6)
     *
     * @link https://www.rfc-editor.org/rfc/rfc2616.html#section-3.6
     * transfer-extension = token *( ";" parameter )
     *
     * @param string $headerValue Header value.
     * @param bool $lowerCaseValue Whether should cast header value to lowercase.
     * @param bool $lowerCaseParameter Whether should cast header parameter name to lowercase.
     * @param bool $lowerCaseParameterValue Whether should cast header parameter value to lowercase.
     *
     * @return array First element is the value, and key-value are the parameters.
     */
    public static function getValueAndParameters(
        string $headerValue,
        bool $lowerCaseValue = true,
        bool $lowerCaseParameter = true,
        bool $lowerCaseParameterValue = true
    ): array {
        $headerValue = trim($headerValue);

        if ($headerValue === '') {
            return [];
        }

        $parts = explode(';', $headerValue, 2);
        $output = [$lowerCaseValue ? strtolower($parts[0]) : $parts[0]];

        if (count($parts) === 1) {
            return $output;
        }

        return $output + self::getParameters($parts[1], $lowerCaseParameter, $lowerCaseParameterValue);
    }

    /**
     * Explodes a header value parameters (eg. q=2;version=6)
     *
     * @link https://tools.ietf.org/html/rfc7230#section-3.2.6
     *
     * @param string $headerValueParameters Header value parameters.
     * @param bool $lowerCaseParameter Whether should cast header parameter name to lowercase.
     * @param bool $lowerCaseParameterValue Whether should cast header parameter value to lowercase.
     *
     * @return array Key-value are the parameters.
     */
    public static function getParameters(
        string $headerValueParameters,
        bool $lowerCaseParameter = true,
        bool $lowerCaseParameterValue = true
    ): array {
        $headerValueParameters = trim($headerValueParameters);

        if ($headerValueParameters === '') {
            return [];
        }

        if (rtrim($headerValueParameters, ';') !== $headerValueParameters) {
            throw new InvalidArgumentException('Cannot end with a semicolon.');
        }

        $output = [];

        do {
            /** @psalm-suppress InvalidArgument */
            $headerValueParameters = preg_replace_callback(
                '/^[ \t]*(?<parameter>' . self::PATTERN_ATTRIBUTE . ')[ \t]*=[ \t]*(?<value>' . self::PATTERN_VALUE . ')[ \t]*(?:;|$)/u',
                static function (array $matches) use (&$output, $lowerCaseParameter, $lowerCaseParameterValue) {
                    $value = $matches['value'];

                    if (mb_strpos($matches['value'], '"') === 0) {
                        // unescape + remove first and last quote
                        $value = preg_replace('/\\\\(.)/u', '$1', mb_substr($value, 1, -1));
                    }

                    $key = $lowerCaseParameter ? mb_strtolower($matches['parameter']) : $matches['parameter'];

                    if (isset($output[$key])) {
                        // The first is the winner.
                        return;
                    }

                    $output[$key] = $lowerCaseParameterValue ? mb_strtolower($value) : $value;
                },
                $headerValueParameters,
                1,
                $count
            );

            if ($count !== 1) {
                throw new InvalidArgumentException('Invalid input: ' . $headerValueParameters);
            }
        } while ($headerValueParameters !== '');

        return $output;
    }

    /**
     * Returns a header value as "q" factor sorted list.
     *
     * @param mixed $values Header value as a comma-separated string or already exploded string array.
     * @param bool $lowerCaseValue Whether should cast header value to lowercase.
     * @param bool $lowerCaseParameter Whether should cast header parameter name to lowercase.
     * @param bool $lowerCaseParameterValue Whether should cast header parameter value to lowercase.
     *
     * @return array The q factor sorted list.
     *
     * @link https://developer.mozilla.org/en-US/docs/Glossary/Quality_values
     * @link https://www.ietf.org/rfc/rfc2045.html#section-2
     * @see getValueAndParameters
     */
    public static function getSortedValueAndParameters(
        $values,
        bool $lowerCaseValue = true,
        bool $lowerCaseParameter = true,
        bool $lowerCaseParameterValue = true
    ): array {
        if (!is_array($values) && !is_string($values)) {
            throw new InvalidArgumentException('Values are neither array nor string.');
        }

        $list = [];

        foreach ((array) $values as $headerValue) {
            $list = [...$list, ...preg_split('/\s*,\s*/', trim($headerValue), -1, PREG_SPLIT_NO_EMPTY)];
        }

        if (count($list) === 0) {
            return [];
        }

        $output = [];

        foreach ($list as $value) {
            $parse = self::getValueAndParameters($value, $lowerCaseValue, $lowerCaseParameter, $lowerCaseParameterValue);
            // case-insensitive "q" parameter
            $q = $parse['q'] ?? $parse['Q'] ?? 1.0;

            // min 0.000 max 1.000, max 3 digits, without digits allowed
            if (is_string($q) && preg_match('/^(?:0(?:\.\d{1,3})?|1(?:\.0{1,3})?)$/', $q) === 0) {
                throw new InvalidArgumentException('Invalid q factor.');
            }

            $parse['q'] = (float) $q;
            unset($parse['Q']);
            $output[] = $parse;
        }

        usort($output, static function (array $a, array $b) {
            $a = $a['q'];
            $b = $b['q'];
            if ($a === $b) {
                return 0;
            }
            return $a > $b ? -1 : 1;
        });

        return $output;
    }

    /**
     * Returns a list of sorted content types from the accept header values.
     *
     * @param string|string[] $values Header value as a comma-separated string or already exploded string array.
     *
     * @return string[] Sorted accept types. Note: According to RFC 7231, special parameters (except the q factor)
     * are added to the type, which are always appended by a semicolon and sorted by string.
     *
     * @link https://tools.ietf.org/html/rfc7231#section-5.3.2
     * @link https://www.ietf.org/rfc/rfc2045.html#section-2
     */
    public static function getSortedAcceptTypes($values): array
    {
        $output = self::getSortedValueAndParameters($values);

        usort($output, static function (array $a, array $b) {
            if ($a['q'] !== $b['q']) {
                // The higher q value wins
                return $a['q'] > $b['q'] ? -1 : 1;
            }

            $typeA = reset($a);
            $typeB = reset($b);

            if (strpos($typeA, '*') === false && strpos($typeB, '*') === false) {
                $countA = count($a);
                $countB = count($b);
                if ($countA === $countB) {
                    // They are equivalent for the same parameter number
                    return 0;
                }
                // No wildcard character, higher parameter number wins
                return $countA > $countB ? -1 : 1;
            }

            $endWildcardA = substr($typeA, -1, 1) === '*';
            $endWildcardB = substr($typeB, -1, 1) === '*';

            if (($endWildcardA && !$endWildcardB) || (!$endWildcardA && $endWildcardB)) {
                // The wildcard ends is the loser.
                return $endWildcardA ? 1 : -1;
            }

            // The wildcard starts is the loser.
            return strpos($typeA, '*') === 0 ? 1 : -1;
        });

        foreach ($output as $key => $value) {
            $type = array_shift($value);
            unset($value['q']);

            if (count($value) === 0) {
                $output[$key] = $type;
                continue;
            }

            foreach ($value as $k => $v) {
                $value[$k] = $k . '=' . $v;
            }

            // Parameters are sorted for easier use of parameter variations.
            asort($value, SORT_STRING);
            $output[$key] = $type . ';' . implode(';', $value);
        }

        return $output;
    }
}