AcceptHeader::__construct() - Code Metrics - Inspection of "- travis quirks" - kodedphp/http - Measure and Improve Code Quality continuously with Scrutinizer

Passed
Push — master ( 4ac306...d2aa89 )

by Mihail
created 2020-12-06 20:59 UTC
AcceptHeader::__construct() A

↳ Parent: AcceptHeader
Complexity

Conditions	6
Paths	4
Size

Total Lines	39
Code Lines	18
Duplication

Lines	0
Ratio	0 %
Code Coverage

Tests	19
CRAP Score	6
Importance

Changes	2
Bugs	1	Features	0
Metric	Value
cc	6
eloc	18
c	2
b	1
f	0
nc	4
nop	1
dl	0
loc	39
ccs	19
cts	19
cp	1
crap	6
rs	9.0444
<?php

/*
 * This file is part of the Koded package.
 *
 * (c) Mihail Binev <[email protected]>
 *
 * Please view the LICENSE distributed with this source code
 * for the full copyright and license information.
 *
 */

namespace Koded\Http;

/**
 * Content negotiation module.
 *
 * Supported HTTP/1.1 Accept headers:
 *
 *  Accept
 *  Accept-Language
 *  Accept-Charset
 *  Accept-Encoding
 *
 * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Content_negotiation
 */

use Generator;
use InvalidArgumentException;
use Koded\Http\Interfaces\HttpStatus;

class AcceptHeaderNegotiator
{
    /** @var AcceptHeader[] */
    private $supports;

    public function __construct(string $supportHeader)
    {
        $this->supports = $supportHeader;

    }


    public function match(string $accepts): AcceptHeader
    {
        /** @var AcceptHeader $support */
        foreach ($this->parse($accepts) as $accept) {
            foreach ($this->parse($this->supports) as $support) {
            foreach ($this->parse(/** @scrutinizer ignore-type */ $this->supports) as $support) {
                $support->matches($accept, $types);
            }
        }

        usort($types, function(AcceptHeader $a, AcceptHeader $b) {
            return $b->weight() <=> $a->weight();
        });

        if (empty($types)) {
            /* Set "q=0", meaning the header is explicitly rejected.
             * The consuming clients should handle this according to
             * their internal logic. This is much better then throwing
             * exceptions which must be handled in every place where
             * match() is called. For example, the client may issue a
             * 406 status code and be done with it.
             */
            $types[] = new class('*;q=0') extends AcceptHeader {};
        }

        return $types[0];
    }

    /**
     * @param string $header
     *
     * @return Generator
     */
    private function parse(string $header): Generator
    {
        foreach (explode(',', $header) as $header) {
            yield new class($header) extends AcceptHeader {};
        }
    }
}


abstract class AcceptHeader
{
    private $header;
    private $separator;
    private $type;
    private $subtype;
    private $quality  = 1.0;
    private $weight   = 0.0;
    private $catchAll = false;
    private $params   = [];

    public function __construct(string $header)
    {
        $this->header = $header;

        $header = preg_replace('/[[:space:]]/', '', $header);
        $bits   = explode(';', $header);
        $type   = array_shift($bits);

        if (!empty($type) && !preg_match('~^(\*|[a-z0-9._]+)([/|_-])?(\*|[a-z0-9.\-_+]+)?$~i', $type, $matches)) {
            throw new InvalidArgumentException(sprintf('"%s" is not a valid Access header', $header),
                HttpStatus::NOT_ACCEPTABLE);
        }

        $this->separator = $matches[2] ?? '/';
        [$type, $subtype] = explode($this->separator, $type, 2) + [1 => '*'];

        if ('*' === $type && '*' !== $subtype) {
            // @see https://tools.ietf.org/html/rfc7231#section-5.3.2
            throw new InvalidArgumentException(sprintf('"%s" is not a valid Access header', $header),
                HttpStatus::NOT_ACCEPTABLE);
        }

        // @see https://tools.ietf.org/html/rfc7540#section-8.1.2
        $this->type = strtolower($type);

        /* Uses a simple heuristic to check if subtype is part of
         * some obscure media type like "vnd.api-v1+json".
         *
         * NOTE: It is a waste of time to negotiate on the basis
         * of obscure parameters while using a meaningless media
         * type like "vnd.whatever". But the web world is a big mess
         * and this module can handle the Dunning-Kruger effect.
         */
        $this->subtype  = explode('+', $subtype)[1] ?? $subtype;
        $this->catchAll = '*' === $this->type && '*' === $this->subtype;

        parse_str(join('&', $bits), $this->params);
        $this->quality = (float)($this->params['q'] ?? 1);
        unset($this->params['q']);
    }


    public function __toString(): string
    {
        return $this->value();
    }


    public function value(): string
    {
        // The header is explicitly rejected
        if (0.0 === $this->quality) {
            return '';
        }

        // If language, encoding or charset
        if ('*' === $this->subtype) {
            return $this->type;
        }

        return $this->type . $this->separator . $this->subtype;
    }


    public function quality(): float
    {
        return $this->quality;
    }


    public function weight(): float
    {
        return $this->weight;
    }

    /**
     * @internal
     *
     * @param AcceptHeader   $accept  The accept header part
     * @param AcceptHeader[] $matches Matched types
     *
     * @return bool TRUE if the accept header part is a match
     * against the supported (this) header part
     *
     * This method finds the best match for the Accept header,
     * including all the nonsense that may be passed by the
     * developers who do not follow RFC standards.
     *
     */
    public function matches(AcceptHeader $accept, array &$matches = null): bool
    {
        $matches = (array)$matches;
        $accept  = clone $accept;

        $typeMatch = $this->type === $accept->type;

        if (1.0 === $accept->quality) {
            $accept->quality = (float)$this->quality;
        }

        if ($accept->catchAll) {
            $accept->type    = $this->type;
            $accept->subtype = $this->subtype;
            $matches[]       = $accept;

            return true;
        }

        // Explicitly denied
        if (0.0 === $this->quality) {
            $matches[] = clone $this;

            return true;
        }

        // Explicitly denied
        if (0.0 === $accept->quality) {
            $matches[] = $accept;

            return true;
        }

        // Explicit type mismatch (w/o asterisk); bail out
        if (false === $typeMatch && '*' !== $this->type) {
            return false;
        }

        if ('*' === $accept->subtype) {
            $accept->subtype = $this->subtype;
        }

        if ($accept->subtype !== $this->subtype && '*' !== $this->subtype) {
            return false;
        }

        $matches[] = $this->rank($accept);

        return true;
    }


    private function rank(AcceptHeader $accept): AcceptHeader
    {
        // +100 if types are exact match w/o asterisk
        if ($this->type === $accept->type && '*' !== $accept->type) {
            $accept->weight += 100;
        }

        $accept->weight += $this->catchAll ? 0.0 : $accept->quality;

        // +1 for each parameter that matches, except "q"
        foreach ($this->params as $k => $v) {
            if (isset($accept->params[$k]) && $accept->params[$k] === $v) {
                $accept->weight += 1;
            } else {
                $accept->weight -= 1;
            }
        }

        // Add "q"
        $accept->weight += $accept->quality;

        return $accept;
    }
}

kodedphp / http

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AcceptHeader::__construct() A

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