<?php
/**
 * HeaderSelector
 * PHP version 7.4
 *
 * @category Class
 * @package  PrestaShop\Module\PolarisPrestaConnector\pol\api\lib
 * @author   OpenAPI Generator team
 * @link     https://openapi-generator.tech
 */

/**
 * Polaris WebConnect
 *
 * L'API WebConnect vous permet d'interconnecter facilement votre solution Polaris avec un site Internet en permettant à ce dernier de télécharger votre catalogue, vos clients, votre fidélité       *Pour rappel, la spécification OpenAPI est une spécification de fichiers d'interface lisibles par une machine pour décrire, produire, consommer et visualiser les services Web REST de manière automatisée. Vous pouvez donc utiliser des outils comme [Swagger](https://editor.swagger.io/) pour générer automatiquement une bibliothèque cliente dans le langage de votre choix.*    **IMPORTANT / NOTE SUR LES ÉNUMÉRATEURS** : si vous générez un client avec OpenAPI Generator ou Swagger, appelez les API avec un User-Agent qui contient la chaîne 'enum_as_str;' afin que les énumérateurs soient gérés sous forme de chaîne de caractères et non de constantes entières.   **Voir la documentation générale : [https://nur1.pl-vega-0001.polarisgestionmag.net:3443/api?doc=WebConnect](https://nur1.pl-vega-0001.polarisgestionmag.net:3443/api?doc=WebConnect)**
 *
 * The version of the OpenAPI document: 14.2.99.65534
 * Contact: assistance@vega-info.fr
 * Generated by: https://openapi-generator.tech
 * Generator version: 7.8.0
 */

/**
 * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
 * https://openapi-generator.tech
 * Do not edit the class manually.
 */

namespace PrestaShop\Module\PolarisPrestaConnector\pol\api\lib;

/**
 * HeaderSelector Class Doc Comment
 *
 * @category Class
 * @package  PrestaShop\Module\PolarisPrestaConnector\pol\api\lib
 * @author   OpenAPI Generator team
 * @link     https://openapi-generator.tech
 */
class HeaderSelector
{
    /**
     * @param string[] $accept
     * @param string   $contentType
     * @param bool     $isMultipart
     * @return string[]
     */
    public function selectHeaders(array $accept, string $contentType, bool $isMultipart): array
    {
        $headers = [];

        $accept = $this->selectAcceptHeader($accept);
        if ($accept !== null) {
            $headers['Accept'] = $accept;
        }

        if (!$isMultipart) {
            if($contentType === '') {
                $contentType = 'application/json';
            }

            $headers['Content-Type'] = $contentType;
        }

        return $headers;
    }

    /**
     * Return the header 'Accept' based on an array of Accept provided.
     *
     * @param string[] $accept Array of header
     *
     * @return null|string Accept (e.g. application/json)
     */
    private function selectAcceptHeader(array $accept): ?string
    {
        # filter out empty entries
        $accept = array_filter($accept);

        if (count($accept) === 0) {
            return null;
        }

        # If there's only one Accept header, just use it
        if (count($accept) === 1) {
            return reset($accept);
        }

        # If none of the available Accept headers is of type "json", then just use all them
        $headersWithJson = preg_grep('~(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$~', $accept);
        if (count($headersWithJson) === 0) {
            return implode(',', $accept);
        }

        # If we got here, then we need add quality values (weight), as described in IETF RFC 9110, Items 12.4.2/12.5.1,
        # to give the highest priority to json-like headers - recalculating the existing ones, if needed
        return $this->getAcceptHeaderWithAdjustedWeight($accept, $headersWithJson);
    }

    /**
    * Create an Accept header string from the given "Accept" headers array, recalculating all weights
    *
    * @param string[] $accept            Array of Accept Headers
    * @param string[] $headersWithJson   Array of Accept Headers of type "json"
    *
    * @return string "Accept" Header (e.g. "application/json, text/html; q=0.9")
    */
    private function getAcceptHeaderWithAdjustedWeight(array $accept, array $headersWithJson): string
    {
        $processedHeaders = [
            'withApplicationJson' => [],
            'withJson' => [],
            'withoutJson' => [],
        ];

        foreach ($accept as $header) {

            $headerData = $this->getHeaderAndWeight($header);

            if (stripos($headerData['header'], 'application/json') === 0) {
                $processedHeaders['withApplicationJson'][] = $headerData;
            } elseif (in_array($header, $headersWithJson, true)) {
                $processedHeaders['withJson'][] = $headerData;
            } else {
                $processedHeaders['withoutJson'][] = $headerData;
            }
        }

        $acceptHeaders = [];
        $currentWeight = 1000;

        $hasMoreThan28Headers = count($accept) > 28;

        foreach($processedHeaders as $headers) {
            if (count($headers) > 0) {
                $acceptHeaders[] = $this->adjustWeight($headers, $currentWeight, $hasMoreThan28Headers);
            }
        }

        $acceptHeaders = array_merge(...$acceptHeaders);

        return implode(',', $acceptHeaders);
    }

    /**
     * Given an Accept header, returns an associative array splitting the header and its weight
     *
     * @param string $header "Accept" Header
     *
     * @return array with the header and its weight
     */
    private function getHeaderAndWeight(string $header): array
    {
        # matches headers with weight, splitting the header and the weight in $outputArray
        if (preg_match('/(.*);\s*q=(1(?:\.0+)?|0\.\d+)$/', $header, $outputArray) === 1) {
            $headerData = [
                'header' => $outputArray[1],
                'weight' => (int)($outputArray[2] * 1000),
            ];
        } else {
            $headerData = [
                'header' => trim($header),
                'weight' => 1000,
            ];
        }

        return $headerData;
    }

    /**
     * @param array[] $headers
     * @param float   $currentWeight
     * @param bool    $hasMoreThan28Headers
     * @return string[] array of adjusted "Accept" headers
     */
    private function adjustWeight(array $headers, float &$currentWeight, bool $hasMoreThan28Headers): array
    {
        usort($headers, function (array $a, array $b) {
            return $b['weight'] - $a['weight'];
        });

        $acceptHeaders = [];
        foreach ($headers as $index => $header) {
            if($index > 0 && $headers[$index - 1]['weight'] > $header['weight'])
            {
                $currentWeight = $this->getNextWeight($currentWeight, $hasMoreThan28Headers);
            }

            $weight = $currentWeight;

            $acceptHeaders[] = $this->buildAcceptHeader($header['header'], $weight);
        }

        $currentWeight = $this->getNextWeight($currentWeight, $hasMoreThan28Headers);

        return $acceptHeaders;
    }

    /**
     * @param string $header
     * @param int    $weight
     * @return string
     */
    private function buildAcceptHeader(string $header, int $weight): string
    {
        if($weight === 1000) {
            return $header;
        }

        return trim($header, '; ') . ';q=' . rtrim(sprintf('%0.3f', $weight / 1000), '0');
    }

    /**
     * Calculate the next weight, based on the current one.
     *
     * If there are less than 28 "Accept" headers, the weights will be decreased by 1 on its highest significant digit, using the
     * following formula:
     *
     *    next weight = current weight - 10 ^ (floor(log(current weight - 1)))
     *
     *    ( current weight minus ( 10 raised to the power of ( floor of (log to the base 10 of ( current weight minus 1 ) ) ) ) )
     *
     * Starting from 1000, this generates the following series:
     *
     * 1000, 900, 800, 700, 600, 500, 400, 300, 200, 100, 90, 80, 70, 60, 50, 40, 30, 20, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1
     *
     * The resulting quality codes are closer to the average "normal" usage of them (like "q=0.9", "q=0.8" and so on), but it only works
     * if there is a maximum of 28 "Accept" headers. If we have more than that (which is extremely unlikely), then we fall back to a 1-by-1
     * decrement rule, which will result in quality codes like "q=0.999", "q=0.998" etc.
     *
     * @param int  $currentWeight varying from 1 to 1000 (will be divided by 1000 to build the quality value)
     * @param bool $hasMoreThan28Headers
     * @return int
     */
    public function getNextWeight(int $currentWeight, bool $hasMoreThan28Headers): int
    {
        if ($currentWeight <= 1) {
            return 1;
        }

        if ($hasMoreThan28Headers) {
            return $currentWeight - 1;
        }

        return $currentWeight - 10 ** floor( log10($currentWeight - 1) );
    }
}
