<?php

namespace Syde\Vendor\Cawl\OnlinePayments\Sdk\Authentication;

use Syde\Vendor\Cawl\OnlinePayments\Sdk\CommunicatorConfiguration;
class V1HmacAuthenticator implements Authenticator
{
    const AUTHORIZATION_ID = 'GCS';
    const AUTHORIZATION_TYPE = 'v1HMAC';
    const HASH_ALGORITHM = 'sha256';
    /**
     * API Key ID obtained in the merchant portal.
     *
     * @var string
     */
    private string $apiKeyId;
    /**
     * API Secret obtained in the merchant portal.
     *
     * @var string
     */
    private string $apiSecret;
    /**
     * @param CommunicatorConfiguration $communicatorConfiguration
     */
    public function __construct(CommunicatorConfiguration $communicatorConfiguration)
    {
        $this->apiKeyId = $communicatorConfiguration->getApiKeyId();
        $this->apiSecret = $communicatorConfiguration->getApiSecret();
    }
    /**
     * @inheritDoc
     */
    public function getAuthorization(string $httpMethod, string $uriPath, array $requestHeaders = []) : string
    {
        return $this->getAuthorizationHeaderValue($httpMethod, $uriPath, $requestHeaders);
    }
    /**
     * Generates authorization header value.
     *
     * @param string $httpMethod
     * @param string $uriPath
     * @param array $requestHeaders
     *
     * @return string
     */
    private function getAuthorizationHeaderValue(string $httpMethod, string $uriPath, array $requestHeaders) : string
    {
        return static::AUTHORIZATION_ID . ' ' . static::AUTHORIZATION_TYPE . ':' . $this->apiKeyId . ':' . \base64_encode(\hash_hmac(static::HASH_ALGORITHM, $this->prepareDataForSignature($httpMethod, $uriPath, $requestHeaders), $this->apiSecret, \true));
    }
    /**
     * Prepares data to be signed.
     *
     * @param string $httpMethod
     * @param string $uriPath
     * @param array $requestHeaders
     *
     * @return string
     */
    private function prepareDataForSignature(string $httpMethod, string $uriPath, array $requestHeaders) : string
    {
        $signData = $httpMethod . "\n";
        if (isset($requestHeaders['Content-Type'])) {
            $signData .= $requestHeaders['Content-Type'] . "\n";
        } else {
            $signData .= "\n";
        }
        if (isset($requestHeaders['Date'])) {
            $signData .= $requestHeaders['Date'] . "\n";
        } else {
            $signData .= "\n";
        }
        $gcsHeaders = array();
        foreach ($requestHeaders as $headerKey => $headerValue) {
            if (\preg_match('/X-GCS/i', $headerKey)) {
                $gcsHeaders[$headerKey] = $headerValue;
            }
        }
        \ksort($gcsHeaders);
        foreach ($gcsHeaders as $gcsHeaderKey => $gcsHeaderValue) {
            $gcsEncodedHeaderValue = \trim(\preg_replace('/\\r?\\n[\\h]*/', ' ', $gcsHeaderValue));
            $signData .= \strtolower($gcsHeaderKey) . ':' . $gcsEncodedHeaderValue . "\n";
        }
        $signData .= $uriPath . "\n";
        return $signData;
    }
}
