<?php

namespace VendorDuplicator\Aws\Signature;

use VendorDuplicator\Aws\Credentials\CredentialsInterface;
use VendorDuplicator\AWS\CRT\Auth\Signable;
use VendorDuplicator\AWS\CRT\Auth\SignatureType;
use VendorDuplicator\AWS\CRT\Auth\Signing;
use VendorDuplicator\AWS\CRT\Auth\SigningAlgorithm;
use VendorDuplicator\AWS\CRT\Auth\SigningConfigAWS;
use VendorDuplicator\AWS\CRT\Auth\StaticCredentialsProvider;
use VendorDuplicator\AWS\CRT\HTTP\Request;
use VendorDuplicator\Aws\Exception\CommonRuntimeException;
use VendorDuplicator\Aws\Exception\CouldNotCreateChecksumException;
use VendorDuplicator\GuzzleHttp\Psr7;
use VendorDuplicator\Psr\Http\Message\RequestInterface;
/**
 * Signature Version 4
 * @link http://docs.aws.amazon.com/general/latest/gr/signature-version-4.html
 */
class SignatureV4 implements SignatureInterface
{
    use SignatureTrait;
    const ISO8601_BASIC = 'Ymd\THis\Z';
    const UNSIGNED_PAYLOAD = 'UNSIGNED-PAYLOAD';
    const AMZ_CONTENT_SHA256_HEADER = 'X-Amz-Content-Sha256';
    /** @var string */
    private $service;
    /** @var string */
    protected $region;
    /** @var bool */
    private $unsigned;
    /** @var bool */
    private $useV4a;
    /**
     * The following headers are not signed because signing these headers
     * would potentially cause a signature mismatch when sending a request
     * through a proxy or if modified at the HTTP client level.
     *
     * @return array
     */
    protected function getHeaderBlacklist()
    {
        return ['cache-control' => \true, 'content-type' => \true, 'content-length' => \true, 'expect' => \true, 'max-forwards' => \true, 'pragma' => \true, 'range' => \true, 'te' => \true, 'if-match' => \true, 'if-none-match' => \true, 'if-modified-since' => \true, 'if-unmodified-since' => \true, 'if-range' => \true, 'accept' => \true, 'authorization' => \true, 'proxy-authorization' => \true, 'from' => \true, 'referer' => \true, 'user-agent' => \true, 'X-Amz-User-Agent' => \true, 'x-amzn-trace-id' => \true, 'aws-sdk-invocation-id' => \true, 'aws-sdk-retry' => \true];
    }
    /**
     * @param string $service Service name to use when signing
     * @param string $region  Region name to use when signing
     * @param array $options Array of configuration options used when signing
     *      - unsigned-body: Flag to make request have unsigned payload.
     *        Unsigned body is used primarily for streaming requests.
     */
    public function __construct($service, $region, array $options = [])
    {
        $this->service = $service;
        $this->region = $region;
        $this->unsigned = isset($options['unsigned-body']) ? $options['unsigned-body'] : \false;
        $this->useV4a = isset($options['use_v4a']) && $options['use_v4a'] === \true;
    }
    /**
     * {@inheritdoc}
     */
    public function signRequest(RequestInterface $request, CredentialsInterface $credentials, $signingService = null)
    {
        $ldt = gmdate(self::ISO8601_BASIC);
        $sdt = substr($ldt, 0, 8);
        $parsed = $this->parseRequest($request);
        $parsed['headers']['X-Amz-Date'] = [$ldt];
        if ($token = $credentials->getSecurityToken()) {
            $parsed['headers']['X-Amz-Security-Token'] = [$token];
        }
        $service = isset($signingService) ? $signingService : $this->service;
        if ($this->useV4a) {
            return $this->signWithV4a($credentials, $request, $service);
        }
        $cs = $this->createScope($sdt, $this->region, $service);
        $payload = $this->getPayload($request);
        if ($payload == self::UNSIGNED_PAYLOAD) {
            $parsed['headers'][self::AMZ_CONTENT_SHA256_HEADER] = [$payload];
        }
        $context = $this->createContext($parsed, $payload);
        $toSign = $this->createStringToSign($ldt, $cs, $context['creq']);
        $signingKey = $this->getSigningKey($sdt, $this->region, $service, $credentials->getSecretKey());
        $signature = hash_hmac('sha256', $toSign, $signingKey);
        $parsed['headers']['Authorization'] = ["AWS4-HMAC-SHA256 " . "Credential={$credentials->getAccessKeyId()}/{$cs}, " . "SignedHeaders={$context['headers']}, Signature={$signature}"];
        return $this->buildRequest($parsed);
    }
    /**
     * Get the headers that were used to pre-sign the request.
     * Used for the X-Amz-SignedHeaders header.
     *
     * @param array $headers
     * @return array
     */
    private function getPresignHeaders(array $headers)
    {
        $presignHeaders = [];
        $blacklist = $this->getHeaderBlacklist();
        foreach ($headers as $name => $value) {
            $lName = strtolower($name);
            if (!isset($blacklist[$lName]) && $name !== self::AMZ_CONTENT_SHA256_HEADER) {
                $presignHeaders[] = $lName;
            }
        }
        return $presignHeaders;
    }
    /**
     * {@inheritdoc}
     */
    public function presign(RequestInterface $request, CredentialsInterface $credentials, $expires, array $options = [])
    {
        $startTimestamp = isset($options['start_time']) ? $this->convertToTimestamp($options['start_time'], null) : time();
        $expiresTimestamp = $this->convertToTimestamp($expires, $startTimestamp);
        if ($this->useV4a) {
            return $this->presignWithV4a($request, $credentials, $this->convertExpires($expiresTimestamp, $startTimestamp));
        }
        $parsed = $this->createPresignedRequest($request, $credentials);
        $payload = $this->getPresignedPayload($request);
        $httpDate = gmdate(self::ISO8601_BASIC, $startTimestamp);
        $shortDate = substr($httpDate, 0, 8);
        $scope = $this->createScope($shortDate, $this->region, $this->service);
        $credential = $credentials->getAccessKeyId() . '/' . $scope;
        if ($credentials->getSecurityToken()) {
            unset($parsed['headers']['X-Amz-Security-Token']);
        }
        $parsed['query']['X-Amz-Algorithm'] = 'AWS4-HMAC-SHA256';
        $parsed['query']['X-Amz-Credential'] = $credential;
        $parsed['query']['X-Amz-Date'] = gmdate('Ymd\THis\Z', $startTimestamp);
        $parsed['query']['X-Amz-SignedHeaders'] = implode(';', $this->getPresignHeaders($parsed['headers']));
        $parsed['query']['X-Amz-Expires'] = $this->convertExpires($expiresTimestamp, $startTimestamp);
        $context = $this->createContext($parsed, $payload);
        $stringToSign = $this->createStringToSign($httpDate, $scope, $context['creq']);
        $key = $this->getSigningKey($shortDate, $this->region, $this->service, $credentials->getSecretKey());
        $parsed['query']['X-Amz-Signature'] = hash_hmac('sha256', $stringToSign, $key);
        return $this->buildRequest($parsed);
    }
    /**
     * Converts a POST request to a GET request by moving POST fields into the
     * query string.
     *
     * Useful for pre-signing query protocol requests.
     *
     * @param RequestInterface $request Request to clone
     *
     * @return RequestInterface
     * @throws \InvalidArgumentException if the method is not POST
     */
    public static function convertPostToGet(RequestInterface $request, $additionalQueryParams = "")
    {
        if ($request->getMethod() !== 'POST') {
            throw new \InvalidArgumentException('Expected a POST request but ' . 'received a ' . $request->getMethod() . ' request.');
        }
        $sr = $request->withMethod('GET')->withBody(Psr7\Utils::streamFor(''))->withoutHeader('Content-Type')->withoutHeader('Content-Length');
        // Move POST fields to the query if they are present
        if ($request->getHeaderLine('Content-Type') === 'application/x-www-form-urlencoded') {
            $body = (string) $request->getBody() . $additionalQueryParams;
            $sr = $sr->withUri($sr->getUri()->withQuery($body));
        }
        return $sr;
    }
    protected function getPayload(RequestInterface $request)
    {
        if ($this->unsigned && $request->getUri()->getScheme() == 'https') {
            return self::UNSIGNED_PAYLOAD;
        }
        // Calculate the request signature payload
        if ($request->hasHeader(self::AMZ_CONTENT_SHA256_HEADER)) {
            // Handle streaming operations (e.g. Glacier.UploadArchive)
            return $request->getHeaderLine(self::AMZ_CONTENT_SHA256_HEADER);
        }
        if (!$request->getBody()->isSeekable()) {
            throw new CouldNotCreateChecksumException('sha256');
        }
        try {
            return Psr7\Utils::hash($request->getBody(), 'sha256');
        } catch (\Exception $e) {
            throw new CouldNotCreateChecksumException('sha256', $e);
        }
    }
    protected function getPresignedPayload(RequestInterface $request)
    {
        return $this->getPayload($request);
    }
    protected function createCanonicalizedPath($path)
    {
        $doubleEncoded = rawurlencode(ltrim($path, '/'));
        return '/' . str_replace('%2F', '/', $doubleEncoded);
    }
    private function createStringToSign($longDate, $credentialScope, $creq)
    {
        $hash = hash('sha256', $creq);
        return "AWS4-HMAC-SHA256\n{$longDate}\n{$credentialScope}\n{$hash}";
    }
    private function createPresignedRequest(RequestInterface $request, CredentialsInterface $credentials)
    {
        $parsedRequest = $this->parseRequest($request);
        // Make sure to handle temporary credentials
        if ($token = $credentials->getSecurityToken()) {
            $parsedRequest['headers']['X-Amz-Security-Token'] = [$token];
        }
        return $this->moveHeadersToQuery($parsedRequest);
    }
    /**
     * @param array  $parsedRequest
     * @param string $payload Hash of the request payload
     * @return array Returns an array of context information
     */
    private function createContext(array $parsedRequest, $payload)
    {
        $blacklist = $this->getHeaderBlacklist();
        // Normalize the path as required by SigV4
        $canon = $parsedRequest['method'] . "\n" . $this->createCanonicalizedPath($parsedRequest['path']) . "\n" . $this->getCanonicalizedQuery($parsedRequest['query']) . "\n";
        // Case-insensitively aggregate all of the headers.
        $aggregate = [];
        foreach ($parsedRequest['headers'] as $key => $values) {
            $key = strtolower($key);
            if (!isset($blacklist[$key])) {
                foreach ($values as $v) {
                    $aggregate[$key][] = $v;
                }
            }
        }
        ksort($aggregate);
        $canonHeaders = [];
        foreach ($aggregate as $k => $v) {
            if (count($v) > 0) {
                sort($v);
            }
            $canonHeaders[] = $k . ':' . preg_replace('/\s+/', ' ', implode(',', $v));
        }
        $signedHeadersString = implode(';', array_keys($aggregate));
        $canon .= implode("\n", $canonHeaders) . "\n\n" . $signedHeadersString . "\n" . $payload;
        return ['creq' => $canon, 'headers' => $signedHeadersString];
    }
    private function getCanonicalizedQuery(array $query)
    {
        unset($query['X-Amz-Signature']);
        if (!$query) {
            return '';
        }
        $qs = '';
        ksort($query);
        foreach ($query as $k => $v) {
            if (!is_array($v)) {
                $qs .= rawurlencode($k) . '=' . rawurlencode($v !== null ? $v : '') . '&';
            } else {
                sort($v);
                foreach ($v as $value) {
                    $qs .= rawurlencode($k) . '=' . rawurlencode($value !== null ? $value : '') . '&';
                }
            }
        }
        return substr($qs, 0, -1);
    }
    private function convertToTimestamp($dateValue, $relativeTimeBase = null)
    {
        if ($dateValue instanceof \DateTimeInterface) {
            $timestamp = $dateValue->getTimestamp();
        } elseif (!is_numeric($dateValue)) {
            $timestamp = strtotime($dateValue, $relativeTimeBase === null ? time() : $relativeTimeBase);
        } else {
            $timestamp = $dateValue;
        }
        return $timestamp;
    }
    private function convertExpires($expiresTimestamp, $startTimestamp)
    {
        $duration = $expiresTimestamp - $startTimestamp;
        // Ensure that the duration of the signature is not longer than a week
        if ($duration > 604800) {
            throw new \InvalidArgumentException('The expiration date of a ' . 'signature version 4 presigned URL must be less than one ' . 'week');
        }
        return $duration;
    }
    private function moveHeadersToQuery(array $parsedRequest)
    {
        //x-amz-user-agent shouldn't be put in a query param
        unset($parsedRequest['headers']['X-Amz-User-Agent']);
        foreach ($parsedRequest['headers'] as $name => $header) {
            $lname = strtolower($name);
            if (substr($lname, 0, 5) == 'x-amz') {
                $parsedRequest['query'][$name] = $header;
            }
            $blacklist = $this->getHeaderBlacklist();
            if (isset($blacklist[$lname]) || $lname === strtolower(self::AMZ_CONTENT_SHA256_HEADER)) {
                unset($parsedRequest['headers'][$name]);
            }
        }
        return $parsedRequest;
    }
    private function parseRequest(RequestInterface $request)
    {
        // Clean up any previously set headers.
        /** @var RequestInterface $request */
        $request = $request->withoutHeader('X-Amz-Date')->withoutHeader('Date')->withoutHeader('Authorization');
        $uri = $request->getUri();
        return ['method' => $request->getMethod(), 'path' => $uri->getPath(), 'query' => Psr7\Query::parse($uri->getQuery()), 'uri' => $uri, 'headers' => $request->getHeaders(), 'body' => $request->getBody(), 'version' => $request->getProtocolVersion()];
    }
    private function buildRequest(array $req)
    {
        if ($req['query']) {
            $req['uri'] = $req['uri']->withQuery(Psr7\Query::build($req['query']));
        }
        return new Psr7\Request($req['method'], $req['uri'], $req['headers'], $req['body'], $req['version']);
    }
    private function verifyCRTLoaded()
    {
        if (!extension_loaded('awscrt')) {
            throw new CommonRuntimeException("AWS Common Runtime for PHP is required to use Signature V4A" . ".  Please install it using the instructions found at" . " https://github.com/aws/aws-sdk-php/blob/master/CRT_INSTRUCTIONS.md");
        }
    }
    private function createCRTStaticCredentialsProvider($credentials)
    {
        return new StaticCredentialsProvider(['access_key_id' => $credentials->getAccessKeyId(), 'secret_access_key' => $credentials->getSecretKey(), 'session_token' => $credentials->getSecurityToken()]);
    }
    private function removeIllegalV4aHeaders(&$request)
    {
        $illegalV4aHeaders = [self::AMZ_CONTENT_SHA256_HEADER, "aws-sdk-invocation-id", "aws-sdk-retry", 'x-amz-region-set'];
        $storedHeaders = [];
        foreach ($illegalV4aHeaders as $header) {
            if ($request->hasHeader($header)) {
                $storedHeaders[$header] = $request->getHeader($header);
                $request = $request->withoutHeader($header);
            }
        }
        return $storedHeaders;
    }
    private function CRTRequestFromGuzzleRequest($request)
    {
        return new Request(
            $request->getMethod(),
            (string) $request->getUri(),
            [],
            //leave empty as the query is parsed from the uri object
            array_map(function ($header) {
                return $header[0];
            }, $request->getHeaders())
        );
    }
    /**
     * @param CredentialsInterface $credentials
     * @param RequestInterface $request
     * @param $signingService
     * @return RequestInterface
     */
    protected function signWithV4a(CredentialsInterface $credentials, RequestInterface $request, $signingService)
    {
        $this->verifyCRTLoaded();
        $credentials_provider = $this->createCRTStaticCredentialsProvider($credentials);
        $signingConfig = new SigningConfigAWS(['algorithm' => SigningAlgorithm::SIGv4_ASYMMETRIC, 'signature_type' => SignatureType::HTTP_REQUEST_HEADERS, 'credentials_provider' => $credentials_provider, 'signed_body_value' => $this->getPayload($request), 'region' => "*", 'service' => $signingService, 'date' => time()]);
        $removedIllegalHeaders = $this->removeIllegalV4aHeaders($request);
        $http_request = $this->CRTRequestFromGuzzleRequest($request);
        Signing::signRequestAws(Signable::fromHttpRequest($http_request), $signingConfig, function ($signing_result, $error_code) use (&$http_request) {
            $signing_result->applyToHttpRequest($http_request);
        });
        foreach ($removedIllegalHeaders as $header => $value) {
            $request = $request->withHeader($header, $value);
        }
        $sigV4AHeaders = $http_request->headers();
        foreach ($sigV4AHeaders->toArray() as $h => $v) {
            $request = $request->withHeader($h, $v);
        }
        return $request;
    }
    protected function presignWithV4a(RequestInterface $request, CredentialsInterface $credentials, $expires)
    {
        $this->verifyCRTLoaded();
        $credentials_provider = $this->createCRTStaticCredentialsProvider($credentials);
        $signingConfig = new SigningConfigAWS(['algorithm' => SigningAlgorithm::SIGv4_ASYMMETRIC, 'signature_type' => SignatureType::HTTP_REQUEST_QUERY_PARAMS, 'credentials_provider' => $credentials_provider, 'signed_body_value' => $this->getPresignedPayload($request), 'region' => "*", 'service' => $this->service, 'date' => time(), 'expiration_in_seconds' => $expires]);
        $this->removeIllegalV4aHeaders($request);
        foreach ($this->getHeaderBlacklist() as $headerName => $headerValue) {
            if ($request->hasHeader($headerName)) {
                $request = $request->withoutHeader($headerName);
            }
        }
        $http_request = $this->CRTRequestFromGuzzleRequest($request);
        Signing::signRequestAws(Signable::fromHttpRequest($http_request), $signingConfig, function ($signing_result, $error_code) use (&$http_request) {
            $signing_result->applyToHttpRequest($http_request);
        });
        return $request->withUri(new Psr7\Uri($http_request->pathAndQuery()));
    }
}
