<?php

namespace YaySMTP\Aws3\Aws;

use YaySMTP\Aws3\Aws\Exception\AwsException;
use YaySMTP\Aws3\GuzzleHttp\Exception\RequestException;
use YaySMTP\Aws3\Psr\Http\Message\RequestInterface;
use YaySMTP\Aws3\GuzzleHttp\Promise\PromiseInterface;
use YaySMTP\Aws3\GuzzleHttp\Promise;
/**
 * @internal Middleware that retries failures.
 */
class RetryMiddleware
{
    private static $retryStatusCodes = [500 => true, 502 => true, 503 => true, 504 => true];
    private static $retryCodes = [
        // Throttling error
        'RequestLimitExceeded' => true,
        'Throttling' => true,
        'ThrottlingException' => true,
        'ThrottledException' => true,
        'ProvisionedThroughputExceededException' => true,
        'RequestThrottled' => true,
        'BandwidthLimitExceeded' => true,
        'RequestThrottledException' => true,
    ];
    private $decider;
    private $delay;
    private $nextHandler;
    private $collectStats;
    public function __construct(callable $decider, callable $delay, callable $nextHandler, $collectStats = false)
    {
        $this->decider = $decider;
        $this->delay = $delay;
        $this->nextHandler = $nextHandler;
        $this->collectStats = (bool) $collectStats;
    }
    /**
     * Creates a default AWS retry decider function.
     *
     * @param int $maxRetries
     *
     * @return callable
     */
    public static function createDefaultDecider($maxRetries = 3)
    {
        $retryCurlErrors = [];
        if (extension_loaded('curl')) {
            $retryCurlErrors[CURLE_RECV_ERROR] = true;
        }
        return function ($retries, \YaySMTP\Aws3\Aws\CommandInterface $command, \YaySMTP\Aws3\Psr\Http\Message\RequestInterface $request, \YaySMTP\Aws3\Aws\ResultInterface $result = null, $error = null) use($maxRetries, $retryCurlErrors) {
            // Allow command-level options to override this value
            $maxRetries = null !== $command['@retries'] ? $command['@retries'] : $maxRetries;
            if ($retries >= $maxRetries) {
                return false;
            }
            if (!$error) {
                return isset(self::$retryStatusCodes[$result['@metadata']['statusCode']]);
            }
            if (!$error instanceof AwsException) {
                return false;
            }
            if ($error->isConnectionError()) {
                return true;
            }
            if (isset(self::$retryCodes[$error->getAwsErrorCode()])) {
                return true;
            }
            if (isset(self::$retryStatusCodes[$error->getStatusCode()])) {
                return true;
            }
            if (count($retryCurlErrors) && ($previous = $error->getPrevious()) && $previous instanceof RequestException) {
                if (method_exists($previous, 'getHandlerContext')) {
                    $context = $previous->getHandlerContext();
                    return !empty($context['errno']) && isset($retryCurlErrors[$context['errno']]);
                }
                $message = $previous->getMessage();
                foreach (array_keys($retryCurlErrors) as $curlError) {
                    if (strpos($message, 'cURL error ' . $curlError . ':') === 0) {
                        return true;
                    }
                }
            }
            return false;
        };
    }
    /**
     * Delay function that calculates an exponential delay.
     *
     * Exponential backoff with jitter, 100ms base, 20 sec ceiling
     *
     * @param $retries - The number of retries that have already been attempted
     *
     * @return int
     */
    public static function exponentialDelay($retries)
    {
        return mt_rand(0, (int) min(20000, (int) pow(2, $retries) * 100));
    }
    /**
     * @param CommandInterface $command
     * @param RequestInterface $request
     *
     * @return PromiseInterface
     */
    public function __invoke(\YaySMTP\Aws3\Aws\CommandInterface $command, \YaySMTP\Aws3\Psr\Http\Message\RequestInterface $request = null)
    {
        $retries = 0;
        $requestStats = [];
        $handler = $this->nextHandler;
        $decider = $this->decider;
        $delay = $this->delay;
        $request = $this->addRetryHeader($request, 0, 0);
        $g = function ($value) use($handler, $decider, $delay, $command, $request, &$retries, &$requestStats, &$g) {
            $this->updateHttpStats($value, $requestStats);
            if ($value instanceof \Exception || $value instanceof \Throwable) {
                if (!$decider($retries, $command, $request, null, $value)) {
                    return \YaySMTP\Aws3\GuzzleHttp\Promise\rejection_for($this->bindStatsToReturn($value, $requestStats));
                }
            } elseif ($value instanceof ResultInterface && !$decider($retries, $command, $request, $value, null)) {
                return $this->bindStatsToReturn($value, $requestStats);
            }
            // Delay fn is called with 0, 1, ... so increment after the call.
            $delayBy = $delay($retries++);
            $command['@http']['delay'] = $delayBy;
            if ($this->collectStats) {
                $this->updateStats($retries, $delayBy, $requestStats);
            }
            // Update retry header with retry count and delayBy
            $request = $this->addRetryHeader($request, $retries, $delayBy);
            return $handler($command, $request)->then($g, $g);
        };
        return $handler($command, $request)->then($g, $g);
    }
    private function addRetryHeader($request, $retries, $delayBy)
    {
        return $request->withHeader('aws-sdk-retry', "{$retries}/{$delayBy}");
    }
    private function updateStats($retries, $delay, array &$stats)
    {
        if (!isset($stats['total_retry_delay'])) {
            $stats['total_retry_delay'] = 0;
        }
        $stats['total_retry_delay'] += $delay;
        $stats['retries_attempted'] = $retries;
    }
    private function updateHttpStats($value, array &$stats)
    {
        if (empty($stats['http'])) {
            $stats['http'] = [];
        }
        if ($value instanceof AwsException) {
            $resultStats = isset($value->getTransferInfo('http')[0]) ? $value->getTransferInfo('http')[0] : [];
            $stats['http'][] = $resultStats;
        } elseif ($value instanceof ResultInterface) {
            $resultStats = isset($value['@metadata']['transferStats']['http'][0]) ? $value['@metadata']['transferStats']['http'][0] : [];
            $stats['http'][] = $resultStats;
        }
    }
    private function bindStatsToReturn($return, array $stats)
    {
        if ($return instanceof ResultInterface) {
            if (!isset($return['@metadata'])) {
                $return['@metadata'] = [];
            }
            $return['@metadata']['transferStats'] = $stats;
        } elseif ($return instanceof AwsException) {
            $return->setTransferInfo($stats);
        }
        return $return;
    }
}