<?php

namespace Dudlewebs\WPMCS\s3\Aws\Credentials;

use Dudlewebs\WPMCS\s3\Aws\Exception\CredentialsException;
use Dudlewebs\WPMCS\s3\GuzzleHttp\Psr7\Request;
use Dudlewebs\WPMCS\s3\GuzzleHttp\Promise\PromiseInterface;
use Dudlewebs\WPMCS\s3\Psr\Http\Message\ResponseInterface;
/**
 * Credential provider that fetches credentials with GET request.
 * ECS environment variable is used in constructing request URI.
 */
class EcsCredentialProvider
{
    const SERVER_URI = 'http://169.254.170.2';
    const ENV_URI = "AWS_CONTAINER_CREDENTIALS_RELATIVE_URI";
    const ENV_FULL_URI = "AWS_CONTAINER_CREDENTIALS_FULL_URI";
    const ENV_AUTH_TOKEN = "AWS_CONTAINER_AUTHORIZATION_TOKEN";
    const ENV_TIMEOUT = 'AWS_METADATA_SERVICE_TIMEOUT';
    /** @var callable */
    private $client;
    /** @var float|mixed */
    private $timeout;
    /**
     *  The constructor accepts following options:
     *  - timeout: (optional) Connection timeout, in seconds, default 1.0
     *  - client: An EcsClient to make request from
     *
     * @param array $config Configuration options
     */
    public function __construct(array $config = [])
    {
        $timeout = \getenv(self::ENV_TIMEOUT);
        if (!$timeout) {
            $timeout = isset($_SERVER[self::ENV_TIMEOUT]) ? $_SERVER[self::ENV_TIMEOUT] : (isset($config['timeout']) ? $config['timeout'] : 1.0);
        }
        $this->timeout = (float) $timeout;
        $this->client = isset($config['client']) ? $config['client'] : \Dudlewebs\WPMCS\s3\Aws\default_http_handler();
    }
    /**
     * Load ECS credentials
     *
     * @return PromiseInterface
     */
    public function __invoke()
    {
        $client = $this->client;
        $request = new Request('GET', self::getEcsUri());
        $headers = $this->setHeaderForAuthToken();
        return $client($request, ['timeout' => $this->timeout, 'proxy' => '', 'headers' => $headers])->then(function (ResponseInterface $response) {
            $result = $this->decodeResult((string) $response->getBody());
            return new Credentials($result['AccessKeyId'], $result['SecretAccessKey'], $result['Token'], \strtotime($result['Expiration']));
        })->otherwise(function ($reason) {
            $reason = \is_array($reason) ? $reason['exception'] : $reason;
            $msg = $reason->getMessage();
            throw new CredentialsException("Error retrieving credential from ECS ({$msg})");
        });
    }
    private function getEcsAuthToken()
    {
        return \getenv(self::ENV_AUTH_TOKEN);
    }
    public function setHeaderForAuthToken()
    {
        $authToken = self::getEcsAuthToken();
        $headers = [];
        if (!empty($authToken)) {
            $headers = ['Authorization' => $authToken];
        }
        return $headers;
    }
    /**
     * Fetch credential URI from ECS environment variable
     *
     * @return string Returns ECS URI
     */
    private function getEcsUri()
    {
        $credsUri = \getenv(self::ENV_URI);
        if ($credsUri === \false) {
            $credsUri = isset($_SERVER[self::ENV_URI]) ? $_SERVER[self::ENV_URI] : '';
        }
        if (empty($credsUri)) {
            $credFullUri = \getenv(self::ENV_FULL_URI);
            if ($credFullUri === \false) {
                $credFullUri = isset($_SERVER[self::ENV_FULL_URI]) ? $_SERVER[self::ENV_FULL_URI] : '';
            }
            if (!empty($credFullUri)) {
                return $credFullUri;
            }
        }
        return self::SERVER_URI . $credsUri;
    }
    private function decodeResult($response)
    {
        $result = \json_decode($response, \true);
        if (!isset($result['AccessKeyId'])) {
            throw new CredentialsException('Unexpected ECS credential value');
        }
        return $result;
    }
}