<?php

namespace DeliciousBrains\WP_Offload_Media\Aws3\Aws\Credentials;

use DeliciousBrains\WP_Offload_Media\Aws3\Aws\Exception\CredentialsException;
use DeliciousBrains\WP_Offload_Media\Aws3\GuzzleHttp\Promise;
use DeliciousBrains\WP_Offload_Media\Aws3\GuzzleHttp\Psr7\Request;
use DeliciousBrains\WP_Offload_Media\Aws3\GuzzleHttp\Promise\PromiseInterface;
use DeliciousBrains\WP_Offload_Media\Aws3\Psr\Http\Message\ResponseInterface;
/**
 * Credential provider that provides credentials from the EC2 metadata server.
 */
class InstanceProfileProvider
{
    const SERVER_URI = 'http://169.254.169.254/latest/';
    const CRED_PATH = 'meta-data/iam/security-credentials/';
    const ENV_DISABLE = 'AWS_EC2_METADATA_DISABLED';
    /** @var string */
    private $profile;
    /** @var callable */
    private $client;
    /**
     * The constructor accepts the following options:
     *
     * - timeout: Connection timeout, in seconds.
     * - profile: Optional EC2 profile name, if known.
     *
     * @param array $config Configuration options.
     */
    public function __construct(array $config = [])
    {
        $this->timeout = isset($config['timeout']) ? $config['timeout'] : 1.0;
        $this->profile = isset($config['profile']) ? $config['profile'] : null;
        $this->client = isset($config['client']) ? $config['client'] : \DeliciousBrains\WP_Offload_Media\Aws3\Aws\default_http_handler();
    }
    /**
     * Loads instance profile credentials.
     *
     * @return PromiseInterface
     */
    public function __invoke()
    {
        return \DeliciousBrains\WP_Offload_Media\Aws3\GuzzleHttp\Promise\coroutine(function () {
            if (!$this->profile) {
                $this->profile = (yield $this->request(self::CRED_PATH));
            }
            $json = (yield $this->request(self::CRED_PATH . $this->profile));
            $result = $this->decodeResult($json);
            (yield new \DeliciousBrains\WP_Offload_Media\Aws3\Aws\Credentials\Credentials($result['AccessKeyId'], $result['SecretAccessKey'], $result['Token'], strtotime($result['Expiration'])));
        });
    }
    /**
     * @param string $url
     * @return PromiseInterface Returns a promise that is fulfilled with the
     *                          body of the response as a string.
     */
    private function request($url)
    {
        $disabled = getenv(self::ENV_DISABLE) ?: false;
        if (strcasecmp($disabled, 'true') === 0) {
            throw new \DeliciousBrains\WP_Offload_Media\Aws3\Aws\Exception\CredentialsException($this->createErrorMessage('EC2 metadata server access disabled'));
        }
        $fn = $this->client;
        $request = new \DeliciousBrains\WP_Offload_Media\Aws3\GuzzleHttp\Psr7\Request('GET', self::SERVER_URI . $url);
        return $fn($request, ['timeout' => $this->timeout])->then(function (\DeliciousBrains\WP_Offload_Media\Aws3\Psr\Http\Message\ResponseInterface $response) {
            return (string) $response->getBody();
        })->otherwise(function (array $reason) {
            $reason = $reason['exception'];
            $msg = $reason->getMessage();
            throw new \DeliciousBrains\WP_Offload_Media\Aws3\Aws\Exception\CredentialsException($this->createErrorMessage($msg));
        });
    }
    private function createErrorMessage($previous)
    {
        return "Error retrieving credentials from the instance profile " . "metadata server. ({$previous})";
    }
    private function decodeResult($response)
    {
        $result = json_decode($response, true);
        if ($result['Code'] !== 'Success') {
            throw new \DeliciousBrains\WP_Offload_Media\Aws3\Aws\Exception\CredentialsException('Unexpected instance profile ' . 'response code: ' . $result['Code']);
        }
        return $result;
    }
}