<?php

namespace Aws\Signature;

use Aws\Credentials\CredentialsInterface;
use DateTime;
use Psr\Http\Message\RequestInterface;

/**
 * Interface used to provide interchangeable strategies for signing requests
 * using the various AWS signature protocols.
 */
interface SignatureInterface {
	/**
	 * Signs the specified request with an AWS signing protocol by using the
	 * provided AWS account credentials and adding the required headers to the
	 * request.
	 *
	 * @param RequestInterface $request Request to sign
	 * @param CredentialsInterface $credentials Signing credentials
	 *
	 * @return RequestInterface Returns the modified request.
	 */
	public function signRequest(
		RequestInterface $request,
		CredentialsInterface $credentials
	);

	/**
	 * Create a pre-signed request.
	 *
	 * @param RequestInterface $request Request to sign
	 * @param CredentialsInterface $credentials Credentials used to sign
	 * @param int|string|DateTime $expires The time at which the URL should
	 *     expire. This can be a Unix timestamp, a PHP DateTime object, or a
	 *     string that can be evaluated by strtotime.
	 *
	 * @return RequestInterface
	 */
	public function presign(
		RequestInterface $request,
		CredentialsInterface $credentials,
		$expires,
		array $options = []
	);
}
