#pragma once

#include <memory>

#include "source/extensions/common/aws/credentials_provider.h"

#include "source/extensions/common/aws/signer_base_impl.h"

#include "source/extensions/common/aws/signers/sigv4a_key_derivation.h"

namespace Envoy {

namespace Extensions {

namespace Common {

namespace Aws {

/**

 * Implementation of the Signature V4A signing process.

 * See https://docs.aws.amazon.com/general/latest/gr/signature-version-4.html

 *

 * Query parameter support is implemented as per:

 * https://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-query-string-auth.html

 */

class SigV4ASignerImpl : public SignerBaseImpl {

  // Allow friend access for signer corpus testing

  friend class SigV4ASignerImplFriend;

public:

  SigV4ASignerImpl(

      absl::string_view service_name, absl::string_view region,

      const CredentialsProviderChainSharedPtr& credentials_provider,

      Server::Configuration::CommonFactoryContext& context,

      const AwsSigningHeaderMatcherVector& exclude_matcher_config,

      const AwsSigningHeaderMatcherVector& include_matcher_config, const bool query_string = false,

      const uint16_t expiration_time = SignatureQueryParameterValues::DefaultExpiration,

      std::unique_ptr<SigV4AKeyDerivationBase> key_derivation_ptr =

          std::make_unique<SigV4AKeyDerivation>())

private:

  void addRegionHeader(Http::RequestHeaderMap& headers,

                       const absl::string_view override_region) const override;

  void addRegionQueryParam(Envoy::Http::Utility::QueryParamsMulti& query_params,

                           const absl::string_view override_region) const override;

  std::string createCredentialScope(const absl::string_view short_date,

                                    const absl::string_view override_region) const override;

  std::string createStringToSign(const absl::string_view canonical_request,

                                 const absl::string_view long_date,

                                 const absl::string_view credential_scope) const override;

  std::string

  createSignature(const absl::string_view access_key_id, const absl::string_view secret_access_key,

                  ABSL_ATTRIBUTE_UNUSED const absl::string_view short_date,

                  const absl::string_view string_to_sign,

                  ABSL_ATTRIBUTE_UNUSED const absl::string_view override_region) const override;

  std::string createAuthorizationHeader(const absl::string_view access_key_id,

                                        const absl::string_view credential_scope,

                                        const std::map<std::string, std::string>& canonical_headers,

                                        const absl::string_view signature) const override;

  absl::string_view getAlgorithmString() const override;

  std::unique_ptr<SigV4AKeyDerivationBase> key_derivation_ptr_;

};

} // namespace Aws

} // namespace Common

} // namespace Extensions

} // namespace Envoy