// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.

#include "azure/attestation/attestation_administration_client.hpp"

#include "private/attestation_client_models_private.hpp"
#include "private/attestation_client_private.hpp"
#include "private/attestation_common_request.hpp"
#include "private/attestation_deserializers_private.hpp"
#include "private/package_version.hpp"

#include <azure/core/base64.hpp>
#include <azure/core/http/policies/policy.hpp>
#include <azure/core/internal/http/pipeline.hpp>

#include <shared_mutex>
#include <string>

// cspell: words jwks
using namespace Azure::Security::Attestation;
using namespace Azure::Security::Attestation::Models;
using namespace Azure::Security::Attestation::_detail;
using namespace Azure::Security::Attestation::Models::_detail;
using namespace Azure::Core::Tracing::_internal;
using namespace Azure::Core::Http;
using namespace Azure::Core::Http::Policies;
using namespace Azure::Core::Http::Policies::_internal;
using namespace Azure::Core::Http::_internal;
using namespace Azure::Core::Diagnostics;
using namespace Azure::Core::_internal;

const Models::AttestationType AttestationType::SgxEnclave("SgxEnclave");
const Models::AttestationType AttestationType::OpenEnclave("OpenEnclave");
const Models::AttestationType AttestationType::Tpm("Tpm");
const Models::PolicyModification PolicyModification::Removed("Removed");
const Models::PolicyModification PolicyModification::Updated("Updated");
const Models::PolicyCertificateModification PolicyCertificateModification::IsAbsent("IsAbsent");
const Models::PolicyCertificateModification PolicyCertificateModification::IsPresent("IsPresent");

AttestationAdministrationClient::AttestationAdministrationClient(
    std::string const& endpoint,
    std::shared_ptr<const Core::Credentials::TokenCredential> credential,
    AttestationAdministrationClientOptions const& options)
    : m_endpoint{endpoint}, m_apiVersion{options.ApiVersion},
      m_tokenValidationOptions{options.TokenValidationOptions},
      m_tracingFactory{
          options,
          "Microsoft.Attestation",
          "azure-security-attestation-cpp",
          PackageVersion::ToString()}
{
  std::vector<std::unique_ptr<HttpPolicy>> perRetryPolicies;
  if (credential)
  {
    Azure::Core::Credentials::TokenRequestContext tokenContext;
    tokenContext.Scopes = {"https://attest.azure.net/.default"};

    perRetryPolicies.emplace_back(
        std::make_unique<BearerTokenAuthenticationPolicy>(credential, tokenContext));
  }
  std::vector<std::unique_ptr<HttpPolicy>> perCallPolicies;

  m_pipeline = std::make_shared<Azure::Core::Http::_internal::HttpPipeline>(
      options,
      "security.attestation",
      PackageVersion::ToString(),
      std::move(perRetryPolicies),
      std::move(perCallPolicies));
}

AttestationAdministrationClient AttestationAdministrationClient::Create(
    std::string const& endpoint,
    std::shared_ptr<const Core::Credentials::TokenCredential> credential,
    AttestationAdministrationClientOptions const& options,
    Azure::Core::Context const& context)
{
  AttestationAdministrationClient returnValue(endpoint, credential, options);
  returnValue.RetrieveResponseValidationCollateral(context);
  return returnValue;
}

namespace {
std::shared_timed_mutex SharedStateLock;
}

Azure::Response<Models::AttestationToken<std::string>>
AttestationAdministrationClient::GetAttestationPolicy(
    AttestationType const& attestationType,
    GetPolicyOptions const& options,
    Azure::Core::Context const& context) const
{
  auto tracingContext(m_tracingFactory.CreateTracingContext("GetAttestationPolicy", context));
  try
  {

    auto request = AttestationCommonRequest::CreateRequest(
        m_endpoint,
        m_apiVersion,
        HttpMethod::Get,
        {"policies/" + attestationType.ToString()},
        nullptr);

    // Send the request to the service.
    auto response = AttestationCommonRequest::SendRequest(*m_pipeline, request, context);

    // Deserialize the Service response token and return the JSON web token returned by the
    // service.
    std::string responseToken = AttestationServiceTokenResponseSerializer::Deserialize(response);

    // Parse the JWT returned by the attestation service.
    const auto resultToken
        = AttestationTokenInternal<Models::_detail::PolicyResult, PolicyResultSerializer>(
            responseToken);

    // Validate the token returned by the service. Use the cached attestation signers in the
    // validation.
    resultToken.ValidateToken(
        options.TokenValidationOptionsOverride ? *options.TokenValidationOptionsOverride
                                               : this->m_tokenValidationOptions,
        m_attestationSigners);

    // Extract the underlying policy token from the response.
    std::string policyTokenValue
        = *static_cast<AttestationToken<Models::_detail::PolicyResult>>(resultToken)
               .Body.PolicyToken;

    // TPM policies are empty by default, at least in our test instances, so handle the empty policy
    // token case.
    const auto policyTokenI
        = AttestationTokenInternal<StoredAttestationPolicy, StoredAttestationPolicySerializer>(
            policyTokenValue);
    AttestationToken<StoredAttestationPolicy> policyToken(policyTokenI);
    std::string returnPolicy;
    if (policyToken.Body.AttestationPolicy)
    {
      std::vector<uint8_t> policyUtf8 = *policyToken.Body.AttestationPolicy;
      returnPolicy = std::string(policyUtf8.begin(), policyUtf8.end());
    }

    // Construct a token whose body is the policy, but whose token is the response from the
    // service.
    const auto returnedToken = AttestationTokenInternal<std::string>(responseToken, &returnPolicy);
    return Response<AttestationToken<std::string>>(returnedToken, std::move(response));
  }
  catch (std::runtime_error const& ex)
  {
    tracingContext.Span.AddEvent(ex);
    throw;
  }
}

Models::AttestationToken<void> AttestationAdministrationClient::CreateAttestationPolicyToken(
    Azure::Nullable<std::string> const& newAttestationPolicy,
    Azure::Nullable<AttestationSigningKey> const& signingKey) const
{
  // Embed the encoded policy in the StoredAttestationPolicy.
  Azure::Nullable<StoredAttestationPolicy> storedPolicy;
  if (newAttestationPolicy)
  {
    storedPolicy = StoredAttestationPolicy{
        std::vector<uint8_t>(newAttestationPolicy->begin(), newAttestationPolicy->end())};
  }

  const auto tokenToSet(
      AttestationTokenInternal<StoredAttestationPolicy, StoredAttestationPolicySerializer>::
          CreateToken(storedPolicy, signingKey));
  const auto tokenToSend(static_cast<AttestationToken<StoredAttestationPolicy>>(tokenToSet));

  // Strip the body type off the returned JWS - the caller of the function doesn't need it.
  return AttestationTokenInternal<void>(tokenToSend.RawToken);
}

Azure::Response<Models::AttestationToken<Models::PolicyResult>>
AttestationAdministrationClient::SetAttestationPolicy(
    AttestationType const& attestationType,
    std::string const& newAttestationPolicy,
    SetPolicyOptions const& options,
    Azure::Core::Context const& context) const
{
  auto tracingContext(m_tracingFactory.CreateTracingContext("SetAttestationPolicy", context));
  try
  {
    // Calculate a signed (or unsigned) attestation policy token to send to the service.
    Models::AttestationToken<void> const tokenToSend(
        CreateAttestationPolicyToken(newAttestationPolicy, options.SigningKey));

    Azure::Core::IO::MemoryBodyStream stream(
        reinterpret_cast<uint8_t const*>(tokenToSend.RawToken.data()), tokenToSend.RawToken.size());

    auto request = AttestationCommonRequest::CreateRequest(
        m_endpoint,
        m_apiVersion,
        HttpMethod::Put,
        {"policies/" + attestationType.ToString()},
        &stream);

    // Send the request to the service.
    auto response = AttestationCommonRequest::SendRequest(*m_pipeline, request, context);

    // Deserialize the Service response token and return the JSON web token returned by the
    // service.
    std::string responseToken = AttestationServiceTokenResponseSerializer::Deserialize(response);

    // Parse the JWT returned by the attestation service.
    auto resultToken
        = AttestationTokenInternal<Models::_detail::PolicyResult, PolicyResultSerializer>(
            responseToken);

    // Validate the token returned by the service. Use the cached attestation signers in the
    // validation.
    resultToken.ValidateToken(
        options.TokenValidationOptionsOverride ? *options.TokenValidationOptionsOverride
                                               : this->m_tokenValidationOptions,
        m_attestationSigners);

    // Extract the underlying policy token from the response.
    auto internalResult
        = static_cast<AttestationToken<Models::_detail::PolicyResult>>(resultToken).Body;

    Models::PolicyResult returnedResult;
    if (internalResult.PolicyResolution)
    {
      returnedResult.PolicyResolution
          = Models::PolicyModification(*internalResult.PolicyResolution);
    }
    if (internalResult.PolicySigner)
    {
      returnedResult.PolicySigner = AttestationSignerInternal(*internalResult.PolicySigner);
    }
    if (internalResult.PolicyTokenHash)
    {
      returnedResult.PolicyTokenHash = Base64Url::Base64UrlDecode(*internalResult.PolicyTokenHash);
    }

    // Construct a token whose body is the policy result, but whose token is the response from
    // the service.
    auto returnedToken
        = AttestationTokenInternal<Models::PolicyResult>(responseToken, &returnedResult);
    return Response<AttestationToken<Models::PolicyResult>>(returnedToken, std::move(response));
  }
  catch (std::runtime_error const& ex)
  {
    tracingContext.Span.AddEvent(ex);
    throw;
  }
}

Azure::Response<Models::AttestationToken<Models::PolicyResult>>
AttestationAdministrationClient::ResetAttestationPolicy(
    AttestationType const& attestationType,
    SetPolicyOptions const& options,
    Azure::Core::Context const& context) const
{
  auto tracingContext(m_tracingFactory.CreateTracingContext("ResetAttestationPolicy", context));
  try
  {
    // Calculate a signed (or unsigned) attestation policy token to send to the service.
    Models::AttestationToken<void> tokenToSend(
        CreateAttestationPolicyToken(Azure::Nullable<std::string>(), options.SigningKey));

    Azure::Core::IO::MemoryBodyStream stream(
        reinterpret_cast<uint8_t const*>(tokenToSend.RawToken.data()), tokenToSend.RawToken.size());

    auto request = AttestationCommonRequest::CreateRequest(
        m_endpoint,
        m_apiVersion,
        HttpMethod::Post,
        {"policies/" + attestationType.ToString() + ":reset"},
        &stream);

    // Send the request to the service.
    auto response = AttestationCommonRequest::SendRequest(*m_pipeline, request, context);

    // Deserialize the Service response token and return the JSON web token returned by the
    // service.
    std::string responseToken = AttestationServiceTokenResponseSerializer::Deserialize(response);

    // Parse the JWT returned by the attestation service.
    auto resultToken
        = AttestationTokenInternal<Models::_detail::PolicyResult, PolicyResultSerializer>(
            responseToken);

    // Validate the token returned by the service. Use the cached attestation signers in the
    // validation.
    resultToken.ValidateToken(
        options.TokenValidationOptionsOverride ? *options.TokenValidationOptionsOverride
                                               : this->m_tokenValidationOptions,
        m_attestationSigners);

    // Extract the underlying policy token from the response.
    auto internalResult
        = static_cast<AttestationToken<Models::_detail::PolicyResult>>(resultToken).Body;

    Models::PolicyResult returnedResult;
    if (internalResult.PolicyResolution)
    {
      returnedResult.PolicyResolution
          = Models::PolicyModification(*internalResult.PolicyResolution);
    }
    // Note that the attestation service currently never returns these values on Reset, even
    // though they are meaningful. Commenting them out to improve code coverage numbers. At
    // some point the attestation service may start returning these values, at which point
    // they can be un-commented out.
    //  if (internalResult.PolicySigner)
    //  {
    //    returnedResult.PolicySigner =
    //    AttestationSignerInternal(*internalResult.PolicySigner);
    //  }
    //  if (internalResult.PolicyTokenHash)
    //  {
    //    returnedResult.PolicyTokenHash =
    //    Base64Url::Base64UrlDecode(*internalResult.PolicyTokenHash);
    //  }

    // Construct a token whose body is the policy result, but whose token is the response from
    // the service.
    auto returnedToken
        = AttestationTokenInternal<Models::PolicyResult>(responseToken, &returnedResult);
    return Response<AttestationToken<Models::PolicyResult>>(returnedToken, std::move(response));
  }
  catch (std::runtime_error const& ex)
  {
    tracingContext.Span.AddEvent(ex);
    throw;
  }
}

Azure::Response<Models::AttestationToken<IsolatedModeCertificateListResult>>
AttestationAdministrationClient::GetIsolatedModeCertificates(
    GetIsolatedModeCertificatesOptions const& options,
    Azure::Core::Context const& context) const
{
  auto tracingContext(
      m_tracingFactory.CreateTracingContext("GetIsolatedModeCertificates", context));
  try
  {
    auto request = AttestationCommonRequest::CreateRequest(
        m_endpoint, m_apiVersion, HttpMethod::Get, {"certificates"}, nullptr);

    // Send the request to the service.
    auto response = AttestationCommonRequest::SendRequest(*m_pipeline, request, context);

    // Deserialize the Service response token and return the JSON web token returned by the
    // service.
    std::string responseToken = AttestationServiceTokenResponseSerializer::Deserialize(response);

    // Parse the JWT returned by the attestation service.
    auto resultToken = AttestationTokenInternal<
        Models::_detail::GetIsolatedModeCertificatesResult,
        IsolatedModeCertificateGetResultSerializer>(responseToken);

    // Validate the token returned by the service. Use the cached attestation signers in the
    // validation.
    resultToken.ValidateToken(
        options.TokenValidationOptionsOverride ? *options.TokenValidationOptionsOverride
                                               : this->m_tokenValidationOptions,
        m_attestationSigners);

    Models::_detail::JsonWebKeySet jwks(
        *static_cast<AttestationToken<Models::_detail::GetIsolatedModeCertificatesResult>>(
             resultToken)
             .Body.PolicyCertificates);
    Models::IsolatedModeCertificateListResult returnedResult;
    for (const auto& certificate : jwks.Keys)
    {
      returnedResult.Certificates.push_back(AttestationSignerInternal(certificate));
    }

    // Construct a token whose body is the get policy certificates result, but whose token
    // is the response from the service.
    auto returnedToken = AttestationTokenInternal<Models::IsolatedModeCertificateListResult>(
        responseToken, &returnedResult);
    return Response<AttestationToken<Models::IsolatedModeCertificateListResult>>(
        returnedToken, std::move(response));
  }
  catch (std::runtime_error const& ex)
  {
    tracingContext.Span.AddEvent(ex);
    throw;
  }
}

std::string AttestationAdministrationClient::CreateIsolatedModeModificationToken(
    std::string const& pemEncodedX509CertificateToAdd,
    AttestationSigningKey const& existingSigningKey) const
{
  // Calculate a signed attestation policy token to send to the service.
  // Embed the encoded policy in the StoredAttestationPolicy.
  const auto x5cToAdd(Cryptography::ImportX509Certificate(pemEncodedX509CertificateToAdd));

  // Create a JWK to add to the body.
  JsonWebKey jwkToSend;
  jwkToSend.Kty = x5cToAdd->GetKeyType();
  jwkToSend.X5c = std::vector<std::string>{x5cToAdd->ExportAsBase64()};

  IsolatedModeCertificateBody bodyToSend{jwkToSend};

  auto const internalTokenToSend(
      AttestationTokenInternal<IsolatedModeCertificateBody, IsolatedModeCertificateBodySerializer>::
          CreateToken(bodyToSend, existingSigningKey));

  auto const tokenToSend(
      static_cast<AttestationToken<IsolatedModeCertificateBody>>(internalTokenToSend));

  // JSON encode the string we're going to send.
  return Azure::Core::Json::_internal::json(tokenToSend.RawToken).dump();
}

Models::AttestationToken<Models::IsolatedModeCertificateModificationResult>
AttestationAdministrationClient::ProcessIsolatedModeModificationResult(
    std::unique_ptr<RawResponse> const& serverResponse,
    AttestationTokenValidationOptions const& tokenValidationOptions) const
{
  // Deserialize the Service response token and return the JSON web token returned by the
  // service.
  std::string responseToken
      = AttestationServiceTokenResponseSerializer::Deserialize(serverResponse);

  // Parse the JWT returned by the attestation service.
  auto const resultToken = AttestationTokenInternal<
      Models::_detail::ModifyIsolatedModeCertificatesResult,
      ModifyIsolatedModeCertificatesResultSerializer>(responseToken);

  // Validate the token returned by the service. Use the cached attestation signers in the
  // validation.
  resultToken.ValidateToken(tokenValidationOptions, m_attestationSigners);

  // Extract the underlying policy token from the response.
  auto internalResult
      = static_cast<AttestationToken<Models::_detail::ModifyIsolatedModeCertificatesResult>>(
            resultToken)
            .Body;

  Models::IsolatedModeCertificateModificationResult returnValue;
  if (internalResult.CertificateResolution)
  {
    returnValue.CertificateModification
        = Models::PolicyCertificateModification(*internalResult.CertificateResolution);
  }
  if (internalResult.CertificateThumbprint)
  {
    returnValue.CertificateThumbprint = (*internalResult.CertificateThumbprint);
  }

  // Construct a token whose body is the policy result, but whose token is the response
  // from the service.
  auto const returnedToken
      = AttestationTokenInternal<Models::IsolatedModeCertificateModificationResult>(
          responseToken, &returnValue);
  return returnedToken;
}

Azure::Response<Models::AttestationToken<Models::IsolatedModeCertificateModificationResult>>
AttestationAdministrationClient::AddIsolatedModeCertificate(
    std::string const& pemEncodedX509CertificateToAdd,
    AttestationSigningKey const& existingSigningKey,
    AddIsolatedModeCertificateOptions const& options,
    Azure::Core::Context const& context) const
{
  auto tracingContext(m_tracingFactory.CreateTracingContext("AddIsolatedModeCertificate", context));
  try
  {
    auto const policyCertToken(
        CreateIsolatedModeModificationToken(pemEncodedX509CertificateToAdd, existingSigningKey));
    Azure::Core::IO::MemoryBodyStream stream(
        reinterpret_cast<uint8_t const*>(policyCertToken.data()), policyCertToken.size());

    auto request = AttestationCommonRequest::CreateRequest(
        m_endpoint, m_apiVersion, HttpMethod::Post, {"certificates:add"}, &stream);

    // Send the request to the service.
    auto response = AttestationCommonRequest::SendRequest(*m_pipeline, request, context);
    AttestationToken<IsolatedModeCertificateModificationResult> returnValue(
        ProcessIsolatedModeModificationResult(
            response,
            options.TokenValidationOptionsOverride ? *options.TokenValidationOptionsOverride
                                                   : this->m_tokenValidationOptions));
    return Response<AttestationToken<Models::IsolatedModeCertificateModificationResult>>(
        returnValue, std::move(response));
  }
  catch (std::runtime_error const& ex)
  {
    tracingContext.Span.AddEvent(ex);
    throw;
  }
}

Azure::Response<Models::AttestationToken<Models::IsolatedModeCertificateModificationResult>>
AttestationAdministrationClient::RemoveIsolatedModeCertificate(
    std::string const& pemEncodedX509CertificateToRemove,
    AttestationSigningKey const& existingSigningKey,
    RemoveIsolatedModeCertificateOptions const& options,
    Azure::Core::Context const& context) const
{
  auto tracingContext(
      m_tracingFactory.CreateTracingContext("RemoveIsolatedModeCertificate", context));
  try
  {
    // Calculate a signed (or unsigned) attestation policy token to send to the service.
    // Embed the encoded policy in the StoredAttestationPolicy.
    auto const policyCertToken(
        CreateIsolatedModeModificationToken(pemEncodedX509CertificateToRemove, existingSigningKey));

    Azure::Core::IO::MemoryBodyStream stream(
        reinterpret_cast<uint8_t const*>(policyCertToken.data()), policyCertToken.size());

    auto request = AttestationCommonRequest::CreateRequest(
        m_endpoint, m_apiVersion, HttpMethod::Post, {"certificates:remove"}, &stream);

    // Send the request to the service.
    auto response = AttestationCommonRequest::SendRequest(*m_pipeline, request, context);
    AttestationToken<IsolatedModeCertificateModificationResult> returnValue(
        ProcessIsolatedModeModificationResult(
            response,
            options.TokenValidationOptionsOverride ? *options.TokenValidationOptionsOverride
                                                   : this->m_tokenValidationOptions));
    return Response<AttestationToken<Models::IsolatedModeCertificateModificationResult>>(
        returnValue, std::move(response));
  }
  catch (std::runtime_error const& ex)
  {
    tracingContext.Span.AddEvent(ex);
    throw;
  }
}

void AttestationAdministrationClient::RetrieveResponseValidationCollateral(
    Azure::Core::Context const& context)
{
  auto tracingContext(m_tracingFactory.CreateTracingContext("Create", context));
  try
  {
    std::unique_lock<std::shared_timed_mutex> stateLock(SharedStateLock);

    if (m_attestationSigners.empty())
    {
      stateLock.unlock();
      auto request = AttestationCommonRequest::CreateRequest(
          m_endpoint, HttpMethod::Get, {"certs"}, nullptr);
      auto response = AttestationCommonRequest::SendRequest(*m_pipeline, request, context);
      auto jsonWebKeySet(JsonWebKeySetSerializer::Deserialize(response));
      std::vector<AttestationSigner> newValue;
      for (const auto& jwk : jsonWebKeySet.Keys)
      {
        AttestationSignerInternal internalSigner(jwk);
        newValue.push_back(internalSigner);
      }
      stateLock.lock();
      if (m_attestationSigners.empty())
      {
        m_attestationSigners = newValue;
      }
    }
  }
  catch (std::runtime_error const& ex)
  {
    tracingContext.Span.AddEvent(ex);
    throw;
  }
}
