/*
 *
 * Copyright 2015, Google Inc.
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 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */

#include <grpc/support/log.h>

#include <grpc++/channel_arguments.h>
#include "src/cpp/client/channel.h"
#include "src/cpp/client/secure_credentials.h"

namespace grpc {

std::shared_ptr<grpc::ChannelInterface> SecureCredentials::CreateChannel(
    const string& target, const grpc::ChannelArguments& args) {
  grpc_channel_args channel_args;
  args.SetChannelArgs(&channel_args);
  return std::shared_ptr<ChannelInterface>(new Channel(
      args.GetSslTargetNameOverride().empty() ? target
                                              : args.GetSslTargetNameOverride(),
      grpc_secure_channel_create(c_creds_, target.c_str(), &channel_args)));
}

namespace {
std::unique_ptr<Credentials> WrapCredentials(grpc_credentials* creds) {
  return creds == nullptr
             ? nullptr
             : std::unique_ptr<Credentials>(new SecureCredentials(creds));
}
}  // namespace

std::unique_ptr<Credentials> GoogleDefaultCredentials() {
  return WrapCredentials(grpc_google_default_credentials_create());
}

// Builds SSL Credentials given SSL specific options
std::unique_ptr<Credentials> SslCredentials(
    const SslCredentialsOptions& options) {
  grpc_ssl_pem_key_cert_pair pem_key_cert_pair = {
      options.pem_private_key.c_str(), options.pem_cert_chain.c_str()};

  grpc_credentials* c_creds = grpc_ssl_credentials_create(
      options.pem_root_certs.empty() ? nullptr : options.pem_root_certs.c_str(),
      options.pem_private_key.empty() ? nullptr : &pem_key_cert_pair);
  return WrapCredentials(c_creds);
}

// Builds credentials for use when running in GCE
std::unique_ptr<Credentials> ComputeEngineCredentials() {
  return WrapCredentials(grpc_compute_engine_credentials_create());
}

// Builds service account credentials.
std::unique_ptr<Credentials> ServiceAccountCredentials(
    const grpc::string& json_key, const grpc::string& scope,
    long token_lifetime_seconds) {
  if (token_lifetime_seconds <= 0) {
    gpr_log(GPR_ERROR,
            "Trying to create ServiceAccountCredentials "
            "with non-positive lifetime");
    return WrapCredentials(nullptr);
  }
  gpr_timespec lifetime = gpr_time_from_seconds(token_lifetime_seconds);
  return WrapCredentials(grpc_service_account_credentials_create(
      json_key.c_str(), scope.c_str(), lifetime));
}

// Builds JWT credentials.
std::unique_ptr<Credentials> JWTCredentials(
    const grpc::string& json_key, long token_lifetime_seconds) {
  if (token_lifetime_seconds <= 0) {
    gpr_log(GPR_ERROR,
            "Trying to create JWTCredentials with non-positive lifetime");
    return WrapCredentials(nullptr);
  }
  gpr_timespec lifetime = gpr_time_from_seconds(token_lifetime_seconds);
  return WrapCredentials(
      grpc_jwt_credentials_create(json_key.c_str(), lifetime));
}

// Builds refresh token credentials.
std::unique_ptr<Credentials> RefreshTokenCredentials(
    const grpc::string& json_refresh_token) {
  return WrapCredentials(
      grpc_refresh_token_credentials_create(json_refresh_token.c_str()));
}

// Builds IAM credentials.
std::unique_ptr<Credentials> IAMCredentials(
    const grpc::string& authorization_token,
    const grpc::string& authority_selector) {
  return WrapCredentials(grpc_iam_credentials_create(
      authorization_token.c_str(), authority_selector.c_str()));
}

// Combines two credentials objects into a composite credentials.
std::unique_ptr<Credentials> CompositeCredentials(
    const std::unique_ptr<Credentials>& creds1,
    const std::unique_ptr<Credentials>& creds2) {
  // Note that we are not saving unique_ptrs to the two credentials
  // passed in here. This is OK because the underlying C objects (i.e.,
  // creds1 and creds2) into grpc_composite_credentials_create will see their
  // refcounts incremented.
  SecureCredentials* s1 = creds1->AsSecureCredentials();
  SecureCredentials* s2 = creds2->AsSecureCredentials();
  if (s1 && s2) {
    return WrapCredentials(grpc_composite_credentials_create(
        s1->GetRawCreds(), s2->GetRawCreds()));
  }
  return nullptr;
}

}  // namespace grpc