////////////////////////////////////////////////////////////////////////////////
// Copyright 2016 Google LLC.
//
// This software is licensed under the terms defined in the Widevine Master
// License Agreement. For a copy of this agreement, please contact
// widevine-licensing@google.com.
////////////////////////////////////////////////////////////////////////////////

#include "common/client_id_util.h"

#include "glog/logging.h"
#include "common/aes_cbc_util.h"
#include "common/drm_service_certificate.h"
#include "common/error_space.h"
#include "protos/public/errors.pb.h"

namespace widevine {

void AddClientInfo(ClientIdentification* client_id, absl::string_view name,
                   absl::string_view value) {
  ClientIdentification_NameValue* nv = client_id->add_client_info();
  nv->set_name(std::string(name));
  nv->set_value(std::string(value));
}

bool SetClientInfo(ClientIdentification* client_id, absl::string_view name,
                   absl::string_view value) {
  int n = client_id->client_info_size();
  for (int i = 0; i < n; i++) {
    if (client_id->client_info(i).name() == name) {
      client_id->mutable_client_info(i)->set_value(std::string(value));
      return true;
    }
  }
  AddClientInfo(client_id, name, value);
  return false;
}

std::string GetClientInfo(const ClientIdentification& client_id,
                     absl::string_view name) {
  return GetClientInfo(client_id, name, std::string());
}

std::string GetClientInfo(const ClientIdentification& client_id,
                     absl::string_view name, const std::string& default_value) {
  for (const auto& nv : client_id.client_info()) {
    if (nv.name() == name) {
      return nv.value();
    }
  }
  return default_value;
}

util::Status DecryptEncryptedClientIdentification(
    const EncryptedClientIdentification& encrypted_client_id,
    ClientIdentification* client_id) {
  return DrmServiceCertificate::DecryptClientIdentification(encrypted_client_id,
                                                            client_id);
}

util::Status DecryptEncryptedClientIdentification(
    const EncryptedClientIdentification& encrypted_client_id,
    const std::string& privacy_key, ClientIdentification* client_id) {
  DCHECK(client_id);
  if (!encrypted_client_id.has_encrypted_client_id() ||
      encrypted_client_id.encrypted_client_id().empty()) {
    return util::Status(error_space, INVALID_ENCRYPTED_CLIENT_IDENTIFICATION,
                        "missing-encrypted-client-id");
  }
  if (!encrypted_client_id.has_encrypted_client_id_iv() ||
      encrypted_client_id.encrypted_client_id_iv().empty()) {
    return util::Status(error_space, INVALID_ENCRYPTED_CLIENT_IDENTIFICATION,
                        "missing-encrypted-client-id-iv");
  }
  std::string serialized_client_id(crypto_util::DecryptAesCbc(
      privacy_key, encrypted_client_id.encrypted_client_id_iv(),
      encrypted_client_id.encrypted_client_id()));
  if (serialized_client_id.empty()) {
    return util::Status(error_space, INVALID_ENCRYPTED_CLIENT_IDENTIFICATION,
                        "client-id-decryption-failed");
  }
  if (!client_id->ParseFromString(serialized_client_id)) {
    return util::Status(error_space, INVALID_ENCRYPTED_CLIENT_IDENTIFICATION,
                        "client-id-parse-failed");
  }
  return util::OkStatus();
}

}  // namespace widevine