////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2016 ArangoDB GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
///     http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Jan Steemann
////////////////////////////////////////////////////////////////////////////////

#include "ArangoClientHelper.h"

#include <velocypack/Iterator.h>
#include <velocypack/velocypack-aliases.h>

#include "Basics/VelocyPackHelper.h"
#include "Shell/ClientFeature.h"
#include "SimpleHttpClient/GeneralClientConnection.h"
#include "SimpleHttpClient/SimpleHttpClient.h"
#include "SimpleHttpClient/SimpleHttpResult.h"

using namespace arangodb;
using namespace arangodb::basics;
using namespace arangodb::httpclient;

ArangoClientHelper::ArangoClientHelper() : _httpClient(nullptr) {}

// helper to rewrite HTTP location
std::string ArangoClientHelper::rewriteLocation(void* data, std::string const& location) {
  if (location.compare(0, 5, "/_db/") == 0) {
    return location;
  }

  ClientFeature* client = static_cast<ClientFeature*>(data);
  std::string const& dbname = client->databaseName();

  if (location[0] == '/') {
    return "/_db/" + dbname + location;
  }
  return "/_db/" + dbname + "/" + location;
}

// extract an error message from a response
std::string ArangoClientHelper::getHttpErrorMessage(SimpleHttpResult* result, int* err) {
  if (err != nullptr) {
    *err = TRI_ERROR_NO_ERROR;
  }
  std::string details;

  try {
    std::shared_ptr<VPackBuilder> parsedBody = result->getBodyVelocyPack();
    VPackSlice const body = parsedBody->slice();

    std::string const& errorMessage =
        arangodb::basics::VelocyPackHelper::getStringValue(body, "errorMessage",
                                                           "");
    int errorNum =
        arangodb::basics::VelocyPackHelper::getNumericValue<int>(body,
                                                                 "errorNum", 0);

    if (errorMessage != "" && errorNum > 0) {
      if (err != nullptr) {
        *err = errorNum;
      }
      details = ": ArangoError " + StringUtils::itoa(errorNum) + ": " + errorMessage;
    }
  } catch (...) {
    // No action, fallthrough for error
  }
  return "got error from server: HTTP " +
         StringUtils::itoa(result->getHttpReturnCode()) + " (" +
         result->getHttpReturnMessage() + ")" + details;
}

// check if server is a coordinator of a cluster
bool ArangoClientHelper::getArangoIsCluster(int* err) {
  std::unique_ptr<SimpleHttpResult> response(
      _httpClient->request(rest::RequestType::GET, "/_admin/server/role", "", 0));

  if (response == nullptr || !response->isComplete()) {
    return false;
  }

  std::string role = "UNDEFINED";

  if (response->getHttpReturnCode() == (int)rest::ResponseCode::OK) {
    try {
      std::shared_ptr<VPackBuilder> parsedBody = response->getBodyVelocyPack();
      VPackSlice const body = parsedBody->slice();
      role = arangodb::basics::VelocyPackHelper::getStringValue(body, "role",
                                                                "UNDEFINED");
    } catch (...) {
      // No Action
    }
  } else {
    if (response->wasHttpError()) {
      _httpClient->setErrorMessage(getHttpErrorMessage(response.get(), err), false);
    }

    _httpClient->disconnect();
  }

  return role == "COORDINATOR";
}