service.hpp

//
// MIT License
//
// Copyright (c) 2017-2018 Thibault Martinez and Simon Ninon
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//
//

#pragma once

#include <cpr/cpr.h>
#include <json.hpp>

#include <iota/constants.hpp>
#include <iota/errors/bad_request.hpp>
#include <iota/errors/internal_server_error.hpp>
#include <iota/errors/network.hpp>
#include <iota/errors/unauthorized.hpp>
#include <iota/errors/unrecognized.hpp>

using json = nlohmann::json;

namespace IOTA {

namespace API {

class Service {
public:
  Service(const std::string& host, const uint16_t& port, int timeout = 60);
  virtual ~Service() = default;

public:
  template <typename Request, typename Response, typename... Args>
  Response request(Args&&... args) const {
    auto request = Request{ args... };

    json data;
    request.serialize(data);

    auto url     = cpr::Url{ "http://" + host_ + ":" + std::to_string(port_) };
    auto body    = cpr::Body{ data.dump() };
    auto headers = cpr::Header{ { "Content-Type", "application/json" },
                                { "Content-Length", std::to_string(body.size()) },
                                { "X-IOTA-API-Version", APIVersion } };
    auto res     = cpr::Post(url, body, headers, cpr::Timeout{ timeout_ * 1000 });

    if (res.error.code != cpr::ErrorCode::OK)
      throw Errors::Network(res.error.message);

    json        resJson;
    std::string error;

    try {
      resJson = json::parse(res.text);

      if (resJson.count("error")) {
        error = resJson["error"].get<decltype(error)>();
      }
    } catch (const std::runtime_error&) {
      if (res.elapsed >= timeout_) {
        throw Errors::Network("Time out after " + std::to_string(timeout_) + "s");
      }

      throw Errors::Unrecognized("Invalid reply from node (unrecognized format): " + res.text);
    }

    Response response;
    switch (res.status_code) {
      case 200:
        return Response{ resJson };
      case 400:
        throw Errors::BadRequest(error);
      case 401:
        throw Errors::Unauthorized(error);
      case 500:
        throw Errors::InternalServerError(error);
      default:
        if (res.elapsed >= timeout_) {
          throw Errors::Network("Time out after " + std::to_string(timeout_) + "s");
        }

        throw Errors::Unrecognized(error);
    }

    return response;
  }

private:
  std::string host_;
  unsigned int port_;
  const int timeout_;
};

}  // namespace API

}  // namespace IOTA