server.hh

#ifndef __VEREIGN_GRPC_SERVER_API_HH
#define __VEREIGN_GRPC_SERVER_API_HH

#include <string>
#include <memory>

namespace vereign::grpc {

/**
 * BindError is thrown when the Server::Server could not start listening.
 */
class BindError: public std::exception {
public:
  auto what() const noexcept -> const char* override {
    return "gRPC listen failed";
  }
};

/**
 * Server is a grpc server that provides the Vereign services.
 *
 * It bootstraps the grpc server, http client, http client session and
 * Vereign services.
 */
class Server {
public:
  /**
   * Constructs and bootstraps the server.
   *
   * When the gRPC could not start listening a BindError is thrown.
   * This can happen for number of reasons like invalid hostname or the listen port is already in use.
   *
   * @param listenAddress gRPC listen address, for example "localhost:".
   * @param vereignHost Vereign restapi host.
   * @param vereignPort Vereign restapi port - https, 443...
   * @throws BindError when the gRPC server could not start listening.
   */
  explicit Server(
    const std::string& listenAddress,
    const std::string& vereignHost,
    const std::string& vereignPort
  );

  /**
   * Shutdowns the server.
   *
   * @see Server::Shutdown
   */
  ~Server();

  // Disable copying
  Server(const Server&) = delete;
  auto operator=(const Server&) -> Server& = delete;

  /**
   * Shutdown the server.
   *
   * It will cancel all pending http requests to the Vereign restapi.
   * Blocks for all pending gRPC handlers to finish.
   */
  void Shutdown();

  /**
   * Returns the port that the gRPC server listens to.
   *
   * This is useful if you construct the server with ephemeral port.
   * Then this method will return the port that the OS assigned to the gRPC
   * socket.
   */
  auto SelectedPort() const -> int;

private:
  class Impl;
  std::unique_ptr<Impl> impl_;
};

} // namespace vereign

#endif