/*
 * This file is a part of the CaosDB Project.
 *
 * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
 * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <https://www.gnu.org/licenses/>.
 *
 */
#include <memory>                  // for allocator, make_shared, shared_ptr
#include <string>                  // for stoi, string
#include "caosdb/authentication.h" // for PlainPasswordAuthenticator
#include "caosdb/connection.h" // for PemFileCertificateProvider, TlsCaosDBC...
#include "caosdb/utility.h"    // for get_env_var

namespace caosdb::connection {
using caosdb::authentication::PlainPasswordAuthenticator;

inline auto create_test_connection_config()
  -> std::unique_ptr<TlsConnectionConfig> {
  auto port_str =
    caosdb::utility::get_env_var("CAOSDB_SERVER_GRPC_PORT_HTTPS", "8443");
  auto port = std::stoi(port_str);
  const auto host =
    caosdb::utility::get_env_var("CAOSDB_SERVER_HOST", "localhost");
  const auto path =
    caosdb::utility::get_env_var("CAOSDB_SERVER_CERT", std::string());
  const auto user = caosdb::utility::get_env_var("CAOSDB_USER", "admin");
  const auto password =
    caosdb::utility::get_env_var("CAOSDB_PASSWORD", "caosdb");

  auto auth = PlainPasswordAuthenticator(user, password);
  auto cert = PemFileCertificateProvider(path);
  return std::make_unique<TlsConnectionConfig>(host, port, cert, auth);
}

/**
 * Return a fresh Connection pointer. The caller has the ownership.
 */
inline auto create_test_connection() -> std::unique_ptr<Connection> {
  auto config = create_test_connection_config();
  return std::make_unique<Connection>(*(config.get()));
};

/**
 * Singleton which holds a single global Connection
 */
class ConnectionProvider {
private:
  std::shared_ptr<Connection> connection;
  ConnectionProvider() : connection(create_test_connection()){};

public:
  static ConnectionProvider &GetInstance() {
    static ConnectionProvider instance;
    return instance;
  };
  inline auto GetConnection() -> std::shared_ptr<Connection> & {
    return this->connection;
  }

  ConnectionProvider(ConnectionProvider const &) = delete;
  void operator=(ConnectionProvider const &) = delete;
};

/**
 * Return a connection for testing purposes.
 */
inline auto get_test_connection() -> const std::shared_ptr<Connection> & {
  return ConnectionProvider::GetInstance().GetConnection();
};

} // namespace caosdb::connection