/*
 * Copyright (c) 2017, 2019, Oracle and/or its affiliates. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2.0,
 * as published by the Free Software Foundation.
 *
 * This program is also distributed with certain software (including
 * but not limited to OpenSSL) that is licensed under separate terms,
 * as designated in a particular file or component or in included license
 * documentation.  The authors of MySQL hereby grant you an additional
 * permission to link the program and your derivative works with the
 * separately licensed software that they have included with MySQL.
 *
 * 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 General Public License, version 2.0, for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
 */

#include "connection_manager.h"

#include <sstream>
#include <stdexcept>
#include <utility>
#include <vector>

#include "my_dbug.h"

#include "../processor/variable_names.h"

google::protobuf::LogHandler *g_lh = nullptr;

Connection_manager::Connection_manager(const Connection_options &co,
                                       Variable_container *variables,
                                       const Console &console)
    : m_default_connection_options(co),
      m_variables(variables),
      m_console(console) {
  g_lh = google::protobuf::SetLogHandler([](google::protobuf::LogLevel level,
                                            const char *filename, int line,
                                            const std::string &message) {
    if (g_lh) g_lh(level, filename, line, message);
    DBUG_LOG("debug",
             "Protobuf error (level:" << level << ", filename:" << filename
                                      << ":" << line << ", text:" << message);
  });
  m_variables->make_special_variable(
      k_variable_option_user,
      new Variable_dynamic_string(m_default_connection_options.user));

  m_variables->make_special_variable(
      k_variable_option_pass,
      new Variable_dynamic_string(m_default_connection_options.password));

  m_variables->make_special_variable(
      k_variable_option_host,
      new Variable_dynamic_string(m_default_connection_options.host));

  m_variables->make_special_variable(
      k_variable_option_socket,
      new Variable_dynamic_string(m_default_connection_options.socket));

  m_variables->make_special_variable(
      k_variable_option_schema,
      new Variable_dynamic_string(m_default_connection_options.schema));

  m_variables->make_special_variable(
      k_variable_option_port,
      new Variable_dynamic_int(m_default_connection_options.port));

  m_variables->make_special_variable(
      k_variable_option_ssl_mode,
      new Variable_dynamic_string(m_default_connection_options.ssl_mode));

  m_variables->make_special_variable(
      k_variable_option_ssl_cipher,
      new Variable_dynamic_string(m_default_connection_options.ssl_cipher));

  m_variables->make_special_variable(
      k_variable_option_tls_version,
      new Variable_dynamic_string(m_default_connection_options.allowed_tls));

  m_variables->make_special_variable(
      k_variable_option_compression_algorithm,
      new Variable_dynamic_array_of_strings(
          m_default_connection_options.compression_algorithm));

  m_variables->make_special_variable(
      k_variable_option_compression_server_style,
      new Variable_dynamic_array_of_strings(
          m_default_connection_options.compression_server_style));

  m_variables->make_special_variable(
      k_variable_option_compression_client_style,
      new Variable_dynamic_array_of_strings(
          m_default_connection_options.compression_client_style));

  m_active_holder.reset(new Session_holder(xcl::create_session(), m_console,
                                           m_default_connection_options));

  m_session_holders[""] = m_active_holder;
}

Connection_manager::~Connection_manager() {
  std::vector<std::string> disconnect_following;

  for (const auto &connection : m_session_holders) {
    if (connection.first != "") {
      disconnect_following.push_back(connection.first);
    }
  }

  for (auto &name : disconnect_following) {
    safe_close(name);
  }

  if (m_session_holders.count("") > 0) {
    safe_close("");
  }
}

void Connection_manager::get_credentials(std::string *ret_user,
                                         std::string *ret_pass) {
  assert(ret_user);
  assert(ret_pass);

  *ret_user = m_default_connection_options.user;
  *ret_pass = m_default_connection_options.password;
}

void Connection_manager::safe_close(const std::string &name) {
  try {
    set_active(name, true);
    close_active(true, true);
  } catch (const std::exception &) {
  } catch (const xcl::XError &) {
  }
}

void Connection_manager::connect_default(const bool send_cap_password_expired,
                                         const bool client_interactive,
                                         const bool no_auth,
                                         const bool connect_attrs) {
  m_console.print_verbose("Connecting...\n");

  auto session = m_active_holder->get_session();

  if (send_cap_password_expired) {
    session->set_capability(
        xcl::XSession::Capability_can_handle_expired_password, true);
  }

  if (client_interactive) {
    session->set_capability(xcl::XSession::Capability_client_interactive, true);
  }

  if (connect_attrs) {
    auto attrs = session->get_connect_attrs();
    attrs.emplace_back("program_name", xcl::Argument_value{"mysqlxtest"});
    session->set_capability(xcl::XSession::Capability_session_connect_attrs,
                            attrs, false);
  }

  xcl::XError error = m_active_holder->connect(no_auth);

  if (error) {
    // In case of configuration error, lets do safe_close to synchronize
    // closing of socket with exist of mysqlxtest (in other case mysqlxtest
    // is going to exit and after a while the connection is going to be
    // accepted on server side).
    if (CR_X_TLS_WRONG_CONFIGURATION != error.error() || no_auth) {
      session->get_protocol().get_connection().close();
    }

    throw error;
  }

  setup_variables(session);

  m_console.print_verbose("Connected client #", session->client_id(), "\n");
}

void Connection_manager::create(const std::string &name,
                                const std::string &user,
                                const std::string &password,
                                const std::string &db,
                                const std::vector<std::string> &auth_methods,
                                const bool is_raw_connection) {
  if (m_session_holders.count(name))
    throw std::runtime_error("a session named " + name + " already exists");

  m_console.print_verbose("Connecting...\n");

  Connection_options co = m_default_connection_options;

  if (!user.empty()) {
    co.user = user;
    co.password = password;
  }

  if (!db.empty()) {
    co.schema = db;
  }

  if (!auth_methods.empty()) {
    co.auth_methods = auth_methods;
  }

  auto session = xcl::create_session();
  std::shared_ptr<Session_holder> holder{
      new Session_holder(std::move(session), m_console, co)};

  xcl::XError error = holder->connect(is_raw_connection);

  if (error) {
    throw error;
  }

  m_active_holder = holder;
  m_session_holders[name] = holder;
  m_active_session_name = name;

  setup_variables(active_xsession());

  m_console.print_verbose("Connected client #", active_xsession()->client_id(),
                          "\n");
}

void Connection_manager::abort_active() {
  if (m_active_holder) {
    if (!m_active_session_name.empty())
      std::cout << "aborting session " << m_active_session_name << "\n";
    /* Close connection first, to stop XSession from executing
     Disconnection flow */
    active_xconnection()->close();
    m_active_holder.reset();
    m_session_holders.erase(m_active_session_name);
    if (m_active_session_name != "") set_active("");
  } else {
    throw std::runtime_error("no active session");
  }
}

bool Connection_manager::is_default_active() {
  return m_active_session_name.empty();
}

void Connection_manager::close_active(const bool shutdown,
                                      const bool be_quiet) {
  if (m_active_holder) {
    if (m_active_session_name.empty() && !shutdown)
      throw std::runtime_error("cannot close default session");
    try {
      if (!m_active_session_name.empty() && !be_quiet)
        m_console.print("closing session ", m_active_session_name, "\n");

      if (active_xconnection()->state().is_connected()) {
/* no close needed
        // send a close message and wait for the corresponding Ok message
        active_xprotocol()->send(Polarx::Connection::Close());
        xcl::XProtocol::Server_message_type_id msgid;
        xcl::XError error;
        Message_ptr msg{
            active_xprotocol()->recv_single_message(&msgid, &error)};

        if (error) throw error;

        if (!be_quiet) m_console.print(*msg);
        if (Polarx::ServerMessages::OK != msgid)
          throw xcl::XError(CR_COMMANDS_OUT_OF_SYNC,
                            "Disconnect was expecting Mysqlx.Ok(bye!), but "
                            "got the one above (one or more calls to -->recv "
                            "are probably missing)");

        std::string text = static_cast<Polarx::Ok *>(msg.get())->msg();
        if (text != "bye!" && text != "tchau!")
          throw xcl::XError(CR_COMMANDS_OUT_OF_SYNC,
                            "Disconnect was expecting Mysqlx.Ok(bye!), but "
                            "got the one above (one or more calls to -->recv "
                            "are probably missing)");

        if (!m_default_connection_options.dont_wait_for_disconnect) {
          Message_ptr msg{
              active_xprotocol()->recv_single_message(&msgid, &error)};

          if (!error && !be_quiet) {
            m_console.print_error("Was expecting closure but got message:",
                                  *msg);
          }
        }
*/

        active_xconnection()->close();
      }
      m_session_holders.erase(m_active_session_name);
      if (!shutdown) set_active("", be_quiet);
    } catch (const std::exception &error) {
      active_xconnection()->close();
      m_session_holders.erase(m_active_session_name);
      if (!shutdown) set_active("", be_quiet);
      throw error;
    } catch (const xcl::XError &error) {
      active_xconnection()->close();
      m_session_holders.erase(m_active_session_name);
      if (!shutdown) set_active("", be_quiet);
      throw error;
    }
  } else {
    if (!shutdown) throw std::runtime_error("no active session");
  }
}

void Connection_manager::set_active(const std::string &name,
                                    const bool be_quiet) {
  if (m_session_holders.count(name) == 0) {
    std::string slist;
    for (auto it = m_session_holders.begin(); it != m_session_holders.end();
         ++it)
      slist.append(it->first).append(", ");
    if (!slist.empty()) slist.resize(slist.length() - 2);
    throw std::runtime_error("no session named '" + name + "': " + slist);
  }
  m_active_holder = m_session_holders[name];
  m_active_session_name = name;

  setup_variables(active_xsession());

  if (!be_quiet)
    m_console.print(
        "switched to session ",
        (m_active_session_name.empty() ? "default" : m_active_session_name),
        "\n");
}

Session_holder &Connection_manager::active_holder() {
  if (!m_active_holder) throw std::runtime_error("no active session");

  return *m_active_holder;
}

xcl::XSession *Connection_manager::active_xsession() {
  if (!m_active_holder) throw std::runtime_error("no active session");
  return m_active_holder->get_session();
}

xcl::XProtocol *Connection_manager::active_xprotocol() {
  return &active_xsession()->get_protocol();
}

xcl::XConnection *Connection_manager::active_xconnection() {
  return &active_xprotocol()->get_connection();
}

uint64_t Connection_manager::active_session_messages_received(
    const std::string &message_name) const {
  uint64_t result = 0;
  m_active_holder->try_get_number_of_received_messages(message_name, &result);

  return result;
}

void Connection_manager::setup_variables(xcl::XSession *session) {
  auto &connection = session->get_protocol().get_connection();
  m_variables->set(k_variable_active_client_id,
                   std::to_string(session->client_id()));

  m_variables->set(k_variable_active_socket_id,
                   std::to_string(connection.get_socket_fd()));
}