// Copyright (c) 2014-2016, The Monero Project
// 
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
// 
// 1. Redistributions of source code must retain the above copyright notice, this list of
//    conditions and the following disclaimer.
// 
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
//    of conditions and the following disclaimer in the documentation and/or other
//    materials provided with the distribution.
// 
// 3. Neither the name of the copyright holder nor the names of its contributors may be
//    used to endorse or promote products derived from this software without specific
//    prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#undef UNICODE
#undef _UNICODE

#include "common/scoped_message_writer.h"
#include "daemonizer/windows_service.h"
#include "string_tools.h"
#include <chrono>
#include <iostream>
#include <utility>
#include <memory>
#include <shellapi.h>
#include <thread>
#include <windows.h>

namespace windows {

namespace {
  typedef std::unique_ptr<std::remove_pointer<SC_HANDLE>::type, decltype(&::CloseServiceHandle)> service_handle;

  std::string get_last_error()
  {
    LPSTR p_error_text = nullptr;

    FormatMessage(
      FORMAT_MESSAGE_FROM_SYSTEM
    | FORMAT_MESSAGE_ALLOCATE_BUFFER
    | FORMAT_MESSAGE_IGNORE_INSERTS
    , nullptr
    , GetLastError()
    , MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT)
    , reinterpret_cast<LPSTR>(&p_error_text)
    , 0
    , nullptr
    );

    if (nullptr == p_error_text)
    {
      return "";
    }
    else
    {
      return std::string{p_error_text};
      LocalFree(p_error_text);
    }
  }

  bool relaunch_as_admin(
      std::string const & command
    , std::string const & arguments
    )
  {
    SHELLEXECUTEINFO info{};
    info.cbSize = sizeof(info);
    info.lpVerb = "runas";
    info.lpFile = command.c_str();
    info.lpParameters = arguments.c_str();
    info.hwnd = nullptr;
    info.nShow = SW_SHOWNORMAL;
    if (!ShellExecuteEx(&info))
    {
      tools::fail_msg_writer() << "Admin relaunch failed: " << get_last_error();
      return false;
    }
    else
    {
      return true;
    }
  }

  // When we relaunch as admin, Windows opens a new window.  This just pauses
  // to allow the user to read any output.
  void pause_to_display_admin_window_messages()
  {
    boost::chrono::milliseconds how_long{1500};
    boost::this_thread::sleep_for(how_long);
  }
}

bool check_admin(bool & result)
{
  BOOL is_admin = FALSE;
  PSID p_administrators_group = nullptr;

  SID_IDENTIFIER_AUTHORITY nt_authority = SECURITY_NT_AUTHORITY;

  if (!AllocateAndInitializeSid(
        &nt_authority
      , 2
      , SECURITY_BUILTIN_DOMAIN_RID
      , DOMAIN_ALIAS_RID_ADMINS
      , 0, 0, 0, 0, 0, 0
      , &p_administrators_group
      ))
  {
    tools::fail_msg_writer() << "Security Identifier creation failed: " << get_last_error();
    return false;
  }

  if (!CheckTokenMembership(
        nullptr
      , p_administrators_group
      , &is_admin
      ))
  {
    tools::fail_msg_writer() << "Permissions check failed: " << get_last_error();
    return false;
  }

  result = is_admin ? true : false;

  return true;
}

bool ensure_admin(
    std::string const & arguments
  )
{
  bool admin;

  if (!check_admin(admin))
  {
    return false;
  }

  if (admin)
  {
    return true;
  }
  else
  {
    std::string command = epee::string_tools::get_current_module_path();
    relaunch_as_admin(command, arguments);
    return false;
  }
}

bool install_service(
    std::string const & service_name
  , std::string const & arguments
  )
{
  std::string command = epee::string_tools::get_current_module_path();
  std::string full_command = command + arguments;

  service_handle p_manager{
    OpenSCManager(
        nullptr
      , nullptr
      , SC_MANAGER_CONNECT | SC_MANAGER_CREATE_SERVICE
      )
  , &::CloseServiceHandle
  };
  if (p_manager == nullptr)
  {
    tools::fail_msg_writer() << "Couldn't connect to service manager: " << get_last_error();
    return false;
  }

  service_handle p_service{
    CreateService(
        p_manager.get()
      , service_name.c_str()
      , service_name.c_str()
      , 0
      //, GENERIC_EXECUTE | GENERIC_READ
      , SERVICE_WIN32_OWN_PROCESS
      , SERVICE_DEMAND_START
      , SERVICE_ERROR_NORMAL
      , full_command.c_str()
      , nullptr
      , nullptr
      , ""
      //, "NT AUTHORITY\\LocalService"
      , nullptr // Implies LocalSystem account
      , nullptr
      )
  , &::CloseServiceHandle
  };
  if (p_service == nullptr)
  {
    tools::fail_msg_writer() << "Couldn't create service: " << get_last_error();
    return false;
  }

  tools::success_msg_writer() << "Service installed";

  pause_to_display_admin_window_messages();

  return true;
}

bool start_service(
    std::string const & service_name
  )
{
  tools::msg_writer() << "Starting service";

  SERVICE_STATUS_PROCESS service_status = {};
  DWORD unused = 0;

  service_handle p_manager{
    OpenSCManager(
        nullptr
      , nullptr
      , SC_MANAGER_CONNECT
      )
  , &::CloseServiceHandle
  };
  if (p_manager == nullptr)
  {
    tools::fail_msg_writer() << "Couldn't connect to service manager: " << get_last_error();
    return false;
  }

  service_handle p_service{
    OpenService(
        p_manager.get()
      , service_name.c_str()
      //, SERVICE_START | SERVICE_QUERY_STATUS
      , SERVICE_START
      )
  , &::CloseServiceHandle
  };
  if (p_service == nullptr)
  {
    tools::fail_msg_writer() << "Couldn't find service: " << get_last_error();
    return false;
  }

  if (!StartService(
      p_service.get()
    , 0
    , nullptr
    ))
  {
    tools::fail_msg_writer() << "Service start request failed: " << get_last_error();
    return false;
  }

  tools::success_msg_writer() << "Service started";

  pause_to_display_admin_window_messages();

  return true;
}

bool stop_service(
    std::string const & service_name
  )
{
  tools::msg_writer() << "Stopping service";

  service_handle p_manager{
    OpenSCManager(
        nullptr
      , nullptr
      , SC_MANAGER_CONNECT
      )
  , &::CloseServiceHandle
  };
  if (p_manager == nullptr)
  {
    tools::fail_msg_writer() << "Couldn't connect to service manager: " << get_last_error();
    return false;
  }

  service_handle p_service{
    OpenService(
        p_manager.get()
      , service_name.c_str()
      , SERVICE_STOP | SERVICE_QUERY_STATUS
      )
  , &::CloseServiceHandle
  };
  if (p_service == nullptr)
  {
    tools::fail_msg_writer() << "Couldn't find service: " << get_last_error();
    return false;
  }

  SERVICE_STATUS status = {};
  if (!ControlService(p_service.get(), SERVICE_CONTROL_STOP, &status))
  {
    tools::fail_msg_writer() << "Couldn't request service stop: " << get_last_error();
    return false;
  }

  tools::success_msg_writer() << "Service stopped";

  pause_to_display_admin_window_messages();

  return true;
}

bool uninstall_service(
    std::string const & service_name
  )
{
  service_handle p_manager{
    OpenSCManager(
        nullptr
      , nullptr
      , SC_MANAGER_CONNECT
      )
  , &::CloseServiceHandle
  };
  if (p_manager == nullptr)
  {
    tools::fail_msg_writer() << "Couldn't connect to service manager: " << get_last_error();
    return false;
  }

  service_handle p_service{
    OpenService(
        p_manager.get()
      , service_name.c_str()
      , SERVICE_QUERY_STATUS | DELETE
      )
  , &::CloseServiceHandle
  };
  if (p_service == nullptr)
  {
    tools::fail_msg_writer() << "Couldn't find service: " << get_last_error();
    return false;
  }

  SERVICE_STATUS status = {};
  if (!DeleteService(p_service.get()))
  {
    tools::fail_msg_writer() << "Couldn't uninstall service: " << get_last_error();
    return false;
  }

  tools::success_msg_writer() << "Service uninstalled";

  pause_to_display_admin_window_messages();

  return true;
}

} // namespace windows
