/* Copyright (C) 2002 The gtkmm Development Team
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <glib.h>
#include <glibmm/exceptionhandler.h>
#include <glibmm/utility.h>

namespace
{

extern "C" {

/* Helper callback to invoke the actual sigc++ slot.
 * We don't need to worry about (un)referencing, since the
 * child process gets its own copy of the parent's memory anyway.
 */
static void
child_setup_callback(void* user_data)
{
  try
  {
    (*reinterpret_cast<Glib::SlotSpawnChildSetup*>(user_data))();
  }
  catch (...)
  {
    Glib::exception_handlers_invoke();
  }
}

static void
copy_output_buf(std::string* dest, const char* buf)
{
  if (dest)
  {
    if (buf)
      *dest = buf;
    else
      dest->erase();
  }
}

} // extern "C"

} // anonymous namespace

namespace Glib
{

/**** process spawning functions *******************************************/

void
spawn_async_with_pipes(const std::string& working_directory,
  const Glib::ArrayHandle<std::string>& argv, const Glib::ArrayHandle<std::string>& envp,
  SpawnFlags flags, const SlotSpawnChildSetup& child_setup, Pid* child_pid, int* standard_input,
  int* standard_output, int* standard_error)
{
  const bool setup_slot = !child_setup.empty();
  auto child_setup_ = child_setup;
  GError* gerror = nullptr;

  g_spawn_async_with_pipes(Glib::c_str_or_nullptr(working_directory),
    const_cast<char**>(argv.data()), const_cast<char**>(envp.data()),
    static_cast<GSpawnFlags>(unsigned(flags)), (setup_slot) ? &child_setup_callback : nullptr,
    (setup_slot) ? &child_setup_ : nullptr, child_pid, standard_input, standard_output,
    standard_error, &gerror);

  if (gerror)
    Glib::Error::throw_exception(gerror);
}

void
spawn_async_with_pipes(const std::string& working_directory,
  const Glib::ArrayHandle<std::string>& argv, SpawnFlags flags,
  const SlotSpawnChildSetup& child_setup, Pid* child_pid, int* standard_input, int* standard_output,
  int* standard_error)
{
  const bool setup_slot = !child_setup.empty();
  auto child_setup_ = child_setup;
  GError* gerror = nullptr;

  g_spawn_async_with_pipes(Glib::c_str_or_nullptr(working_directory),
    const_cast<char**>(argv.data()), nullptr, static_cast<GSpawnFlags>(unsigned(flags)),
    (setup_slot) ? &child_setup_callback : nullptr, (setup_slot) ? &child_setup_ : nullptr,
    child_pid, standard_input, standard_output, standard_error, &gerror);

  if (gerror)
    Glib::Error::throw_exception(gerror);
}

void
spawn_async(const std::string& working_directory, const Glib::ArrayHandle<std::string>& argv,
  const Glib::ArrayHandle<std::string>& envp, SpawnFlags flags,
  const SlotSpawnChildSetup& child_setup, Pid* child_pid)
{
  const bool setup_slot = !child_setup.empty();
  auto child_setup_ = child_setup;
  GError* gerror = nullptr;

  g_spawn_async(Glib::c_str_or_nullptr(working_directory), const_cast<char**>(argv.data()),
    const_cast<char**>(envp.data()), static_cast<GSpawnFlags>(unsigned(flags)),
    (setup_slot) ? &child_setup_callback : nullptr, (setup_slot) ? &child_setup_ : nullptr,
    child_pid, &gerror);

  if (gerror)
    Glib::Error::throw_exception(gerror);
}

void
spawn_async(const std::string& working_directory, const Glib::ArrayHandle<std::string>& argv,
  SpawnFlags flags, const SlotSpawnChildSetup& child_setup, Pid* child_pid)
{
  const bool setup_slot = !child_setup.empty();
  auto child_setup_ = child_setup;
  GError* gerror = nullptr;

  g_spawn_async(Glib::c_str_or_nullptr(working_directory), const_cast<char**>(argv.data()), nullptr,
    static_cast<GSpawnFlags>(unsigned(flags)), (setup_slot) ? &child_setup_callback : nullptr,
    (setup_slot) ? &child_setup_ : nullptr, child_pid, &gerror);

  if (gerror)
    Glib::Error::throw_exception(gerror);
}

void
spawn_sync(const std::string& working_directory, const Glib::ArrayHandle<std::string>& argv,
  const Glib::ArrayHandle<std::string>& envp, SpawnFlags flags,
  const SlotSpawnChildSetup& child_setup, std::string* standard_output, std::string* standard_error,
  int* exit_status)
{
  const bool setup_slot = !child_setup.empty();
  auto child_setup_ = child_setup;

  GError* gerror = nullptr;
  char* pch_buf_standard_output = nullptr;
  char* pch_buf_standard_error = nullptr;
  g_spawn_sync(Glib::c_str_or_nullptr(working_directory), const_cast<char**>(argv.data()),
    const_cast<char**>(envp.data()), static_cast<GSpawnFlags>(unsigned(flags)),
    (setup_slot) ? &child_setup_callback : nullptr, (setup_slot) ? &child_setup_ : nullptr,
    (standard_output) ? &pch_buf_standard_output : nullptr,
    (standard_error) ? &pch_buf_standard_error : nullptr, exit_status, &gerror);
  auto buf_standard_output = make_unique_ptr_gfree(pch_buf_standard_output);
  auto buf_standard_error = make_unique_ptr_gfree(pch_buf_standard_error);

  if (gerror)
    Glib::Error::throw_exception(gerror);

  copy_output_buf(standard_output, buf_standard_output.get());
  copy_output_buf(standard_error, buf_standard_error.get());
}

void
spawn_sync(const std::string& working_directory, const Glib::ArrayHandle<std::string>& argv,
  SpawnFlags flags, const SlotSpawnChildSetup& child_setup, std::string* standard_output,
  std::string* standard_error, int* exit_status)
{
  const bool setup_slot = !child_setup.empty();
  auto child_setup_ = child_setup;

  char* pch_buf_standard_output = nullptr;
  char* pch_buf_standard_error = nullptr;
  GError* gerror = nullptr;

  g_spawn_sync(Glib::c_str_or_nullptr(working_directory), const_cast<char**>(argv.data()), nullptr,
    static_cast<GSpawnFlags>(unsigned(flags)), (setup_slot) ? &child_setup_callback : nullptr,
    (setup_slot) ? &child_setup_ : nullptr, (standard_output) ? &pch_buf_standard_output : nullptr,
    (standard_error) ? &pch_buf_standard_error : nullptr, exit_status, &gerror);
  auto buf_standard_output = make_unique_ptr_gfree(pch_buf_standard_output);
  auto buf_standard_error = make_unique_ptr_gfree(pch_buf_standard_error);

  if (gerror)
    Glib::Error::throw_exception(gerror);

  copy_output_buf(standard_output, buf_standard_output.get());
  copy_output_buf(standard_error, buf_standard_error.get());
}

void
spawn_command_line_async(const std::string& command_line)
{
  GError* gerror = nullptr;
  g_spawn_command_line_async(command_line.c_str(), &gerror);

  if (gerror)
    Glib::Error::throw_exception(gerror);
}

void
spawn_command_line_sync(const std::string& command_line, std::string* standard_output,
  std::string* standard_error, int* exit_status)
{
  char* pch_buf_standard_output = nullptr;
  char* pch_buf_standard_error = nullptr;
  GError* gerror = nullptr;

  g_spawn_command_line_sync(command_line.c_str(),
    (standard_output) ? &pch_buf_standard_output : nullptr,
    (standard_error) ? &pch_buf_standard_error : nullptr, exit_status, &gerror);
  auto buf_standard_output = make_unique_ptr_gfree(pch_buf_standard_output);
  auto buf_standard_error = make_unique_ptr_gfree(pch_buf_standard_error);

  if (gerror)
    Glib::Error::throw_exception(gerror);

  copy_output_buf(standard_output, buf_standard_output.get());
  copy_output_buf(standard_error, buf_standard_error.get());
}

void
spawn_close_pid(Pid pid)
{
  g_spawn_close_pid(pid);
}

} // namespace Glib