// -*- coding: utf-8 -*-
// Copyright (C) by the Spot authors, see the AUTHORS file for details.
//
// This file is part of Spot, a model checking library.
//
// Spot is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
//
// Spot 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 for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#include "common_setup.hh"
#include "common_aoutput.hh"

#include <argp.h>
#include <closeout.h>
#include <cstdlib>
#include <unistd.h>
#include <iostream>
#include <signal.h>
#include <sys/wait.h>
#include <error.h>
#include <spot/misc/tmpfile.hh>

static void
display_version(FILE *stream, struct argp_state*)
{
  fputs(program_name, stream);
  fputs(" (" PACKAGE_NAME ") " PACKAGE_VERSION "\n\
\n\
Copyright (C) 2025 by the Spot authors, see the AUTHORS File for details.\n\
License GPLv3+: \
GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.\n\
This is free software: you are free to change and redistribute it.\n\
There is NO WARRANTY, to the extent permitted by law.\n", stream);
}

// This is called on normal exit (i.e., when leaving
// main or calling exit(), even via error()).
static void atexit_cleanup()
{
  spot::cleanup_tmpfiles();
}

#ifdef HAVE_SIGACTION
// This is called on abnormal exit, i.e. when the process is killed by
// some signal.
static void sig_handler(int sig)
{
  spot::cleanup_tmpfiles();
  // Send the signal again, this time to the default handler, so that
  // we return a meaningful error code.
  raise(sig);
}

static void setup_sig_handler()
{
  struct sigaction sa;
  sa.sa_handler = sig_handler;
  sigemptyset(&sa.sa_mask);
  sa.sa_flags = SA_RESETHAND;
  // Catch termination signals, so we can cleanup temporary files.
  sigaction(SIGALRM, &sa, nullptr);
  sigaction(SIGHUP, &sa, nullptr);
  sigaction(SIGINT, &sa, nullptr);
  sigaction(SIGPIPE, &sa, nullptr);
  sigaction(SIGQUIT, &sa, nullptr);
  sigaction(SIGTERM, &sa, nullptr);
}
#else
# define setup_sig_handler() while (0);
#endif


static void bad_alloc_handler()
{
  std::set_new_handler(nullptr);
  std::cerr << "not enough memory\n";
  abort();
}

void
setup(char** argv)
{
  argp_program_bug_address = "<" PACKAGE_BUGREPORT ">";

  // Simplify the program name, because argp() uses it to report
  // errors and display help text.
  set_program_name(argv[0]);

  argv[0] = const_cast<char*>(program_name);

  argp_program_version_hook = display_version;

  argp_err_exit_status = 2;

  if (getenv("SPOT_OOM_ABORT"))
    std::set_new_handler(bad_alloc_handler);

  std::ios_base::sync_with_stdio(false);
  // Do not flush std::cout every time we read from std::cin, unless
  // we are reading from a terminal.  Note that we do flush regularly
  // in check_cout().
  if (!isatty(STDIN_FILENO))
    std::cin.tie(nullptr);

  setup_default_output_format();
  setup_sig_handler();
  atexit(atexit_cleanup);
}


// argp's default behavior of offering -? for --help is just too silly.
// I mean, come on, why not also add -* to Darwinise more shell users?
// We disable this option as well as -V (because --version don't need
// a short version).
enum {
  OPT_HELP = 1,
  OPT_VERSION,
};

static const argp_option options[] =
  {
    { "version", OPT_VERSION, nullptr, 0, "print program version", -1 },
    { "help", OPT_HELP, nullptr, 0, "print this help", -1 },
    // We support --usage as a synonym for --help because argp's
    // hardcoded error message for unknown options mentions it.
    { "usage", OPT_HELP, nullptr, OPTION_HIDDEN, nullptr, -1 },
    { nullptr, 0, nullptr, 0, nullptr, 0 }
  };

static const argp_option options_hidden[] =
  {
    { "version", OPT_VERSION, nullptr, OPTION_HIDDEN,
      "print program version", -1 },
    { "help", OPT_HELP, nullptr, OPTION_HIDDEN, "print this help", -1 },
    // We support --usage as a synonym for --help because argp's
    // hardcoded error message for unknown options mentions it.
    { "usage", OPT_HELP, nullptr, OPTION_HIDDEN, nullptr, -1 },
    { nullptr, 0, nullptr, 0, nullptr, 0 }
  };

static int
parse_opt_misc(int key, char*, struct argp_state* state)
{
  // Called from C code, so should not raise any exception.
  BEGIN_EXCEPTION_PROTECT;
  // This switch is alphabetically-ordered.
  switch (key)
    {
    case OPT_HELP:
      argp_state_help(state, state->out_stream,
                      // Do not let argp exit: we want to diagnose a
                      // failure to print --help by closing stdout
                      // properly.
                      ARGP_HELP_STD_HELP & ~ARGP_HELP_EXIT_OK);
      close_stdout();
      exit(0);
      break;
    case OPT_VERSION:
      display_version(state->out_stream, state);
      close_stdout();
      exit(0);
      break;
    default:
      return ARGP_ERR_UNKNOWN;
    }
  END_EXCEPTION_PROTECT;
  return 0;
}


const struct argp misc_argp = { options, parse_opt_misc,
                                nullptr, nullptr, nullptr, nullptr, nullptr };

const struct argp misc_argp_hidden = { options_hidden, parse_opt_misc,
                                       nullptr, nullptr, nullptr,
                                       nullptr, nullptr };

[[noreturn]] void handle_any_exception()
{
  try
    {
      throw;
    }
  catch (const std::exception& e)
    {
      error(2, 0, "%s", e.what());
    }
  SPOT_UNREACHABLE();
}

int protected_main(char** progname, std::function<int()> mainfun)
{
  try
    {
      setup(progname);
      return mainfun();
    }
  catch (...)
    {
      handle_any_exception();
    }
  SPOT_UNREACHABLE();
  return 2;
}
