#include <pthread.h>

#include <stddef.h>

#include <errno.h>

#include <signal.h>

#include <termios.h>

#include <winpr/atexit.h>

#include <winpr/wlog.h>

#include <winpr/debug.h>

#include <freerdp/log.h>

#include <freerdp/utils/signal.h>

#include "platform_signal.h"

#define TAG FREERDP_TAG("utils.signal.posix")

static pthread_mutex_t signal_handler_lock = PTHREAD_MUTEX_INITIALIZER;

void fsig_lock(void)

{

  const int rc = pthread_mutex_lock(&signal_handler_lock);

  if (rc != 0)

  {

    char ebuffer[256] = WINPR_C_ARRAY_INIT;

    WLog_ERR(TAG, "[pthread_mutex_lock] failed with %s [%d]",

             winpr_strerror(rc, ebuffer, sizeof(ebuffer)), rc);

  }

}

void fsig_unlock(void)

{

  const int rc = pthread_mutex_unlock(&signal_handler_lock);

  if (rc != 0)

  {

    char ebuffer[256] = WINPR_C_ARRAY_INIT;

    WLog_ERR(TAG, "[pthread_mutex_lock] failed with %s [%d]",

             winpr_strerror(rc, ebuffer, sizeof(ebuffer)), rc);

  }

}

static void fatal_handler(int signum)

{

  struct sigaction default_sigaction;

  sigset_t this_mask;

  static BOOL recursive = FALSE;

  if (!recursive)

  {

    recursive = TRUE;

    // NOLINTNEXTLINE(concurrency-mt-unsafe)

    WLog_ERR(TAG, "Caught signal '%s' [%d]", strsignal(signum), signum);

    winpr_log_backtrace(TAG, WLOG_ERROR, 20);

  }

  default_sigaction.sa_handler = SIG_DFL;

  sigfillset(&(default_sigaction.sa_mask));

  default_sigaction.sa_flags = 0;

  sigaction(signum, &default_sigaction, nullptr);

  sigemptyset(&this_mask);

  sigaddset(&this_mask, signum);

  pthread_sigmask(SIG_UNBLOCK, &this_mask, nullptr);

  (void)raise(signum);

}

static const int term_signals[] = { SIGINT, SIGKILL, SIGQUIT, SIGSTOP, SIGTERM };

static const int fatal_signals[] = { SIGABRT,   SIGALRM, SIGBUS,  SIGFPE,  SIGHUP,

                                   SIGILL,    SIGSEGV, SIGTTIN, SIGTTOU,

#ifdef SIGPOLL

                                   SIGPOLL,

#endif

#ifdef SIGPROF

                                   SIGPROF,

#endif

#ifdef SIGSYS

                                   SIGSYS,

#endif

                                   SIGTRAP,

#ifdef SIGVTALRM

                                   SIGVTALRM,

#endif

                                   SIGXCPU,   SIGXFSZ };

static BOOL register_handlers(const int* signals, size_t count, void (*handler)(int))

{

  WINPR_ASSERT(signals || (count == 0));

  WINPR_ASSERT(handler);

  sigset_t orig_set = WINPR_C_ARRAY_INIT;

  struct sigaction saction = WINPR_C_ARRAY_INIT;

  pthread_sigmask(SIG_BLOCK, &(saction.sa_mask), &orig_set);

  sigfillset(&(saction.sa_mask));

  sigdelset(&(saction.sa_mask), SIGCONT);

  saction.sa_handler = handler;

  saction.sa_flags = 0;

  for (size_t x = 0; x < count; x++)

  {

    struct sigaction orig_sigaction = WINPR_C_ARRAY_INIT;

    if (sigaction(signals[x], nullptr, &orig_sigaction) == 0)

    {

      if (orig_sigaction.sa_handler != SIG_IGN)

      {

        sigaction(signals[x], &saction, nullptr);

      }

    }

  }

  pthread_sigmask(SIG_SETMASK, &orig_set, nullptr);

  return TRUE;

}

static void unregister_handlers(const int* signals, size_t count)

{

  WINPR_ASSERT(signals || (count == 0));

  sigset_t orig_set = WINPR_C_ARRAY_INIT;

  struct sigaction saction = WINPR_C_ARRAY_INIT;

  pthread_sigmask(SIG_BLOCK, &(saction.sa_mask), &orig_set);

  sigfillset(&(saction.sa_mask));

  sigdelset(&(saction.sa_mask), SIGCONT);

  saction.sa_handler = SIG_IGN;

  saction.sa_flags = 0;

  for (size_t x = 0; x < count; x++)

  {

    sigaction(signals[x], &saction, nullptr);

  }

  pthread_sigmask(SIG_SETMASK, &orig_set, nullptr);

}

static void unregister_all_handlers(void)

{

  unregister_handlers(fatal_signals, ARRAYSIZE(fatal_signals));

  unregister_handlers(term_signals, ARRAYSIZE(term_signals));

}

int freerdp_handle_signals(void)

{

  int rc = -1;

  fsig_lock();

  WLog_DBG(TAG, "Registering signal hook...");

  (void)winpr_atexit(unregister_all_handlers);

  if (!register_handlers(fatal_signals, ARRAYSIZE(fatal_signals), fatal_handler))

    goto fail;

  if (!register_handlers(term_signals, ARRAYSIZE(term_signals), fsig_term_handler))

    goto fail;

  /* Ignore SIGPIPE signal. */

  (void)signal(SIGPIPE, SIG_IGN);

  fsig_handlers_registered = TRUE;

  rc = 0;

fail:

  fsig_unlock();

  return rc;

}