/*
 *  gcsd
 *
 *  gcsd the generic command sequencer daemon can be used to serialize
 *  commands sent over various paralell communication channels to a
 *  single command output. It can be seen as a multiplexer for any
 *  kind of communication between a single resource and various clients
 *  which want to submit commands to it or query information from it.
 *  gcsd is written in C and Lua. The goal is to provide an easy to
 *  understand high level API based on Lua which can be used to
 *  implement the business logic of the so formed multiplexer daemon.
 *
 *
 *  Copyright (C) 2009-2010 Markus Grueneis <gimpf@spreadspace.org>
 *                          Christian Pointner <equinox@spreadspace.org>
 *
 *  This file is part of gcsd.
 *
 *  gcsd 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
 *  any later version.
 *
 *  gcsd 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 gcsd. If not, see <http://www.gnu.org/licenses/>.
 */

#include "datatypes.h"

#include "log.h"

#include "sig_handler.h"
#include <errno.h>
#include <string.h>

#ifndef WINVER

#include <signal.h>
#include <unistd.h>
#include <fcntl.h>

static int sig_pipe_fds[2];

static void sig_handler(int sig)
{
  sigset_t set;
  int ret = read(sig_pipe_fds[0], &set, sizeof(sigset_t));
  if(ret != sizeof(sigset_t))
    sigemptyset(&set);

  sigaddset(&set, sig);
  ret = write(sig_pipe_fds[1], &set, sizeof(sigset_t));
}


int signal_init()
{
  if(pipe(sig_pipe_fds)) {
    log_printf(ERROR, "signal handling init failed (pipe error: %s)", strerror(errno));
    return -1;
  }

  int i;
  for(i=0; i<2; ++i) {
    int fd_flags = fcntl(sig_pipe_fds[i], F_GETFL);
    if(fd_flags == -1) {
      log_printf(ERROR, "signal handling init failed (pipe fd[%d] read flags error: %s)", i, strerror(errno));
      return -1;
    }
    if(fcntl(sig_pipe_fds[i], F_SETFL, fd_flags | O_NONBLOCK) == -1){
      log_printf(ERROR, "signal handling init failed (pipe fd[%d] write flags error: %s)", i, strerror(errno));
      return -1;
    }
  }

  struct sigaction act, act_ign;
  act.sa_handler = sig_handler;
  sigfillset(&act.sa_mask);
  act.sa_flags = 0;
  act_ign.sa_handler = SIG_IGN;
  sigfillset(&act_ign.sa_mask);
  act_ign.sa_flags = 0;

  if((sigaction(SIGINT, &act, NULL) < 0) ||
     (sigaction(SIGQUIT, &act, NULL) < 0) ||
     (sigaction(SIGTERM, &act, NULL) < 0) ||
     (sigaction(SIGHUP, &act, NULL) < 0) ||
     (sigaction(SIGUSR1, &act, NULL) < 0) ||
     (sigaction(SIGUSR2, &act, NULL) < 0) ||
     (sigaction(SIGPIPE, &act_ign, NULL) < 0)) {

    log_printf(ERROR, "signal handling init failed (sigaction error: %s)", strerror(errno));
    close(sig_pipe_fds[0]);
    close(sig_pipe_fds[1]);
  }

  return sig_pipe_fds[0];
}

int signal_handle()
{
  sigset_t set, oldset, tmpset;

  sigemptyset(&tmpset);
  sigaddset(&tmpset, SIGINT);
  sigaddset(&tmpset, SIGQUIT);
  sigaddset(&tmpset, SIGTERM);
  sigaddset(&tmpset, SIGHUP);
  sigaddset(&tmpset, SIGUSR1);
  sigaddset(&tmpset, SIGUSR2);
  sigprocmask(SIG_BLOCK, &tmpset, &oldset);

  int ret = read(sig_pipe_fds[0], &set, sizeof(sigset_t));
  if(ret != sizeof(sigset_t))
    sigemptyset(&set);

  int return_value = 0;
  int sig;
  for(sig=1; sig < NSIG; ++sig) {
    if(sigismember(&set, sig)) {
      switch(sig) {
      case SIGINT: log_printf(NOTICE, "SIG-Int caught, exitting"); return_value = 1; break;
      case SIGQUIT: log_printf(NOTICE, "SIG-Quit caught, exitting"); return_value = 1; break;
      case SIGTERM: log_printf(NOTICE, "SIG-Term caught, exitting"); return_value = 1; break;
      case SIGHUP: log_printf(NOTICE, "SIG-Hup caught"); break;
      case SIGUSR1: log_printf(NOTICE, "SIG-Usr1 caught"); break;
      case SIGUSR2: log_printf(NOTICE, "SIG-Usr2 caught"); break;
      default: log_printf(WARNING, "unknown signal %d caught, ignoring", sig); break;
      }
      sigdelset(&set, sig);
    }
  }

  sigprocmask(SIG_SETMASK, &oldset, NULL);
  return return_value;
}

void signal_stop()
{
  struct sigaction act;
  act.sa_handler = SIG_DFL;
  sigemptyset(&act.sa_mask);
  act.sa_flags = 0;

  sigaction(SIGINT, &act, NULL);
  sigaction(SIGQUIT, &act, NULL);
  sigaction(SIGTERM, &act, NULL);
  sigaction(SIGHUP, &act, NULL);
  sigaction(SIGUSR1, &act, NULL);
  sigaction(SIGUSR2, &act, NULL);
  sigaction(SIGPIPE, &act, NULL);

  close(sig_pipe_fds[0]);
  close(sig_pipe_fds[1]);
}


#else


#include <winsock2.h>
#include <windows.h>

static SOCKET sig_sock_fds[2];
static SOCKET server_sock;

static DWORD WINAPI signal_connect_thread(void* p)
{
  uint16_t port = *((uint16_t*)p);

  SOCKET client;
  client = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  if(client == INVALID_SOCKET) {
    log_printf(ERROR, "Error at socket(): 0x%04X\n", WSAGetLastError());
    return -1;
  }

  struct sockaddr_in server;
  server.sin_family = AF_INET;
  server.sin_addr.s_addr = inet_addr("127.0.0.1");
  server.sin_port = port;

  int cnt = 0;
  int ret = SOCKET_ERROR;
  do {
    Sleep(100);
    ret = connect(client, (SOCKADDR*) &server, sizeof(server));
    cnt++;
  }
  while(ret != 0 && cnt < 10);

  if(ret != 0) {
    log_printf(ERROR, "connect() failed: 0x%04X", WSAGetLastError());
    closesocket(client);
    return -1;
  }

  log_printf(DEBUG, "sig_handler connected to port %d", port);

  sig_sock_fds[1] = client;

  return 0;
}

static BOOL WINAPI signal_ctrl_handler(DWORD ctrlType)
{
  char c = (char)ctrlType;
  send(sig_sock_fds[1], &c, 1, 0);
  return 1;
}

int signal_init()
{
  WSADATA wsaData;
  int ret = WSAStartup(MAKEWORD(2,2), &wsaData);
  if(ret != NO_ERROR) {
    log_printf(ERROR, "Error at WSAStartup(): 0x%04X", WSAGetLastError());
    return -1;
  }

  server_sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  if(server_sock == INVALID_SOCKET) {
    log_printf(ERROR, "Error at socket(): 0x%04X\n", WSAGetLastError());
    WSACleanup();
    return -1;
  }

  struct sockaddr_in service;
  service.sin_family = AF_INET;
  service.sin_addr.s_addr = inet_addr("127.0.0.1");
  service.sin_port = 0;

  if(bind(server_sock, (SOCKADDR*) &service, sizeof(service)) == SOCKET_ERROR) {
    log_printf(ERROR, "bind() failed: 0x%04X", WSAGetLastError());
    closesocket(server_sock);
    WSACleanup();
    return -1;
  }

  struct sockaddr_in hugo;
  int hugo_len = sizeof(hugo);
  if(getsockname(server_sock, (SOCKADDR*) &hugo, &hugo_len) == SOCKET_ERROR) {
    log_printf(ERROR, "getsockname() failed: 0x%04X", WSAGetLastError());
    closesocket(server_sock);
    WSACleanup();
    return -1;
  }

  if(listen(server_sock, 1) == SOCKET_ERROR) {
    log_printf(ERROR, "listen() failed: 0x%04X", WSAGetLastError());
    closesocket(server_sock);
    WSACleanup();
    return -1;
  }

  log_printf(DEBUG, "sig_handler listening on port %d", hugo.sin_port);

  HANDLE t = CreateThread(NULL, 0, signal_connect_thread, &(hugo.sin_port), 0, NULL);
  if(t == INVALID_HANDLE_VALUE) {
    log_printf(ERROR, "CreateThread() failed: 0x%04X", GetLastError());
    closesocket(server_sock);
    WSACleanup();
    return -1;
  }

  sig_sock_fds[0] = accept(server_sock, NULL, NULL);
  if(sig_sock_fds[0] == INVALID_SOCKET) {
    log_printf(ERROR, "accept() failed: 0x%04X", WSAGetLastError());
    closesocket(server_sock);
    WSACleanup();
    WaitForSingleObject(t, INFINITE);
    return -1;
  }

  WaitForSingleObject(t, INFINITE);

  if(!SetConsoleCtrlHandler(signal_ctrl_handler, 1)) {
    log_printf(ERROR, "adding console ctrl handler failed: 0x%04X" , GetLastError());
  }

  return sig_sock_fds[0];
}

int signal_handle()
{
  char c;
  int ret = recv(sig_sock_fds[0], &c, 1, 0);
  if(ret == 1) {
    switch(c) {
    case CTRL_C_EVENT: log_printf(NOTICE, "CTRL-C Event received, exitting"); return 1;
    case CTRL_BREAK_EVENT: log_printf(NOTICE, "CTRL-Break Event received, ignoring"); return 1;
    case CTRL_CLOSE_EVENT: log_printf(NOTICE, "Close Event received, exitting"); return 1;
    case CTRL_LOGOFF_EVENT: log_printf(NOTICE, "LogOff Event received, exitting"); return 1;
    case CTRL_SHUTDOWN_EVENT: log_printf(NOTICE, "Shutdown Event received, exitting"); return 1;
    default: log_printf(NOTICE, "unknown event received 0x%02X, ignoring", c); return 0;
    }
  }

  if(ret == 0) {
    log_printf(ERROR, "signal socket closed normally, exitting");
    return 1;
  }

  log_printf(ERROR, "signal socket closed with error 0x%04X, exitting", GetLastError());
  return 1;
}

void signal_stop()
{
  if(!SetConsoleCtrlHandler(signal_ctrl_handler, 0)) {
    log_printf(ERROR, "removeing console ctrl handler failed: 0x%04X" , GetLastError());
  }
  closesocket(sig_sock_fds[0]);
  closesocket(sig_sock_fds[1]);
  closesocket(server_sock);
  WSACleanup();
  return;
}
#endif