/*
 *  rhctl
 *
 *  Copyright (C) 2009 Christian Pointner <equinox@spreadspace.org>
 *
 *  This file is part of rhctl.
 *
 *  rhctl 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.
 *
 *  rhctl 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 rhctl. If not, see <http://www.gnu.org/licenses/>.
 */

#include "datatypes.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>

#include "log.h"
#include "sig_handler.h"
#include "options.h"

#include "daemon.h"
#include "utils.h"

int process_data(int src_fd, int dest_fd)
{
  char* buffer[100];
  int ret = read(src_fd, buffer, 100);
  if(!ret)
    return 2;
  if(ret == -1 && errno == EAGAIN)
    return 0;
  if(ret < 0)
    return ret;
  
  int len = ret;
  int offset = 0;
  for(;;) {
    ret = write(dest_fd, &buffer[offset], len - offset);
    if(ret < 0) {
      if(errno != EINTR)
        return ret;

      ret = 0;
    }

    offset += ret;
    if(offset+1 >= len)
      break;
  }
  return ret;
}

int main_loop(int serial_fd, int cmd_fd, options_t* opt)
{
  log_printf(NOTICE, "entering main loop");

  fd_set readfds, tmpfds;
  FD_ZERO(&readfds);
  FD_SET(serial_fd, &readfds);
  FD_SET(cmd_fd, &readfds);
  int max_fd = serial_fd > cmd_fd ? serial_fd : cmd_fd;

  int sig_fd = signal_init();
  if(sig_fd < 0)
    return -1;
  FD_SET(sig_fd, &readfds);
  max_fd = (max_fd < sig_fd) ? sig_fd : max_fd;

  int return_value = 0;

  return_value = send_string(cmd_fd, opt->type);

  while(!return_value) {
    memcpy(&tmpfds, &readfds, sizeof(tmpfds));

    int ret = select(max_fd+1, &tmpfds, NULL, NULL, NULL);
    if(ret == -1 && errno != EINTR) {
      log_printf(ERROR, "select returned with error: %s", strerror(errno));
      return_value = -1;
      break;
    }
    if(ret == -1 || !ret)
      continue;

    if(FD_ISSET(sig_fd, &tmpfds)) {
      if(signal_handle()) {
        return_value = 1;
        break;
      }
    }
   
    if(FD_ISSET(serial_fd, &tmpfds)) {
      return_value = process_data(serial_fd, cmd_fd);
      if(return_value)
        break;
    }

    if(FD_ISSET(cmd_fd, &tmpfds)) {
      return_value = process_data(cmd_fd, serial_fd);
    }
  }

  signal_stop();
  return return_value;
}

int main(int argc, char* argv[])
{
  log_init();

  options_t opt;
  int ret = options_parse(&opt, argc, argv);
  if(ret) {
    if(ret > 0) {
      fprintf(stderr, "syntax error near: %s\n\n", argv[ret]);
    }
    if(ret == -2) {
      fprintf(stderr, "memory error on options_parse, exiting\n");
    }

    if(ret != -2)
      options_print_usage();

    options_clear(&opt);
    log_close();
    exit(ret);
  }
  string_list_element_t* tmp = opt.log_targets_.first_;
  if(!tmp) {
    log_add_target("syslog:3,serialclient,daemon");
  }
  else {
    while(tmp) {
      ret = log_add_target(tmp->string_);
      if(ret) {
        switch(ret) {
        case -2: fprintf(stderr, "memory error on log_add_target, exitting\n"); break;
        case -3: fprintf(stderr, "unknown log target: '%s', exitting\n", tmp->string_); break;
        case -4: fprintf(stderr, "this log target is only allowed once: '%s', exitting\n", tmp->string_); break;
        default: fprintf(stderr, "syntax error near: '%s', exitting\n", tmp->string_); break;
        }
        
        options_clear(&opt);
        log_close();
        exit(ret);
      }
      tmp = tmp->next_;
    }
  }
  log_printf(NOTICE, "just started...");
  if(options_parse_post(&opt)) {
    options_clear(&opt);
    log_close();
    exit(-1);
  }

  priv_info_t priv;
  if(opt.username_)
    if(priv_init(&priv, opt.username_, opt.groupname_)) {
      options_clear(&opt);
      log_close();
      exit(-1);
    }

  FILE* pid_file = NULL;
  if(opt.pid_file_) {
    pid_file = fopen(opt.pid_file_, "w");
    if(!pid_file) {
      log_printf(WARNING, "unable to open pid file: %s", strerror(errno));
    }
  }

  if(opt.chroot_dir_)
    if(do_chroot(opt.chroot_dir_)) {
      options_clear(&opt);
      log_close();
      exit(-1);
    }
  if(opt.username_)
    if(priv_drop(&priv)) {
      options_clear(&opt);
      log_close();
      exit(-1);
    }

  if(opt.daemonize_) {
    pid_t oldpid = getpid();
    daemonize();
    log_printf(INFO, "running in background now (old pid: %d)", oldpid);
  }

  if(pid_file) {
    pid_t pid = getpid();
    fprintf(pid_file, "%d", pid);
    fclose(pid_file);
  }

  int cmd_fd = init_command_socket(opt.command_sock_);
  if(cmd_fd < 0) {
    options_clear(&opt);
    log_close();
    exit(-1);
  }
  
  int serial_fd = 0;
  for(;;) {
    serial_fd = open(opt.serial_dev_, O_RDWR | O_NOCTTY);
    if(serial_fd < 0)
      ret = 2;
    else {
      ret = setup_tty(serial_fd, B38400);
      if(ret)
        ret = 2;
      else
        ret = main_loop(serial_fd, cmd_listen_fd, &opt);
    }

    if(ret == 2) {
      log_printf(ERROR, "%s error, trying to reopen in 5 seconds..", opt.serial_dev_);
      if(serial_fd > 0)
        close(serial_fd);
      sleep(5);
    }
    else
      break;
  }

  close(cmd_listen_fd);
  if(serial_fd > 0)
    close(serial_fd);

  if(!ret)
    log_printf(NOTICE, "normal shutdown");
  else if(ret < 0)
    log_printf(NOTICE, "shutdown after error");
  else
    log_printf(NOTICE, "shutdown after signal");

  options_clear(&opt);
  log_close();

  return ret;
}