/**
 * Fd-enum is a simple tool to list open file descriptors of a pid by type
 * Copyright (C) 2023  Aaron Ball <nullspoon@oper.io>
 * 
 * This program 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.
 * 
 * This program 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 "fdstats.h"

long _fgetsize(char* path) {
  FILE* fd = NULL;
  long size = 0;
  fd = fopen(path, "r");

  fseek(fd, 0, SEEK_END);
  size = ftell(fd);

  fclose(fd);
  return size;
}

int fdstats_read(struct fdstats* fds, char* fdpath, struct config* c) {
  int retval       = 0;
  int len          = 0;
  char lnpath[512] = {'\0'};
  struct stat sb;

  retval = stat(fdpath, &sb);
  len = readlink(fdpath, lnpath, 512);

  if(len <= 0)
    return -1;
  lnpath[len] = '\0';

  // Sockets
  if(S_ISSOCK(sb.st_mode)) {
    fds->sockets++;
    if(c->sockets)
      printf("%s -> %s\n", fdpath, lnpath);

  // Pipes
  } else if(S_ISFIFO(sb.st_mode)) {
    fds->pipes++;
    if(c->pipes)
      printf("%s -> %s\n", fdpath, lnpath);

  // Char device links
  } else if(S_ISCHR(sb.st_mode)) {
    fds->live++;
    if(c->live)
      printf("%s -> %s\n", fdpath, lnpath);

  // File desccriptors
  } else if(S_ISREG(sb.st_mode) || S_ISDIR(sb.st_mode)) {
    // Exists
    if(retval == 0 && access(lnpath, F_OK) == 0) {
      fds->live++;
      if(c->live)
        printf("%s -> %s\n", fdpath, lnpath);
      if(c->showsizefd || c->showsizelive)
        fds->livesize += _fgetsize(fdpath);

    // Does not exist
    } else {
      fds->dead++;
      if(c->dead)
        printf("%s -> %s\n", fdpath, lnpath);
      if(c->showsizefd || c->showsizedead)
        fds->deadsize += _fgetsize(fdpath);
      if(c->truncate_dead)
        truncate(fdpath, 0);
    }

  // Inodes
  } else if(sb.st_mode == 384) {
    fds->inodes++;
    if(c->inodes)
      printf("%s -> %s\n", fdpath, lnpath);

  } else {
    fds->unknown++;
  }
  return 0;
}