/*
 * Secure X Message Passing Library v2 examples.
 *
 * (c) Alexander Vdolainen 2016 <avdolainen@zoho.com>
 *
 * libsxmp is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * libsxmp 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 Lesser 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 <stdio.h>
#include <dirent.h>
#define __USE_GNU
#include <stdlib.h>
#include <stdarg.h>
#include <sys/types.h>
#include <limits.h>
#include <sys/select.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <sys/resource.h>
#include <netdb.h>
#include <unistd.h>
#include <uuid/uuid.h>
#include <execinfo.h>
#include <netinet/in.h>
#include <pthread.h>
#include <stdint.h>
#include <getopt.h>
#include <errno.h>

#include <tdata/usrtc.h>
#include <tdata/list.h>
#include <sexpr/sexp.h>
#include <sxmp/limits.h>
#include <sxmp/sxmp.h>

#include <readline/readline.h>
#include <readline/history.h>

#include "smpf.h"
#include "misc.h"
#include "../config.h"

#define FULL_PROGRAM_NAME        "SMPF (secure message passing file) client"
#include "helpers.h"

struct _session {
  list_head_t channels;
  char cwd[MAX_CWDLEN];
};

struct _remote_host {
  char *root_x509;
  char *user_x509;
  char *hostname;
  char *login;
  char *password;
  int port;
  sxhub_t *hub;
  sxlink_t *link;
};

/* session processing itself */
static void __shell(sxlink_t *link)
{
  struct _session *s = (struct _session *)sxlink_getpriv(link);
  char *line;

  for(;;) {
    line = readline("$>");

    if(line && *line)      add_history(line);
    else break;

    if(!strcmp(line, "exit")) break;
  }
  return;
}

/* sxmp stuff below */
static void __session_free(sxlink_t *l)
{
  struct _session *s = (struct _session *)sxlink_getpriv(l);

  /* TODO: free all list entries if exists */
  free(s);
  return;
}

static int __rpcscheck_onclient(sxlink_t *l, int ch_tid, char *description)
{
  struct _session *s = (struct _session *)sxlink_getpriv(l);

  /* TODO: add all stuff to the list */

  return SXE_SUCCESS;
}

static int __remote_host_connect(struct _remote_host *rh)
{
  int r = 0;
  struct _session *s = malloc(sizeof(struct _session));

  sxhub_set_channelcall(rh->hub, __rpcscheck_onclient);
  sxhub_set_ondestroy(rh->hub, __session_free);
  if(!s) return SXE_ENOMEM;

  /* here we go, connect to the hist i.e. create a link to it */
  rh->link = sxlink_connect_at(rh->hub, rh->hostname, rh->port, rh->user_x509,
                               rh->login, rh->password, s);
  if(!rh->link) r = errno;

  return r;
}

/* standard output helpers */
static void __help_print(FILE *fso, const char *fmtname)
{
  fprintf(fso, "\n%s\n\n", FULL_PROGRAM_NAME);

  /* usage options */
  fprintf(fso, "Usage:\n");
  fprintf(fso, "\t%s -r | --root-x509 <path> -u | --user-x509 <path> <user>@<hostname>[:port]\n", fmtname);

  /* defaults */
  fprintf(fso, "\t%s -h | --help\n", fmtname);
  fprintf(fso, "\t%s -v | --version\n", fmtname);

  /* options description */
  fprintf(fso, "\nOptions:\n");
  fprintf(fso, "\t%-33s Set pathname of the remote root X.509 public certificate.\n", "-r | --root-x509 <path>");
  fprintf(fso, "\t%-33s Set pathname of the user X.509 public and private certificate.\n",
          "-u | --user-x509 <path>");
  fprintf(fso, "\t%-33s Show help screen.\n", "-h | --help");
  fprintf(fso, "\t%-33s Print version information.\n", "-v | --version");
  return;
}

int main(int argc, char **argv)
{
  char *rootca, *cert, *host, *cline;
  char *login, *password;
  int port = DEFAULT_PORT, opt, i = 0;
  struct _remote_host *rh = malloc(sizeof(struct _remote_host));
  sxhub_t *lhub;

  if(!rh) return ENOMEM;
  else memset(rh, 0, sizeof(struct _remote_host));

  rootca = cert = host = login = password = NULL;

  while(1) {
    int option_index = 0;
    static struct option long_options[] = {
      /* These options a generic ones. */
      {"help", no_argument, NULL, 'h'}, /* print out help and version info */
      {"version", no_argument, NULL, 'v'}, /* just out a version info */
      /*  The following options about settings . */
      {"root-x509", required_argument, NULL, 'r'},
      {"user-x509", required_argument, NULL, 'u'},
      { NULL, 0, NULL, 0 },
    };

    if((opt = getopt_long(argc, argv, "hvr:u:", long_options,
                          &option_index)) == -1) break;

    switch(opt) {
    case 'h':
      __help_print(stdout, argv[0]);
      return 0;
      break;
    case 'v':
      version_print(stdout);
      return 0;
      break;
    case 'r':
      if(!(rootca = strdup(optarg))) return ENOMEM;
      break;
    case 'u':
      if(!(cert = strdup(optarg))) return ENOMEM;
      break;
    }
  }

  if(optind < argc) cline = argv[optind];
  else {
    fprintf(stderr, "No remote address given connect to.\n\n");
    __help_print(stderr, argv[0]);
    return EINVAL;
  }

  /* TODO: better check */
  exmps_getaddrs(cline, &login, &host, &port);

  if(!host) {
    fprintf(stderr, "Host not pointed.\n");
    __help_print(stderr, argv[0]);
    return EINVAL;
  }

  /* ok validate all before doing any stuff */
  if(!rootca || !cert) {
    fprintf(stderr, "One or more x.509 certificates files not pointed.\n");
    __help_print(stderr, argv[0]);
    return EINVAL;
  }
  if(!login) {
    fprintf(stderr, "Login not pointed.\n");
    __help_print(stderr, argv[0]);
    return EINVAL;
  }
  if(port <= 0) {
    fprintf(stderr, "Port number has invalid value.\n");
    __help_print(stderr, argv[0]);
    return EINVAL;
  }

  /* read the password */
  password = exmps_getpass("Password: ");
  fprintf(stdout, "\n");

  /* initialize sxmp first */
  sxmp_init(); /* init library */
  lhub = sxhub_create(); /* create sxhub for link creation */
  if(!lhub) return ENOMEM;

  i = sxhub_setsslserts(lhub, rootca, cert, cert);
  if(i) return i;

  /* ok setup our structure */
  rh->port = port;
  rh->root_x509 = rootca;
  rh->user_x509 = cert;
  rh->hostname = host;
  rh->login = login;
  rh->password = password;
  rh->hub = lhub;

  i = __remote_host_connect(rh);
  if(i) {
    fprintf(stderr, "Failed to create link to %s@%s:%d with %d.\n", rh->login, rh->hostname,
            rh->port, i);
  } else {
    /* hooray now we ready to do something */
    __shell(rh->link);

    sxlink_close(rh->link); /* don't forget to do this */
  }

  /* free all stuff */
  if(rh->root_x509) free(rh->root_x509);
  if(rh->user_x509) free(rh->user_x509);
  if(rh->hostname) free(rh->hostname);
  if(rh->password) free(rh->password);
  if(rh->login) free(rh->login);
  free(rh);

  if(lhub) sxhub_destroy(lhub);

  return 0;
}