#include <libssh/libssh.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

int verify_host(ssh_session session) {
  enum ssh_known_hosts_e state;

  state = ssh_session_is_known_server(session);

  // only handling known hosts for now
  // will implement other responses later.
  switch (state) {
  case SSH_KNOWN_HOSTS_OK:
    break;
  default:
    return -1;
  }
  return 0;
}

int get_movies(ssh_session session, char **buffer, size_t size) {
  ssh_channel channel;
  int rc;
  char read_buffer[256];
  int nbytes;
  size_t len = 0;
  char *temp;

  channel = ssh_channel_new(session);
  if (channel == NULL)
    return SSH_ERROR;

  rc = ssh_channel_open_session(channel);
  if (rc != SSH_OK) {
    fprintf(stderr, "Failed to open channel");
    ssh_channel_free(channel);
    return rc;
  }

  rc = ssh_channel_request_exec(
      channel, "find /var/www/public/media -type f -name \"*mp4\"");
  if (rc != SSH_OK) {
    fprintf(stderr, "Failed to request exec");
    ssh_channel_close(channel);
    ssh_channel_free(channel);
    return rc;
  }

  nbytes = ssh_channel_read(channel, read_buffer, sizeof(read_buffer), 0);
  while (nbytes > 0) {
    if ((len += nbytes) > size) {
      size = len;
      temp = realloc(*buffer, len);
      if (!temp) {
        fprintf(stderr, "Failed to reallocate char buffer");
        ssh_channel_close(channel);
        ssh_channel_free(channel);
        return -1;
      }
      *buffer = temp;
    }

    memcpy(*buffer + len - nbytes, read_buffer, nbytes);

    nbytes = ssh_channel_read(channel, read_buffer, sizeof(read_buffer), 0);

    if (nbytes < 0) {
      fprintf(stderr, "Failed to read bytes from channel");
      ssh_channel_close(channel);
      ssh_channel_free(channel);
      return SSH_ERROR;
    }
  }
  ssh_channel_send_eof(channel);
  ssh_channel_close(channel);
  ssh_channel_free(channel);
  return SSH_OK;
}

int main(int argc, char *argv[]) {
  char *host = "localhost";
  char *user = getlogin();
  int opt;
  int rc;

  while ((opt = getopt(argc, argv, "h:u:")) != -1)
    switch (opt) {
    case 'h':
      host = optarg;
      break;
    case 'u':
      user = optarg;
      break;
    case '?':
      printf("Unknown option\n");
      break;
    }

  ssh_session session = ssh_new();
  if (session == NULL) {
    fprintf(stderr, "Failed to get new ssh_session");
    exit(-1);
  }

  ssh_options_set(session, SSH_OPTIONS_HOST, host);
  ssh_options_set(session, SSH_OPTIONS_USER, user);

  if (ssh_connect(session) != SSH_OK) {
    fprintf(stderr, "Unable to connect to host: %s\n", ssh_get_error(session));
    exit(-1);
  }

  if (verify_host(session) != 0) {
    fprintf(stderr, "Attempted to connect to unknown host\n");
    ssh_disconnect(session);
    ssh_free(session);
    exit(-1);
  }

  rc = ssh_userauth_publickey_auto(session, NULL, NULL);
  if (rc == SSH_AUTH_ERROR) {
    fprintf(stderr, "Authentication failed: %s\n", ssh_get_error(session));
    exit(-1);
  }

  int size = 16;
  char *b = malloc(size);
  memset(b, 0, size);
  if (get_movies(session, &b, size) != SSH_OK) {
    fprintf(stderr, "Unable to list movies: %s\n", ssh_get_error(session));
    exit(-1);
  }

  ssh_disconnect(session);
  ssh_free(session);
}