#include <string.h>
#include <pcap.h>
#include <gio/gio.h>
#include <gst/gst.h>

static gchar *_omvs_net_dev;
static gchar *_omvs_output = "omvs_out.txt";
static gint _omvs_jobs = 1;
static gint _omvs_sleep = 1000;
static gint _omvs_timeout = 10000;

static GOptionEntry _omvs_entries[] =
{
  { "interface", 'i', 0, G_OPTION_ARG_STRING, &_omvs_net_dev,
    "Network device interface", "dev" },
  { "jobs", 'j', 0, G_OPTION_ARG_INT, &_omvs_jobs,
    "Number of jobs", "jobs" },
  { "output", 'o', 0, G_OPTION_ARG_FILENAME, &_omvs_output,
    "Output filename", "filename" },
  { "sleep", 's', 0, G_OPTION_ARG_INT, &_omvs_sleep,
    "Sleep time(milliseconds) between scans", "ms" },
  { "timeout", 't', 0, G_OPTION_ARG_INT, &_omvs_timeout,
    "Timeout time(milliseconds) in each scan", "ms" },
  { NULL }
};

typedef struct _OMVSPort {
  gint port;
  gint type;
} OMVSPort;

typedef struct _OMVSIPAddr {
  guint32 addr;
  OMVSPort *ports;
  gint num_ports;
} OMVSIPAddr;

typedef struct _OMVSScanner {
  OMVSIPAddr *ipaddrs;
  gint num_ipaddrs;
} OMVSScanner;

static gint _omvs_start_scan(OMVSScanner *scanner);

static gint _omvs_start_scan(OMVSScanner *scanner) {
  gint i;
  for (i = 0; i < scanner->num_ipaddrs; i++) {
    g_print("%08x\n", scanner->ipaddrs[i].addr);
  }
  return 0;
}

int main(int argc, char *argv[]) {
  GError *error = NULL;
  GOptionContext *context;
  int ret = 0;
  gint i;
  gint num_ipaddrs;
  gint idx_ipaddr;
  OMVSScanner omvs_scanner;

  context = g_option_context_new("<multicast ip address or net ... [#N]>");
  g_option_context_set_summary(context,
    "omvs scans to find free video streaming multicast ip addresses."
  );
  g_option_context_set_description(context,
    "Oh! Multicast Video Scanner " OMVS_VERSION " is"
      " Written by Taeho Oh <ohhara@postech.edu>.\n"
    "http://ohhara.sarang.net");
  g_option_context_add_main_entries(context, _omvs_entries, NULL);
  g_option_context_add_group(context, gst_init_get_option_group());
  if (!g_option_context_parse(context, &argc, &argv, &error)) {
    g_print("option parsing failed: %s\n", error->message);
    ret = -1;
    goto finish_return;
  }

  if (argc < 2) {
    gchar *help_msg;
    help_msg = g_option_context_get_help(context, TRUE, NULL);
    g_print("%s", help_msg);
    g_free(help_msg);
    ret = -2;
    goto finish_return;
  }

  num_ipaddrs = 0;
  for (i = 1; i < argc; i++) {
    GInetAddressMask *mask;
    GInetAddress *addr;
    guint len;
    mask = g_inet_address_mask_new_from_string(argv[i], &error);
    if (!mask) {
      g_print("%s parsing failed: %s\n", argv[i], error->message);
      ret = -3;
      goto finish_return;
    }
    if (g_inet_address_mask_get_family(mask) != G_SOCKET_FAMILY_IPV4) {
      g_print("%s is not ipv4 ip address\n", argv[i]);
      g_object_unref(mask);
      ret = -4;
      goto finish_return;
    }
    addr = g_inet_address_mask_get_address(mask);
    if (!g_inet_address_get_is_multicast(addr)) {
      g_print("%s is not multicast ip address\n", argv[i]);
      g_object_unref(mask);
      ret = -4;
      goto finish_return;
    }
    len = g_inet_address_mask_get_length(mask);
    if (len) {
      num_ipaddrs += (1 << (32 - len));
    } else {
      num_ipaddrs++;
    }
    g_object_unref(mask);
  }

  memset(&omvs_scanner, 0, sizeof(OMVSScanner));
  omvs_scanner.ipaddrs = g_malloc0(num_ipaddrs * sizeof(OMVSIPAddr));
  omvs_scanner.num_ipaddrs = num_ipaddrs;

  idx_ipaddr = 0;
  for (i = 1; i < argc; i++) {
    GInetAddressMask *mask;
    GInetAddress *addr;
    guint len;
    guint32 start_ipaddr;
    const guint8 *addr_bytes;
    mask = g_inet_address_mask_new_from_string(argv[i], &error);
    addr = g_inet_address_mask_get_address(mask);
    len = g_inet_address_mask_get_length(mask);
    addr_bytes = g_inet_address_to_bytes(addr);
    start_ipaddr =
      (((guint32)addr_bytes[0]) << 24) |
      (((guint32)addr_bytes[1]) << 16) |
      (((guint32)addr_bytes[2]) << 8) |
      (((guint32)addr_bytes[3]) << 0);
    if (len) {
      guint n;
      guint j;
      n = (1 << (32 - len));
      for (j = 0; j < n; j++) {
        omvs_scanner.ipaddrs[idx_ipaddr].addr = start_ipaddr;
        idx_ipaddr++;
        start_ipaddr++;
      }
    } else {
      omvs_scanner.ipaddrs[idx_ipaddr].addr = start_ipaddr;
      idx_ipaddr++;
    }
  }

  _omvs_start_scan(&omvs_scanner);
  g_free(omvs_scanner.ipaddrs);

finish_return:
  g_option_context_free(context);

  return ret;
}