/*
 * This file is part of the rtap localisation project.
 */

#include <owlps-client.h>

#define DEBUG

/* Error codes */
#define ERR_BAD_USAGE 1 // Bad program call (bad number of arguments)

/* Number of packets to send */
#define DEFAULT_NBPKT_CALIB 20 // 20 packets when calibrating
#define DEFAULT_NBPKT_NORMAL 10 // 10 packets when requesting the position

/* Delay between two packet transmissions (in microseconds) */
#define DEFAULT_DELAY_CALIB 50000 // Calibration request
#define DEFAULT_DELAY_NORMAL 25000 // Localisation request

/* Program arguments (getopt string) */
#define OPTIONS "d:hi:l::n:p:t:"


/* Function headers */
void parse_command_line(int argc, char **argv) ;
void parse_main_options(int argc, char **argv) ;
void check_destination_ip(void) ;
void parse_calibration_data(int argc, char **argv) ;
void check_configuration(void) ;
#ifdef DEBUG
void print_configuration(void) ;
#endif // DEBUG
void create_socket(void) ;
void make_packet(void) ;
void send_request(void) ;
void receive_position(void) ;
void print_usage(void) ;


/* Options */
struct {
  char dest_ip[INET_ADDRSTRLEN] ; // Destination IP of the packets
  uint_fast16_t dest_port ;
  char iface[IFNAMSIZ + 1] ; // Source network interface
  int_fast32_t delay ; // Time between two packet transmissions
  uint_fast16_t nb_pkt ; // Number of packets to send
  uint_fast16_t listening_port ;
  // Calibration data:
  owl_direction direction ;
  float x ;
  float y ;
  float z ;
} options = {
  "",
  LOC_REQUEST_DEFAULT_PORT,
  "",
  -1,
  0,
  0,
  0, 0, 0, 0
} ;

char *program_name = NULL ;

// TRUE if the packet is a calibration request, FALSE if it is a simple
// positioning request:
owl_bool is_calibration_request = FALSE ;

int sockfd ; // Sending socket descriptor
struct sockaddr_in server ; // Server info
uint8_t *packet = NULL ; // Packet to send
uint_fast16_t packet_size ; // Packet size



int main(int argc, char *argv[])
{
  program_name = argv[0] ;
  parse_command_line(argc, argv) ;

  create_socket() ;
  make_packet() ;
  send_request() ;

  free(packet) ;
  close(sockfd) ;

  if (options.listening_port > 0)
    receive_position() ;

  return 0 ;
}



void parse_command_line(int argc, char **argv)
{
  parse_main_options(argc, argv) ;
  check_destination_ip() ;
  parse_calibration_data(argc, argv) ;
  check_configuration() ;

#ifdef DEBUG
  print_configuration() ;
#endif // DEBUG
}



void parse_main_options(int argc, char **argv)
{
  int opt ;

  while ((opt = getopt(argc, argv, OPTIONS)) != -1)
    {
      switch (opt)
        {
        case 'd' :
          strncpy(options.dest_ip, optarg, INET_ADDRSTRLEN) ;
          break ;
        case 'h' :
          print_usage() ;
          exit(0) ;
        case 'i' :
          strncpy(options.iface, optarg, IFNAMSIZ + 1) ;
          break ;
        case 'l' :
          /* Facultative getopt options does not handle separated
           * values (like -l <port>) */
          if (optarg == 0)
            {
              /* If we are at the end of the string, or the next optind
               * is an option, we have -l without a port number */
              if (argv[optind] == NULL || argv[optind][0] == '-')
                // Take the default value:
                options.listening_port = MOBILE_DEFAULT_PORT ;
              else
                {
                  // Take the optind value:
                  options.listening_port =
                    strtoul(argv[optind], NULL, 0) ;
                  optind++ ;
                }
            }
          else // We got an option like -l<port>, it's OK
            options.listening_port = strtoul(optarg, NULL, 0) ;
          break ;
        case 'n' :
          options.nb_pkt = strtoul(optarg, NULL, 0) ;
          break ;
        case 'p' :
          options.dest_port = strtoul(optarg, NULL, 0) ;
          break ;
        case 't' :
          options.delay = strtol(optarg, NULL, 0) ;
          break ;
        default :
          print_usage() ;
          exit(ERR_BAD_USAGE) ;
        }
    }
}



void check_destination_ip()
{
  /* Check if we got a destination IP address */
  if (options.dest_ip[0] == '\0')
    {
      fprintf(stderr, "Error! You must specify a destination IP address"
              " (-d).\n") ;
      print_usage() ;
      exit(ERR_BAD_USAGE) ;
    }
}



void parse_calibration_data(int argc, char **argv)
{
  /* Parse remaining arguments (possible calibration data) */
  if (argc - optind != 0)
    {
      if (argc - optind == 4)
        {
          is_calibration_request = TRUE ;
          options.direction = strtoul(argv[optind++], NULL, 0) ;
          options.x = strtod(argv[optind++], NULL) ;
          options.y = strtod(argv[optind++], NULL) ;
          options.z = strtod(argv[optind], NULL) ;
        }
      else // Bad number of arguments
        {
          print_usage() ;
          exit(ERR_BAD_USAGE) ;
        }
    }
}



void check_configuration()
{
  // Delay not specified (or bad delay):
  if (options.delay < 0)
    {
#ifdef DEBUG
      fprintf(stderr,
              "Warning! delay: failing back to default value.\n") ;
#endif // DEBUG
      if (is_calibration_request)
        options.delay = DEFAULT_DELAY_CALIB ;
      else
        options.delay = DEFAULT_DELAY_NORMAL ;
    }

  // Number of packet not specified (or bad number)
  if (options.nb_pkt < 1)
    {
#ifdef DEBUG
      fprintf(stderr,
              "Warning! nb_pkt: failing back to default value.\n") ;
#endif // DEBUG
      if (is_calibration_request)
        options.nb_pkt = DEFAULT_NBPKT_CALIB ;
      else
        options.nb_pkt = DEFAULT_NBPKT_NORMAL ;
    }

  // Calibration request but bad direction
  if (is_calibration_request)
    if (options.direction < OWL_DIRECTION_MIN ||
        options.direction > OWL_DIRECTION_MAX)
      {
        fprintf(stderr, "Error! « %"PRIu8" » is not a valid"
                " direction.\n", options.direction) ;
        exit(ERR_BAD_USAGE) ;
      }

  // Check port numbers
  if (options.dest_port < 1 || options.dest_port > 65535)
    {
#ifdef DEBUG
      fprintf(stderr, "Warning! Bad dest_port:"
              " failing back to default value.\n") ;
      options.dest_port = LOC_REQUEST_DEFAULT_PORT ;
#endif // DEBUG
    }
  if (options.listening_port > 65535)
    {
#ifdef DEBUG
      fprintf(stderr, "Warning! listening_port too high: ignored.\n") ;
      options.listening_port = 0 ;
#endif // DEBUG
    }

  // We want to send a calibration request AND to be located, which is
  // not allowed:
  if (is_calibration_request && options.listening_port > 0)
    {
#ifdef DEBUG
      fprintf(stderr, "Warning! You cannot wait for a server answer when"
              " you calibrate. Option -l ignored…\n") ;
#endif // DEBUG      
      options.listening_port = 0 ;
    }
}



#ifdef DEBUG
void print_configuration()
{
  fprintf(stderr, "Options:\n"
          "\tDestination IP: %s\n"
          "\tDestination port: %"PRIuFAST16"\n"
          "\tInterface: %s\n"
          "\tDelay: %"PRIuFAST32"\n"
          "\tNumber of packets: %"PRIuFAST16"\n"
          "\tListening port: %"PRIuFAST16"\n"
          "\tDirection: %d\n"
          "\tX: %f\n"
          "\tY: %f\n"
          "\tZ: %f\n"
          ,
          options.dest_ip,
          options.dest_port,
          options.iface,
          options.delay,
          options.nb_pkt,
          options.listening_port,
          options.direction,
          options.x,
          options.y,
          options.z
          ) ;
}
#endif // DEBUG



void create_socket()
{
  sockfd =
    owlclient_create_trx_socket(options.dest_ip, options.dest_port,
                                &server, options.iface) ;
}



/* Creates the packet to send. */
void make_packet()
{
  uint_fast16_t offset ; // Index used to create the packet
  owl_timestamp request_time ;
  char request_time_str[OWL_TIMESTAMP_STR_LEN] ;

  // Get the current time and copy it as a string before to switch it to
  // network endianess:
  owl_timestamp_now(&request_time) ;
  owl_timestamp_to_string(request_time_str, request_time) ;
  request_time = owl_hton_timestamp(request_time) ;

  if (is_calibration_request) // Calibration packet
    {
      printf("Preparing calibration request packet…\n") ;

      offset = 0 ;
      packet_size =
        sizeof(uint8_t) * 2 + sizeof(owl_timestamp) + sizeof(float) * 3 ;
      packet = malloc(packet_size) ;

      memset(&packet[offset], OWL_REQUEST_CALIBRATION, 1) ; // Packet type
      ++offset ;
      memcpy(&packet[offset], &request_time, sizeof(request_time)) ;
      offset += sizeof(request_time) ;
      packet[offset++] = options.direction ; // Direction
#ifdef DEBUG
      printf("Direction = %d, X = %f, Y = %f, Z = %f\n",
             packet[offset - 1], options.x, options.y, options.z) ;
#endif // DEBUG
      memcpy(&packet[offset], &options.x, sizeof(float)) ;
      offset += sizeof(float) ;
      memcpy(&packet[offset], &options.y, sizeof(float)) ;
      offset += sizeof(float) ;
      memcpy(&packet[offset], &options.z, sizeof(float)) ;
    }

  else // Standard packet
    {
      printf("Preparing request packet…\n") ;
      packet_size = sizeof(uint8_t) + sizeof(owl_timestamp) ;
      packet = malloc(packet_size) ;
      memset(&packet[0], OWL_REQUEST_NORMAL, 1) ; // Packet type
      memcpy(&packet[1], &request_time, sizeof(request_time)) ;
    }

  printf("Packet timestamp: %s\n", request_time_str) ;
}



void send_request()
{
  owlclient_send_request(sockfd, &server, packet, packet_size,
                         options.nb_pkt, options.delay) ;
}



void receive_position()
{
  // Position of the mobile as computed by the infrastructure:
  float x, y, z ;

  sockfd = owl_create_udp_listening_socket(options.listening_port) ;
  recvfrom(sockfd, &x, sizeof(float), 0, NULL, NULL) ;
  recvfrom(sockfd, &y, sizeof(float), 0, NULL, NULL) ;
  recvfrom(sockfd, &z, sizeof(float), 0, NULL, NULL) ;
  close(sockfd) ;

  printf("Computed position: (%.4f;%.4f;%.4f)\n", x, y, z) ;
}



void print_usage()
{
  printf("Usage:\n"
         "Localisation request:\n"
         "\t%s -d dest_ip [-p dest_port] [-i iface] [-t delay]"
         " [-n nb_packets] [-l [port]]\n"
         "Calibration request:\n"
         "\t%s -d dest_ip [-p dest_port] [-i iface] [-t delay]"
         " [-n nb_packets] direction x y z\n"
         "\n"
         "Options:\n"
         "\t-h\t\tPrint this help.\n"
         "\t-d dest_ip\tDestination IP address of the localisation request.\n"
         "\t-p dest_port\tDestination port of the localisation request"
         " (default: %d).\n"
         "\t-t delay\tTime between each packet transmission (default: %d"
         " µs for a normal request, %d µs for a calibration request).\n"
         "\t-n nb_packets\tNumber of packet transmitted for the request"
         " (default: %d for a normal request, %d for a calibration"
         " request).\n"
         "\t-i iface\tName of the network interface used to transmit the"
         " request (e.g. \"eth2\"). If this option is absent, interface"
         " is selected automatically. You must be root to use this"
         " option.\n"
         "\t-l [port]\tWait for the computed position and display it."
         " Optional argument 'port' allows to specify the listening"
         " port (default: %d).\n"
         ,
         program_name,
         program_name,
         LOC_REQUEST_DEFAULT_PORT,
         DEFAULT_DELAY_NORMAL,
         DEFAULT_DELAY_CALIB,
         DEFAULT_NBPKT_NORMAL,
         DEFAULT_NBPKT_CALIB,
         MOBILE_DEFAULT_PORT
         ) ;
}