/*
  MQTT-SN command-line subscribe client
  Copyright (C) Nicholas Humfrey

  Permission is hereby granted, free of charge, to any person obtaining
  a copy of this software and associated documentation files (the
  "Software"), to deal in the Software without restriction, including
  without limitation the rights to use, copy, modify, merge, publish,
  distribute, sublicense, and/or sell copies of the Software, and to
  permit persons to whom the Software is furnished to do so, subject to
  the following conditions:

  The above copyright notice and this permission notice shall be
  included in all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#include <stdio.h>
#include <unistd.h>
#include <getopt.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <string.h>
#include <stdint.h>
#include <unistd.h>
#include <signal.h>
#include <time.h>

#include "mqtt-sn.h"

const char *client_id = NULL;
// Array of pointers to topic names
char **topic_name_ar = NULL;
// Topic names array size. When too small it is incremented by ARRAY_INCREMENT.
uint16_t topic_name_ar_size = 0;
uint16_t topic_name_index = 0;
// Array of predefined topic IDs to subscribe to
uint16_t *predef_topic_id_ar = NULL;
// Predefined topic IDs array size. When too small it is incremented by ARRAY_INCREMENT.
uint16_t predef_topic_id_ar_size = 0;
uint16_t predef_topic_id_index = 0;
#define ARRAY_INCREMENT 10
const char *mqtt_sn_host = "127.0.0.1";
const char *mqtt_sn_port = MQTT_SN_DEFAULT_PORT;
uint16_t source_port = 0;
uint16_t keep_alive = MQTT_SN_DEFAULT_KEEP_ALIVE;
uint16_t sleep_duration = 0;
int8_t qos = 0;
uint8_t retain = FALSE;
uint8_t debug = 0;
uint8_t single_message = FALSE;
uint8_t clean_session = TRUE;
uint8_t verbose = 0;

uint8_t keep_running = TRUE;

static void usage()
{
    fprintf(stderr, "Usage: mqtt-sn-sub [opts] -t <topic>\n");
    fprintf(stderr, "\n");
    fprintf(stderr, "  -1             exit after receiving a single message.\n");
    fprintf(stderr, "  -c             disable 'clean session' (store subscription and pending messages when client disconnects).\n");
    fprintf(stderr, "  -d             Increase debug level by one. -d can occur multiple times.\n");
    fprintf(stderr, "  -h <host>      MQTT-SN host to connect to. Defaults to '%s'.\n", mqtt_sn_host);
    fprintf(stderr, "  -i <clientid>  ID to use for this client. Defaults to 'mqtt-sn-tools-' with process id.\n");
    fprintf(stderr, "  -k <keepalive> keep alive in seconds for this client. Defaults to %d.\n", keep_alive);
    fprintf(stderr, "  -e <sleep>     sleep duration in seconds when disconnecting. Defaults to %d.\n", sleep_duration);
    fprintf(stderr, "  -p <port>      Network port to connect to. Defaults to %s.\n", mqtt_sn_port);
    fprintf(stderr, "  -q <qos>       QoS level to subscribe with (0 or 1). Defaults to %d.\n", qos);
    fprintf(stderr, "  -t <topic>     MQTT-SN topic name to subscribe to. It may repeat multiple times.\n");
    fprintf(stderr, "  -T <topicid>   Pre-defined MQTT-SN topic ID to subscribe to. It may repeat multiple times.\n");
    fprintf(stderr, "  --fe           Enables Forwarder Encapsulation. Mqtt-sn packets are encapsulated according to MQTT-SN Protocol Specification v1.2, chapter 5.5 Forwarder Encapsulation.\n");
    fprintf(stderr, "  --wlnid        If Forwarder Encapsulation is enabled, wireless node ID for this client. Defaults to process id.\n");
    fprintf(stderr, "  --cport <port> Source port for outgoing packets. Uses port in ephemeral range if not specified or set to %d.\n", source_port);
    fprintf(stderr, "  -v             Print messages verbosely, showing the topic name.\n");
    fprintf(stderr, "  -V             Print messages verbosely, showing current time and the topic name.\n");
    exit(EXIT_FAILURE);
}

static void parse_opts(int argc, char** argv)
{

    static struct option long_options[] = {
        {"fe",    no_argument,       0, 1000 },
        {"wlnid", required_argument, 0, 1001 },
        {"cport", required_argument, 0, 1002 },
        {0, 0, 0, 0}
    };

    int ch;
    /* getopt_long stores the option index here. */
    int option_index = 0;

    // Parse the options/switches
    while ((ch = getopt_long(argc, argv, "1cdh:i:k:e:p:q:t:T:vV?", long_options, &option_index)) != -1)
        switch (ch) {
            case '1':
                single_message = TRUE;
                break;

            case 'c':
                clean_session = FALSE;
                break;

            case 'd':
                debug++;
                break;

            case 'h':
                mqtt_sn_host = optarg;
                break;

            case 'i':
                client_id = optarg;
                break;

            case 'k':
                keep_alive = atoi(optarg);
                break;

            case 'e':
                sleep_duration = atoi(optarg);
                break;

            case 'p':
                mqtt_sn_port = optarg;
                break;

            case 'q':
                qos = atoi(optarg);
                break;

            case 't':
                // Resize topic names array when too small
                if (topic_name_index == topic_name_ar_size) {
                    topic_name_ar = realloc(topic_name_ar, (topic_name_ar_size + ARRAY_INCREMENT) * sizeof(char*)) ;
                    topic_name_ar_size += ARRAY_INCREMENT;
                }
                topic_name_ar[topic_name_index++] = optarg;
                break;

            case 'T':
                // Resize predefined topic IDs array when too small
                if (predef_topic_id_index == predef_topic_id_ar_size) {
                    predef_topic_id_ar = realloc(predef_topic_id_ar, (predef_topic_id_ar_size + ARRAY_INCREMENT) * sizeof(uint16_t));
                    predef_topic_id_ar_size += ARRAY_INCREMENT;
                }
                predef_topic_id_ar[predef_topic_id_index++] = atoi(optarg);
                break;

            case 1000:
                mqtt_sn_enable_frwdencap();
                break;

            case 1001:
                mqtt_sn_set_frwdencap_parameters((uint8_t*)optarg, strlen(optarg));
                break;

            case 1002:
                source_port = atoi(optarg);
                break;

            case 'v':
                // Prevent -v setting verbose level back down to 1 if already set to 2 by -V
                verbose = (verbose == 0) ? 1 : verbose;
                break;

            case 'V':
                verbose = 2;
                break;

            case '?':
            default:
                usage();
                break;
        }

    // Missing Parameter?
    if (!topic_name_index && !predef_topic_id_index) {
        usage();
    }
}

static void termination_handler (int signum)
{
    switch(signum) {
        case SIGHUP:
            mqtt_sn_log_debug("Got hangup signal.");
            break;
        case SIGTERM:
            mqtt_sn_log_debug("Got termination signal.");
            break;
        case SIGINT:
            mqtt_sn_log_debug("Got interrupt signal.");
            break;
    }

    // Signal the main thread to stop
    keep_running = FALSE;
}

int main(int argc, char* argv[])
{
    int sock;

    mqtt_sn_disable_frwdencap();

    // Parse the command-line options
    parse_opts(argc, argv);

    // Enable debugging?
    mqtt_sn_set_debug(debug);
    mqtt_sn_set_verbose(verbose);
    mqtt_sn_set_timeout(keep_alive / 2);

    // Setup signal handlers
    signal(SIGTERM, termination_handler);
    signal(SIGINT, termination_handler);
    signal(SIGHUP, termination_handler);

    // Create a UDP socket
    sock = mqtt_sn_create_socket(mqtt_sn_host, mqtt_sn_port, source_port);
    if (sock) {
        // Connect to server
        mqtt_sn_log_debug("Connecting...");
        mqtt_sn_send_connect(sock, client_id, keep_alive, clean_session);
        mqtt_sn_receive_connack(sock);

        uint16_t i;
        // Subscribe to the each topic name
        for (i = 0; i < topic_name_index; i++) {
            mqtt_sn_log_debug("Subscribing to topic name: %s ...", topic_name_ar[i]);
            mqtt_sn_send_subscribe_topic_name(sock, topic_name_ar[i], qos);

            // Wait for the subscription acknowledgment
            uint16_t topic_id = mqtt_sn_receive_suback(sock);
            if (topic_id && strlen(topic_name_ar[i]) > 2) {
                mqtt_sn_register_topic(topic_id, topic_name_ar[i]);
            }
        }

        // Subscribe to the each predefined topic ID
        for (i = 0; i < predef_topic_id_index; i++) {
            mqtt_sn_log_debug("Subscribing to predefined topic ID: %u ...", predef_topic_id_ar[i]);
            mqtt_sn_send_subscribe_topic_id(sock, predef_topic_id_ar[i], qos);

            // Wait for the subscription acknowledgment
            mqtt_sn_receive_suback(sock);
        }

        // Keep processing packets until process is terminated
        while(keep_running) {
            publish_packet_t *packet = mqtt_sn_wait_for(MQTT_SN_TYPE_PUBLISH, sock);
            if (packet) {
                uint8_t packet_qos = packet->flags & MQTT_SN_FLAG_QOS_MASK;
                if (packet_qos == MQTT_SN_FLAG_QOS_1) {
                    mqtt_sn_send_puback(sock, packet, MQTT_SN_ACCEPTED);
                }

                if (single_message) {
                    break;
                }
            }
        }

        // Finally, disconnect
        mqtt_sn_log_debug("Disconnecting...");
        mqtt_sn_send_disconnect(sock, sleep_duration);
        mqtt_sn_receive_disconnect(sock);

        close(sock);
    }

    mqtt_sn_cleanup();
    free(topic_name_ar);
    free(predef_topic_id_ar);

    return 0;
}