/* -*- c++ -*- */
/*
 * Copyright 2018 Nikos Karamolegkos, Pieter Robyns.
 *
 * This is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3, or (at your option)
 * any later version.
 *
 * This software 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this software; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <lora/loratap.h>
#include <lora/loraphy.h>
#include <gnuradio/io_signature.h>
#include "message_socket_source_impl.h"

#define RECEIVE_BUFFER_SIZE 1500

namespace gr {
  namespace lora {
    message_socket_source::sptr
    message_socket_source::make (const std::string& addr, uint16_t port) {
      return gnuradio::get_initial_sptr(new message_socket_source_impl(addr, port));
    }

    /*
     * The private constructor
     */
    message_socket_source_impl::message_socket_source_impl (const std::string& addr, uint16_t port) :
        gr::block("message_socket_source", gr::io_signature::make (0, 0, 0), gr::io_signature::make (0, 0, 0)),
        d_addr(addr),
        d_udp_port(port),
        d_running(true)
    {
        message_port_register_out(pmt::mp("out"));
        boost::shared_ptr<boost::thread>(new boost::thread(boost::bind (&message_socket_source_impl::msg_receive_udp, this)));
    }

    void message_socket_source_impl::msg_receive_udp() {
        int sock;
        struct sockaddr_in sin;
        struct sockaddr client_addr;
        socklen_t client_addr_len;
        ssize_t num_bytes_received;
        uint8_t buf[RECEIVE_BUFFER_SIZE];

        if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
            perror("Error creating UDP socket");
            exit(EXIT_FAILURE);
        }

        memset(&client_addr, 0, sizeof(struct sockaddr));
        memset(&sin, 0, sizeof(struct sockaddr_in));
        sin.sin_family = AF_INET;
        sin.sin_port = htons(d_udp_port);

        if (inet_aton(d_addr.c_str(), &(sin.sin_addr)) == 0) {
            printf("Invalid IPv4 address\n");
            close(sock);
            exit(EXIT_FAILURE);
        }

        if(bind(sock, (struct sockaddr *)&sin, sizeof(struct sockaddr_in)) == -1) {
            perror("Failed to bind UDP port");
            close(sock);
            exit(EXIT_FAILURE);
        }

        while (d_running) {
            memset(buf, 0, RECEIVE_BUFFER_SIZE);
            num_bytes_received = recvfrom(sock, buf, RECEIVE_BUFFER_SIZE, 0, &client_addr, &client_addr_len);
            if (num_bytes_received > 0) {
                pmt::pmt_t lora_tap = pmt::make_blob(buf, num_bytes_received);
                message_port_pub(pmt::mp("out"), lora_tap);
            } else {
                perror("Error receiving UDP datagram");
                close(sock);
                exit(EXIT_FAILURE);
            }
        }

        close(sock);
        exit(EXIT_SUCCESS);
    }

    /*
     * Our virtual destructor.
     */
    message_socket_source_impl::~message_socket_source_impl() {
        d_running = false;
        d_thread->join();
    }

  } /* namespace lora */
} /* namespace gr */