#include "wifi-triangulator/core.h"

#include <iostream>
#include <unistd.h>

#include <arpa/inet.h>
#include <cstring>

using namespace std;
using namespace wifi_triangulator;

void on_probe_request(const pb::probe &p) {
    cerr << "PROBE REQUEST"
         << ", src=" << eth_mac(p.src()).to_string()
         << ", dst=" << eth_mac(p.dst()).to_string()
         << ", rssi=" << p.rssi()
         << endl;
}

int main(int argc, char *argv[]) {
    if (argc != 1) {
        fprintf(stderr, "usage: %s\n", argv[0]);
        return EXIT_FAILURE;
    }

    GOOGLE_PROTOBUF_VERIFY_VERSION;

    uint16_t port = 3333;
    int s;
    struct sockaddr_in si_me;
    if ((s = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
        throw std::runtime_error("socket");

    memset((char *) &si_me, 0, sizeof(si_me));
    si_me.sin_family = AF_INET;
    si_me.sin_port = htons(port);
    si_me.sin_addr.s_addr = htonl(INADDR_ANY);
    if (::bind(s, reinterpret_cast<struct sockaddr *>(&si_me), sizeof(si_me)) == -1) {
        throw std::runtime_error("bind");
    }

    pb::envelope envelope;
    while (true) {
        size_t len = 64 * 1024;
        uint8_t bytes[len];
        ssize_t n_read;

        struct sockaddr_in si_other;
        socklen_t addr_len;
        if ((n_read = ::recvfrom(s, bytes, len, 0, reinterpret_cast<struct sockaddr *>(&si_other), &addr_len)) == -1) {
            throw std::runtime_error("recvfrom");
        }

        string str;
        for (socklen_t i = 0; i < n_read; i++) {
            str += bytes[i];
        }

        istringstream ss{str};
        bool ok = envelope.ParseFromIstream(&ss);
        if (ok) {
            if (envelope.type() == pb::probe_request) {
                on_probe_request(envelope.probe());
            }
        } else {
            cerr << "FAIL n_read=" << n_read << flush << endl;
        }
    }

    google::protobuf::ShutdownProtobufLibrary();
}