//
// Copyright 2010-2011,2014 Ettus Research LLC
// Copyright 2018 Ettus Research, a National Instruments Company
//
// SPDX-License-Identifier: GPL-3.0-or-later
//

#include <uhd/types/tune_request.hpp>
#include <uhd/utils/thread.hpp>
#include <uhd/utils/safe_main.hpp>
#include <uhd/usrp/multi_usrp.hpp>
#include <uhd/exception.hpp>
#include <boost/program_options.hpp>
#include <boost/format.hpp>
#include <boost/lexical_cast.hpp>
#include <iostream>
#include <fstream>
#include <csignal>
#include <complex>
#include <thread>
#include <chrono>

namespace po = boost::program_options;

static bool stop_signal_called = false;
void sig_int_handler(int){stop_signal_called = true;}

template<typename samp_type> void recv_to_file(
    uhd::usrp::multi_usrp::sptr usrp,
    const std::string &cpu_format,
    const std::string &wire_format,
    const size_t &channel,
    const std::string &file,
    size_t samps_per_buff,
    unsigned long long num_requested_samples,
    double time_requested = 0.0,
    bool bw_summary = false,
    bool stats = false,
    bool null = false,
    bool enable_size_map = false,
    bool continue_on_bad_packet = false
){
    unsigned long long num_total_samps = 0;
    //create a receive streamer
    uhd::stream_args_t stream_args(cpu_format,wire_format);
    std::vector<size_t> channel_nums;
    channel_nums.push_back(channel);
    stream_args.channels = channel_nums;
    uhd::rx_streamer::sptr rx_stream = usrp->get_rx_stream(stream_args);

    uhd::rx_metadata_t md;
    std::vector<samp_type> buff(samps_per_buff);
    std::ofstream outfile;
    if (not null)
        outfile.open(file.c_str(), std::ofstream::binary);
    bool overflow_message = true;

    //setup streaming
    uhd::stream_cmd_t stream_cmd((num_requested_samples == 0)?
        uhd::stream_cmd_t::STREAM_MODE_START_CONTINUOUS:
        uhd::stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE
    );
    stream_cmd.num_samps = size_t(num_requested_samples);
    stream_cmd.stream_now = true;
    stream_cmd.time_spec = uhd::time_spec_t();
    rx_stream->issue_stream_cmd(stream_cmd);

    typedef std::map<size_t,size_t> SizeMap;
    SizeMap mapSizes;
    const auto start_time = std::chrono::steady_clock::now();
    const auto stop_time =
        start_time
        + std::chrono::milliseconds(int64_t(1000 * time_requested));
    // Track time and samps between updating the BW summary
    auto last_update = start_time;
    unsigned long long last_update_samps = 0;

    // Run this loop until either time expired (if a duration was given), until
    // the requested number of samples were collected (if such a number was
    // given), or until Ctrl-C was pressed.
    while (not stop_signal_called
            and (num_requested_samples != num_total_samps
                 or num_requested_samples == 0)
            and (time_requested == 0.0
                 or std::chrono::steady_clock::now() <= stop_time)
            ) {
        const auto now = std::chrono::steady_clock::now();

        size_t num_rx_samps =
            rx_stream->recv(&buff.front(), buff.size(), md, 3.0, enable_size_map);

        if (md.error_code == uhd::rx_metadata_t::ERROR_CODE_TIMEOUT) {
            std::cout << boost::format("Timeout while streaming") << std::endl;
            break;
        }
        if (md.error_code == uhd::rx_metadata_t::ERROR_CODE_OVERFLOW){
            if (overflow_message) {
                overflow_message = false;
                std::cerr << boost::format(
                    "Got an overflow indication. Please consider the following:\n"
                    "  Your write medium must sustain a rate of %fMB/s.\n"
                    "  Dropped samples will not be written to the file.\n"
                    "  Please modify this example for your purposes.\n"
                    "  This message will not appear again.\n"
                ) % (usrp->get_rx_rate(channel)*sizeof(samp_type)/1e6);
            }
            continue;
        }
        if (md.error_code != uhd::rx_metadata_t::ERROR_CODE_NONE){
            std::string error = str(boost::format("Receiver error: %s") % md.strerror());
            if (continue_on_bad_packet){
                std::cerr << error << std::endl;
                continue;
            }
            else
                throw std::runtime_error(error);
        }

        if (enable_size_map) {
            SizeMap::iterator it = mapSizes.find(num_rx_samps);
            if (it == mapSizes.end())
                mapSizes[num_rx_samps] = 0;
            mapSizes[num_rx_samps] += 1;
        }

        num_total_samps += num_rx_samps;

        if (outfile.is_open()) {
            outfile.write(
                (const char*)&buff.front(),
                num_rx_samps*sizeof(samp_type)
            );
        }

        if (bw_summary) {
            last_update_samps += num_rx_samps;
            const auto time_since_last_update = now - last_update;
            if (time_since_last_update > std::chrono::seconds(1)) {
                const double time_since_last_update_s =
                    std::chrono::duration<double>(time_since_last_update).count();
                const double rate =
                    double(last_update_samps) / time_since_last_update_s;
                std::cout << "\t" << (rate/1e6) << " Msps" << std::endl;
                last_update_samps = 0;
                last_update = now;
            }
        }
    }
    const auto actual_stop_time = std::chrono::steady_clock::now();

    stream_cmd.stream_mode = uhd::stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS;
    rx_stream->issue_stream_cmd(stream_cmd);

    if (outfile.is_open()) {
        outfile.close();
    }

    if (stats) {
        std::cout << std::endl;
        const double actual_duration_seconds =
            std::chrono::duration<float>(actual_stop_time - start_time).count();

        std::cout
            << boost::format("Received %d samples in %f seconds")
               % num_total_samps
               % actual_duration_seconds
            << std::endl;
        const double rate = (double)num_total_samps / actual_duration_seconds;
        std::cout << (rate/1e6) << " Msps" << std::endl;

        if (enable_size_map) {
            std::cout << std::endl;
            std::cout << "Packet size map (bytes: count)" << std::endl;
            for (SizeMap::iterator it = mapSizes.begin(); it != mapSizes.end(); it++)
                std::cout << it->first << ":\t" << it->second << std::endl;
        }
    }
}

typedef std::function<uhd::sensor_value_t(const std::string&)> get_sensor_fn_t;

bool check_locked_sensor(
    std::vector<std::string> sensor_names,
    const char* sensor_name,
    get_sensor_fn_t get_sensor_fn,
    double setup_time
) {
    if (std::find(sensor_names.begin(), sensor_names.end(), sensor_name) == sensor_names.end())
        return false;

    auto setup_timeout =
        std::chrono::steady_clock::now()
        + std::chrono::milliseconds(int64_t(setup_time * 1000));
    bool lock_detected = false;

    std::cout << boost::format("Waiting for \"%s\": ") % sensor_name;
    std::cout.flush();

    while (true) {
        if (lock_detected and
            (std::chrono::steady_clock::now() > setup_timeout)) {
            std::cout << " locked." << std::endl;
            break;
        }
        if (get_sensor_fn(sensor_name).to_bool()) {
            std::cout << "+";
            std::cout.flush();
            lock_detected = true;
        }
        else {
            if (std::chrono::steady_clock::now() > setup_timeout) {
                std::cout << std::endl;
                throw std::runtime_error(str(
                    boost::format("timed out waiting for consecutive locks on sensor \"%s\"")
                    % sensor_name
                ));
            }
            std::cout << "_";
            std::cout.flush();
        }
        std::this_thread::sleep_for(std::chrono::milliseconds(100));
    }
    std::cout << std::endl;
    return true;
}

int UHD_SAFE_MAIN(int argc, char *argv[]){
    uhd::set_thread_priority_safe();

    //variables to be set by po
    std::string args, file, type, ant, subdev, ref, wirefmt;
    size_t channel, total_num_samps, spb;
    double rate, freq, gain, bw, total_time, setup_time, lo_offset;

    //setup the program options
    po::options_description desc("Allowed options");
    desc.add_options()
        ("help", "help message")
        ("args", po::value<std::string>(&args)->default_value(""), "multi uhd device address args")
        ("file", po::value<std::string>(&file)->default_value("usrp_samples.dat"), "name of the file to write binary samples to")
        ("type", po::value<std::string>(&type)->default_value("short"), "sample type: double, float, or short")
        ("nsamps", po::value<size_t>(&total_num_samps)->default_value(0), "total number of samples to receive")
        ("duration", po::value<double>(&total_time)->default_value(0), "total number of seconds to receive")
        ("time", po::value<double>(&total_time), "(DEPRECATED) will go away soon! Use --duration instead")
        ("spb", po::value<size_t>(&spb)->default_value(10000), "samples per buffer")
        ("rate", po::value<double>(&rate)->default_value(1e6), "rate of incoming samples")
        ("freq", po::value<double>(&freq)->default_value(0.0), "RF center frequency in Hz")
        ("lo-offset", po::value<double>(&lo_offset)->default_value(0.0),
            "Offset for frontend LO in Hz (optional)")
        ("gain", po::value<double>(&gain), "gain for the RF chain")
        ("ant", po::value<std::string>(&ant), "antenna selection")
        ("subdev", po::value<std::string>(&subdev), "subdevice specification")
        ("channel", po::value<size_t>(&channel)->default_value(0), "which channel to use")
        ("bw", po::value<double>(&bw), "analog frontend filter bandwidth in Hz")
        ("ref", po::value<std::string>(&ref)->default_value("internal"), "reference source (internal, external, mimo)")
        ("wirefmt", po::value<std::string>(&wirefmt)->default_value("sc16"), "wire format (sc8, sc16 or s16)")
        ("setup", po::value<double>(&setup_time)->default_value(1.0), "seconds of setup time")
        ("progress", "periodically display short-term bandwidth")
        ("stats", "show average bandwidth on exit")
        ("sizemap", "track packet size and display breakdown on exit")
        ("null", "run without writing to file")
        ("continue", "don't abort on a bad packet")
        ("skip-lo", "skip checking LO lock status")
        ("int-n", "tune USRP with integer-N tuning")
    ;
    po::variables_map vm;
    po::store(po::parse_command_line(argc, argv, desc), vm);
    po::notify(vm);

    //print the help message
    if (vm.count("help")) {
        std::cout << boost::format("UHD RX samples to file %s") % desc << std::endl;
        std::cout
            << std::endl
            << "This application streams data from a single channel of a USRP device to a file.\n"
            << std::endl;
        return ~0;
    }

    bool bw_summary = vm.count("progress") > 0;
    bool stats = vm.count("stats") > 0;
    bool null = vm.count("null") > 0;
    bool enable_size_map = vm.count("sizemap") > 0;
    bool continue_on_bad_packet = vm.count("continue") > 0;

    if (enable_size_map)
        std::cout << "Packet size tracking enabled - will only recv one packet at a time!" << std::endl;

    //create a usrp device
    std::cout << std::endl;
    std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
    uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args);

    //Lock mboard clocks
    usrp->set_clock_source(ref);

    //always select the subdevice first, the channel mapping affects the other settings
    if (vm.count("subdev")) usrp->set_rx_subdev_spec(subdev);

    std::cout << boost::format("Using Device: %s") % usrp->get_pp_string() << std::endl;

    //set the sample rate
    if (rate <= 0.0){
        std::cerr << "Please specify a valid sample rate" << std::endl;
        return ~0;
    }
    std::cout << boost::format("Setting RX Rate: %f Msps...") % (rate/1e6) << std::endl;
    usrp->set_rx_rate(rate, channel);
    std::cout << boost::format("Actual RX Rate: %f Msps...") % (usrp->get_rx_rate(channel)/1e6) << std::endl << std::endl;

    //set the center frequency
    if (vm.count("freq")) { //with default of 0.0 this will always be true
        std::cout << boost::format("Setting RX Freq: %f MHz...") % (freq/1e6) << std::endl;
        std::cout << boost::format("Setting RX LO Offset: %f MHz...") % (lo_offset/1e6)
                  << std::endl;
        uhd::tune_request_t tune_request(freq, lo_offset);
        if(vm.count("int-n")) tune_request.args = uhd::device_addr_t("mode_n=integer");
        usrp->set_rx_freq(tune_request, channel);
        std::cout << boost::format("Actual RX Freq: %f MHz...") % (usrp->get_rx_freq(channel)/1e6) << std::endl << std::endl;
    }

    //set the rf gain
    if (vm.count("gain")) {
        std::cout << boost::format("Setting RX Gain: %f dB...") % gain << std::endl;
        usrp->set_rx_gain(gain, channel);
        std::cout << boost::format("Actual RX Gain: %f dB...") % usrp->get_rx_gain(channel) << std::endl << std::endl;
    }

    //set the IF filter bandwidth
    if (vm.count("bw")) {
        std::cout << boost::format("Setting RX Bandwidth: %f MHz...") % (bw/1e6) << std::endl;
        usrp->set_rx_bandwidth(bw, channel);
        std::cout << boost::format("Actual RX Bandwidth: %f MHz...") % (usrp->get_rx_bandwidth(channel)/1e6) << std::endl << std::endl;
    }

    //set the antenna
    if (vm.count("ant")) usrp->set_rx_antenna(ant, channel);

    std::this_thread::sleep_for(
        std::chrono::milliseconds(int64_t(1000 * setup_time))
    );

    //check Ref and LO Lock detect
    if (not vm.count("skip-lo")){
        check_locked_sensor(
            usrp->get_rx_sensor_names(channel),
            "lo_locked",
            [usrp,channel](const std::string& sensor_name){
                return usrp->get_rx_sensor(sensor_name, channel);
            },
            setup_time
        );
        if (ref == "mimo") {
            check_locked_sensor(
                usrp->get_mboard_sensor_names(0),
                "mimo_locked",
                [usrp](const std::string& sensor_name){
                    return usrp->get_mboard_sensor(sensor_name);
                },
                setup_time
            );
        }
        if (ref == "external") {
            check_locked_sensor(
                usrp->get_mboard_sensor_names(0),
                "ref_locked",
                [usrp](const std::string& sensor_name){
                    return usrp->get_mboard_sensor(sensor_name);
                },
                setup_time
            );
        }
    }

    if (total_num_samps == 0){
        std::signal(SIGINT, &sig_int_handler);
        std::cout << "Press Ctrl + C to stop streaming..." << std::endl;
    }

#define recv_to_file_args(format) \
    (usrp, format, wirefmt, channel, file, spb, total_num_samps, total_time, bw_summary, stats, null, enable_size_map, continue_on_bad_packet)
    //recv to file
    if (wirefmt == "s16") {
        if (type == "double") recv_to_file<double>recv_to_file_args("f64");
        else if (type == "float") recv_to_file<float>recv_to_file_args("f32");
        else if (type == "short") recv_to_file<short>recv_to_file_args("s16");
        else throw std::runtime_error("Unknown type " + type);
    } else {
        if (type == "double") recv_to_file<std::complex<double> >recv_to_file_args("fc64");
        else if (type == "float") recv_to_file<std::complex<float> >recv_to_file_args("fc32");
        else if (type == "short") recv_to_file<std::complex<short> >recv_to_file_args("sc16");
        else throw std::runtime_error("Unknown type " + type);
    }

    //finished
    std::cout << std::endl << "Done!" << std::endl << std::endl;

    return EXIT_SUCCESS;
}