/*!
 * \file nsr_file_signal_source.cc
 * \brief Implementation of a class that reads signals samples from a NSR 2 bits sampler front-end file
 * and adapts it to a SignalSourceInterface. More information about the front-end here
 * http://www.ifen.com/products/sx-scientific-gnss-solutions/nsr-software-receiver.html
 * \author Javier Arribas, 2013 jarribas(at)cttc.es
 *
 * -------------------------------------------------------------------------
 *
 * Copyright (C) 2010-2019  (see AUTHORS file for a list of contributors)
 *
 * GNSS-SDR is a software defined Global Navigation
 *          Satellite Systems receiver
 *
 * This file is part of GNSS-SDR.
 *
 * GNSS-SDR 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 of the License, or
 * (at your option) any later version.
 *
 * GNSS-SDR 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 GNSS-SDR. If not, see <https://www.gnu.org/licenses/>.
 *
 * -------------------------------------------------------------------------
 */

#include "nsr_file_signal_source.h"
#include "configuration_interface.h"
#include "gnss_sdr_flags.h"
#include "gnss_sdr_valve.h"
#include <glog/logging.h>
#include <exception>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <utility>


NsrFileSignalSource::NsrFileSignalSource(ConfigurationInterface* configuration,
    const std::string& role, unsigned int in_streams, unsigned int out_streams,
    std::shared_ptr<Concurrent_Queue<pmt::pmt_t>> queue) : role_(role), in_streams_(in_streams), out_streams_(out_streams), queue_(std::move(queue))
{
    std::string default_filename = "../data/my_capture.dat";
    std::string default_item_type = "byte";
    std::string default_dump_filename = "../data/my_capture_dump.dat";

    samples_ = configuration->property(role + ".samples", 0);
    sampling_frequency_ = configuration->property(role + ".sampling_frequency", 0);
    filename_ = configuration->property(role + ".filename", default_filename);

    // override value with commandline flag, if present
    if (FLAGS_signal_source != "-")
        {
            filename_ = FLAGS_signal_source;
        }
    if (FLAGS_s != "-")
        {
            filename_ = FLAGS_s;
        }

    item_type_ = configuration->property(role + ".item_type", default_item_type);
    repeat_ = configuration->property(role + ".repeat", false);
    dump_ = configuration->property(role + ".dump", false);
    dump_filename_ = configuration->property(role + ".dump_filename", default_dump_filename);
    enable_throttle_control_ = configuration->property(role + ".enable_throttle_control", false);

    if (item_type_ == "byte")
        {
            item_size_ = sizeof(char);
        }
    else
        {
            LOG(WARNING) << item_type_ << " unrecognized item type. Using byte.";
            item_size_ = sizeof(char);
        }
    try
        {
            file_source_ = gr::blocks::file_source::make(item_size_, filename_.c_str(), repeat_);
            unpack_byte_ = make_unpack_byte_2bit_samples();
        }
    catch (const std::exception& e)
        {
            std::cerr
                << "The receiver was configured to work with a file signal source "
                << std::endl
                << "but the specified file is unreachable by GNSS-SDR."
                << std::endl
                << "Please modify your configuration file"
                << std::endl
                << "and point SignalSource.filename to a valid raw data file. Then:"
                << std::endl
                << "$ gnss-sdr --config_file=/path/to/my_GNSS_SDR_configuration.conf"
                << std::endl
                << "Examples of configuration files available at:"
                << std::endl
                << GNSSSDR_INSTALL_DIR "/share/gnss-sdr/conf/"
                << std::endl;

            LOG(WARNING) << "file_signal_source: Unable to open the samples file "
                         << filename_.c_str() << ", exiting the program.";
            throw(e);
        }

    DLOG(INFO) << "file_source(" << file_source_->unique_id() << ")";

    if (samples_ == 0)  // read all file
        {
            /*!
             * BUG workaround: The GNU Radio file source does not stop the receiver after reaching the End of File.
             * A possible solution is to compute the file length in samples using file size, excluding the last 2 milliseconds, and enable always the
             * valve block
             */
            std::ifstream file(filename_.c_str(), std::ios::in | std::ios::binary | std::ios::ate);
            std::ifstream::pos_type size;

            if (file.is_open())
                {
                    size = file.tellg();
                    LOG(INFO) << "Total samples in the file= " << floor(static_cast<double>(size) / static_cast<double>(item_size()));
                }
            else
                {
                    std::cout << "file_signal_source: Unable to open the samples file " << filename_.c_str() << std::endl;
                    LOG(ERROR) << "file_signal_source: Unable to open the samples file " << filename_.c_str();
                }
            std::streamsize ss = std::cout.precision();
            std::cout << std::setprecision(16);
            std::cout << "Processing file " << filename_ << ", which contains " << size << " [bytes]" << std::endl;
            std::cout.precision(ss);

            if (size > 0)
                {
                    int sample_packet_factor = 4;  // 1 byte -> 4 samples
                    samples_ = floor(static_cast<double>(size) / static_cast<double>(item_size())) * sample_packet_factor;
                    samples_ = samples_ - ceil(0.002 * static_cast<double>(sampling_frequency_));  //process all the samples available in the file excluding the last 2 ms
                }
        }

    CHECK(samples_ > 0) << "File does not contain enough samples to process.";
    double signal_duration_s;
    signal_duration_s = static_cast<double>(samples_) * (1 / static_cast<double>(sampling_frequency_));
    LOG(INFO) << "Total number samples to be processed= " << samples_ << " GNSS signal duration= " << signal_duration_s << " [s]";
    std::cout << "GNSS signal recorded time to be processed: " << signal_duration_s << " [s]" << std::endl;

    valve_ = gnss_sdr_make_valve(sizeof(float), samples_, queue_);
    DLOG(INFO) << "valve(" << valve_->unique_id() << ")";

    if (dump_)
        {
            //sink_ = gr_make_file_sink(item_size_, dump_filename_.c_str());
            sink_ = gr::blocks::file_sink::make(sizeof(float), dump_filename_.c_str());
            DLOG(INFO) << "file_sink(" << sink_->unique_id() << ")";
        }

    if (enable_throttle_control_)
        {
            throttle_ = gr::blocks::throttle::make(sizeof(float), sampling_frequency_);
        }
    DLOG(INFO) << "File source filename " << filename_;
    DLOG(INFO) << "Samples " << samples_;
    DLOG(INFO) << "Sampling frequency " << sampling_frequency_;
    DLOG(INFO) << "Item type " << item_type_;
    DLOG(INFO) << "Item size " << item_size_;
    DLOG(INFO) << "Repeat " << repeat_;
    DLOG(INFO) << "Dump " << dump_;
    DLOG(INFO) << "Dump filename " << dump_filename_;
    if (in_streams_ > 0)
        {
            LOG(ERROR) << "A signal source does not have an input stream";
        }
    if (out_streams_ > 1)
        {
            LOG(ERROR) << "This implementation only supports one output stream";
        }
}


void NsrFileSignalSource::connect(gr::top_block_sptr top_block)
{
    if (samples_ > 0)
        {
            if (enable_throttle_control_ == true)
                {
                    top_block->connect(file_source_, 0, unpack_byte_, 0);
                    top_block->connect(unpack_byte_, 0, throttle_, 0);
                    DLOG(INFO) << "connected file source to throttle";
                    top_block->connect(throttle_, 0, valve_, 0);
                    DLOG(INFO) << "connected throttle to valve";
                    if (dump_)
                        {
                            top_block->connect(valve_, 0, sink_, 0);
                            DLOG(INFO) << "connected valve to file sink";
                        }
                }
            else
                {
                    top_block->connect(file_source_, 0, unpack_byte_, 0);
                    top_block->connect(unpack_byte_, 0, valve_, 0);
                    DLOG(INFO) << "connected file source to valve";
                    if (dump_)
                        {
                            top_block->connect(valve_, 0, sink_, 0);
                            DLOG(INFO) << "connected valve to file sink";
                        }
                }
        }
    else
        {
            if (enable_throttle_control_ == true)
                {
                    top_block->connect(file_source_, 0, unpack_byte_, 0);
                    top_block->connect(unpack_byte_, 0, throttle_, 0);
                    DLOG(INFO) << "connected file source to throttle";
                    if (dump_)
                        {
                            top_block->connect(throttle_, 0, sink_, 0);
                            DLOG(INFO) << "connected file source to sink";
                        }
                }
            else
                {
                    if (dump_)
                        {
                            top_block->connect(file_source_, 0, unpack_byte_, 0);
                            top_block->connect(unpack_byte_, 0, sink_, 0);
                            DLOG(INFO) << "connected file source to sink";
                        }
                }
        }
}


void NsrFileSignalSource::disconnect(gr::top_block_sptr top_block)
{
    if (samples_ > 0)
        {
            if (enable_throttle_control_ == true)
                {
                    top_block->disconnect(file_source_, 0, unpack_byte_, 0);
                    DLOG(INFO) << "disconnected file source to unpack_byte_";
                    top_block->connect(unpack_byte_, 0, throttle_, 0);
                    DLOG(INFO) << "disconnected unpack_byte_ to throttle_";
                    top_block->disconnect(throttle_, 0, valve_, 0);
                    DLOG(INFO) << "disconnected throttle to valve";
                    if (dump_)
                        {
                            top_block->disconnect(valve_, 0, sink_, 0);
                            DLOG(INFO) << "disconnected valve to file sink";
                        }
                }
            else
                {
                    top_block->disconnect(file_source_, 0, unpack_byte_, 0);
                    DLOG(INFO) << "disconnected file source to unpack_byte_";
                    top_block->disconnect(unpack_byte_, 0, valve_, 0);
                    DLOG(INFO) << "disconnected unpack_byte_ to valve";
                    if (dump_)
                        {
                            top_block->disconnect(valve_, 0, sink_, 0);
                            DLOG(INFO) << "disconnected valve to file sink";
                        }
                }
        }
    else
        {
            if (enable_throttle_control_ == true)
                {
                    top_block->disconnect(file_source_, 0, unpack_byte_, 0);
                    DLOG(INFO) << "disconnected file source to unpack_byte_";
                    top_block->disconnect(unpack_byte_, 0, throttle_, 0);
                    DLOG(INFO) << "disconnected unpack_byte_ to throttle";
                    if (dump_)
                        {
                            top_block->disconnect(unpack_byte_, 0, sink_, 0);
                            DLOG(INFO) << "disconnected funpack_byte_ to sink";
                        }
                }
            else
                {
                    if (dump_)
                        {
                            top_block->disconnect(file_source_, 0, unpack_byte_, 0);
                            DLOG(INFO) << "disconnected file source to unpack_byte_";
                            top_block->disconnect(unpack_byte_, 0, sink_, 0);
                            DLOG(INFO) << "disconnected unpack_byte_ to sink";
                        }
                }
        }
}


gr::basic_block_sptr NsrFileSignalSource::get_left_block()
{
    LOG(WARNING) << "Left block of a signal source should not be retrieved";
    //return gr_block_sptr();
    return gr::blocks::file_source::sptr();
}


gr::basic_block_sptr NsrFileSignalSource::get_right_block()
{
    if (samples_ > 0)
        {
            return valve_;
        }
    if (enable_throttle_control_ == true)
        {
            return throttle_;
        }
    return unpack_byte_;
}