/* -*- c++ -*- */
/*
 * Copyright 2006-2008,2010-2012 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio
 *
 * GNU Radio 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.
 *
 * GNU Radio 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 GNU Radio; 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 "ofdm_mapper_bcv_impl.h"
#include <gnuradio/io_signature.h>
#include <stdexcept>
#include <string>

namespace gr {
namespace digital {

ofdm_mapper_bcv::sptr ofdm_mapper_bcv::make(const std::vector<gr_complex>& constellation,
                                            unsigned int msgq_limit,
                                            unsigned int occupied_carriers,
                                            unsigned int fft_length)
{
    return gnuradio::get_initial_sptr(new ofdm_mapper_bcv_impl(
        constellation, msgq_limit, occupied_carriers, fft_length));
}

// Consumes 1 packet and produces as many OFDM symbols of
// fft_length to hold the full packet
ofdm_mapper_bcv_impl::ofdm_mapper_bcv_impl(const std::vector<gr_complex>& constellation,
                                           unsigned int msgq_limit,
                                           unsigned int occupied_carriers,
                                           unsigned int fft_length)
    : sync_block(
          "ofdm_mapper_bcv",
          io_signature::make(0, 0, 0),
          io_signature::make2(1, 2, sizeof(gr_complex) * fft_length, sizeof(char))),
      d_constellation(constellation),
      d_msgq(msg_queue::make(msgq_limit)),
      d_msg_offset(0),
      d_eof(false),
      d_occupied_carriers(occupied_carriers),
      d_fft_length(fft_length),
      d_bit_offset(0),
      d_pending_flag(0),
      d_resid(0),
      d_nresid(0)
{
    GR_LOG_WARN(d_logger, "The gr::digital::ofdm_mapper_bcv block has been deprecated.");

    if (!(d_occupied_carriers <= d_fft_length))
        throw std::invalid_argument(
            "ofdm_mapper_bcv_impl: occupied carriers must be <= fft_length");

    // this is not the final form of this solution since we still
    // use the occupied_tones concept, which would get us into
    // trouble if the number of carriers we seek is greater than the
    // occupied carriers.
    // Eventually, we will get rid of the occupied_carriers concept.
    std::string carriers = "FE7F";

    // A bit hacky to fill out carriers to occupied_carriers length
    int diff = (d_occupied_carriers - 4 * carriers.length());
    while (diff > 7) {
        carriers.insert(0, "f");
        carriers.insert(carriers.length(), "f");
        diff -= 8;
    }

    // if there's extras left to be processed divide remaining to
    // put on either side of current map all of this is done to
    // stick with the concept of a carrier map string that can be
    // later passed by the user, even though it'd be cleaner to just
    // do this on the carrier map itself
    int diff_left = 0;
    int diff_right = 0;

    // dictionary to convert from integers to ascii hex representation
    char abc[16] = { '0', '1', '2', '3', '4', '5', '6', '7',
                     '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
    if (diff > 0) {
        char c[2] = { 0, 0 };

        diff_left =
            (int)ceil((float)diff / 2.0f); // number of carriers to put on the left side
        c[0] = abc[(1 << diff_left) - 1];  // convert to bits and move to ASCI integer
        carriers.insert(0, c);

        diff_right = diff - diff_left; // number of carriers to put on the right side
        c[0] = abc[0xF ^
                   ((1 << diff_right) - 1)]; // convert to bits and move to ASCI integer
        carriers.insert(carriers.length(), c);
    }

    // find out how many zeros to pad on the sides; the difference between the fft length
    // and the subcarrier mapping size in chunks of four. This is the number to pack on
    // the left and this number plus any residual nulls (if odd) will be packed on the
    // right.
    diff = (d_fft_length / 4 - carriers.length()) / 2;

    unsigned int i, j, k;
    for (i = 0; i < carriers.length(); i++) {
        char c = carriers[i];     // get the current hex character from the string
        for (j = 0; j < 4; j++) { // walk through all four bits
            k = (strtol(&c, NULL, 16) >> (3 - j)) &
                0x1; // convert to int and extract next bit
            if (k) { // if bit is a 1,
                d_subcarrier_map.push_back(4 * (i + diff) + j); // use this subcarrier
            }
        }
    }

    // make sure we stay in the limit currently imposed by the occupied_carriers
    if (d_subcarrier_map.size() > d_occupied_carriers) {
        throw std::invalid_argument("ofdm_mapper_bcv_impl: subcarriers allocated exceeds "
                                    "size of occupied carriers");
    }

    d_nbits = (unsigned long)ceil(log10(float(d_constellation.size())) / log10(2.0));
}

ofdm_mapper_bcv_impl::~ofdm_mapper_bcv_impl() {}

int ofdm_mapper_bcv_impl::randsym() { return (rand() % d_constellation.size()); }

int ofdm_mapper_bcv_impl::work(int noutput_items,
                               gr_vector_const_void_star& input_items,
                               gr_vector_void_star& output_items)
{
    gr_complex* out = (gr_complex*)output_items[0];

    unsigned int i = 0;

    // printf("OFDM BPSK Mapper:  ninput_items: %d   noutput_items: %d\n",
    // ninput_items[0], noutput_items);

    if (d_eof) {
        return -1;
    }

    if (!d_msg) {
        d_msg = d_msgq->delete_head(); // block, waiting for a message
        d_msg_offset = 0;
        d_bit_offset = 0;
        d_pending_flag = 1; // new packet, write start of packet flag

        if ((d_msg->length() == 0) && (d_msg->type() == 1)) {
            d_msg.reset();
            return -1; // We're done; no more messages coming.
        }
    }

    char* out_flag = 0;
    if (output_items.size() == 2)
        out_flag = (char*)output_items[1];


    // Build a single symbol:
    // Initialize all bins to 0 to set unused carriers
    memset(out, 0, d_fft_length * sizeof(gr_complex));

    i = 0;
    unsigned char bits = 0;
    // while((d_msg_offset < d_msg->length()) && (i < d_occupied_carriers)) {
    while ((d_msg_offset < d_msg->length()) && (i < d_subcarrier_map.size())) {

        // need new data to process
        if (d_bit_offset == 0) {
            d_msgbytes = d_msg->msg()[d_msg_offset];
            // printf("mod message byte: %x\n", d_msgbytes);
        }

        if (d_nresid > 0) {
            // take the residual bits, fill out nbits with info from the new byte, and put
            // them in the symbol
            d_resid |= (((1 << d_nresid) - 1) & d_msgbytes) << (d_nbits - d_nresid);
            bits = d_resid;

            out[d_subcarrier_map[i]] = d_constellation[bits];
            i++;

            d_bit_offset += d_nresid;
            d_nresid = 0;
            d_resid = 0;
            // printf("mod bit(r): %x   resid: %x   nresid: %d    bit_offset: %d\n",
            //     bits, d_resid, d_nresid, d_bit_offset);
        } else {
            if ((8 - d_bit_offset) >= d_nbits) { // test to make sure we can fit nbits
                // take the nbits number of bits at a time from the byte to add to the
                // symbol
                bits = ((1 << d_nbits) - 1) & (d_msgbytes >> d_bit_offset);
                d_bit_offset += d_nbits;

                out[d_subcarrier_map[i]] = d_constellation[bits];
                i++;
            } else { // if we can't fit nbits, store them for the next
                // saves d_nresid bits of this message where d_nresid < d_nbits
                unsigned int extra = 8 - d_bit_offset;
                d_resid = ((1 << extra) - 1) & (d_msgbytes >> d_bit_offset);
                d_bit_offset += extra;
                d_nresid = d_nbits - extra;
            }
        }

        if (d_bit_offset == 8) {
            d_bit_offset = 0;
            d_msg_offset++;
        }
    }

    // Ran out of data to put in symbol
    if (d_msg_offset == d_msg->length()) {
        if (d_nresid > 0) {
            d_resid |= 0x00;
            bits = d_resid;
            d_nresid = 0;
            d_resid = 0;
        }

        // while(i < d_occupied_carriers) {   // finish filling out the symbol
        while (i < d_subcarrier_map.size()) { // finish filling out the symbol
            out[d_subcarrier_map[i]] = d_constellation[randsym()];
            i++;
        }

        if (d_msg->type() == 1) // type == 1 sets EOF
            d_eof = true;
        d_msg.reset(); // finished packet, free message
        assert(d_bit_offset == 0);
    }

    if (out_flag)
        out_flag[0] = d_pending_flag;
    d_pending_flag = 0;

    return 1; // produced symbol
}

} /* namespace digital */
} /* namespace gr */
