/* -*- c++ -*- */
/*
 * Copyright 2015,2017,2018 Free Software Foundation, Inc.
 *
 * 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 "dvbt2_modulator_bc_impl.h"
#include <gnuradio/io_signature.h>
#include <gnuradio/math.h>

namespace gr {
namespace dtv {

dvbt2_modulator_bc::sptr dvbt2_modulator_bc::make(dvb_framesize_t framesize,
                                                  dvb_constellation_t constellation,
                                                  dvbt2_rotation_t rotation)
{
    return gnuradio::get_initial_sptr(
        new dvbt2_modulator_bc_impl(framesize, constellation, rotation));
}

/*
 * The private constructor
 */
dvbt2_modulator_bc_impl::dvbt2_modulator_bc_impl(dvb_framesize_t framesize,
                                                 dvb_constellation_t constellation,
                                                 dvbt2_rotation_t rotation)
    : gr::block("dvbt2_modulator_bc",
                gr::io_signature::make(1, 1, sizeof(unsigned char)),
                gr::io_signature::make(1, 1, sizeof(gr_complex)))
{
    double normalization;
    double rotation_angle;
    double m_16qam_lookup[4] = { 3.0, 1.0, -3.0, -1.0 };
    double m_64qam_lookup[8] = { 7.0, 5.0, 1.0, 3.0, -7.0, -5.0, -1.0, -3.0 };
    double m_256qam_lookup[16] = { 15.0,  13.0,  9.0,  11.0,  1.0,  3.0,  7.0,  5.0,
                                   -15.0, -13.0, -9.0, -11.0, -1.0, -3.0, -7.0, -5.0 };
    int real_index, imag_index;
    gr_complex temp;
    cyclic_delay = FALSE;
    if (framesize == FECFRAME_NORMAL) {
        switch (constellation) {
        case MOD_QPSK:
            cell_size = 32400;
            break;
        case MOD_16QAM:
            cell_size = 16200;
            break;
        case MOD_64QAM:
            cell_size = 10800;
            break;
        case MOD_256QAM:
            cell_size = 8100;
            break;
        default:
            cell_size = 0;
            break;
        }
    } else {
        switch (constellation) {
        case MOD_QPSK:
            cell_size = 8100;
            break;
        case MOD_16QAM:
            cell_size = 4050;
            break;
        case MOD_64QAM:
            cell_size = 2700;
            break;
        case MOD_256QAM:
            cell_size = 2025;
            break;
        default:
            cell_size = 0;
            break;
        }
    }
    switch (constellation) {
    case MOD_QPSK:
        normalization = std::sqrt(2.0);
        m_qpsk[0] = gr_complex(1.0 / normalization, 1.0 / normalization);
        m_qpsk[1] = gr_complex(1.0 / normalization, -1.0 / normalization);
        m_qpsk[2] = gr_complex(-1.0 / normalization, 1.0 / normalization);
        m_qpsk[3] = gr_complex(-1.0 / normalization, -1.0 / normalization);
        if (rotation == ROTATION_ON) {
            cyclic_delay = TRUE;
            rotation_angle = (2.0 * GR_M_PI * 29.0) / 360.0;
            temp = std::exp(gr_complexd(0.0, rotation_angle));
            for (int i = 0; i < 4; i++) {
                m_qpsk[i] *= temp;
            }
        }
        break;
    case MOD_16QAM:
        normalization = std::sqrt(10.0);
        for (int i = 0; i < 16; i++) {
            real_index = ((i & 0x8) >> 2) | ((i & 0x2) >> 1);
            imag_index = ((i & 0x4) >> 1) | ((i & 0x1) >> 0);
            m_16qam[i] = gr_complex(m_16qam_lookup[real_index] / normalization,
                                    m_16qam_lookup[imag_index] / normalization);
        }
        if (rotation == ROTATION_ON) {
            cyclic_delay = TRUE;
            rotation_angle = (2.0 * GR_M_PI * 16.8) / 360.0;
            temp = std::exp(gr_complexd(0.0, rotation_angle));
            for (int i = 0; i < 16; i++) {
                m_16qam[i] *= temp;
            }
        }
        break;
    case MOD_64QAM:
        normalization = std::sqrt(42.0);
        for (int i = 0; i < 64; i++) {
            real_index = ((i & 0x20) >> 3) | ((i & 0x8) >> 2) | ((i & 0x2) >> 1);
            imag_index = ((i & 0x10) >> 2) | ((i & 0x4) >> 1) | ((i & 0x1) >> 0);
            m_64qam[i] = gr_complex(m_64qam_lookup[real_index] / normalization,
                                    m_64qam_lookup[imag_index] / normalization);
        }
        if (rotation == ROTATION_ON) {
            cyclic_delay = TRUE;
            rotation_angle = (2.0 * GR_M_PI * 8.6) / 360.0;
            temp = std::exp(gr_complexd(0.0, rotation_angle));
            for (int i = 0; i < 64; i++) {
                m_64qam[i] *= temp;
            }
        }
        break;
    case MOD_256QAM:
        normalization = std::sqrt(170.0);
        for (int i = 0; i < 256; i++) {
            real_index = ((i & 0x80) >> 4) | ((i & 0x20) >> 3) | ((i & 0x8) >> 2) |
                         ((i & 0x2) >> 1);
            imag_index = ((i & 0x40) >> 3) | ((i & 0x10) >> 2) | ((i & 0x4) >> 1) |
                         ((i & 0x1) >> 0);
            m_256qam[i] = gr_complex(m_256qam_lookup[real_index] / normalization,
                                     m_256qam_lookup[imag_index] / normalization);
        }
        if (rotation == ROTATION_ON) {
            cyclic_delay = TRUE;
            rotation_angle = (2.0 * GR_M_PI * 3.576334375) / 360.0;
            temp = std::exp(gr_complexd(0.0, rotation_angle));
            for (int i = 0; i < 256; i++) {
                m_256qam[i] *= temp;
            }
        }
        break;
    default:
        normalization = std::sqrt(2.0);
        m_qpsk[0] = gr_complex(1.0 / normalization, 1.0 / normalization);
        m_qpsk[1] = gr_complex(1.0 / normalization, -1.0 / normalization);
        m_qpsk[2] = gr_complex(-1.0 / normalization, 1.0 / normalization);
        m_qpsk[3] = gr_complex(-1.0 / normalization, -1.0 / normalization);
        if (rotation == ROTATION_ON) {
            cyclic_delay = TRUE;
            rotation_angle = (2.0 * GR_M_PI * 29.0) / 360.0;
            temp = std::exp(gr_complexd(0.0, rotation_angle));
            for (int i = 0; i < 4; i++) {
                m_qpsk[i] *= temp;
            }
        }
        break;
    }
    signal_constellation = constellation;
    set_output_multiple(cell_size);
}

/*
 * Our virtual destructor.
 */
dvbt2_modulator_bc_impl::~dvbt2_modulator_bc_impl() {}

void dvbt2_modulator_bc_impl::forecast(int noutput_items,
                                       gr_vector_int& ninput_items_required)
{
    ninput_items_required[0] = noutput_items;
}

int dvbt2_modulator_bc_impl::general_work(int noutput_items,
                                          gr_vector_int& ninput_items,
                                          gr_vector_const_void_star& input_items,
                                          gr_vector_void_star& output_items)
{
    const unsigned char* in = (const unsigned char*)input_items[0];
    gr_complex* out = (gr_complex*)output_items[0];
    const unsigned char* in_delay;
    int index, index_delay;

    switch (signal_constellation) {
    case MOD_QPSK:
        for (int i = 0; i < noutput_items; i += cell_size) {
            if (cyclic_delay == FALSE) {
                for (int j = 0; j < cell_size; j++) {
                    index = *in++;
                    *out++ = m_qpsk[index & 0x3];
                }
            } else {
                in_delay = in;
                for (int j = 0; j < cell_size; j++) {
                    index = *in++;
                    index_delay = in_delay[(j + cell_size - 1) % cell_size];
                    *out++ = gr_complex(m_qpsk[index & 0x3].real(),
                                        m_qpsk[index_delay & 0x3].imag());
                }
            }
        }
        break;
    case MOD_16QAM:
        for (int i = 0; i < noutput_items; i += cell_size) {
            if (cyclic_delay == FALSE) {
                for (int j = 0; j < cell_size; j++) {
                    index = *in++;
                    *out++ = m_16qam[index & 0xf];
                }
            } else {
                in_delay = in;
                for (int j = 0; j < cell_size; j++) {
                    index = *in++;
                    index_delay = in_delay[(j + cell_size - 1) % cell_size];
                    *out++ = gr_complex(m_16qam[index & 0xf].real(),
                                        m_16qam[index_delay & 0xf].imag());
                }
            }
        }
        break;
    case MOD_64QAM:
        for (int i = 0; i < noutput_items; i += cell_size) {
            if (cyclic_delay == FALSE) {
                for (int j = 0; j < cell_size; j++) {
                    index = *in++;
                    *out++ = m_64qam[index & 0x3f];
                }
            } else {
                in_delay = in;
                for (int j = 0; j < cell_size; j++) {
                    index = *in++;
                    index_delay = in_delay[(j + cell_size - 1) % cell_size];
                    *out++ = gr_complex(m_64qam[index & 0x3f].real(),
                                        m_64qam[index_delay & 0x3f].imag());
                }
            }
        }
        break;
    case MOD_256QAM:
        for (int i = 0; i < noutput_items; i += cell_size) {
            if (cyclic_delay == FALSE) {
                for (int j = 0; j < cell_size; j++) {
                    index = *in++;
                    *out++ = m_256qam[index & 0xff];
                }
            } else {
                in_delay = in;
                for (int j = 0; j < cell_size; j++) {
                    index = *in++;
                    index_delay = in_delay[(j + cell_size - 1) % cell_size];
                    *out++ = gr_complex(m_256qam[index & 0xff].real(),
                                        m_256qam[index_delay & 0xff].imag());
                }
            }
        }
        break;
    }

    // Tell runtime system how many input items we consumed on
    // each input stream.
    consume_each(noutput_items);

    // Tell runtime system how many output items we produced.
    return noutput_items;
}

} /* namespace dtv */
} /* namespace gr */
