/* -*- c++ -*- */
/*
 * Copyright 2004,2008,2010,2013 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 "wavfile_source_impl.h"
#include <gnuradio/blocks/wavfile.h>
#include <gnuradio/io_signature.h>
#include <fcntl.h>
#include <sys/types.h>
#include <stdexcept>

// win32 (mingw/msvc) specific
#ifdef HAVE_IO_H
#include <io.h>
#endif
#ifdef O_BINARY
#define OUR_O_BINARY O_BINARY
#else
#define OUR_O_BINARY 0
#endif
// should be handled via configure
#ifdef O_LARGEFILE
#define OUR_O_LARGEFILE O_LARGEFILE
#else
#define OUR_O_LARGEFILE 0
#endif

namespace gr {
namespace blocks {

wavfile_source::sptr wavfile_source::make(const char* filename, bool repeat)
{
    return gnuradio::get_initial_sptr(new wavfile_source_impl(filename, repeat));
}

wavfile_source_impl::wavfile_source_impl(const char* filename, bool repeat)
    : sync_block("wavfile_source",
                 io_signature::make(0, 0, 0),
                 io_signature::make(1, 2, sizeof(float))),
      d_fp(NULL),
      d_repeat(repeat),
      d_sample_rate(1),
      d_nchans(1),
      d_bytes_per_sample(2),
      d_first_sample_pos(0),
      d_samples_per_chan(0),
      d_sample_idx(0)
{
    // we use "open" to use to the O_LARGEFILE flag

    int fd;
    if ((fd = open(filename, O_RDONLY | OUR_O_LARGEFILE | OUR_O_BINARY)) < 0) {
        perror(filename);
        throw std::runtime_error("can't open file");
    }

    if ((d_fp = fdopen(fd, "rb")) == NULL) {
        perror(filename);
        throw std::runtime_error("can't open file");
    }

    // Scan headers, check file validity
    if (!wavheader_parse(d_fp,
                         d_sample_rate,
                         d_nchans,
                         d_bytes_per_sample,
                         d_first_sample_pos,
                         d_samples_per_chan)) {
        throw std::runtime_error("is not a valid wav file");
    }

    if (d_samples_per_chan == 0) {
        throw std::runtime_error("WAV file does not contain any samples");
    }

    if (d_bytes_per_sample == 1) {
        d_normalize_fac = 128;
        d_normalize_shift = 1;
    } else {
        d_normalize_fac = 0x7FFF;
        d_normalize_shift = 0;
    }

    // Re-set the output signature
    set_output_signature(io_signature::make(1, d_nchans, sizeof(float)));
}

wavfile_source_impl::~wavfile_source_impl() { fclose(d_fp); }

float wavfile_source_impl::convert_to_float(short int sample)
{
    float sample_out = (float)sample;
    sample_out /= d_normalize_fac;
    sample_out -= d_normalize_shift;
    return sample_out;
}

int wavfile_source_impl::work(int noutput_items,
                              gr_vector_const_void_star& input_items,
                              gr_vector_void_star& output_items)
{
    float** out = (float**)&output_items[0];
    int n_out_chans = output_items.size();

    int i;
    short sample;

    for (i = 0; i < noutput_items; i++) {
        if (d_sample_idx >= d_samples_per_chan) {
            if (!d_repeat) {
                // if nothing was read at all, say we're done.
                return i ? i : -1;
            }

            if (fseek(d_fp, d_first_sample_pos, SEEK_SET) == -1) {
                fprintf(stderr, "[%s] fseek failed\n", __FILE__);
                exit(-1);
            }

            d_sample_idx = 0;
        }

        for (int chan = 0; chan < d_nchans; chan++) {
            sample = wav_read_sample(d_fp, d_bytes_per_sample);

            if (chan < n_out_chans) {
                out[chan][i] = convert_to_float(sample);
            }
        }

        d_sample_idx++;

        // OK, EOF is not necessarily an error. But we're not going to
        // deal with handling corrupt wav files, so if they give us any
        // trouble they won't be processed. Serves them bloody right.
        if (feof(d_fp) || ferror(d_fp)) {
            if (i == 0) {
                fprintf(stderr,
                        "[%s] WAV file has corrupted header or i/o error\n",
                        __FILE__);
                return -1;
            }
            return i;
        }
    }

    return noutput_items;
}

} /* namespace blocks */
} /* namespace gr */
