/* -*- 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/io_signature.h>
#include <gnuradio/blocks/wavfile.h>
#include <sys/types.h>
#include <fcntl.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 */