/* -*- c++ -*- */

/*

 * Copyright 2006 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 <gr_stream_mux.h>

#include <gr_io_signature.h>

#include <string.h>

#include <cstdio>

#define VERBOSE 0

gr_stream_mux_sptr

gr_make_stream_mux (size_t itemsize, const std::vector<int> &lengths)

{

  return gr_stream_mux_sptr (new gr_stream_mux (itemsize, lengths));

}

gr_stream_mux::gr_stream_mux (size_t itemsize, const std::vector<int> &lengths)

  : gr_block ("stream_mux",

              gr_make_io_signature (1, -1, itemsize),

              gr_make_io_signature (1, 1, itemsize)),

    d_itemsize(itemsize),

    d_stream(0),

    d_residual(0),

    d_lengths(lengths)

{

  if(d_lengths[d_stream] == 0) {

    increment_stream();

  }

  d_residual = d_lengths[d_stream];

}    

gr_stream_mux::~gr_stream_mux(void)

{

}

void 

gr_stream_mux::forecast (int noutput_items, gr_vector_int &ninput_items_required)

{

  unsigned ninputs = ninput_items_required.size ();

  for (unsigned i = 0; i < ninputs; i++)

    ninput_items_required[i] = (d_lengths[i] == 0 ? 0 : 1);

}

void gr_stream_mux::increment_stream()

{

  do {

    d_stream = (d_stream+1) % d_lengths.size();

  } while(d_lengths[d_stream] == 0);

  d_residual = d_lengths[d_stream];

}

int

gr_stream_mux::general_work(int noutput_items,

                            gr_vector_int &ninput_items,

                            gr_vector_const_void_star &input_items,

                            gr_vector_void_star &output_items)

{

    char *out = (char *) output_items[0];

    const char *in;

    int out_index = 0;

    std::vector<int> input_index(d_lengths.size(), 0);

    if(VERBOSE) {

      printf("mux: nouput_items: %d   d_stream: %d\n", noutput_items, d_stream);

      for(size_t i = 0; i < d_lengths.size(); i++)

        printf("\tninput_items[%zu]: %d\n", i, ninput_items[i]);

    }

    while (1) {

      int r = std::min(noutput_items - out_index,

                       std::min(d_residual,

                                ninput_items[d_stream] - input_index[d_stream]));

      if(VERBOSE) {

        printf("mux: r=%d\n", r);

        printf("\tnoutput_items - out_index: %d\n", 

               noutput_items - out_index);

        printf("\td_residual: %d\n", 

               d_residual);

        printf("\tninput_items[d_stream] - input_index[d_stream]: %d\n", 

               ninput_items[d_stream] - input_index[d_stream]);

      }

      if(r <= 0) {

        return out_index;

      }

      in = (const char *) input_items[d_stream] + input_index[d_stream]*d_itemsize;

      memcpy(&out[out_index*d_itemsize], in, r*d_itemsize);

      out_index += r;

      input_index[d_stream] += r;

      d_residual -= r;

      consume(d_stream, r);

      if(d_residual == 0) {

        increment_stream();

      }

    }

}