/* -*- c++ -*- */
/*
 * Copyright 2002 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.
 */

#include <cstdlib> 
#include <cstdio>
#include <iostream>
#include <string>
#include <fstream>
#include <stdexcept>
#include <cmath>
#include "quicksort_index.h"
#include "interleaver.h"




interleaver::interleaver()
{
  d_K=0;
  d_INTER.resize(0);
  d_DEINTER.resize(0);
}

interleaver::interleaver(const interleaver &INTERLEAVER)
{
  d_K=INTERLEAVER.K();
  d_INTER=INTERLEAVER.INTER();
  d_DEINTER=INTERLEAVER.DEINTER();
}

interleaver::interleaver(int K, const std::vector<int> &INTER)
{
  d_K=K;
  d_INTER=INTER;
  d_DEINTER.resize(d_K);
  
  // generate DEINTER table
  for(int i=0;i<d_K;i++) {
    d_DEINTER[d_INTER[i]]=i;
  }
}

//######################################################################
//# Read an INTERLEAVER specification from a file.
//# Format (hopefully will become more flexible in the future...):
//# K
//# blank line
//# list of space separated K integers from 0 to K-1 in appropriate order
//# optional comments
//######################################################################
interleaver::interleaver(const char *name) 
{
  FILE *interleaverfile;

  if((interleaverfile=fopen(name,"r"))==NULL) 
    throw std::runtime_error ("file open error in interleaver()");
    //printf("file open error in interleaver()\n");
  
  if(fscanf(interleaverfile,"%d\n",&d_K) == EOF) {
    if(ferror(interleaverfile) != 0)
      throw std::runtime_error ("interleaver::interleaver(const char *name): file read error\n");
  }

  d_INTER.resize(d_K);
  d_DEINTER.resize(d_K);

  for(int i=0;i<d_K;i++) {
    if(fscanf(interleaverfile,"%d",&(d_INTER[i])) == EOF) {
      if(ferror(interleaverfile) != 0)
	throw std::runtime_error ("interleaver::interleaver(const char *name): file read error\n");
    }
  }
  
  // generate DEINTER table
  for(int i=0;i<d_K;i++) {
    d_DEINTER[d_INTER[i]]=i;
  }
}

//######################################################################
//# Generate a random interleaver
//######################################################################
interleaver::interleaver(int K, int seed)
{
  d_K=K;
  d_INTER.resize(d_K);
  d_DEINTER.resize(d_K);

  if(seed>=0) srand((unsigned int)seed); 
  std::vector<int> tmp(d_K);
  for(int i=0;i<d_K;i++) {
    d_INTER[i]=i;
    tmp[i] = rand(); 
  }
  quicksort_index <int> (tmp,d_INTER,0,d_K-1);

  // generate DEINTER table
  for(int i=0;i<d_K;i++) {
    d_DEINTER[d_INTER[i]]=i;
  }
}





//######################################################################
//# Write an INTERLEAVER specification from a file.
//# Format
//# K
//# blank line
//# list of space separated K integers from 0 to K-1 in appropriate order
//# optional comments
//######################################################################
void interleaver::write_interleaver_txt(std::string filename)
{
   std::ofstream interleaver_fname (filename.c_str());
   if (!interleaver_fname) {std::cout << "file not found " << std::endl ; exit(-1);}
   interleaver_fname << d_K << std::endl;
   interleaver_fname << std::endl;
   for(int i=0;i<d_K;i++)
     interleaver_fname << d_INTER[i] << ' ';
   interleaver_fname << std::endl;
   interleaver_fname.close();
}