/*!
 * \file
 * \brief Implementation of a fixed-point data type Fix
 * \author Johan Bergman
 *
 * -------------------------------------------------------------------------
 *
 * IT++ - C++ library of mathematical, signal processing, speech processing,
 *        and communications classes and functions
 *
 * Copyright (C) 1995-2008  (see AUTHORS file for a list of contributors)
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * -------------------------------------------------------------------------
 */

#include <itpp/fixed/fix.h>
#include <itpp/base/itassert.h>
#include <iostream>


namespace itpp {

  Fix& Fix::operator=(const Fix &x)
  {
    shift = x.shift;
    re = apply_o_mode(x.re);
    return *this;
  }

  Fix& Fix::operator=(const int x)
  {
    shift = 0;
    re = apply_o_mode(x);
    return *this;
  }

  Fix& Fix::operator+=(const Fix &x)
  {
    shift = assert_shifts(*this, x);
    re = apply_o_mode(re + x.re);
    return *this;
  }

  Fix& Fix::operator+=(const int x)
  {
    assert_shifts(*this, x);
    re = apply_o_mode(re + x);
    return *this;
  }

  Fix& Fix::operator-=(const Fix &x)
  {
    shift = assert_shifts(*this, x);
    re = apply_o_mode(re - x.re);
    return *this;
  }

  Fix& Fix::operator-=(const int x)
  {
    assert_shifts(*this, x);
    re = apply_o_mode(re - x);
    return *this;
  }

  Fix& Fix::operator*=(const Fix &x)
  {
    shift += x.shift;
    re = apply_o_mode(re*x.re);
    return *this;
  }

  Fix& Fix::operator*=(const int x)
  {
    re = apply_o_mode(re*x);
    return *this;
  }

  Fix& Fix::operator/=(const Fix &x)
  {
    shift -= x.shift;
    re = apply_o_mode(re/x.re);
    return *this;
  }

  Fix& Fix::operator/=(const int x)
  {
    re = apply_o_mode(re/x);
    return *this;
  }

  Fix Fix::operator-() const
  {
    return Fix(-re, shift, 0, 0);
  }

  Fix& Fix::operator<<=(const int n)
  {
    it_assert_debug(n >= 0, "Fix::operator<<=: n cannot be negative!");
    shift += n;
    re = apply_o_mode(re << n);
    return *this;
  }

  Fix& Fix::operator>>=(const int n)
  {
    shift -= n;
    re = rshift_and_apply_q_mode(re, n);
    return *this;
  }

  void Fix::set(double x, int n)
  {
    shift = n;
    re = scale_and_apply_modes(x);
  }

  void Fix::set(double x, int n, q_mode q)
  {
    shift = n;
    re = scale_and_apply_modes(x, q);
  }

  void Fix::lshift(int n)
  {
    it_assert_debug(n >= 0, "Fix::lshift: n cannot be negative!");
    shift += n;
    re = apply_o_mode(re << n);
  }

  void Fix::rshift(int n)
  {
    shift -= n;
    re = rshift_and_apply_q_mode(re, n);
  }

  void Fix::rshift(int n, q_mode q)
  {
    shift -= n;
    re = rshift_and_apply_q_mode(re, n, q);
  }

  double Fix::unfix() const
  {
    it_assert_debug(shift>=-63 && shift<=64, "Fix::unfix: Illegal shift!");
    return double(re)*DOUBLE_POW2[64 - shift];
  }

  void Fix::print() const
  {
    Fix_Base::print();
    std::cout << "re = " << re << std::endl;
  }

  int assert_shifts(const Fix &x, const Fix &y)
  {
    int ret = 0;

    if (x.shift == y.shift)
      ret = x.shift;
    else if (x.re == 0)
      ret = y.shift;
    else if (y.re == 0)
      ret = x.shift;
    else
      it_error("assert_shifts: Different shifts not allowed!");

    return ret;
  }

  int assert_shifts(const Fix &x, int y)
  {
    if ((x.shift != 0) && (x.re != 0) && (y != 0))
      it_error("assert_shifts: Different shifts not allowed!");
    return x.shift;
  }

  std::istream &operator>>(std::istream &is, Fix &x)
  {
    double value;
    is >> value;
    if (!is.eof() && (is.peek() == '<')) {
      int shift;
      is.get();  // Swallow '<' sign
      if (is.peek() == '<') {
        is.get();  // Swallow '<' sign
        is >> shift;
        x.set(value, shift);
      } else {
        is >> shift;
        is.get();  // Swallow '>' sign
        x.set_re(fixrep(value));
        x.set_shift(shift);
      }
    } else {
      // Change data representation but keep shift
      x.set_re(fixrep(value));
    }
    return is;
  }

  std::ostream &operator<<(std::ostream &os, const Fix &x)
  {
    switch (x.get_output_mode()) {
    case OUTPUT_FIX:
      os << x.get_re();
      break;
    case OUTPUT_FIX_SHIFT:
      os << x.get_re() << '<' << x.get_shift() << '>';
      break;
    case OUTPUT_FLOAT:
      os << double(x);
      break;
    case OUTPUT_FLOAT_SHIFT:
      os << double(x) << "<<" << x.get_shift();
      break;
    default:
      it_error("operator<<: Illegal output mode!");
    }
    return os;
  }

  // Specialization of template definition in vec.cpp
  template<>
  void fixvec::set(const char *values)
  {
    std::istringstream buffer(values);
    int b, c;
    int default_shift=0, pos=0, maxpos=10;
    if (datasize > 0) {
      // Assume that all elements have the same shift
      default_shift = data[0].get_shift();
    }
    alloc(maxpos);
    while (buffer.peek()!=EOF) {
      switch (buffer.peek()) {
      case ':': // reads format a:b:c or a:b
        buffer.get();
        if (!buffer.eof()) {
          buffer >> b;
        }
        if (!buffer.eof() && buffer.peek() == ':') {
          buffer.get();
          if (!buffer.eof()) {
            buffer >> c;
            while (int(double(data[pos-1]))+b-c<=0) {
              pos++;
              if (pos > maxpos) {
                maxpos=maxpos*2;
                set_size(maxpos, true);
              }
              data[pos-1]=data[pos-2];
              data[pos-1]+=b;
            }
          }
        } else {
          while (int(double(data[pos-1]))<b) {
            pos++;
            if (pos > maxpos) {
              maxpos=maxpos*2;
              set_size(maxpos, true);
            }
            data[pos-1]=data[pos-2];
            data[pos-1]+=1;
          }
        }
        break;
      case ',':
        buffer.get();
        break;
      default:
        pos++;
        if (pos > maxpos) {
          maxpos *= 2;
          set_size(maxpos, true);
        }
        data[pos-1].set_shift(default_shift);
        buffer >> data[pos-1];  // May override default_shift
        while (buffer.peek()==' ') { buffer.get(); }
        break;
      }
    }
    set_size(pos, true);
  }

  // Specialization of template definition in mat.cpp
  template<>
  void fixmat::set(const char *values)
  {
    std::istringstream buffer(values);
    int default_shift=0, rows=0, maxrows=10, cols=0, nocols=0, maxcols=10;
    if (datasize > 0) {
      // Assume that all elements have the same shift
      default_shift = data[0].get_shift();
    }
    alloc(maxrows, maxcols);
    while (buffer.peek()!=EOF) {
      rows++;
      if (rows > maxrows) {
        maxrows=maxrows*2;
        set_size(maxrows, maxcols, true);
      }
      cols=0;
      while ( (buffer.peek() != ';') && (buffer.peek() != EOF) ) {
        if (buffer.peek()==',') {
          buffer.get();
        } else {
          cols++;
          if (cols > nocols) {
            nocols=cols;
            if (cols > maxcols) {
              maxcols=maxcols*2;
              set_size(maxrows, maxcols, true);
            }
          }
          this->operator()(rows-1,cols-1).set_shift(default_shift);
          buffer >> this->operator()(rows-1,cols-1);  // May override default_shift
          while (buffer.peek()==' ') { buffer.get(); }
        }
      }
      if (!buffer.eof())
        buffer.get();
    }
    set_size(rows, nocols, true);
  }

} //namespace itpp