/* mpc_get_dc, mpc_get_ldc -- Transform mpc number into C complex number

   mpc_get_str -- Convert a complex number into a string.

Copyright (C) 2009, 2010, 2011 INRIA

This file is part of GNU MPC.

GNU MPC is free software; you can redistribute it and/or modify it under

the terms of the GNU Lesser General Public License as published by the

Free Software Foundation; either version 3 of the License, or (at your

option) any later version.

GNU MPC 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 Lesser General Public License for

more details.

You should have received a copy of the GNU Lesser General Public License

along with this program. If not, see http://www.gnu.org/licenses/ .

*/

#include "config.h"

#ifdef HAVE_COMPLEX_H

#include <complex.h>

#endif

#ifdef HAVE_LOCALE_H

#include <locale.h>

#endif

#include <stdio.h> /* for sprintf, fprintf */

#include <ctype.h>

#include <string.h>

#include "mpc-impl.h"

#ifdef HAVE_COMPLEX_H

double _Complex

mpc_get_dc (mpc_srcptr op, mpc_rnd_t rnd) {

   return I * mpfr_get_d (mpc_imagref (op), MPC_RND_IM (rnd))

          + mpfr_get_d (mpc_realref (op), MPC_RND_RE (rnd));

}

long double _Complex

mpc_get_ldc (mpc_srcptr op, mpc_rnd_t rnd) {

   return I * mpfr_get_ld (mpc_imagref (op), MPC_RND_IM (rnd))

          + mpfr_get_ld (mpc_realref (op), MPC_RND_RE (rnd));

}

#endif

/* Code for mpc_get_str. The output format is "(real imag)", the decimal point

   of the locale is used. */

/* mpfr_prec_t can be either int or long int */

#if (__GMP_MP_SIZE_T_INT == 1)

#define MPC_EXP_FORMAT_SPEC "i"

#elif (__GMP_MP_SIZE_T_INT == 0)

#define MPC_EXP_FORMAT_SPEC "li"

#else

#error "mpfr_exp_t size not supported"

#endif

static char *

pretty_zero (mpfr_srcptr zero)

{

  char *pretty;

  pretty = mpc_alloc_str (3);

  pretty[0] = mpfr_signbit (zero) ? '-' : '+';

  pretty[1] = '0';

  pretty[2] = '\0';

  return pretty;

}

static char *

prettify (const char *str, const mp_exp_t expo, int base, int special)

{

  size_t sz;

  char *pretty;

  char *p;

  const char *s;

  mp_exp_t x;

  int sign;

  sz = strlen (str) + 1; /* + terminal '\0' */

  if (special)

    {

      /* special number: nan or inf */

      pretty = mpc_alloc_str (sz);

      strcpy (pretty, str);

      return pretty;

    }

  /* regular number */

  sign = (str[0] == '-' || str[0] == '+');

  x = expo - 1; /* expo is the exponent value with decimal point BEFORE

                   the first digit, we wants decimal point AFTER the first

                   digit */

  if (base == 16)

    x <<= 2; /* the output exponent is a binary exponent */

  ++sz; /* + decimal point */

  if (x != 0)

    {

      /* augment sz with the size needed for an exponent written in base

         ten */

      mp_exp_t xx;

      sz += 3; /* + exponent char + sign + 1 digit */

      if (x < 0)

        {

          /* avoid overflow when changing sign (assuming that, for the

             mp_exp_t type, (max value) is greater than (- min value / 10)) */

          if (x < -10)

            {

              xx = - (x / 10);

              sz++;

            }

          else

            xx = -x;

        }

      else

        xx = x;

      /* compute sz += floor(log(expo)/log(10)) without using libm

         functions */

      while (xx > 9)

        {

          sz++;

          xx /= 10;

        }

    }

  pretty = mpc_alloc_str (sz);

  p = pretty;

  /* 1. optional sign plus first digit */

  s = str;

  *p++ = *s++;

  if (sign)

    *p++ = *s++;

  /* 2. decimal point */

#ifdef HAVE_LOCALECONV

  *p++ = *localeconv ()->decimal_point;

#else

  *p++ = '.';

#endif

  *p = '\0';

  /* 3. other significant digits */

  strcat (pretty, s);

  /* 4. exponent (in base ten) */

  if (x == 0)

    return pretty;

  p = pretty + strlen (str) + 1;

  switch (base)

    {

    case 10:

      *p++ = 'e';

      break;

    case 2:

    case 16:

      *p++ = 'p';

      break;

    default:

      *p++ = '@';

    }

  *p = '\0';

  sprintf (p, "%+"MPC_EXP_FORMAT_SPEC, x);

  return pretty;

}

static char *

get_pretty_str (const int base, const size_t n, mpfr_srcptr x, mpfr_rnd_t rnd)

{

  mp_exp_t expo;

  char *ugly;

  char *pretty;

  if (mpfr_zero_p (x))

    return pretty_zero (x);

  ugly = mpfr_get_str (NULL, &expo, base, n, x, rnd);

  MPC_ASSERT (ugly != NULL);

  pretty = prettify (ugly, expo, base, !mpfr_number_p (x));

  mpfr_free_str (ugly);

  return pretty;

}

char *

mpc_get_str (int base, size_t n, mpc_srcptr op, mpc_rnd_t rnd)

{

  size_t needed_size;

  char *real_str;

  char *imag_str;

  char *complex_str = NULL;

  if (base < 2 || base > 36)

    return NULL;

  real_str = get_pretty_str (base, n, mpc_realref (op), MPC_RND_RE (rnd));

  imag_str = get_pretty_str (base, n, mpc_imagref (op), MPC_RND_IM (rnd));

  needed_size = strlen (real_str) + strlen (imag_str) + 4;

  complex_str = mpc_alloc_str (needed_size);

MPC_ASSERT (complex_str != NULL);

  strcpy (complex_str, "(");

  strcat (complex_str, real_str);

  strcat (complex_str, " ");

  strcat (complex_str, imag_str);

  strcat (complex_str, ")");

  mpc_free_str (real_str);

  mpc_free_str (imag_str);

  return complex_str;

}