/* -*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*- */
/* vim: set filetype=c tabstop=8 shiftwidth=4 expandtab: */

/*
    ceiling.d  -- Implementation of CL:CEILING
*/
/*
    Copyright (c) 2010, Juan Jose Garcia Ripoll.

    ECL is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    See file '../../Copyright' for full details.
*/

#define ECL_INCLUDE_MATH_H
#include <ecl/ecl.h>
#include <float.h>
#ifndef HAVE_ISOC99
# define ceilf ceil
#endif
#include <ecl/internal.h>

@(defun ceiling (x &optional (y OBJNULL))
@
        if (narg == 1)
                return ecl_ceiling1(x);
        else
                return ecl_ceiling2(x, y);
@)

cl_object
ecl_ceiling1(cl_object x)
{
        cl_object v0, v1;
        switch (ecl_t_of(x)) {
        case t_fixnum:
        case t_bignum:
                v0 = x;
                v1 = ecl_make_fixnum(0);
                break;
        case t_ratio: {
                const cl_env_ptr the_env = ecl_process_env();
                v0 = ecl_ceiling2(x->ratio.num, x->ratio.den);
                v1 = ecl_make_ratio(ecl_nth_value(the_env, 1), x->ratio.den);
                break;
        }
        case t_singlefloat: {
                float d = ecl_single_float(x);
                float y = ceilf(d);
                v0 = _ecl_float_to_integer(y);
                v1 = ecl_make_single_float(d - y);
                break;
        }
        case t_doublefloat: {
                double d = ecl_double_float(x);
                double y = ceil(d);
                v0 = _ecl_double_to_integer(y);
                v1 = ecl_make_double_float(d - y);
                break;
        }
#ifdef ECL_LONG_FLOAT
        case t_longfloat: {
                long double d = ecl_long_float(x);
                long double y = ceill(d);
                v0 = _ecl_long_double_to_integer(y);
                v1 = ecl_make_long_float(d - y);
                break;
        }
#endif
        default:
                FEwrong_type_nth_arg(@[ceiling],1,x,@[real]);
        }
        @(return v0 v1)
}

cl_object
ecl_ceiling2(cl_object x, cl_object y)
{
        const cl_env_ptr the_env = ecl_process_env();
        cl_object v0, v1;
        cl_type ty;
        ty = ecl_t_of(y);
        if (ecl_unlikely(!ECL_REAL_TYPE_P(ty))) {
                FEwrong_type_nth_arg(@[ceiling],2, y, @[real]);
        }
        switch(ecl_t_of(x)) {
        case t_fixnum:
                switch(ty) {
                case t_fixnum: {        /* FIX / FIX */
                  cl_fixnum a = ecl_fixnum(x); cl_fixnum b = ecl_fixnum(y);
                  cl_fixnum q = a / b;  cl_fixnum r = a % b;
                  if ((r^b) > 0 && r) { /* same signs and some remainder */
                    v0 = ecl_make_fixnum(q+1);
                    v1 = ecl_make_fixnum(r-b);
                  } else {
                    v0 = ecl_make_fixnum(q);
                    v1 = ecl_make_fixnum(r);
                  }
                  break;
                }
                case t_bignum: {        /* FIX / BIG */
                  /* We must perform the division because there is the
                   * pathological case
                   *    x = MOST_NEGATIVE_FIXNUM
                   *    y = - MOST_NEGATIVE_FIXNUM
                   */
                  ECL_WITH_TEMP_BIGNUM(bx,4);
                  _ecl_big_set_fixnum(bx, ecl_fixnum(x));
                  v0 = _ecl_big_ceiling(bx, y, &v1);
                  break;
                }
                case t_ratio:           /* FIX / RAT */
                  v0 = ecl_ceiling2(ecl_times(x, y->ratio.den), y->ratio.num);
                  v1 = ecl_make_ratio(ecl_nth_value(the_env, 1), y->ratio.den);
                  break;
                case t_singlefloat: {   /* FIX / SF */
                  float n = ecl_single_float(y);
                  float p = ecl_fixnum(x)/n;
                  float q = ceilf(p);
                  v0 = _ecl_float_to_integer(q);
                  v1 = ecl_make_single_float(p*n - q*n);
                  break;
                }
                case t_doublefloat: {   /* FIX / DF */
                  double n = ecl_double_float(y);
                  double p = ecl_fixnum(x)/n;
                  double q = ceil(p);
                  v0 = _ecl_double_to_integer(q);
                  v1 = ecl_make_double_float(p*n - q*n);
                  break;
                }
#ifdef ECL_LONG_FLOAT
                case t_longfloat: {     /* FIX / LF */
                  long double n = ecl_long_float(y);
                  long double p = ecl_fixnum(x)/n;
                  long double q = ceill(p);
                  v0 = _ecl_long_double_to_integer(q);
                  v1 = ecl_make_long_float(p*n - q*n);
                  break;
                }
#endif
                default:
                  (void)0; /*Never reached */
                }
                break;
        case t_bignum:
                switch(ecl_t_of(y)) {
                case t_fixnum: {        /* BIG / FIX */
                  ECL_WITH_TEMP_BIGNUM(by,4);
                  _ecl_big_set_fixnum(by, ecl_fixnum(y));
                  v0 = _ecl_big_ceiling(x, by, &v1);
                  break;
                }
                case t_bignum: {        /* BIG / BIG */
                  v0 = _ecl_big_ceiling(x, y, &v1);
                  break;
                }
                case t_ratio:           /* BIG / RAT */
                  v0 = ecl_ceiling2(ecl_times(x, y->ratio.den), y->ratio.num);
                  v1 = ecl_make_ratio(ecl_nth_value(the_env, 1), y->ratio.den);
                  break;
                case t_singlefloat: {   /* BIG / SF */
                  float n = ecl_single_float(y);
                  float p = _ecl_big_to_double(x)/n;
                  float q = ceilf(p);
                  v0 = _ecl_float_to_integer(q);
                  v1 = ecl_make_single_float(p*n - q*n);
                  break;
                }
                case t_doublefloat: {   /* BIG / DF */
                  double n = ecl_double_float(y);
                  double p = _ecl_big_to_double(x)/n;
                  double q = ceil(p);
                  v0 = _ecl_double_to_integer(q);
                  v1 = ecl_make_double_float(p*n - q*n);
                  break;
                }
#ifdef ECL_LONG_FLOAT
                case t_longfloat: {     /* BIG / LF */
                  long double n = ecl_long_float(y);
                  long double p = _ecl_big_to_double(x)/n;
                  long double q = ceill(p);
                  v0 = _ecl_long_double_to_integer(q);
                  v1 = ecl_make_long_float(p*n - q*n);
                  break;
                }
#endif
                default:
                  (void)0; /*Never reached */
                }
                break;
        case t_ratio:
                switch(ecl_t_of(y)) {
                case t_ratio:           /* RAT / RAT */
                  v0 = ecl_ceiling2(ecl_times(x->ratio.num, y->ratio.den),
                                    ecl_times(x->ratio.den, y->ratio.num));
                  v1 = ecl_make_ratio(ecl_nth_value(the_env, 1), ecl_times(x->ratio.den, y->ratio.den));
                  break;
                default:                /* RAT / ANY */
                  v0 = ecl_ceiling2(x->ratio.num, ecl_times(x->ratio.den, y));
                  v1 = ecl_divide(ecl_nth_value(the_env, 1), x->ratio.den);
                }
                break;
        case t_singlefloat: {           /* SF / ANY */
                float n = ecl_to_double(y);
                float p = ecl_single_float(x)/n;
                float q = ceilf(p);
                v0 = _ecl_float_to_integer(q);
                v1 = ecl_make_single_float(p*n - q*n);
                break;
        }
        case t_doublefloat: {           /* DF / ANY */
                double n = ecl_to_double(y);
                double p = ecl_double_float(x)/n;
                double q = ceil(p);
                v0 = _ecl_double_to_integer(q);
                v1 = ecl_make_double_float(p*n - q*n);
                break;
        }
#ifdef ECL_LONG_FLOAT
        case t_longfloat: {             /* LF / ANY */
                long double n = ecl_to_long_double(y);
                long double p = ecl_long_float(x)/n;
                long double q = ceill(p);
                v0 = _ecl_long_double_to_integer(q);
                v1 = ecl_make_long_float(p*n - q*n);
                break;
        }
#endif
        default:
                FEwrong_type_nth_arg(@[ceiling], 1, x, @[real]);
        }
        ecl_return2(the_env, v0, v1);
}
