//
// C++ Interface: BuiltinFuncs
//
// Description: 
//
//
// Author: Carmelo Piccione <carmelo.piccione@gmail.com>, (C) 2007
//
// Copyright: See COPYING file that comes with this distribution
//
//

#ifndef _BUILTIN_FUNCS_HPP
#define _BUILTIN_FUNCS_HPP

#include "Common.hpp"
#include "Func.hpp"
#include <cmath>
#include <cstdlib>
#include <cassert>

#include "RandomNumberGenerators.hpp"


/* Wrappers for all the builtin functions
   The arg_list pointer is a list of floats. Its
   size is equal to the number of arguments the parameter
   takes */
class FuncWrappers {

/* Values to optimize the sigmoid function */
static const int R =  32767;
static const int RR = 65534;

public:

static inline float
int_wrapper(float * arg_list)
{
  return floor(arg_list[0]);
}


static inline float
sqr_wrapper(float * arg_list)
{
  return pow(arg_list[0], 2);
}


static inline float
sigmoid_wrapper(float * arg_list)
{
  const double t = (1+exp(-arg_list[0]*arg_list[1]));
  return (fabs(t) > 0.00001) ? 1.0/t : 0;
}

static inline float
sign_wrapper(float * arg_list)
{
  return -arg_list[0];
}

static inline float
min_wrapper(float * arg_list)
{
  if (arg_list[0] > arg_list[1])
    return arg_list[1];

  return arg_list[0];
}

static inline float
max_wrapper(float * arg_list)
{
  if (arg_list[0] > arg_list[1])
    return arg_list[0];

  return arg_list[1];
}


static inline float
bor_wrapper(float * arg_list)
{
  return (float)((int)arg_list[0] || (int)arg_list[1]);
}

static inline float
band_wrapper(float * arg_list)
{
  return (float)((int)arg_list[0] && (int)arg_list[1]);
}

static inline float
bnot_wrapper(float * arg_list)
{
  return (float)(!(int)arg_list[0]);
}

static inline float
if_wrapper(float * arg_list)
{
  if ((int)arg_list[0] == 0)
    return arg_list[2];
  return arg_list[1];
}


static inline float
rand_wrapper(float * arg_list)
{
  float l=1;

  //  printf("RAND ARG:(%d)\n", (int)arg_list[0]);
  if ((int)arg_list[0] > 0)
    l  = (float) RandomNumberGenerators::uniformInteger((int)arg_list[0]);

  return l;
}

static inline float
equal_wrapper(float * arg_list)
{
  return (arg_list[0] == arg_list[1]);
}


static inline float
above_wrapper(float * arg_list)
{
  return (arg_list[0] > arg_list[1]);
}


static inline float
below_wrapper(float * arg_list)
{
  return (arg_list[0] < arg_list[1]);
}

static float
sin_wrapper(float * arg_list)
{
  assert(arg_list);
  //return .5;
  float d = sinf(*arg_list);
  return d;
  //return (sin (arg_list[0]));
}


static inline float
cos_wrapper(float * arg_list)
{
  return (cos (arg_list[0]));
}

static inline float
tan_wrapper(float * arg_list)
{
  return (tan(arg_list[0]));
}

static inline float
asin_wrapper(float * arg_list)
{
  return (asin (arg_list[0]));
}

static inline float
acos_wrapper(float * arg_list)
{
  return (acos (arg_list[0]));
}

static inline float
atan_wrapper(float * arg_list)
{
  return (atan (arg_list[0]));
}

static inline float
atan2_wrapper(float * arg_list)
{
  return (atan2 (arg_list[0], arg_list[1]));
}

static inline float
pow_wrapper(float * arg_list)
{
  return (pow (arg_list[0], arg_list[1]));
}

static inline float
exp_wrapper(float * arg_list)
{
  return (exp(arg_list[0]));
}

static inline float
abs_wrapper(float * arg_list)
{
  return (fabs(arg_list[0]));
}

static inline float
log_wrapper(float* arg_list)
{
  return (log (arg_list[0]));
}

static inline float
log10_wrapper(float * arg_list)
{
  return (log10 (arg_list[0]));
}

static inline float
sqrt_wrapper(float * arg_list)
{
  return (sqrt (arg_list[0]));
}


static inline float
nchoosek_wrapper(float * arg_list)
{
  unsigned long cnm = 1UL;
  int           i, f;
  int           n, m;

  n = (int)arg_list[0];
  m = (int)arg_list[1];

  if (m * 2 > n)
    m = n - m;
  for (i = 1;  i <= m;  n--, i++)
  {
    if ((f = n) % i == 0)
      f   /= i;
    else
      cnm /= i;
    cnm *= f;
  }
  return (float)cnm;
}


static inline float
fact_wrapper(float * arg_list)
{
  int result = 1;

  int n = (int)arg_list[0];

  while (n > 1) {
    result = result * n;
    n--;
  }
  return (float)result;
}

};  /*  class FuncWrappers  */

#include <map>


class BuiltinFuncs {
public:
  static int  init_builtin_func_db();
  static int  destroy_builtin_func_db();
  static int  load_all_builtin_func();
  static int  load_builtin_func( const std::string & name, float (*func_ptr)(float*), int num_args );

  static int  insert_func( Func *func );
  static int  remove_func( Func *func );
  static Func *find_func( const std::string & name );

private:
  static std::map<std::string, Func*> builtin_func_tree;
  static volatile bool                initialized;
};

#endif