#include <stdio.h>
#include <math.h>

#include "testfuncs.h"
#include "config.h"

#define UNUSED(x) (void) x

static double sqr(double x) { return x * x; }

int testfuncs_verbose = 0;
int testfuncs_counter = 0;

static double testfuncs_status(unsigned n, const double *x, double f)
{
     ++testfuncs_counter;
     if (testfuncs_verbose) {
	  unsigned i;
	  printf("f_%d (%g", testfuncs_counter, x[0]);
	  for (i = 1; i < n; ++i) printf(", %g", x[i]);
	  printf(") = %g\n", f);
     }
     return f;
}

#define RETURN(f) return testfuncs_status(n, x, f);

#define PI2 6.283185307179586 /* 2*pi */
#define PI3 9.424777960769379 /* 3*pi */
#define PI4 12.5663706143592 /* 4*pi */

/****************************************************************************/
static double rosenbrock_f(unsigned n, const double *x, double *grad, void *data)
{
     double a = x[1] - x[0] * x[0], b = 1 - x[0];
     UNUSED(data);
     if (grad) {
	  grad[0] = -400 * a * x[0] - 2*b;
	  grad[1] = 200 * a;
     }
     RETURN(100 * sqr(a) + sqr(b));
}

static const double rosenbrock_lb[2] = {-2, -2};
static const double rosenbrock_ub[2] = {2, 2};
static const double rosenbrock_xmin[2] = {1, 1};

/****************************************************************************/
static double mccormic_f(unsigned n, const double *x, double *grad, void *data)
{
     double a = x[0] + x[1], b = x[0] - x[1];
     UNUSED(data);
     if (grad) {
	  grad[0] = cos(a) + 2*b - 1.5;
	  grad[1] = cos(a) - 2*b + 2.5;
     }
     RETURN(sin(a) + sqr(b) - 1.5*x[0] + 2.5*x[1] + 1);
}

static const double mccormic_lb[2] = {-1.5, -3};
static const double mccormic_ub[2] = {4, 4};
static const double mccormic_xmin[2] = {-0.547197553, -1.54719756};

/****************************************************************************/
static double boxbetts_f(unsigned n, const double *x, double *grad, void *data)
{
     unsigned i;
     double f = 0;
     UNUSED(data);
     if (grad)
	  grad[0] = grad[1] = grad[2] = 0;
     for (i = 1; i <= 10; ++i) {
	  double e0 = exp(-0.1*i*x[0]);
	  double e1 = exp(-0.1*i*x[1]);
	  double e2 = exp(-0.1*i) - exp((double) -i);
	  double g = e0 - e1 - e2 * x[2];
	  f += sqr(g);
	  if (grad) {
	       grad[0] += (2 * g) * (-0.1*i*e0);
	       grad[1] += (2 * g) * (0.1*i*e1);
	       grad[2] += -(2 * g) * e2;
	  }
     }
     RETURN(f);
}

static const double boxbetts_lb[3] = {0.9,9,0.9};
static const double boxbetts_ub[3] = {1.2,11.2,1.2};
static const double boxbetts_xmin[3] = {1,10,1};

/****************************************************************************/
static double paviani_f(unsigned n, const double *x, double *grad, void *data)
{
     unsigned i;
     double f = 0, prod = 1;
     UNUSED(data);
     if (grad) for (i = 0; i < 10; ++i) grad[i] = 0;
     for (i = 0; i < 10; ++i) {
	  double ln1 = log(x[i] - 2);
	  double ln2 = log(10 - x[i]);
	  f += sqr(ln1) + sqr(ln2);
	  if (grad)
	       grad[i] += 2 * ln1 / (x[i] - 2) - 2 * ln2 / (10 - x[i]);
	  prod *= x[i];
     }
     f -= (prod = pow(prod, 0.2));
     if (grad)
	  for (i = 0; i < 10; ++i)
	       grad[i] -= 0.2 * prod / x[i];
     RETURN(f);
}

static const double paviani_lb[10] = {2.001,2.001,2.001,2.001,2.001,2.001,2.001,2.001,2.001,2.001};
static const double paviani_ub[10] = {9.999,9.999,9.999,9.999,9.999,9.999,9.999,9.999,9.999,9.999};
static const double paviani_xmin[10] = {9.35026583,9.35026583,9.35026583,9.35026583,9.35026583,9.35026583,9.35026583,9.35026583,9.35026583,9.35026583};

/****************************************************************************/
static double grosenbrock_f(unsigned n, const double *x, double *grad, void *data)
{
     unsigned i;
     double f = 0;
     UNUSED(data);
     if (grad) grad[0] = 0;
     for (i = 0; i < 29; ++i) {
	  double a = x[i+1] - x[i] * x[i], b = 1 - x[i];
	  if (grad) {
	       grad[i] += -400 * a * x[i] - 2*b;
	       grad[i+1] = 200 * a;
	  }
	  f += 100 * sqr(a) + sqr(b);
     }
     RETURN(f);
}

static const double grosenbrock_lb[30] = {-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30,-30};
static const double grosenbrock_ub[30] = {30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30,30};
static const double grosenbrock_xmin[30] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1};

/****************************************************************************/
static double goldsteinprice_f(unsigned n, const double *x, double *grad, void *data)
{
     double x0, x1, a1, a12, a2, b1, b12, b2;
     UNUSED(data);
     x0 = x[0]; x1 = x[1];
     a1 = x0+x1+1; a12 = sqr(a1);
     a2 = 19 - 14*x0 + 3*x0*x0 - 14*x1 + 6*x0*x1 + 3*x1*x1;
     b1 = 2*x0-3*x1; b12 = sqr(b1);
     b2 = 18 - 32*x0 + 12*x0*x0 + 48*x1 - 36*x0*x1 + 27*x1*x1;
     if (grad) {
	  grad[0] = (1 + a12 * a2) * (2 * b1 * 2 * b2 
				      + b12 * (-32 + 24*x0 - 36*x1))
	       + (2 * a1 * a2 + a12 * (-14 + 6*x0 + 6*x1)) * (30 + b12 * b2);
	  grad[1] = (1 + a12 * a2) * (2 * b1 * (-3) * b2
				      + b12 * (48 - 36*x0 + 54 * x1))
	       + (2 * a1 * a2 + a12 * (-14 + 6*x0 + 6*x1)) * (30 + b12 * b2);
     }
     RETURN((1 + a12 * a2) * (30 + b12 * b2));
}

static const double goldsteinprice_lb[2] = {-2, -2};
static const double goldsteinprice_ub[2] = {2, 2};
static const double goldsteinprice_xmin[2] = {0, -1};

/****************************************************************************/
static double shekel_f(unsigned n, const double *x, double *grad, void *data)
{
     static const double A[10][4] = { {4,4,4,4},
				      {1,1,1,1},
				      {8,8,8,8},
				      {6,6,6,6},
				      {3,7,3,7},
				      {2,9,2,9},
				      {5,5,3,3},
				      {8,1,8,1},
				      {6,2,6,2},
				      {7,3.6,7,3.6} };
     static const double c[10] = {.1,.2,.2,.4,.4,.6,.3,.7,.5,.5};
     unsigned i;
     double f = 0;
     if (grad) for (i = 0; i < n; ++i) grad[i] = 0;
     unsigned m = *((unsigned *) data);
     for (i = 0; i < m; ++i) {
	  double fi = 1.0 / (c[i] 
			     + sqr(x[0]-A[i][0])
			     + sqr(x[1]-A[i][1])
			     + sqr(x[2]-A[i][2])
			     + sqr(x[3]-A[i][3]));
	  f -= fi;
	  if (grad) {
	       grad[0] += (2*fi*fi) * (x[0]-A[i][0]);
	       grad[1] += (2*fi*fi) * (x[1]-A[i][1]);
	       grad[2] += (2*fi*fi) * (x[2]-A[i][2]);
	       grad[3] += (2*fi*fi) * (x[3]-A[i][3]);
	  }
     }
     RETURN(f);
}

static unsigned shekel_m[3] = {5,7,10};
static const double shekel_lb[4] = {0,0,0,0};
static const double shekel_ub[4] = {10,10,10,10};
static const double shekel0_xmin[4] = {4.000037154,4.000133276,4.000037154,4.000133276};
static const double shekel1_xmin[4] = {4.000572917,4.000689366,3.999489709,3.999606158};
static const double shekel2_xmin[4] = {4.000746531,4.000592935,3.999663399,3.999509801};

/****************************************************************************/
static double levy_f(unsigned n, const double *x, double *grad, void *data)
{
     UNUSED(data);
     unsigned i;
     double a = x[n-1] - 1, b = 1 + sqr(sin(PI2*x[n-1]));
     double f = sqr(sin(PI3*x[0])) + a * b;
     if (grad) {
	  for (i = 0; i < n; ++i) grad[i] = 0;
	  grad[0] = 2 * PI3 * sin(PI3*x[0]) * cos(PI3*x[0]);
	  grad[n-1] += b + a * 2 * PI2 * sin(PI2*x[n-1]) * cos(PI2*x[n-1]);
     }
     for (i = 0; i < n-1; ++i) {
	  a = x[i] - 1;
	  b = 1 + sqr(sin(PI3*x[i+1]));
	  f += sqr(a) * b;
	  if (grad) {
	       grad[i] += 2 * a * b;
	       grad[i+1] += 2*PI3 * sqr(a) * sin(PI3*x[i+1])*cos(PI3*x[i+1]);
	  }
     }
     RETURN(f);
}

static const double levy_lb[7] = {-5,-5,-5,-5,-5,-5,-5};
static const double levy_ub[7] = {5,5,5,5,5,5,5};
static const double levy_xmin[7] = {1,1,1,1,1,1,-4.75440246};
static const double levy4_lb[4] = {-10,-10,-10,-10};
static const double levy4_ub[4] = {10,10,10,10};
static const double levy4_xmin[4] = {1,1,1,-9.75235596};

/****************************************************************************/
static double griewank_f(unsigned n, const double *x, double *grad, void *data)
{
     unsigned i;
     double f = 1, p = 1;
     UNUSED(data);
     for (i = 0; i < n; ++i) {
	  f += sqr(x[i]) * 0.00025;
	  p *= cos(x[i] / sqrt(i + 1.));
	  if (grad) grad[i] = x[i] * 0.0005;
     }
     f -= p;
     if (grad)
	  for (i = 0; i < n; ++i)
	       grad[i] += p * tan(x[i] / sqrt(i + 1.)) / sqrt(i + 1.);
     RETURN(f);
}

static const double griewank_lb[10] = {-500,-500,-500,-500,-500,-500,-500,-500,-500,-500};
static const double griewank_ub[10] = {600,600,600,600,600,600,600,600,600,600};
static const double griewank_xmin[10] = {0,0,0,0,0,0,0,0,0,0};

/****************************************************************************/
static double sixhumpcamel_f(unsigned n, const double *x, double *grad, void *data)
{
     UNUSED(data);
     if (grad) {
	  grad[0] = 8*x[0] - 2.1*4*pow(x[0],3.) + 2*pow(x[0],5.) + x[1];
	  grad[1] = x[0] - 8*x[1] + 16*pow(x[1],3.);
     }
     RETURN(4*sqr(x[0]) - 2.1 * pow(x[0],4.) + pow(x[0],6.)/3. 
	    + x[0]*x[1] - 4*sqr(x[1]) + 4*pow(x[1],4.));
}

static const double sixhumpcamel_lb[2] = {-5,-5};
static const double sixhumpcamel_ub[2] = {5,5};
static const double sixhumpcamel_xmin[2] = {0.08984201317, -0.7126564032};

/****************************************************************************/
static double convexcosh_f(unsigned n, const double *x, double *grad, void *data)
{
     unsigned i;
     double f = 1;
     UNUSED(data);
     for (i = 0; i < n; ++i)
	  f *= cosh((x[i] - i) * (i+1));
     if (grad)
	  for (i = 0; i < n; ++i)
	       grad[i] = f * tanh((x[i] - i) * (i+1)) * (i+1);
     RETURN(f);
}

static const double convexcosh_lb[10] = {-1,0,0,0,0,0,0,0,0,0};
static const double convexcosh_ub[10] = {2,3,6,7,8,10,11,13,14,16};
static const double convexcosh_xmin[10] = {0,1,2,3,4,5,6,7,8,9};

/****************************************************************************/
static double branin_f(unsigned n, const double *x, double *grad, void *data)
{
     double a = 1 - 2*x[1] + 0.05 * sin(PI4 * x[1]) - x[0];
     double b = x[1] - 0.5 * sin(PI2 * x[0]);
     UNUSED(data);
     if (grad) {
	  grad[0] = -2*a - cos(PI2 * x[0]) * PI2 * b;
	  grad[1] = 2*a*(0.05 * PI4 * cos(PI4*x[1]) - 2) + 2*b;
     }
     RETURN(sqr(a) + sqr(b));
}

static const double branin_lb[2] = {-10,-10};
static const double branin_ub[2] = {10,10};
static const double branin_xmin[2] = {1,0};

/****************************************************************************/
static double shubert_f(unsigned n, const double *x, double *grad, void *data)
{
     UNUSED(data);
     unsigned i, j;
     double f = 0;
     for (j = 1; j <= 5; ++j)
	  for (i = 0; i < n; ++i)
	       f -= j * sin((j+1) * x[i] + j);
     if (grad) {
	  for (i = 0; i < n; ++i) {
	       grad[i] = 0;
	       for (j = 1; j <= 5; ++j)
		    grad[i] -= j * (j+1) * cos((j+1) * x[i] + j);
	  }
     }
     RETURN(f);
}

static const double shubert_lb[2] = {-10,-10};
static const double shubert_ub[2] = {10,10};
static const double shubert_xmin[2] = {-6.774576143, -6.774576143};

/****************************************************************************/
static double hansen_f(unsigned n, const double *x, double *grad, void *data)
{
     unsigned i;
     double a = 0, b = 0;
     UNUSED(data);
     for (i = 1; i <= 5; ++i)
	  a += i * cos((i-1) * x[0] + i);
     for (i = 1; i <= 5; ++i)
	  b += i * cos((i+1) * x[1] + i);
     if (grad) {
	  grad[0] = 0;
	  for (i = 1; i <= 5; ++i)
	       grad[0] -= i * (i-1) * sin((i-1) * x[0] + i);
	  grad[0] *= b;
	  grad[1] = 0;
	  for (i = 1; i <= 5; ++i)
	       grad[1] -= i * (i+1) * sin((i+1) * x[1] + i);
	  grad[1] *= a;
     }
     RETURN(a*b);
}

static const double hansen_lb[2] = {-10,-10};
static const double hansen_ub[2] = {10,10};
static const double hansen_xmin[2] = {-1.306707704,-1.425128429};

/****************************************************************************/
static double osc1d_f(unsigned n, const double *x, double *grad, void *data)
{
     double y = *x - 1.23456789;
     UNUSED(data);
     if (grad) grad[0] = y*0.02 + sin(y - 2*sin(3*y)) * (1 - 6*cos(3*y));
     RETURN(sqr(y*0.1) - cos(y - 2*sin(3*y)));
}

static const double osc1d_lb[1] = {-5};
static const double osc1d_ub[1] = {5};
static const double osc1d_xmin[1] = {1.23456789};

/****************************************************************************/
static double corner4d_f(unsigned n, const double *x, double *grad, void *data)
{
     UNUSED(data);
     UNUSED(n);
     double u = x[0] + x[1] * x[2] * sin(2 * x[3]);
     double v = x[0] + 2*sin(u);
     if (grad) {
	  grad[0] = 2*v * (1 + 2*cos(u));
	  grad[1] = 2*v * 2*cos(u) * x[2] * sin(2*x[3]) + 0.1;
	  grad[2] = 2*v * 2*cos(u) * x[1] * sin(2*x[3]) + 0.1;
	  grad[3] = 2*v * 2*cos(u) * x[1]*x[2] * cos(2*x[3]) * 2 + 0.1;
     }
     RETURN(1 + v*v + 0.1*(x[1]+x[2]+x[3]));
}

static const double corner4d_lb[4] = {0,0,0,0};
static const double corner4d_ub[4] = {1,1,1,1};
static const double corner4d_xmin[4] = {0,0,0,0};

/****************************************************************************/
static double side4d_f(unsigned n, const double *x, double *grad, void *data)
{
     UNUSED(data);
     UNUSED(n);
     double x0, x1, x2, x3, d0,d1,d2,d3;
     const double w0 = 0.1, w1 = 0.2, w2 = 0.3, w3 = 0.4;
     x0 = +0.4977 * x[0] - 0.3153 * x[1] - 0.5066 * x[2] - 0.4391 * x[3];
     x1 = -0.3153 * x[0] + 0.3248 * x[1] - 0.4382 * x[2] - 0.4096 * x[3];
     x2 = -0.5066 * x[0] - 0.4382 * x[1] + 0.3807 * x[2] - 0.4543 * x[3];
     x3 = -0.4391 * x[0] - 0.4096 * x[1] - 0.4543 * x[2] + 0.5667 * x[3];

     d0 = -1. / (x0*x0 + w0*w0);
     d1 = -1. / (x1*x1 + w1*w1);
     d2 = -1. / (x2*x2 + w2*w2);
     d3 = -1. / (x3*x3 + w3*w3);

     if (grad) {
	  grad[0] = 2 * (x0*d0*d0 * +0.4977 +
			 x1*d1*d1 * -0.3153 +
			 x2*d2*d2 * -0.5066 +
			 x3*d3*d3 * -0.4391);
	  grad[1] = 2 * (x0*d0*d0 * -0.3153 +
			 x1*d1*d1 * +0.3248 +
			 x2*d2*d2 * -0.4382 +
			 x3*d3*d3 * -0.4096);
	  grad[2] = 2 * (x0*d0*d0 * -0.5066 +
			 x1*d1*d1 * -0.4382 +
			 x2*d2*d2 * +0.3807 +
			 x3*d3*d3 * -0.4543);
	  grad[3] = 2 * (x0*d0*d0 * -0.4391 +
			 x1*d1*d1 * -0.4096 +
			 x2*d2*d2 * -0.4543 +
			 x3*d3*d3 * +0.5667);
     }
     RETURN(d0 + d1 + d2 + d3);
}

static const double side4d_lb[4] = {0.1,-1,-1,-1};
static const double side4d_ub[4] = {1,1,1,1};
static const double side4d_xmin[4] = {0.1,0.102971169,0.0760520641,-0.0497098571};

/****************************************************************************/
/****************************************************************************/

const testfunc testfuncs[NTESTFUNCS] = {
     { rosenbrock_f, NULL, 1, 2,
       rosenbrock_lb, rosenbrock_ub, rosenbrock_xmin,
       0.0, "Rosenbrock function" },
     { mccormic_f, NULL, 1, 2,
       mccormic_lb, mccormic_ub, mccormic_xmin,
       -1.91322295, "McCormic function" },
     { boxbetts_f, NULL, 1, 3,
       boxbetts_lb, boxbetts_ub, boxbetts_xmin,
       0.0, "Box and Betts exponential quadratic sum" },
     { paviani_f, NULL, 1, 10,
       paviani_lb, paviani_ub, paviani_xmin,
       -45.7784697, "Paviani function" },
     { grosenbrock_f, NULL, 1, 30,
       grosenbrock_lb, grosenbrock_ub, grosenbrock_xmin,
       0.0, "Generalized Rosenbrock function" },
     { goldsteinprice_f, NULL, 1, 2,
       goldsteinprice_lb, goldsteinprice_ub, goldsteinprice_xmin,
       3.0, "Goldstein and Price function" },
     { shekel_f, shekel_m + 0, 1, 4,
       shekel_lb, shekel_ub, shekel0_xmin,
       -10.15319968, "Shekel m=5 function" },
     { shekel_f, shekel_m + 1, 1, 4,
       shekel_lb, shekel_ub, shekel1_xmin,
       -10.40294057, "Shekel m=7 function" },
     { shekel_f, shekel_m + 2, 1, 4,
       shekel_lb, shekel_ub, shekel2_xmin,
       -10.53640982, "Shekel m=10 function" },
     { levy_f, NULL, 1, 4,
       levy4_lb, levy4_ub, levy4_xmin,
       -21.50235596, "Levy n=4 function" },
     { levy_f, NULL, 1, 5,
       levy_lb, levy_ub, levy_xmin+2,
       -11.50440302, "Levy n=5 function" },
     { levy_f, NULL, 1, 6,
       levy_lb, levy_ub, levy_xmin+1,
       -11.50440302, "Levy n=6 function" },
     { levy_f, NULL, 1, 7,
       levy_lb, levy_ub, levy_xmin,
       -11.50440302, "Levy n=7 function" },
     { griewank_f, NULL, 1, 10,
       griewank_lb, griewank_ub, griewank_xmin,
       0.0, "Griewank function" },
     { sixhumpcamel_f, NULL, 1, 2,
       sixhumpcamel_lb, sixhumpcamel_ub, sixhumpcamel_xmin,
       -1.031628453, "Six-hump camel back function" },
     { convexcosh_f, NULL, 1, 10,
       convexcosh_lb, convexcosh_ub, convexcosh_xmin,
       1.0, "Convex product of cosh functions" },
     { branin_f, NULL, 1, 2,
       branin_lb, branin_ub, branin_xmin,
       -.0, "Branin function" },
     { shubert_f, NULL, 1, 2,
       shubert_lb, shubert_ub, shubert_xmin,
       -24.06249888, "Shubert function" },
     { hansen_f, NULL, 1, 2,
       hansen_lb, hansen_ub, hansen_xmin,
       -176.5417931367, "Hansen function" },
     { osc1d_f, NULL, 1, 1,
       osc1d_lb, osc1d_ub, osc1d_xmin,
       -1.0, "1d oscillating function with a single minimum" },
     { corner4d_f, NULL, 1, 4,
       corner4d_lb, corner4d_ub, corner4d_xmin,
       1.0, "4d function with minimum at corner" },
     { side4d_f, NULL, 1, 4,
       side4d_lb, side4d_ub, side4d_xmin,
       -141.285020472, "4d function with minimum at side" }
};