#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include "include/externs.h"
#include "include/cephes.h"

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
                         U N I V E R S A L  T E S T
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

int
Universal(int n, BitSequence *epsilon)
{
    int ret = 0;
	int		i, j, p, L, Q, K;
	double	arg, sqrt2, sigma, phi, sum, p_value, c;
	long	*T, decRep;
	const double	expected_value[17] = { 0, 0, 0, 0, 0, 0, 5.2177052, 6.1962507, 7.1836656,
				8.1764248, 9.1723243, 10.170032, 11.168765,
				12.168070, 13.167693, 14.167488, 15.167379 };
	const double   variance[17] = { 0, 0, 0, 0, 0, 0, 2.954, 3.125, 3.238, 3.311, 3.356, 3.384,
				3.401, 3.410, 3.416, 3.419, 3.421 };
	
	/* * * * * * * * * ** * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
	 * THE FOLLOWING REDEFINES L, SHOULD THE CONDITION:     n >= 1010*2^L*L       *
	 * NOT BE MET, FOR THE BLOCK LENGTH L.                                        *
	 * * * * * * * * * * ** * * * * * * * * * * * * * * * * * * * * * * * * * * * */
	L = 5;
	if ( n >= 387840 )     L = 6;
	if ( n >= 904960 )     L = 7;
	if ( n >= 2068480 )    L = 8;
	if ( n >= 4654080 )    L = 9;
	if ( n >= 10342400 )   L = 10;
	if ( n >= 22753280 )   L = 11;
	if ( n >= 49643520 )   L = 12;
	if ( n >= 107560960 )  L = 13;
	if ( n >= 231669760 )  L = 14;
	if ( n >= 496435200 )  L = 15;
	if ( n >= 1059061760 ) L = 16;
	
	Q = 10*(int)pow(2, L);
	K = (int) (floor(n/L) - (double)Q);	 		    /* BLOCKS TO TEST */
	
	p = (int)pow(2, L);
	if ( (L < 6) || (L > 16) || ((double)Q < 10*pow(2, L)) ||
		 ((T = (long *)calloc(p, sizeof(long))) == NULL) ) {
		return 0;
	}
	
	/* COMPUTE THE EXPECTED:  Formula 16, in Marsaglia's Paper */
	c = 0.7 - 0.8/(double)L + (4 + 32/(double)L)*pow(K, -3/(double)L)/15;
	sigma = c * sqrt(variance[L]/(double)K);
	sqrt2 = sqrt(2);
	sum = 0.0;
	for ( i=0; i<p; i++ )
		T[i] = 0;
	for ( i=1; i<=Q; i++ ) {		/* INITIALIZE TABLE */
		decRep = 0;
		for ( j=0; j<L; j++ )
			decRep += epsilon[(i-1)*L+j] * (long)pow(2, L-1-j);
		T[decRep] = i;
	}
	for ( i=Q+1; i<=Q+K; i++ ) { 	/* PROCESS BLOCKS */
		decRep = 0;
		for ( j=0; j<L; j++ )
			decRep += epsilon[(i-1)*L+j] * (long)pow(2, L-1-j);
		sum += log(i - T[decRep])/log(2);
		T[decRep] = i;
	}
	phi = (double)(sum/(double)K);

	arg = fabs(phi-expected_value[L])/(sqrt2 * sigma);
	p_value = erfc(arg);
	if ( isNegative(p_value) || isGreaterThanOne(p_value) ) {
        goto end;
    }

    if (p_value < ALPHA) {
        goto end;
    }

    ret = 1;

	end:
	free(T);
    return ret;
}