#include <stdlib.h>
//#include <windows.h>
#include <time.h>
#include <stdio.h>
#include <Math.h>


typedef unsigned int uint32_t;


void initRandomizer();
uint32_t getRandomUint32(uint32_t length);

void f2m_rand(uint32_t t, uint32_t m, uint32_t *A);
void f2m_print(uint32_t t, uint32_t *A);
void f2m_assign(uint32_t t, uint32_t *A, uint32_t *B);
void f2m_and(uint32_t t, uint32_t *A, uint32_t *B, uint32_t *C);
void f2m_or(uint32_t t, uint32_t *A, uint32_t *B, uint32_t *C);
void f2m_xor(uint32_t t, uint32_t *A, uint32_t *B, uint32_t *C);
void f2m_shiftleft(uint32_t t, uint32_t *A, uint32_t *B);
void f2m_shiftright(uint32_t t, uint32_t *A, uint32_t *B);
uint32_t getbit(uint32_t U, uint32_t i);
uint32_t f2m_bitm(uint32_t t, uint32_t m, uint32_t *A);

uint32_t f2m_biti(uint32_t t,uint32_t i,uint32_t *A);
void f2m_one(uint32_t t,uint32_t *A);
void f2m_zero(uint32_t t,uint32_t *A);
uint32_t f2m_is_equal(uint32_t t,uint32_t *A,uint32_t *B);
uint32_t f2m_is_one(uint32_t t,uint32_t *A);
uint32_t f2m_is_zero(uint32_t t,uint32_t *A);
void f2m_mul(uint32_t t,uint32_t m,uint32_t *A,uint32_t *B,uint32_t *F,uint32_t *C,uint32_t *T1,uint32_t *T2);
void f2m_inv(uint32_t t,uint32_t m,uint32_t *A,uint32_t *F,uint32_t *B,uint32_t *U,uint32_t *V,uint32_t *T1,uint32_t *T2);
uint32_t f2m_deg(uint32_t,uint32_t,uint32_t*);
void build_f(uint32_t,uint32_t,uint32_t*);

int main(int argc, char* argv[])
{
	initRandomizer();
	uint32_t m = 163;
	//double x = static_cast<double>(m>>5);
	double x = static_cast<double>( ((double)m) / 32);
	uint32_t t = ceil(x);
	uint32_t *A,*B,*C,*U,*V,*T1,*T2,*F,*R1,*R2,*R3,*R4;
	long s = sizeof(uint32_t);
	long bytes = s*t;
	A = (uint32_t*) malloc(bytes);
	B = (uint32_t*) malloc(bytes);
	C = (uint32_t*) malloc(bytes);
	U = (uint32_t*) malloc(bytes);
	V = (uint32_t*) malloc(bytes);
	T1 = (uint32_t*) malloc(bytes);
	T2 = (uint32_t*) malloc(bytes);
	F = (uint32_t*) malloc(bytes);
	R1 = (uint32_t*) malloc(bytes);
	R2 = (uint32_t*) malloc(bytes);
	R3 = (uint32_t*) malloc(bytes);
	R4 = (uint32_t*) malloc(bytes);
	
	f2m_zero(t,A);
	f2m_print(t,A);
	if(f2m_is_zero(t,A))
		printf("A is zero \n");

	f2m_one(t,A);
	f2m_print(t,A);
	if(f2m_is_one(t,A))
		printf("A is one \n");

	uint32_t bit;
	bit = f2m_biti(t,0,A);
	if(bit == 1)
		printf("Bit 1 of A is 1\n");
	else
		printf("Bit 1 of A is %u\n",bit);
	
	if (f2m_is_equal(t,A,A) )
		printf("A equal A\n");
	else
		printf("A not equal A ?!\n");
	build_f(t,m,F);
	uint32_t degF = f2m_deg(t,m,F);
	printf("Deg(F) = %u\n",degF);
	bool hasError = false;
	for(uint32_t n = 0;n<10000;n++) {
		f2m_rand(t,m,A);
		/*f2m_rand(t,m,B);
		f2m_rand(t,m,C);
		
		f2m_mul(t,m,A,B,F,R1,T1,T2);
		f2m_mul(t,m,R1,C,F,R2,T1,T2);

		f2m_mul(t,m,B,C,F,R3,T1,T2);
		f2m_mul(t,m,A,R3,F,R4,T1,T2);
		
		if(f2m_is_equal(t,R2,R4))
			printf("Mul works correctly\n");
		else
			printf("Mul is not working correctly\n");
		*/
		f2m_inv(t,m,A,F,R1,U,V,T1,T2);
		f2m_mul(t,m,A,R1,F,R2,T1,T2);
		
		if(n%100 == 0){
			printf("%u\n",n );
		}

		if(!f2m_is_one(t,R2))
		{
			hasError = true;
			break;
		}
	}
	if(!hasError)
		printf("Inv works correctly\n");
	else
		printf("Inv is not working correctly\n");

	//f2m_assign(t,A,B);
	//printf("\n\n\n");
	//f2m_print(t,B);
	
	/*

	f2m_and(t,A,A,C);
	
	printf("A&A: \n");
	f2m_print(t,C);
	
	printf("A: \n");
	f2m_print(t,A);
	
	printf("B: \n");
	f2m_print(t,B);
	
	f2m_and(t,A,B,C);
	
	printf("A&B: \n");
	f2m_print(t,C);
	
	printf("A << 1: \n");
	f2m_shiftleft(t,A,B);
	f2m_print(t,B);
	uint32_t test[] = {0x1,0x0};
	f2m_print(2,&test[0]);
	for(int i=0;i<63;i++) {
		f2m_shiftleft(2,&test[0],&test[0]);
		f2m_print(2,&test[0]);
	}
	for(int i=0;i<63;i++) {
		f2m_shiftright(2,&test[0],&test[0]);
		f2m_print(2,&test[0]);
	}
	printf("0 OR 1: \n");
	test[0] = 0x0;
	test[1] = 0x0;
	uint32_t test2[] = {0x1,0x0};
	uint32_t test3[2];
	f2m_or(2,&test[0],&test2[0],&test3[0]);
	f2m_print(2,&test3[0]);

	printf("1 XOR 1: \n");
	test[0] = 0x1;
	test[1] = 0x0;
	test2[0] = 0x1;
	test2[1] = 0x0;
	f2m_xor(2,&test[0],&test2[0],&test3[0]);
	f2m_print(2,&test3[0]);
	*/
	getchar();
	free(A);
	free(B);
	free(C);
	free(F);
	free(U);
	free(V);
	free(T1);
	free(T2);
	free(R1);
	free(R2);
	free(R3);
	free(R4);
	return 0;
}

void initRandomizer()
{
	srand(time(NULL));
}
uint32_t getRandomUint32()
{
	uint32_t resLow = rand();
	uint32_t resHigh = rand();
	uint32_t res;
	res = resHigh << 15;
	res = res | (resLow);
	return res;
}

void f2m_rand(uint32_t t, uint32_t m, uint32_t *A)
{
	for(int i=t-1;i>=0;i--)
	{
		A[i]= getRandomUint32();
	}
	
	uint32_t mask = 0x0;
	uint32_t unEvenBytes = m%32;
	if (unEvenBytes != 0) {
		for(uint32_t i=0;i<(unEvenBytes)-1;i++) {
			mask |= (1<<i);
		}
		A[t-1] &= mask;
	}
}

void f2m_print(uint32_t t, uint32_t *A)
{
	for(int i=t-1;i>=0;i--)
	{
		printf("%08X ",A[i]);
		if(!(i%4))
			printf("\n");
	}
}

void f2m_assign(uint32_t t, uint32_t *A, uint32_t *B)
{
	for(int i=t-1;i>=0;i--)
	{
		B[i]=A[i];
	}
}
void f2m_and(uint32_t t, uint32_t *A, uint32_t *B, uint32_t *C)
{
	for(int i=t-1;i>=0;i--)
	{
		C[i] = (B[i] & A[i]);
	}
}

void f2m_or(uint32_t t, uint32_t *A, uint32_t *B, uint32_t *C)
{
	for(int i=t-1;i>=0;i--)
	{
		C[i] = (B[i] | A[i]);
	}
}

void f2m_xor(uint32_t t, uint32_t *A, uint32_t *B, uint32_t *C)
{
	for(int i=t-1;i>=0;i--)
	{
		C[i] = (B[i] ^ A[i]);
	}
}

void f2m_shiftleft(uint32_t t, uint32_t *A, uint32_t *B)
{
	for(int i=t-1;i>0;i--)
	{
		B[i] = ((A [i] << 1)| getbit(A[i-1],31));
	}
	B[0] = A [0] << 1;
}
void f2m_shiftright(uint32_t t, uint32_t *A, uint32_t *B)
{
	for(uint32_t n=0;n<(t-1);n++)
	{
		B[n] = ((A[n]>> 1)| (getbit(A[n+1],0)<<31));
	}
	B[t-1] = A[t-1]>> 1;
}

uint32_t getbit(uint32_t U, uint32_t i)
{
	if(i==0)
		return U & 0x1;
	else
		return ((U>> i)& 0x1);
}

uint32_t f2m_bitm(uint32_t t, uint32_t m, uint32_t *A)
{
	/*
	int modul = m%32;
	if(modul!=0)
		return getbit(A[t-1],(m%32)-1);
	else 
		return getbit(A[t-1],31);
	*/
	return f2m_biti(t,m,A);
}

uint32_t f2m_biti(uint32_t t,uint32_t i,uint32_t *A)
{
	return getbit(A[i / 32],i % 32);
}
void f2m_one(uint32_t t,uint32_t *A)
{
	for(uint32_t i=1; i<t; i++)
	{
		A[i] = 0;
	}
	A[0]=1;
}
void f2m_zero(uint32_t t,uint32_t *A)
{
	for(uint32_t i=0; i<t; i++)
	{
		A[i] = 0;
	}
}
uint32_t f2m_is_equal(uint32_t t,uint32_t *A,uint32_t *B)
{
	for(uint32_t i=0; i<t; i++)
	{
		if(A[i] != B[i])
			return 0;
	}
	return 1;
}
uint32_t f2m_is_one(uint32_t t,uint32_t *A)
{
	for(uint32_t i=1; i<t; i++)
	{
		if(A[i] != 0)
			return 0;
	}
	if(A[0] != 1)
		return 0;
	return 1;
}
uint32_t f2m_is_zero(uint32_t t,uint32_t *A)
{
	for(uint32_t i=0; i<t; i++)
	{
		if(A[i] != 0)
			return 0;
	}
	return 1;
}
void f2m_mul(uint32_t t,uint32_t m,uint32_t *A,uint32_t *B,uint32_t *F,uint32_t *C,uint32_t *T1,uint32_t *T2)
{
	f2m_assign(t,B,T1);
	f2m_zero(t,T2);
	for(uint32_t i=0;i<m-1;i++){
		if( f2m_biti(t,m,T1) == 1 )
		{
			f2m_xor(t,T1, F ,T1);
		}
		if ( f2m_biti(t,i,A) == 1)
		{
			f2m_xor(t,T2,T1,T2);
		}
		f2m_shiftleft(t,T1,T1);
	}
	f2m_assign(t,T2,C);
}

uint32_t f2m_deg(uint32_t t,uint32_t m, uint32_t* A)
{
	/*
	for(uint32_t i = t-1; i >= 0; i--)
	{
		if(A[i] != 0)
		{
			for(uint32_t x=31;x>=0;x--)
			{
				if( getbit(A[i],x) == 0x1 )
				{
					return (i*32)+x+1;
				}
			}
		}
	}
	*/
	for(uint32_t pos=m;pos>=0;pos--)
	{
		if(f2m_biti(t,pos,A) == 0x1)
		{
			return pos;
		}
	}
	return 0;
}

void f2m_inv(uint32_t t,uint32_t m,uint32_t *A,uint32_t *F,uint32_t *B,uint32_t *U,uint32_t *V,uint32_t *T1,uint32_t *T2)
{
	f2m_assign(t,A,U);
	f2m_assign(t,F,V);
	f2m_one(t,T1);
	f2m_zero(t,T2);
	while( !f2m_is_one(t,U) && !f2m_is_one(t,V) )
	{
		while(f2m_biti(t,0,U) == 0 &&  !f2m_is_zero(t,U) )
		{
			f2m_shiftright(t,U,U);
			if(f2m_biti(t,0,T1) == 0 && !f2m_is_zero(t,T1) )
			{
				f2m_shiftright(t,T1,T1);
			}
			else
			{
				f2m_xor(t,T1,F,T1);
				f2m_shiftright(t,T1,T1);
			}
		}
		while(f2m_biti(t,0,V) == 0 &&  !f2m_is_zero(t,V) )
		{
			f2m_shiftright(t,V,V);
			if(f2m_biti(t,0,T2) == 0 && !f2m_is_zero(t,T2) )
			{
				f2m_shiftright(t,T2,T2);
			}
			else
			{
				f2m_xor(t,T2,F,T2);
				f2m_shiftright(t,T2,T2);
			}
		}
		if(f2m_deg(t,m,U) > f2m_deg(t,m,V))
		{
			f2m_xor(t,U,V,U);
			f2m_xor(t,T1,T2,T1);
		}
		else
		{
			f2m_xor(t,U,V,V);
			f2m_xor(t,T1,T2,T2);
		}
	}
	if(f2m_is_one(t,U))
	{
		f2m_assign(t,T1,B);
	}
	else
	{
		f2m_assign(t,T2,B);
	}
}
void build_f(uint32_t t,uint32_t m,uint32_t* F)
{
	f2m_zero(t,F);
	F[5] = 1<<3;
	F[0] = 0xC9;
	f2m_print(t,F);
}