#include "LCBitVector.h"
#include "LCIndexInput.h"
#include "LCIndexOutput.h"
#include "GNUstep.h"

@implementation LCBitVector

- (id) initWithSize: (int) n
{
	self = [super init];
	count = -1;
	size = n;
	it = ((n >> 3) + 1);
	bits = calloc(it, sizeof(unsigned char));
	return self;
}

- (void) dealloc
{
	free(bits);
	bits = NULL;
	[super dealloc];
}

- (void) setBit: (int) bit
{
	unsigned char b;
	it = (bit >> 3);
	b = bits[it];
	b |= 1 << (bit & 7);
	bits[it] = b;
	count = -1; // Recalculate count
}

- (void) clearBit: (int) bit
{
	unsigned char b;
	it = (bit >> 3);
	b = bits[it];
	b &= ~(1 << (bit & 7));
	bits[it] = b;
	count = -1; //Recalculate count
}

- (BOOL) bit: (int) bit
{
	it = (bit >> 3);
	unsigned char b;
	b = bits[it];
	int result = b & (1 << (bit & 7));
	return ((result != 0) ? YES : NO);
}

- (int) size
{
	return size;
}

static char BYTE_COUNTS[] = {	  // table of bits/byte
    0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,
    1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
    1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
    2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
    1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
    2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
    2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
    3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
    1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
    2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
    2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
    3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
    2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
    3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
    3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
    4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8
};

- (int) count
{
	if (count == -1) 
    {
		int i, c = 0;
		unsigned char b;
		NSRange r;
		int end = ((size >> 3) + 1);
		for (i = 0; i < end; i++)
        {
			b = bits[i];
			c += BYTE_COUNTS[b & 0xFF];	  // sum bits per byte
		}
		count = c;
    }
	return count;
}

- (void) writeToDirectory: (id <LCDirectory>) d
				 name: (NSString *) name
{
	LCIndexOutput *output = [d createOutput: name];
	if (output)
	{
		[output writeInt: [self size]];
		[output writeInt: [self count]];
		NSData *data = [NSData dataWithBytes: bits length: (size >> 3) + 1];
		[output writeBytes: data length: [data length]];
		[output close];
	}
}

- (id) initWithDirectory: (id <LCDirectory>) d
				 name: (NSString *) name
{
	self = [self init];
	LCIndexInput *input = [d openInput: name];
	if (input)
	{
		size = [input readInt];
		self = [self initWithSize: size];
		count = [input readInt];
		NSMutableData *b = [[NSMutableData alloc] init];
		[input readBytes: b offset: 0 length: (size >> 3) + 1];
		[b getBytes: bits];
		DESTROY(b);
		[input close];
		return self;
	}
	else
	{
		NSLog(@"Cannot get saved bit-vector");
		return nil;
	}
}

@end