/*
 * BLAKE implementation.
 *
 * ==========================(LICENSE BEGIN)============================
 *
 * Copyright (c) 2007-2010  Projet RNRT SAPHIR
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * ===========================(LICENSE END)=============================
 *
 * @author   Thomas Pornin <thomas.pornin@cryptolog.com>
 *
 * Modified for more speed by BlueDragon747 for the Blakecoin project
 */

#include <stddef.h>
#include <string.h>
#include <limits.h>
#include <stdint.h>

#include "sph/sph_blake.h"
#include "algorithm/blakecoin.h"

/*
* Encode a length len/4 vector of (uint32_t) into a length len vector of
* (unsigned char) in big-endian form.  Assumes len is a multiple of 4.
*/
static inline void
be32enc_vect(uint32_t *dst, const uint32_t *src, uint32_t len)
{
  uint32_t i;

  for (i = 0; i < len; i++)
    dst[i] = htobe32(src[i]);
}

static const uint32_t diff1targ_blake256 = 0x000000ff;

inline void blakecoinhash(void *state, const void *input)
{
  sph_blake256_context     ctx_blake;
  sph_blake256_init(&ctx_blake);
  sph_blake256r8(&ctx_blake, input, 80);
  sph_blake256r8_close(&ctx_blake, state);
}

static const uint32_t diff1targ = 0x0000ffff;


/* Used externally as confirmation of correct OCL code */
int blakecoin_test(unsigned char *pdata, const unsigned char *ptarget, uint32_t nonce)
{
	uint32_t tmp_hash7, Htarg = le32toh(((const uint32_t *)ptarget)[7]);
	uint32_t data[20], ohash[8];

	be32enc_vect(data, (const uint32_t *)pdata, 19);
	data[19] = htobe32(nonce);
	blakecoinhash(ohash, data);
	tmp_hash7 = be32toh(ohash[7]);

	applog(LOG_DEBUG, "htarget %08lx diff1 %08lx hash %08lx",
				(long unsigned int)Htarg,
				(long unsigned int)diff1targ,
				(long unsigned int)tmp_hash7);
	if (tmp_hash7 > diff1targ)
		return -1;
	if (tmp_hash7 > Htarg)
		return 0;
	return 1;
}

void blakecoin_regenhash(struct work *work)
{
        uint32_t data[20];
        uint32_t *nonce = (uint32_t *)(work->data + 76);
        uint32_t *ohash = (uint32_t *)(work->hash);

        be32enc_vect(data, (const uint32_t *)work->data, 19);
        data[19] = htobe32(*nonce);
        blakecoinhash(ohash, data);
}

bool scanhash_blakecoin(struct thr_info *thr, const unsigned char __maybe_unused *pmidstate,
		     unsigned char *pdata, unsigned char __maybe_unused *phash1,
		     unsigned char __maybe_unused *phash, const unsigned char *ptarget,
		     uint32_t max_nonce, uint32_t *last_nonce, uint32_t n)
{
	uint32_t *nonce = (uint32_t *)(pdata + 76);
	uint32_t data[20];
	uint32_t tmp_hash7;
	uint32_t Htarg = le32toh(((const uint32_t *)ptarget)[7]);
	bool ret = false;

	be32enc_vect(data, (const uint32_t *)pdata, 19);

	while(1) {
		uint32_t ostate[8];

		*nonce = ++n;
		data[19] = (n);
		blakecoinhash(ostate, data);
		tmp_hash7 = (ostate[7]);

		applog(LOG_INFO, "data7 %08lx",
					(long unsigned int)data[7]);

		if (unlikely(tmp_hash7 <= Htarg)) {
			((uint32_t *)pdata)[19] = htobe32(n);
			*last_nonce = n;
			ret = true;
			break;
		}

		if (unlikely((n >= max_nonce) || thr->work_restart)) {
			*last_nonce = n;
			break;
		}
	}

	return ret;
}