#include <stdio.h>
#include <openssl/sha.h>
#include <cuda.h>
#include <map>

// include thrust if possible
#if defined(__GNUC__) && __GNUC__ == 5 && __GNUC_MINOR__ >= 2 && CUDA_VERSION < 7000
#warning "Heavy: incompatible GCC version!"
#define USE_THRUST 0
#else
#define USE_THRUST 1
#endif

#if USE_THRUST
#include <thrust/remove.h>
#include <thrust/device_vector.h>
#endif

#include "miner.h"

extern "C" {
#include "sph/sph_keccak.h"
#include "sph/sph_blake.h"
#include "sph/sph_groestl.h"
}
#include "hefty1.h"
#include "heavy/heavy.h"
#include "cuda_helper.h"

extern uint32_t *d_hash2output[MAX_GPUS];
extern uint32_t *d_hash3output[MAX_GPUS];
extern uint32_t *d_hash4output[MAX_GPUS];
extern uint32_t *d_hash5output[MAX_GPUS];

#define HEAVYCOIN_BLKHDR_SZ 84
#define MNR_BLKHDR_SZ       80

// nonce-array für die threads
uint32_t *heavy_nonceVector[MAX_GPUS];

extern uint32_t *heavy_heftyHashes[MAX_GPUS];

/* Combines top 64-bits from each hash into a single hash */
static void combine_hashes(uint32_t *out, const uint32_t *hash1, const uint32_t *hash2, const uint32_t *hash3, const uint32_t *hash4)
{
	const uint32_t *hash[4] = { hash1, hash2, hash3, hash4 };
	int bits;
	unsigned int i;
	uint32_t mask;
	unsigned int k;

	/* Transpose first 64 bits of each hash into out */
	memset(out, 0, 32);
	bits = 0;
	for (i = 7; i >= 6; i--) {
		for (mask = 0x80000000; mask; mask >>= 1) {
			for (k = 0; k < 4; k++) {
				out[(255 - bits)/32] <<= 1;
				if ((hash[k][i] & mask) != 0)
					out[(255 - bits)/32] |= 1;
				bits++;
			}
		}
	}
}

#ifdef _MSC_VER
#include <intrin.h>
static uint32_t __inline bitsset( uint32_t x )
{
	DWORD r = 0;
	_BitScanReverse(&r, x);
	return r;
}
#else
static uint32_t bitsset( uint32_t x )
{
	return 31-__builtin_clz(x);
}
#endif

// Finde das high bit in einem Multiword-Integer.
static int findhighbit(const uint32_t *ptarget, int words)
{
	int i;
	int highbit = 0;
	for (i=words-1; i >= 0; --i)
	{
		if (ptarget[i] != 0) {
			highbit = i*32 + bitsset(ptarget[i])+1;
			break;
		}
	}
	return highbit;
}

// Generiere ein Multiword-Integer das die Zahl
// (2 << highbit) - 1 repräsentiert.
static void genmask(uint32_t *ptarget, int words, int highbit)
{
	int i;
	for (i=words-1; i >= 0; --i)
	{
		if ((i+1)*32 <= highbit)
			ptarget[i] = UINT32_MAX;
		else if (i*32 > highbit)
			ptarget[i] = 0x00000000;
		else
			ptarget[i] = (1 << (highbit-i*32)) - 1;
	}
}

struct check_nonce_for_remove
{
	check_nonce_for_remove(uint64_t target, uint32_t *hashes, uint32_t hashlen, uint32_t startNonce) :
		m_target(target),
		m_hashes(hashes),
		m_hashlen(hashlen),
		m_startNonce(startNonce) { }

	uint64_t  m_target;
	uint32_t *m_hashes;
	uint32_t  m_hashlen;
	uint32_t  m_startNonce;

	__device__
	bool operator()(const uint32_t x)
	{
		// Position im Hash Buffer
		uint32_t hashIndex = x - m_startNonce;
		// Wert des Hashes (als uint64_t) auslesen.
		// Steht im 6. und 7. Wort des Hashes (jeder dieser Hashes hat 512 Bits)
		uint64_t hashValue = *((uint64_t*)(&m_hashes[m_hashlen*hashIndex + 6]));
		bool res = (hashValue & m_target) != hashValue;
		//printf("ndx=%x val=%08x target=%lx\n", hashIndex, hashValue, m_target);
		// gegen das Target prüfen. Es dürfen nur Bits aus dem Target gesetzt sein.
		return res;
	}
};

static bool init[MAX_GPUS] = { 0 };

__host__
int scanhash_heavy(int thr_id, struct work *work, uint32_t max_nonce, unsigned long *hashes_done, uint32_t maxvote, int blocklen)
{
	uint32_t *pdata = work->data;
	uint32_t *ptarget = work->target;
	const uint32_t first_nonce = pdata[19];
	// CUDA will process thousands of threads.
	uint32_t throughput = cuda_default_throughput(thr_id, (1U << 19) - 256);
	if (init[thr_id]) throughput = min(throughput, max_nonce - first_nonce);

	int rc = 0;
	uint32_t *hash = NULL;
	uint32_t *cpu_nonceVector = NULL;

	int nrmCalls[6];
	memset(nrmCalls, 0, sizeof(int) * 6);

	if (opt_benchmark)
	   ptarget[7] = 0x000f;

	// für jeden Hash ein individuelles Target erstellen basierend
	// auf dem höchsten Bit, das in ptarget gesetzt ist.
	int highbit = findhighbit(ptarget, 8);
	uint32_t target2[2], target3[2], target4[2], target5[2];
	genmask(target2, 2, highbit/4+(((highbit%4)>3)?1:0) ); // SHA256
	genmask(target3, 2, highbit/4+(((highbit%4)>2)?1:0) ); // keccak512
	genmask(target4, 2, highbit/4+(((highbit%4)>1)?1:0) ); // groestl512
	genmask(target5, 2, highbit/4+(((highbit%4)>0)?1:0) ); // blake512

	if (!init[thr_id])
	{
		cudaSetDevice(device_map[thr_id]);
		if (opt_cudaschedule == -1 && gpu_threads == 1) {
			cudaDeviceReset();
			// reduce cpu usage
			cudaSetDeviceFlags(cudaDeviceScheduleBlockingSync);
			CUDA_LOG_ERROR();
		}
		gpulog(LOG_INFO, thr_id, "Intensity set to %g, %u cuda threads", throughput2intensity(throughput), throughput);

		hefty_cpu_init(thr_id, throughput);
		sha256_cpu_init(thr_id, throughput);
		keccak512_cpu_init(thr_id, throughput);
		groestl512_cpu_init(thr_id, throughput);
		blake512_cpu_init(thr_id, throughput);
		combine_cpu_init(thr_id, throughput);

		CUDA_SAFE_CALL(cudaMalloc(&heavy_nonceVector[thr_id], sizeof(uint32_t) * throughput));

		init[thr_id] = true;
	}

	// weird but require at least one cudaSetDevice first
	CUDA_SAFE_CALL(cudaMallocHost(&hash, (size_t) 32 * throughput));
	CUDA_SAFE_CALL(cudaMallocHost(&cpu_nonceVector, sizeof(uint32_t) * throughput));

	if (blocklen == HEAVYCOIN_BLKHDR_SZ)
	{
		uint16_t *ext = (uint16_t*) &pdata[20];

		if (opt_vote > maxvote && !opt_benchmark) {
			applog(LOG_WARNING, "Your block reward vote (%hu) exceeds the maxvote reported by the pool (%hu).",
					opt_vote, maxvote);
		}

		if (opt_trust_pool && opt_vote > maxvote) {
			applog(LOG_WARNING, "Capping block reward vote to maxvote reported by pool.");
			ext[0] = maxvote;
		}
		else
			ext[0] = opt_vote;
	}

	// Setze die Blockdaten
	hefty_cpu_setBlock(thr_id, throughput, pdata, blocklen);
	sha256_cpu_setBlock(pdata, blocklen);
	keccak512_cpu_setBlock(pdata, blocklen);
	groestl512_cpu_setBlock(pdata, blocklen);
	blake512_cpu_setBlock(pdata, blocklen);

	do {
		uint32_t actualNumberOfValuesInNonceVectorGPU = throughput;

		////// Compaction init

		hefty_cpu_hash(thr_id, throughput, pdata[19]);
		sha256_cpu_hash(thr_id, throughput, pdata[19]);

		// Hier ist die längste CPU Wartephase. Deshalb ein strategisches MyStreamSynchronize() hier.
		MyStreamSynchronize(NULL, 1, thr_id);

#if USE_THRUST
		thrust::device_ptr<uint32_t> devNoncePtr(heavy_nonceVector[thr_id]);
		thrust::device_ptr<uint32_t> devNoncePtrEnd((heavy_nonceVector[thr_id]) + throughput);

		////// Compaction
		uint64_t *t = (uint64_t*) target2;
		devNoncePtrEnd = thrust::remove_if(devNoncePtr, devNoncePtrEnd, check_nonce_for_remove(*t, d_hash2output[thr_id], 8, pdata[19]));
		actualNumberOfValuesInNonceVectorGPU = (uint32_t)(devNoncePtrEnd - devNoncePtr);
		if(actualNumberOfValuesInNonceVectorGPU == 0)
			goto emptyNonceVector;

		keccak512_cpu_hash(thr_id, actualNumberOfValuesInNonceVectorGPU, pdata[19]);

		////// Compaction
		t = (uint64_t*) target3;
		devNoncePtrEnd = thrust::remove_if(devNoncePtr, devNoncePtrEnd, check_nonce_for_remove(*t, d_hash3output[thr_id], 16, pdata[19]));
		actualNumberOfValuesInNonceVectorGPU = (uint32_t)(devNoncePtrEnd - devNoncePtr);
		if(actualNumberOfValuesInNonceVectorGPU == 0)
			goto emptyNonceVector;

		blake512_cpu_hash(thr_id, actualNumberOfValuesInNonceVectorGPU, pdata[19]);

		////// Compaction
		t = (uint64_t*) target5;
		devNoncePtrEnd = thrust::remove_if(devNoncePtr, devNoncePtrEnd, check_nonce_for_remove(*t, d_hash5output[thr_id], 16, pdata[19]));
		actualNumberOfValuesInNonceVectorGPU = (uint32_t)(devNoncePtrEnd - devNoncePtr);
		if(actualNumberOfValuesInNonceVectorGPU == 0)
			goto emptyNonceVector;

		groestl512_cpu_hash(thr_id, actualNumberOfValuesInNonceVectorGPU, pdata[19]);

		////// Compaction
		t = (uint64_t*) target4;
		devNoncePtrEnd = thrust::remove_if(devNoncePtr, devNoncePtrEnd, check_nonce_for_remove(*t, d_hash4output[thr_id], 16, pdata[19]));
		actualNumberOfValuesInNonceVectorGPU = (uint32_t)(devNoncePtrEnd - devNoncePtr);
#else
		// todo (nvlabs cub ?)
		actualNumberOfValuesInNonceVectorGPU = 0;
#endif
		if(actualNumberOfValuesInNonceVectorGPU == 0)
			goto emptyNonceVector;

		// combine
		combine_cpu_hash(thr_id, actualNumberOfValuesInNonceVectorGPU, pdata[19], hash);

		if (opt_tracegpu) {
			applog(LOG_BLUE, "heavy GPU hash:");
			applog_hash((uchar*)hash);
		}

		// Ergebnisse kopieren
		if(actualNumberOfValuesInNonceVectorGPU > 0)
		{
			size_t size = sizeof(uint32_t) * actualNumberOfValuesInNonceVectorGPU;
			cudaMemcpy(cpu_nonceVector, heavy_nonceVector[thr_id], size, cudaMemcpyDeviceToHost);

			for (uint32_t i=0; i < actualNumberOfValuesInNonceVectorGPU; i++)
			{
				uint32_t nonce = cpu_nonceVector[i];
				uint32_t *foundhash = &hash[8*i];
				if (foundhash[7] <= ptarget[7] && fulltest(foundhash, ptarget)) {
					uint32_t vhash[8];
					pdata[19] += nonce - pdata[19];
					heavycoin_hash((uchar*)vhash, (uchar*)pdata, blocklen);
					if (memcmp(vhash, foundhash, 32)) {
						gpulog(LOG_WARNING, thr_id, "result for %08x does not validate on CPU!", nonce);
					} else {
						work_set_target_ratio(work, vhash);
						rc = 1;
						goto exit;
					}
				}
			}
		}

emptyNonceVector:
		if ((uint64_t) throughput + pdata[19] >= max_nonce) {
			pdata[19] = max_nonce;
			break;
		}
		pdata[19] += throughput;

	} while (!work_restart[thr_id].restart);

exit:
	*hashes_done = pdata[19] - first_nonce;

	cudaFreeHost(cpu_nonceVector);
	cudaFreeHost(hash);
	CUDA_LOG_ERROR();

	return rc;
}

// cleanup
extern "C" void free_heavy(int thr_id)
{
	if (!init[thr_id])
		return;

	cudaThreadSynchronize();

	cudaFree(heavy_nonceVector[thr_id]);

	blake512_cpu_free(thr_id);
	groestl512_cpu_free(thr_id);
	hefty_cpu_free(thr_id);
	keccak512_cpu_free(thr_id);
	sha256_cpu_free(thr_id);
	combine_cpu_free(thr_id);

	init[thr_id] = false;

	cudaDeviceSynchronize();
}

__host__
void heavycoin_hash(uchar* output, const uchar* input, int len)
{
	unsigned char hash1[32];
	unsigned char hash2[32];
	uint32_t hash3[16];
	uint32_t hash4[16];
	uint32_t hash5[16];
	uint32_t *final;
	SHA256_CTX ctx;
	sph_keccak512_context keccakCtx;
	sph_groestl512_context groestlCtx;
	sph_blake512_context blakeCtx;

	HEFTY1(input, len, hash1);

	/* HEFTY1 is new, so take an extra security measure to eliminate
	 * the possiblity of collisions:
	 *
	 *     Hash(x) = SHA256(x + HEFTY1(x))
	 *
	 * N.B. '+' is concatenation.
	 */
	SHA256_Init(&ctx);
	SHA256_Update(&ctx, input, len);
	SHA256_Update(&ctx, hash1, sizeof(hash1));
	SHA256_Final(hash2, &ctx);

	/* Additional security: Do not rely on a single cryptographic hash
	 * function.  Instead, combine the outputs of 4 of the most secure
	 * cryptographic hash functions-- SHA256, KECCAK512, GROESTL512
	 * and BLAKE512.
	 */

	sph_keccak512_init(&keccakCtx);
	sph_keccak512(&keccakCtx, input, len);
	sph_keccak512(&keccakCtx, hash1, sizeof(hash1));
	sph_keccak512_close(&keccakCtx, (void *)&hash3);

	sph_groestl512_init(&groestlCtx);
	sph_groestl512(&groestlCtx, input, len);
	sph_groestl512(&groestlCtx, hash1, sizeof(hash1));
	sph_groestl512_close(&groestlCtx, (void *)&hash4);

	sph_blake512_init(&blakeCtx);
	sph_blake512(&blakeCtx, input, len);
	sph_blake512(&blakeCtx, (unsigned char *)&hash1, sizeof(hash1));
	sph_blake512_close(&blakeCtx, (void *)&hash5);

	final = (uint32_t *)output;
	combine_hashes(final, (uint32_t *)hash2, hash3, hash4, hash5);
}