#include "uint256.h"
#include "sph/sph_groestl.h"

#include "miner.h"

#include <string.h>
#include <stdint.h>
#include <algorithm>
#include <openssl/sha.h>

#include "cuda_groestlcoin.h"

#define SWAP32(x) \
    ((((x) << 24) & 0xff000000u) | (((x) << 8) & 0x00ff0000u)   | \
      (((x) >> 8) & 0x0000ff00u) | (((x) >> 24) & 0x000000ffu))

#ifdef _MSC_VER
#define MIN min
#else
#define MIN std::min
#endif

void sha256func(unsigned char *hash, const unsigned char *data, int len)
{
    uint32_t S[16], T[16];
    int i, r;

    sha256_init(S);
    for (r = len; r > -9; r -= 64) {
        if (r < 64)
            memset(T, 0, 64);
        memcpy(T, data + len - r, r > 64 ? 64 : (r < 0 ? 0 : r));
        if (r >= 0 && r < 64)
            ((unsigned char *)T)[r] = 0x80;
        for (i = 0; i < 16; i++)
            T[i] = be32dec(T + i);
        if (r < 56)
            T[15] = 8 * len;
        sha256_transform(S, T, 0);
    }
    /*
    memcpy(S + 8, sha256d_hash1 + 8, 32);
    sha256_init(T);
    sha256_transform(T, S, 0);
    */
    for (i = 0; i < 8; i++)
        be32enc((uint32_t *)hash + i, T[i]);
}

extern "C" void groestlhash(void *state, const void *input)
{
    // CPU-groestl
    sph_groestl512_context ctx_groestl[2];

    //these uint512 in the c++ source of the client are backed by an array of uint32
    uint32_t hashA[16], hashB[16];    

    sph_groestl512_init(&ctx_groestl[0]);
    sph_groestl512 (&ctx_groestl[0], input, 80); //6
    sph_groestl512_close(&ctx_groestl[0], hashA); //7    

    sph_groestl512_init(&ctx_groestl[1]);
    sph_groestl512 (&ctx_groestl[1], hashA, 64); //6
    sph_groestl512_close(&ctx_groestl[1], hashB); //7

    memcpy(state, hashB, 32);
}

extern bool opt_benchmark;

extern "C" int scanhash_groestlcoin(int thr_id, uint32_t *pdata, const uint32_t *ptarget,
    uint32_t max_nonce, unsigned long *hashes_done)
{    
    uint32_t start_nonce = pdata[19]++;
    uint32_t throughPut = opt_work_size ? opt_work_size : (1 << 19); // 256*2048
    throughPut = MIN(throughPut, max_nonce - start_nonce);

    uint32_t *outputHash = (uint32_t*)malloc(throughPut * 16 * sizeof(uint32_t));

    if (opt_benchmark)
        ((uint32_t*)ptarget)[7] = 0x000000ff;

    // init
    static bool init[8] = { false, false, false, false, false, false, false, false };
    if(!init[thr_id])
    {
        groestlcoin_cpu_init(thr_id, throughPut);
        init[thr_id] = true;
    }
    
    // Endian Drehung ist notwendig
    uint32_t endiandata[32];
    for (int kk=0; kk < 32; kk++)
        be32enc(&endiandata[kk], pdata[kk]);

    // Context mit dem Endian gedrehten Blockheader vorbereiten (Nonce wird später ersetzt)
    groestlcoin_cpu_setBlock(thr_id, endiandata, (void*)ptarget);
    
    do {
        // GPU
        uint32_t foundNounce = 0xFFFFFFFF;
        const uint32_t Htarg = ptarget[7];

        groestlcoin_cpu_hash(thr_id, throughPut, pdata[19], outputHash, &foundNounce);

        if(foundNounce < 0xffffffff)
        {
            uint32_t tmpHash[8];
            endiandata[19] = SWAP32(foundNounce);
            groestlhash(tmpHash, endiandata);

            if (tmpHash[7] <= Htarg && fulltest(tmpHash, ptarget)) {
                pdata[19] = foundNounce;
                *hashes_done = foundNounce - start_nonce + 1;
                free(outputHash);
                return true;
            } else {
                applog(LOG_INFO, "GPU #%d: result for nonce $%08X does not validate on CPU!", thr_id, foundNounce);
            }

            foundNounce = 0xffffffff;
        }

        if (pdata[19] + throughPut < pdata[19])
            pdata[19] = max_nonce;
        else pdata[19] += throughPut;

    } while (pdata[19] < max_nonce && !work_restart[thr_id].restart);
    
    *hashes_done = pdata[19] - start_nonce + 1;
    free(outputHash);
    return 0;
}