#include "strmap.h"

#include <vector>
#include <string>
#include <cstdint>

#ifndef HAVE_OLD_CPP
# include <unordered_map>
#else
# include <tr1/unordered_map>
namespace std { using std::tr1::unordered_map; }
#endif

using namespace std;

#undef HAVE_64_BITS

#if INTPTR_MAX == INT32_MAX
# define HAVE_64_BITS 0
#elif INTPTR_MAX >= INT64_MAX
# define HAVE_64_BITS 1
#else
# error "couldn't tell if HAVE_64_BITS from INTPTR_MAX INT32_MAX INT64_MAX"
#endif

typedef uintptr_t MurmurInt;

// MurmurHash2, by Austin Appleby

static const uint32_t DEFAULT_SEED=2654435769U;

#if HAVE_64_BITS
//MurmurInt MurmurHash(void const *key, int len, uint32_t seed=DEFAULT_SEED);

inline uint64_t MurmurHash64( const void * key, int len, unsigned int seed=DEFAULT_SEED )
{
  const uint64_t m = 0xc6a4a7935bd1e995ULL;
  const int r = 47;

  uint64_t h = seed ^ (len * m);

  const uint64_t * data = (const uint64_t *)key;
  const uint64_t * end = data + (len/8);

  while(data != end)
  {
    uint64_t k = *data++;

    k *= m;
    k ^= k >> r;
    k *= m;

    h ^= k;
    h *= m;
  }

  const unsigned char * data2 = (const unsigned char*)data;

  switch(len & 7)
  {
  case 7: h ^= uint64_t(data2[6]) << 48;
  case 6: h ^= uint64_t(data2[5]) << 40;
  case 5: h ^= uint64_t(data2[4]) << 32;
  case 4: h ^= uint64_t(data2[3]) << 24;
  case 3: h ^= uint64_t(data2[2]) << 16;
  case 2: h ^= uint64_t(data2[1]) << 8;
  case 1: h ^= uint64_t(data2[0]);
    h *= m;
  };

  h ^= h >> r;
  h *= m;
  h ^= h >> r;

  return h;
}

inline uint32_t MurmurHash32(void const *key, int len, uint32_t seed=DEFAULT_SEED)
{
  return (uint32_t) MurmurHash64(key,len,seed);
}

inline MurmurInt MurmurHash(void const *key, int len, uint32_t seed=DEFAULT_SEED)
{
  return MurmurHash64(key,len,seed);
}

#else
// 32-bit

// Note - This code makes a few assumptions about how your machine behaves -
// 1. We can read a 4-byte value from any address without crashing
// 2. sizeof(int) == 4
inline uint32_t MurmurHash32 ( const void * key, int len, uint32_t seed=DEFAULT_SEED)
{
  // 'm' and 'r' are mixing constants generated offline.
  // They're not really 'magic', they just happen to work well.

  const uint32_t m = 0x5bd1e995;
  const int r = 24;

  // Initialize the hash to a 'random' value

  uint32_t h = seed ^ len;

  // Mix 4 bytes at a time into the hash

  const unsigned char * data = (const unsigned char *)key;

  while(len >= 4)
  {
    uint32_t k = *(uint32_t *)data;

    k *= m;
    k ^= k >> r;
    k *= m;

    h *= m;
    h ^= k;

    data += 4;
    len -= 4;
  }

  // Handle the last few bytes of the input array

  switch(len)
  {
  case 3: h ^= data[2] << 16;
  case 2: h ^= data[1] << 8;
  case 1: h ^= data[0];
    h *= m;
  };

  // Do a few final mixes of the hash to ensure the last few
  // bytes are well-incorporated.

  h ^= h >> 13;
  h *= m;
  h ^= h >> 15;

  return h;
}

inline MurmurInt MurmurHash ( const void * key, int len, uint32_t seed=DEFAULT_SEED) {
  return MurmurHash32(key,len,seed);
}

// 64-bit hash for 32-bit platforms

inline uint64_t MurmurHash64 ( const void * key, int len, uint32_t seed=DEFAULT_SEED)
{
  const uint32_t m = 0x5bd1e995;
  const int r = 24;

  uint32_t h1 = seed ^ len;
  uint32_t h2 = 0;

  const uint32_t * data = (const uint32_t *)key;

  while(len >= 8)
  {
    uint32_t k1 = *data++;
    k1 *= m; k1 ^= k1 >> r; k1 *= m;
    h1 *= m; h1 ^= k1;
    len -= 4;

    uint32_t k2 = *data++;
    k2 *= m; k2 ^= k2 >> r; k2 *= m;
    h2 *= m; h2 ^= k2;
    len -= 4;
  }

  if(len >= 4)
  {
    uint32_t k1 = *data++;
    k1 *= m; k1 ^= k1 >> r; k1 *= m;
    h1 *= m; h1 ^= k1;
    len -= 4;
  }

  switch(len)
  {
  case 3: h2 ^= ((unsigned char*)data)[2] << 16;
  case 2: h2 ^= ((unsigned char*)data)[1] << 8;
  case 1: h2 ^= ((unsigned char*)data)[0];
    h2 *= m;
  };

  h1 ^= h2 >> 18; h1 *= m;
  h2 ^= h1 >> 22; h2 *= m;
  h1 ^= h2 >> 17; h1 *= m;
  h2 ^= h1 >> 19; h2 *= m;

  uint64_t h = h1;

  h = (h << 32) | h2;

  return h;
}

#endif
//32bit

struct MurmurHasher {
  size_t operator()(const string& s) const {
    return MurmurHash(s.c_str(), s.size());
  }
};

struct StrMap {
  StrMap() { keys_.reserve(10000); keys_.push_back("<bad0>"); map_[keys_[0]] = 0; }
  unordered_map<string, int, MurmurHasher> map_;
  vector<string> keys_;
};

StrMap* stringmap_new() {
  return new StrMap;
}

void stringmap_delete(StrMap *vocab) {
  delete vocab;
}

int stringmap_index(StrMap *vocab, char *s) {
  int& cell = vocab->map_[s];
  if (!cell) {
    cell = vocab->keys_.size();
    vocab->keys_.push_back(s);
  }
  return cell;
}

char* stringmap_word(StrMap *vocab, int i) {
  return const_cast<char *>(vocab->keys_[i].c_str());
}