#include <unordered_set>
#include <vector>
#include <functional>
#include <cstdint>
#include <cstdlib>
#include <cstring>

#include "benchmark/benchmark.h"

#include "ContainerBenchmarks.h"
#include "GenerateInput.h"
#include "test_macros.h"

using namespace ContainerBenchmarks;

constexpr std::size_t TestNumInputs = 1024;

template <class _Size>
inline TEST_ALWAYS_INLINE
_Size loadword(const void* __p) {
    _Size __r;
    std::memcpy(&__r, __p, sizeof(__r));
    return __r;
}

inline TEST_ALWAYS_INLINE
std::size_t rotate_by_at_least_1(std::size_t __val, int __shift) {
    return (__val >> __shift) | (__val << (64 - __shift));
}

inline TEST_ALWAYS_INLINE
std::size_t hash_len_16(std::size_t __u, std::size_t __v) {
    const  std::size_t __mul = 0x9ddfea08eb382d69ULL;
    std::size_t __a = (__u ^ __v) * __mul;
    __a ^= (__a >> 47);
    std::size_t __b = (__v ^ __a) * __mul;
    __b ^= (__b >> 47);
    __b *= __mul;
    return __b;
}


template <std::size_t _Len>
inline TEST_ALWAYS_INLINE
std::size_t hash_len_0_to_8(const char* __s) {
    static_assert(_Len == 4 || _Len == 8, "");
    const uint64_t __a = loadword<uint32_t>(__s);
    const uint64_t __b = loadword<uint32_t>(__s + _Len - 4);
    return hash_len_16(_Len + (__a << 3), __b);
}

struct UInt32Hash {
  UInt32Hash() = default;
  inline TEST_ALWAYS_INLINE
  std::size_t operator()(uint32_t data) const {
      return hash_len_0_to_8<4>(reinterpret_cast<const char*>(&data));
  }
};

struct UInt64Hash {
  UInt64Hash() = default;
  inline TEST_ALWAYS_INLINE
  std::size_t operator()(uint64_t data) const {
      return hash_len_0_to_8<8>(reinterpret_cast<const char*>(&data));
  }
};

struct UInt128Hash {
  UInt128Hash() = default;
  inline TEST_ALWAYS_INLINE
  std::size_t operator()(__uint128_t data) const {
      const __uint128_t __mask = static_cast<std::size_t>(-1);
      const std::size_t __a = (std::size_t)(data & __mask);
      const std::size_t __b = (std::size_t)((data & (__mask << 64)) >> 64);
      return hash_len_16(__a, rotate_by_at_least_1(__b + 16, 16)) ^ __b;
  }
};

struct UInt32Hash2 {
  UInt32Hash2() = default;
  inline TEST_ALWAYS_INLINE
  std::size_t operator()(uint32_t data) const {
      const uint32_t __m = 0x5bd1e995;
      const uint32_t __r = 24;
      uint32_t __h = 4;
      uint32_t __k = data;
        __k *= __m;
        __k ^= __k >> __r;
        __k *= __m;
        __h *= __m;
        __h ^= __k;
        __h ^= __h >> 13;
        __h *= __m;
        __h ^= __h >> 15;
    return __h;
  }
};

struct UInt64Hash2 {
  UInt64Hash2() = default;
  inline TEST_ALWAYS_INLINE
  std::size_t operator()(uint64_t data) const {
      return hash_len_0_to_8<8>(reinterpret_cast<const char*>(&data));
  }
};

// The sole purpose of this comparator is to be used in BM_Rehash, where
// we need something slow enough to be easily noticable in benchmark results.
// The default implementation of operator== for strings seems to be a little
// too fast for that specific benchmark to reliably show a noticeable
// improvement, but unoptimized bytewise comparison fits just right.
// Early return is there just for convenience, since we only compare strings
// of equal length in BM_Rehash.
struct SlowStringEq {
  SlowStringEq() = default;
  inline TEST_ALWAYS_INLINE
  bool operator()(const std::string& lhs, const std::string& rhs) const {
      if (lhs.size() != rhs.size()) return false;

      bool eq = true;
      for (size_t i = 0; i < lhs.size(); ++i) {
          eq &= lhs[i] == rhs[i];
      }
      return eq;
  }
};

//----------------------------------------------------------------------------//
//                               BM_Hash
// ---------------------------------------------------------------------------//

template <class HashFn, class GenInputs>
void BM_Hash(benchmark::State& st, HashFn fn, GenInputs gen) {
    auto in = gen(st.range(0));
    const auto end = in.data() + in.size();
    std::size_t last_hash = 0;
    benchmark::DoNotOptimize(&last_hash);
    while (st.KeepRunning()) {
        for (auto it = in.data(); it != end; ++it) {
            benchmark::DoNotOptimize(last_hash += fn(*it));
        }
        benchmark::ClobberMemory();
    }
}

BENCHMARK_CAPTURE(BM_Hash,
    uint32_random_std_hash,
    std::hash<uint32_t>{},
    getRandomIntegerInputs<uint32_t>) -> Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_Hash,
    uint32_random_custom_hash,
    UInt32Hash{},
    getRandomIntegerInputs<uint32_t>) -> Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_Hash,
    uint32_top_std_hash,
    std::hash<uint32_t>{},
    getSortedTopBitsIntegerInputs<uint32_t>) -> Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_Hash,
    uint32_top_custom_hash,
    UInt32Hash{},
    getSortedTopBitsIntegerInputs<uint32_t>) -> Arg(TestNumInputs);


//----------------------------------------------------------------------------//
//                       BM_InsertValue
// ---------------------------------------------------------------------------//


// Sorted Ascending //
BENCHMARK_CAPTURE(BM_InsertValue,
    unordered_set_uint32,
    std::unordered_set<uint32_t>{},
    getRandomIntegerInputs<uint32_t>)->Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_InsertValue,
    unordered_set_uint32_sorted,
    std::unordered_set<uint32_t>{},
    getSortedIntegerInputs<uint32_t>)->Arg(TestNumInputs);

// Top Bytes //
BENCHMARK_CAPTURE(BM_InsertValue,
    unordered_set_top_bits_uint32,
    std::unordered_set<uint32_t>{},
    getSortedTopBitsIntegerInputs<uint32_t>)->Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_InsertValueRehash,
    unordered_set_top_bits_uint32,
    std::unordered_set<uint32_t, UInt32Hash>{},
    getSortedTopBitsIntegerInputs<uint32_t>)->Arg(TestNumInputs);

// String //
BENCHMARK_CAPTURE(BM_InsertValue,
    unordered_set_string,
    std::unordered_set<std::string>{},
    getRandomStringInputs)->Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_InsertValueRehash,
    unordered_set_string,
    std::unordered_set<std::string>{},
    getRandomStringInputs)->Arg(TestNumInputs);

//----------------------------------------------------------------------------//
//                         BM_Find
// ---------------------------------------------------------------------------//

// Random //
BENCHMARK_CAPTURE(BM_Find,
    unordered_set_random_uint64,
    std::unordered_set<uint64_t>{},
    getRandomIntegerInputs<uint64_t>)->Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_FindRehash,
    unordered_set_random_uint64,
    std::unordered_set<uint64_t, UInt64Hash>{},
    getRandomIntegerInputs<uint64_t>)->Arg(TestNumInputs);

// Sorted //
BENCHMARK_CAPTURE(BM_Find,
    unordered_set_sorted_uint64,
    std::unordered_set<uint64_t>{},
    getSortedIntegerInputs<uint64_t>)->Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_FindRehash,
    unordered_set_sorted_uint64,
    std::unordered_set<uint64_t, UInt64Hash>{},
    getSortedIntegerInputs<uint64_t>)->Arg(TestNumInputs);


// Sorted //
#if 1
BENCHMARK_CAPTURE(BM_Find,
    unordered_set_sorted_uint128,
    std::unordered_set<__uint128_t, UInt128Hash>{},
    getSortedTopBitsIntegerInputs<__uint128_t>)->Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_FindRehash,
    unordered_set_sorted_uint128,
    std::unordered_set<__uint128_t, UInt128Hash>{},
    getSortedTopBitsIntegerInputs<__uint128_t>)->Arg(TestNumInputs);
#endif

// Sorted //
BENCHMARK_CAPTURE(BM_Find,
    unordered_set_sorted_uint32,
    std::unordered_set<uint32_t>{},
    getSortedIntegerInputs<uint32_t>)->Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_FindRehash,
    unordered_set_sorted_uint32,
    std::unordered_set<uint32_t, UInt32Hash2>{},
    getSortedIntegerInputs<uint32_t>)->Arg(TestNumInputs);

// Sorted Ascending //
BENCHMARK_CAPTURE(BM_Find,
    unordered_set_sorted_large_uint64,
    std::unordered_set<uint64_t>{},
    getSortedLargeIntegerInputs<uint64_t>)->Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_FindRehash,
    unordered_set_sorted_large_uint64,
    std::unordered_set<uint64_t, UInt64Hash>{},
    getSortedLargeIntegerInputs<uint64_t>)->Arg(TestNumInputs);


// Top Bits //
BENCHMARK_CAPTURE(BM_Find,
    unordered_set_top_bits_uint64,
    std::unordered_set<uint64_t>{},
    getSortedTopBitsIntegerInputs<uint64_t>)->Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_FindRehash,
    unordered_set_top_bits_uint64,
    std::unordered_set<uint64_t, UInt64Hash>{},
    getSortedTopBitsIntegerInputs<uint64_t>)->Arg(TestNumInputs);

// String //
BENCHMARK_CAPTURE(BM_Find,
    unordered_set_string,
    std::unordered_set<std::string>{},
    getRandomStringInputs)->Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_FindRehash,
    unordered_set_string,
    std::unordered_set<std::string>{},
    getRandomStringInputs)->Arg(TestNumInputs);

//----------------------------------------------------------------------------//
//                         BM_Rehash
// ---------------------------------------------------------------------------//

BENCHMARK_CAPTURE(BM_Rehash,
    unordered_set_string_arg,
    std::unordered_set<std::string, std::hash<std::string>, SlowStringEq>{},
    getRandomStringInputs)->Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_Rehash,
    unordered_set_int_arg,
    std::unordered_set<int>{},
    getRandomIntegerInputs<int>)->Arg(TestNumInputs);

///////////////////////////////////////////////////////////////////////////////
BENCHMARK_CAPTURE(BM_InsertDuplicate,
    unordered_set_int,
    std::unordered_set<int>{},
    getRandomIntegerInputs<int>)->Arg(TestNumInputs);
BENCHMARK_CAPTURE(BM_InsertDuplicate,
    unordered_set_string,
    std::unordered_set<std::string>{},
    getRandomStringInputs)->Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_EmplaceDuplicate,
    unordered_set_int,
    std::unordered_set<int>{},
    getRandomIntegerInputs<int>)->Arg(TestNumInputs);
BENCHMARK_CAPTURE(BM_EmplaceDuplicate,
    unordered_set_string,
    std::unordered_set<std::string>{},
    getRandomStringInputs)->Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_InsertDuplicate,
    unordered_set_int_insert_arg,
    std::unordered_set<int>{},
    getRandomIntegerInputs<int>)->Arg(TestNumInputs);
BENCHMARK_CAPTURE(BM_InsertDuplicate,
    unordered_set_string_insert_arg,
    std::unordered_set<std::string>{},
    getRandomStringInputs)->Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_EmplaceDuplicate,
    unordered_set_int_insert_arg,
    std::unordered_set<int>{},
    getRandomIntegerInputs<unsigned>)->Arg(TestNumInputs);

BENCHMARK_CAPTURE(BM_EmplaceDuplicate,
    unordered_set_string_arg,
    std::unordered_set<std::string>{},
    getRandomCStringInputs)->Arg(TestNumInputs);

BENCHMARK_MAIN();