// SPDX-License-Identifier: MIT
#include <catch2/catch_test_macros.hpp>
#include <catch2/generators/catch_generators_range.hpp>

#include "Utils/Allocator/FlexBitSet.h"
#include <sys/mman.h>

TEST_CASE("FlexBitSet - Sizing") {
  // Ensure that FlexBitSet sizing is correct.

  // Size of zero shouldn't take any space.
  CHECK(FEXCore::FlexBitSet<uint8_t>::SizeInBytes(0) == 0);
  CHECK(FEXCore::FlexBitSet<uint16_t>::SizeInBytes(0) == 0);
  CHECK(FEXCore::FlexBitSet<uint32_t>::SizeInBytes(0) == 0);
  CHECK(FEXCore::FlexBitSet<uint64_t>::SizeInBytes(0) == 0);

  CHECK(FEXCore::FlexBitSet<uint8_t>::SizeInBits(0) == 0);
  CHECK(FEXCore::FlexBitSet<uint16_t>::SizeInBits(0) == 0);
  CHECK(FEXCore::FlexBitSet<uint32_t>::SizeInBits(0) == 0);
  CHECK(FEXCore::FlexBitSet<uint64_t>::SizeInBits(0) == 0);

  // Size of 1 should take one sizeof(ElementSize) size
  CHECK(FEXCore::FlexBitSet<uint8_t>::SizeInBytes(1) == sizeof(uint8_t));
  CHECK(FEXCore::FlexBitSet<uint16_t>::SizeInBytes(1) == sizeof(uint16_t));
  CHECK(FEXCore::FlexBitSet<uint32_t>::SizeInBytes(1) == sizeof(uint32_t));
  CHECK(FEXCore::FlexBitSet<uint64_t>::SizeInBytes(1) == sizeof(uint64_t));

  CHECK(FEXCore::FlexBitSet<uint8_t>::SizeInBits(1) == sizeof(uint8_t) * 8);
  CHECK(FEXCore::FlexBitSet<uint16_t>::SizeInBits(1) == sizeof(uint16_t) * 8);
  CHECK(FEXCore::FlexBitSet<uint32_t>::SizeInBits(1) == sizeof(uint32_t) * 8);
  CHECK(FEXCore::FlexBitSet<uint64_t>::SizeInBits(1) == sizeof(uint64_t) * 8);

  // Size of `sizeof(ElementSize) * 8` should take one sizeof(ElementSize) size
  CHECK(FEXCore::FlexBitSet<uint8_t>::SizeInBytes(sizeof(uint8_t) * 8) == sizeof(uint8_t));
  CHECK(FEXCore::FlexBitSet<uint16_t>::SizeInBytes(sizeof(uint16_t) * 8) == sizeof(uint16_t));
  CHECK(FEXCore::FlexBitSet<uint32_t>::SizeInBytes(sizeof(uint32_t) * 8) == sizeof(uint32_t));
  CHECK(FEXCore::FlexBitSet<uint64_t>::SizeInBytes(sizeof(uint64_t) * 8) == sizeof(uint64_t));

  CHECK(FEXCore::FlexBitSet<uint8_t>::SizeInBits(sizeof(uint8_t) * 8) == sizeof(uint8_t) * 8);
  CHECK(FEXCore::FlexBitSet<uint16_t>::SizeInBits(sizeof(uint16_t) * 8) == sizeof(uint16_t) * 8);
  CHECK(FEXCore::FlexBitSet<uint32_t>::SizeInBits(sizeof(uint32_t) * 8) == sizeof(uint32_t) * 8);
  CHECK(FEXCore::FlexBitSet<uint64_t>::SizeInBits(sizeof(uint64_t) * 8) == sizeof(uint64_t) * 8);
}

TEST_CASE("FlexBitSet - Limit") {
  // Ensure that the FlexBitSet doesn't read past the limits, and returns correct indexes.
  const auto Size = 4096 * 3;
  auto Ptr = mmap(nullptr, Size, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  auto PtrMiddle = reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(Ptr) + 4096);
  REQUIRE(mprotect(PtrMiddle, 4096, PROT_READ | PROT_WRITE) != -1);

  using ElementType = uint8_t;
  const size_t NumElements = 4096 * 8;
  auto FlexBit = reinterpret_cast<FEXCore::FlexBitSet<ElementType>*>(PtrMiddle);

  for (size_t i = 0; i < NumElements; ++i) {
    auto Result = FlexBit->ForwardScanForRange<true>(i, 1, NumElements);
    CHECK(Result.FoundElement == i);
  }

  for (size_t i = 0; i < NumElements; ++i) {
    auto Result = FlexBit->BackwardScanForRange<true>(i, 1, 0);
    CHECK(Result.FoundElement == i);
  }
}