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#pragma once

/// @file copy_traits_sm90_tma_swizzle.hpp
/// @brief Functions for converting swizzle layout to TMA descriptor

#if !defined(__CUDACC_RTC__)
#include <cuda.h>
#endif

#include <cute/arch/copy_sm90_desc.hpp>
#include <cute/swizzle_layout.hpp>

namespace cute::detail {

template <int B, int M, int S>
CUTE_HOST_DEVICE constexpr
TMA::SmemSwizzleBits
get_tma_swizzle_bits(Swizzle<B,M,S>)
{
  if constexpr (M == 4) {
    static_assert(0 <= B && B <= 3, "Expected B = 0,1,2, or 3 when M == 4. Unsupported layout swizzle.");
    if constexpr (B == 3) { return TMA::SmemSwizzleBits::B128; }
    if constexpr (B == 2) { return TMA::SmemSwizzleBits::B64; }
    if constexpr (B == 1) { return TMA::SmemSwizzleBits::B32; }
    if constexpr (B == 0) { return TMA::SmemSwizzleBits::DISABLE; }
  } else

  if constexpr (M == 5 || M == 6) {
    static_assert(B == 2, "Expected B = 2 when M == 5 or 6. Unsupported layout swizzle.");
    // S-condition as well?
    return TMA::SmemSwizzleBits::B128;
  } else

  {
    static_assert(M < 0, "Unsupported layout swizzle.");
  }
}

template <class Layout>
TMA::SmemSwizzleBits
get_tma_swizzle_bits(Layout const& layout)
{
  return get_tma_swizzle_bits(get_swizzle_portion(layout));
}

template <int B, int M, int S>
CUTE_HOST_DEVICE constexpr
TMA::SmemSwizzleBase
get_tma_swizzle_base(Swizzle<B,M,S>)
{
  if constexpr (M == 4) {
    static_assert(0 <= B && B <= 3, "Expected B = 0,1,2, or 3 when M == 4. Unsupported layout swizzle.");
    static_assert(S == 3, "Expected S = 3 when M == 4. Unsupported layout swizzle.");
    return TMA::SmemSwizzleBase::SWIZZLE_BASE_16B;
  } 
  
  else if constexpr (M == 5) {
    static_assert(B == 2, "Expected B = 2 when M == 5. Unsupported layout swizzle.");
    static_assert(S == 2, "Expected S = 2 when M == 5. Unsupported layout swizzle.");
    return TMA::SmemSwizzleBase::SWIZZLE_BASE_32B;
  } else if constexpr (M == 6) {
    static_assert(B == 2, "Expected B = 2 when M == 5. Unsupported layout swizzle.");
    return TMA::SmemSwizzleBase::SWIZZLE_BASE_64B;
  } 
  #if 1
  else {
    static_assert(4 <= M && M <= 6, "Expected 128b=16B=(2^4)B to 512b=64B=(2^6)B base swizzle.");
  }
  #else 
  
  else {
    static_assert(M == 4, "Expected 128b=16B=(2^4)B base swizzle.");
  }
  #endif 
}

template <class Layout>
TMA::SmemSwizzleBase
get_tma_swizzle_base(Layout const& layout)
{
  return get_tma_swizzle_base(get_swizzle_portion(layout));
}

} // namespace cute::detail