//Definition of input feature quantity K of NNUE evaluation function

#include "enpassant.h"
#include "index_list.h"

namespace Eval {

  namespace NNUE {

    namespace Features {

      // Get a list of indices with a value of 1 among the features
      void EnPassant::AppendActiveIndices(
        const Position& pos, Color perspective, IndexList* active) {
        // do nothing if array size is small to avoid compiler warning
        if (RawFeatures::kMaxActiveDimensions < kMaxActiveDimensions) return;

        auto epSquare = pos.state()->epSquare;
        if (epSquare == SQ_NONE) {
          return;
        }

        if (perspective == BLACK) {
          epSquare = rotate180(epSquare);
        }

        auto file = file_of(epSquare);
        active->push_back(file);
      }

      // Get a list of indices whose values ??have changed from the previous one in the feature quantity
      void EnPassant::AppendChangedIndices(
        const Position& pos, Color perspective,
        IndexList* removed, IndexList* added) {
        // Not implemented.
        assert(false);
      }

    }  // namespace Features

  }  // namespace NNUE

}  // namespace Eval