#ifndef TMVA_SOFIE_SOFIE_COMMON
#define TMVA_SOFIE_SOFIE_COMMON

#include "TMVA/RTensor.hxx"

#include "ROOT/RSpan.hxx"

#include <stdexcept>
#include <type_traits>
#include <cstdint>
#include <cstring>
#include <complex>
#include <string>
#include <vector>
#include <map>
#include <memory>
#include <regex>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cassert>
#include <limits>

namespace TMVA {
namespace Experimental {
namespace SOFIE {

enum class ETensorType{
   UNDEFINED = 0, FLOAT = 1, UINT8 = 2, INT8 = 3, UINT16 = 4, INT16 = 5, INT32 = 6, INT64 = 7, STRING = 8, BOOL = 9, //order sensitive
    FLOAT16 = 10, DOUBLE = 11, UINT32 = 12, UINT64 = 13, COMPLEX64 = 14, COMPLEX28 = 15, BFLOAT16 = 16
};

enum class EActivationType{
   UNDEFINED = 0, RELU = 1, SOFTMAX = 2, SIGMOID = 3, LEAKYRELU = 4, TANH = 5, ELU = 6
};

constexpr size_t GetTypeSize(ETensorType type) {
    switch (type) {
        case ETensorType::FLOAT:     return sizeof(float);
        case ETensorType::DOUBLE:    return sizeof(double);
        case ETensorType::UINT8:     return sizeof(uint8_t);
        case ETensorType::INT8:      return sizeof(int8_t);
        case ETensorType::UINT16:    return sizeof(uint16_t);
        case ETensorType::INT16:     return sizeof(int16_t);
        case ETensorType::INT32:     return sizeof(int32_t);
        case ETensorType::INT64:     return sizeof(int64_t);
        case ETensorType::UINT32:    return sizeof(uint32_t);
        case ETensorType::UINT64:    return sizeof(uint64_t);
        case ETensorType::BOOL:      return sizeof(bool);
        case ETensorType::STRING:    return sizeof(std::string);
        default: return 0;
    }
}

typedef std::int64_t int_t;

std::string ConvertTypeToString(ETensorType type);
ETensorType ConvertStringToType(std::string type);

// find if a string represents a number
bool IsInteger(const std::string & s);

struct Dim{
   bool isParam = false;
   size_t dim = 0;
   std::string param;

    // default constructor (for I/O)
   Dim() {}

   // constructor for a parametric dimension with the option to pass a default dim value
   // We use -1 for dim to indicate that the param dimension is an expression (e.g. "d1+d2")
   // in case the string represents a number make Dim not parametric
   Dim(const std::string & p, size_t d = 0) : isParam(true), dim(d), param(p)
   {
      if (IsInteger(p)) {
            isParam = false;
            dim = std::stoi(p);
      }
   }

   // constructor for a non-parametric dimension
   Dim(size_t d) : dim(d) {}

   std::string GetVal() const {
      // cast to int64_t for negative shape values
      return (isParam) ? param : std::to_string(static_cast<int64_t>(dim));
   }

   std::ostream& operator<< (std::ostream& os) const {
      os << GetVal();
      return os;
   }

   bool operator==(const Dim& rhs) const {
       return (isParam && rhs.isParam) ? param == rhs.param : dim == rhs.dim;
   }
   bool operator!=(const Dim& rhs) const {
       return !(*this == rhs);
   }
};

//bool operator==(const Dim& lhs, const Dim& rhs);
inline std::ostream & operator<< (std::ostream &os, const Dim &d) {
   os << d.GetVal();
   return os;
}

struct InputTensorInfo{
   ETensorType type;
   std::vector<Dim> shape;
};

struct TensorInfo{
   ETensorType type;
   std::vector<size_t> shape;
};

struct DynamicTensorInfo{
   ETensorType type;
   std::vector<Dim> shape;
};

// template traits for Tensor Shape
template <typename T>
struct TensorShape {};
template<>
struct TensorShape<Dim> {
   static bool IsDim() { return true; }
};
template<>
struct TensorShape<size_t> {
   static bool IsDim() { return false; }
};

// template traits for Tensor type
template <typename T>
struct TensorType {};
template<>
struct TensorType<float> {
   static const std::string Name() { return "float"; }
};
template<>
struct TensorType<double> {
   static const std::string Name() { return "double"; }
};
template<>
struct TensorType<int64_t> {
   static const std::string Name() { return "int64_t"; }
};
template<>
struct TensorType<int32_t> {
   static const std::string Name() { return "int32_t"; }
};
template<>
struct TensorType<uint32_t> {
   static const std::string Name() { return "uint32_t"; }
};
template<>
struct TensorType<uint64_t> {
   static const std::string Name() { return "uint64_t"; }
};
template<>
struct TensorType<bool> {
   static const std::string Name() { return "bool"; }
};

struct TensorMemoryInfo {
   std::string_view tensor_name;
   size_t tensor_size;

   TensorMemoryInfo split(const std::string_view new_name, size_t new_size) {
        if (new_size > tensor_size) {
            throw std::invalid_argument("New size exceeds available tensor size.");
        }
        tensor_size -= new_size;
        return TensorMemoryInfo{new_name, new_size};
   }

    // Method to merge another struct into this one
   void merge(const TensorMemoryInfo& other) {
        tensor_size += other.tensor_size;
   }
};

struct MemoryPoolInfo {

   // ordered map with chunk_idx as key and TensorMemoryInfo as value
   std::map<size_t, TensorMemoryInfo> total_stack;

   // ordered map with chunk_idx as key and chunk_size as value
   std::map<size_t, size_t> available_stack;
};

std::vector<Dim> ConvertShapeToDim(const std::vector<size_t> & shape);

std::vector<size_t> ConvertShapeToInt(const std::vector<Dim> & shape);

std::size_t ConvertShapeToLength(const std::vector<size_t> & shape);

std::string ConvertShapeToString(const std::vector<size_t> & shape);
std::string ConvertDimShapeToString(const std::vector<Dim> & shape);
std::string ConvertShapeToString(const std::vector<Dim> & shape);



std::string ConvertDimShapeToLength(const std::vector<Dim> & shape);
std::string ConvertDynamicShapeToLength(const std::vector<Dim> & shape);


template<class T>
std::string ConvertValToString(T value) {
   std::stringstream ret;
   if (std::is_floating_point_v<T>)
      ret << std::setprecision(std::numeric_limits<T>::max_digits10);
   ret << value;
   return ret.str();
}


// convert list of values in a string taking into account the precision
template<class T>
std::string ConvertValuesToString(size_t n, const T * data) {
   std::stringstream ret;
   ret << "{ ";
   for (size_t i = 0; i < n; i++) {
      if (std::is_floating_point_v<T>)
         ret << std::setprecision(std::numeric_limits<T>::max_digits10);
      ret << data[i];
      if (i < n-1) ret << ", ";
   }
   ret << "}";
   return ret.str();
}
template<class T>
std::string ConvertValuesToString(const std::vector<T> & data) {
  return ConvertValuesToString(data.size(), data.data());
}

class InitializedTensor {
public:
   InitializedTensor() = default;
   InitializedTensor(ETensorType type, std::span<std::size_t> shape, std::shared_ptr<void> data, bool typeConstant = false)
      : fConstant(typeConstant), fType{type}, fShape{shape.begin(), shape.end()}, fData{data}
   {
   }

   ETensorType const &type() const { return fType; }
   std::vector<std::size_t> const &shape() const { return fShape; }
   std::shared_ptr<void> const &sharedptr() const { return fData; }
   // query if tensor comes from a Constant operator
   bool IsConstantTensor() const { return fConstant;}
   // query if tensor needs to be written in a weight file. Constant tensors are not written in a file
   bool IsWeightTensor() const { return !fConstant && !fIsNotWritable;}
   // set not writable initialized tensors - i.e. tensor that must not be written in a file
   void SetNotWritable() { fIsNotWritable = true;}

   template <class T = void>
   T const *data() const
   {
      return static_cast<T const *>(fData.get());
   }

   void CastSharedToPersistent()
   {
      // We only calculate fSize here, because it is only used for IO to know
      // the size of the persistent data.
      fSize = 1;
      for (std::size_t item : fShape) {
         fSize *= static_cast<int>(item);
      }
      switch (fType) {
      case ETensorType::FLOAT: fSize *= sizeof(float); break;
      case ETensorType::DOUBLE: fSize *= sizeof(double); break;
      case ETensorType::INT32: fSize *= sizeof(int32_t); break;
      case ETensorType::INT64: fSize *= sizeof(int64_t); break;
      case ETensorType::BOOL: fSize *= sizeof(bool); break;
      default:
         throw std::runtime_error("TMVA::SOFIE doesn't yet supports serialising data-type " +
                                  ConvertTypeToString(fType));
      }
      fPersistentData = static_cast<char *>(fData.get());
   }
   void CastPersistentToShared()
   {
      // If there is no persistent data, do nothing
      if (fSize == 0 || fPersistentData == nullptr) {
         return;
      }

      // Nothing to be done if the pointed-to data is the same
      if (fPersistentData == static_cast<char *>(fData.get())) {
         return;
      }

      // Initialize the shared_ptr
      fData = std::shared_ptr<void>{malloc(fSize), free};
      std::memcpy(fData.get(), fPersistentData, fSize);

      // Make sure the data read from disk doesn't leak and delete the
      // persistent data
      delete[] fPersistentData;
      fPersistentData = nullptr;
      fSize = 0;
   }

private:
   bool  fConstant = false;      ///< Flag specifying if tensor is a Constant one (coming from a Constant operator)
   bool  fIsNotWritable = false; ///< Flag to indicate that tensor values do not need to be written as weight or generated code
   ETensorType fType;               ///< Encodes the type of the data
   std::vector<std::size_t> fShape; ///< The shape of the data in terms of elements in each dimension
   std::shared_ptr<void> fData;     ///<! Transient shared data
   int fSize = 0;                   ///< The size of the persistent data in bytes (not number of elements!)
   char *fPersistentData = nullptr; ///<[fSize] Persistent version of the data
};

template <typename T>
ETensorType GetTemplatedType(T /*obj*/ ){
   if (std::is_same<T, float>::value) return ETensorType::FLOAT;
   if (std::is_same<T, uint8_t>::value) return ETensorType::UINT8;
   if (std::is_same<T, int8_t>::value) return ETensorType::INT8;
   if (std::is_same<T, uint16_t>::value) return ETensorType::UINT16;
   if (std::is_same<T, int16_t>::value) return ETensorType::INT16;
   if (std::is_same<T, int32_t>::value) return ETensorType::INT32;
   if (std::is_same<T, int64_t>::value) return ETensorType::INT64;
   if (std::is_same<T, std::string>::value) return ETensorType::STRING;
   if (std::is_same<T, bool>::value) return ETensorType::BOOL;
   //float16 unimplemented
   if (std::is_same<T, double>::value) return ETensorType::DOUBLE;
   if (std::is_same<T, uint32_t>::value) return ETensorType::UINT32;
   if (std::is_same<T, uint64_t>::value) return ETensorType::UINT64;
   //complex 64, 28, bfloat 16 unimplemented
}

namespace UTILITY{



// clean operator and tensor names
std::string Clean_name(std::string input_tensor_name);

// Check if two shapes are equal
bool AreSameShape(const std::vector<size_t>&, const std::vector<size_t>&);
bool AreSameShape(const std::vector<size_t>&, const std::vector<Dim>&);
bool AreSameShape(const std::vector<Dim>&, const std::vector<Dim>&);


// Multidirectional broadcast a list of tensors to the same shape
std::vector<size_t> MultidirectionalBroadcastShape(std::vector<std::vector<size_t>>);

// Multidirectional broadcast two shapes to the same shape

std::pair<int, std::vector<size_t>> MultidirectionalBroadcastShape(std::vector<size_t> &, std::vector<size_t> &);
std::vector<size_t> UnidirectionalBroadcastShape(std::vector<size_t> &, std::vector<size_t> &);

std::pair<int, std::vector<Dim>> MultidirectionalBroadcastShape(std::vector<Dim> &, std::vector<Dim> &);



template<typename T>
T* BroadcastConvBias(const T* data, const size_t channel, const std::vector<size_t>& targetShape) {
   size_t size = targetShape.size();
   if (targetShape[1] != channel) {
      std::stringstream ss;
      ss << "TMVA::SOFIE - Error broadcasting Conv Bias of shape {";
      ss << std::to_string(channel);
      ss << "} to ";
      ss << ConvertShapeToString(targetShape);
      throw
         std::runtime_error(ss.str());
   }

   size_t targetLength = ConvertShapeToLength(targetShape);
   T* newData = new T[targetLength];

   if (targetLength == channel) {
      std::copy(data, data + channel, newData);
      return newData;
   }

   // cStride = OutDepth * outHeight * outWidth
   size_t cStride = 1;
   for (size_t i = 2; i < size; i++)
      cStride *= targetShape[i];
   // Broadcast each element of the bias to a vector of size cStride and concatenate them
   // into a vector of size channel * cStride
   for (size_t i = 0; i < channel; i++) {
      std::fill(newData + i * cStride, newData + (i + 1) * cStride, data[i]);
   }
   // Broadcast newData[0...channel * cStride) to newData[0...batch * channel * cStride)
   size_t batch = targetShape[0];
   size_t bStride = channel * cStride;
   for (size_t i = 1; i < batch; i++) {
      std::copy(newData, newData + bStride, newData + i * bStride);
   }
   return newData;
}

// Broadcast a tensor from shape to targetShape according to numpy broadcasting rules
// See more at https://numpy.org/doc/stable/user/basics.broadcasting.html
// and https://github.com/onnx/onnx/blob/main/docs/Broadcasting.md .
template<typename T, class ConstContT = std::span<const T>, class ContT = std::span<T> >
void BroadcastTensor(ConstContT data, const std::vector<size_t>& shape, const std::vector<size_t>& targetShape, ContT broadcastedData) {
   // Size of the shapes (tensor input here have shapes with same sizes, we have already added the needed ones )
   size_t size = shape.size();
   // Current length of the broadcasted tensor
   size_t curLength = data.size();
   size_t targetLength = broadcastedData.size();
   assert(ConvertShapeToLength(targetShape) == targetLength);
   // special case when broadcasting last dimensions (initial shapes must be the same)
   if (size > 1 && shape.front() == targetShape.front() && shape.back() == 1) {
      size_t bsize = targetShape.back();
      // compute the size of the data to broadcast
      for (int k = int(size)-2; k >=0; k--) {
         if (shape[k] != 1) break;
         bsize *= targetShape[k];
      }
      for (size_t i = 0; i < curLength; i++) {
         std::fill(broadcastedData.begin() + i*bsize, broadcastedData.begin() + (i+1)*bsize , data[i]);
      }
      return;
   }

   std::copy(data.begin(), data.end(), broadcastedData.begin());
   // Product of the previous dimensions of targetShape
   size_t arrayNum = 1;
   // New broadcasted data: is this needed?
   std::vector<T> newData(targetLength);

   for (size_t idx = 0; idx < size; idx++) {
      size_t dim = shape[idx];
      size_t targetDim = targetShape[idx];
      if (dim == 1 && targetDim > 1) {
         // Set the new length of the data
         size_t newLength = curLength * targetDim;
         // View the data as a list of arrayNum arrays of size arrayLength
         size_t arrayLength = curLength / arrayNum;
         // Broadcast each array dim times
         if (arrayLength > 1) {
            // If each array has at least two elements
            for (size_t arrayIdx = 0; arrayIdx < arrayNum; arrayIdx++) {
               for (size_t targetIdx = 0; targetIdx < targetDim; targetIdx++) {
                  size_t offset = arrayIdx * arrayLength * targetDim + targetIdx * arrayLength;
                  std::copy(broadcastedData.begin() + arrayIdx * arrayLength,
                     broadcastedData.begin() + (arrayIdx + 1) * arrayLength,
                     newData.begin() + offset);
               }
            }
         } else {
            // If each array has one element
            for (size_t arrayIdx = 0; arrayIdx < arrayNum; arrayIdx++) {
               std::fill(newData.begin() + arrayIdx * targetDim,
                  newData.begin() + (arrayIdx + 1) * targetDim, broadcastedData[arrayIdx]);
            }
         }
         // Update current length
         curLength = newLength;
         // Update broadcasted data
         std::copy(newData.begin(), newData.begin() + newLength, broadcastedData.begin());
      }
      // Update the number of arrays
      arrayNum *= targetDim;
   }
   //return broadcastedData;
}

// interface where we allocate a new array for broadcasted data
template<typename T>
T* CreateBroadcastTensor(const T* data, const std::vector<size_t>& shape, const std::vector<size_t>& targetShape, size_t targetLength) {
   // newShape is an array of size equal to dimension along which we are broadcasting the tensor
   T* broadcastedData = new T[targetLength];
   std::span<T> bData(broadcastedData, broadcastedData+targetLength);
   size_t curLength = ConvertShapeToLength(shape);
   std::span<const T> inData(data, curLength);
   BroadcastTensor<T, std::span<const T>, std::span<T>>(inData, shape, targetShape, bData);
   return broadcastedData;
}
// Unidirectional broadcasting shape to targetShape// In unidirectional broadcast - only tensor B can have the shape changed not
// tensor A - otherwise is a multidirectional broadcast
template<typename T>
T* UnidirectionalBroadcast(const T* data, const std::vector<size_t>& shape, const std::vector<size_t>& targetShape) {
   // Prepend shape with ones
   if (shape.size() < targetShape.size()) {
      size_t targetSize = targetShape.size();
      std::vector<size_t> newShape(targetSize, 1);
      size_t offset = targetSize - shape.size();
      std::copy(shape.begin(), shape.end(), newShape.begin() + offset);
      return CreateBroadcastTensor<T>(data, newShape, targetShape, ConvertShapeToLength(targetShape));
   }
   return CreateBroadcastTensor<T>(data, shape, targetShape, ConvertShapeToLength(targetShape));
}

// Unidirectional broadcasting shape to targetShape using a passed vector to avoid allocations
template<typename T>
void UnidirectionalBroadcast(const T* data, const std::vector<size_t>& shape, const std::vector<size_t>& targetShape, std::span<T> broadcastedData) {
   size_t curLength = ConvertShapeToLength(shape);
   std::span<T> inData(const_cast<T*>(data), curLength);
   // Prepend shape with ones
   if (shape.size() < targetShape.size()) {
      size_t targetSize = targetShape.size();
      std::vector<size_t> newShape(targetSize, 1);
      size_t offset = targetSize - shape.size();
      std::copy(shape.begin(), shape.end(), newShape.begin() + offset);
      BroadcastTensor<T>(inData, newShape, targetShape, broadcastedData);
   }
   BroadcastTensor<T, std::span<T>>(inData, shape, targetShape, broadcastedData);
}

/// compute stride of a tensor given its shape (assume layout is row-major)
std::vector<size_t> ComputeStrideFromShape(const std::vector<size_t> & shape);
std::vector<Dim> ComputeStrideFromShape(const std::vector<Dim> & shape);

/// function to check if a >> 0 and a < MAX using a single comparison
//// use trick casting to unsigned values so it becomes a single comparison
inline bool is_a_ge_zero_and_a_lt_b(int a, int b) {
   return static_cast<unsigned>(a) < static_cast<unsigned>(b);
}


/// im2col : efficient function to re-arrange input data of convolution to a matrix
/// that can be used by BLAS
/// Use trick to loop on each element of filtered region first and follow input data layout
/// By doing this reads and writes are of consecutive data in memory and one gains in efficiency
/// The resulting matrix will be already transposed and can be used directly in BLAS
/// since output will be a matrix : (channels*kernel_h*kernel_w , output_h*output_w)
/// Example: with an input matrix
///    a1 a2 a3
///    b1 b2 b3    and a 2x2 kernel    (k1,k2,k3,k4) and padding 1 :
///    c1 c2 c3
///     outpout will be a matrix (4 x 16)
///  the routine will follow output order :
//     first all elements which will be operated by k1 then k2 then k3
///  -> ( 0  0  0  0  0  a1 a2 a3 0  b1 b2 b3  0 c1 c2 c3  )    all elements for k1
///     ( 0  0  0  0  a1 a2 a3  0 b1 b2 b3  0 c1 c2 c3  0  )     for k2
///     ( 0  a1 a2 a3 0  b1 b2 b3 0  c1 c2 c3  0  0  0  0  )     for k3
///     ( a1 a2 a3 0  b1 b2 b3  0 c1 c2 c3  0  0  0  0  0  )     for k4
///

template <typename T>
void Im2col(const T *data_im, const int channels, const int height, const int width, const int kernel_h,
                const int kernel_w, const int pad_h, const int pad_w, const int stride_h, const int stride_w,
                const int dilation_h, const int dilation_w, T *data_col)
{
   const int output_h = (height + 2 * pad_h - (dilation_h * (kernel_h - 1) + 1)) / stride_h + 1;
   const int output_w = (width + 2 * pad_w - (dilation_w * (kernel_w - 1) + 1)) / stride_w + 1;
   const int channel_size = height * width;
   for (int channel = channels; channel--; data_im += channel_size) {
      for (int kernel_row = 0; kernel_row < kernel_h; kernel_row++) {
         for (int kernel_col = 0; kernel_col < kernel_w; kernel_col++) {
            int input_row = -pad_h + kernel_row * dilation_h;
            for (int output_rows = output_h; output_rows; output_rows--) {
               if (!is_a_ge_zero_and_a_lt_b(input_row, height)) {
                  for (int output_cols = output_w; output_cols; output_cols--) {
                     *(data_col++) = 0;
                  }
               } else {
                  int input_col = -pad_w + kernel_col * dilation_w;
                  for (int output_col = output_w; output_col; output_col--) {
                     if (is_a_ge_zero_and_a_lt_b(input_col, width)) {
                        *(data_col++) = data_im[input_row * width + input_col];
                     } else {
                        *(data_col++) = 0;
                     }
                     input_col += stride_w;
                  }
               }
               input_row += stride_h;
            }
         }
      }
   }
}

/// 3d implementation
template <typename T>
void Im2col_3d(const T *data_im, const int channels,
            const int depth, const int height, const int width,
            const int kernel_d, const int kernel_h, const int kernel_w,
            const int pad_d, const int pad_h, const int pad_w,
            const int stride_d, const int stride_h, const int stride_w,
            const int dilation_d, const int dilation_h,  const int dilation_w, T *data_col)
{
   const int output_h = (height + 2 * pad_h - (dilation_h * (kernel_h - 1) + 1)) / stride_h + 1;
   const int output_w = (width + 2 * pad_w - (dilation_w * (kernel_w - 1) + 1)) / stride_w + 1;
   const int output_d = (depth + 2 * pad_d - (dilation_d * (kernel_d - 1) + 1)) / stride_d + 1;
   const int channel_size = height * width * depth;
   // assume data are c x d x h x w
   for (int channel = channels; channel--; data_im += channel_size) {
      for (int kernel_depth = 0; kernel_depth < kernel_d; kernel_depth++) {
         for (int kernel_row = 0; kernel_row < kernel_h; kernel_row++) {
            for (int kernel_col = 0; kernel_col < kernel_w; kernel_col++) {
               int input_dep = -pad_d + kernel_depth * dilation_d;
               for (int output_dep = output_d; output_dep; output_dep--) {
                  if (!is_a_ge_zero_and_a_lt_b(input_dep, depth)) {
                     for (int output_rows = output_h; output_rows; output_rows--) {
                        for (int output_cols = output_w; output_cols; output_cols--) {
                           *(data_col++) = 0;
                        }
                     }
                  } else {
                     int input_row = -pad_h + kernel_row * dilation_h;
                     for (int output_rows = output_h; output_rows; output_rows--) {
                        if (!is_a_ge_zero_and_a_lt_b(input_row, height)) {
                           for (int output_cols = output_w; output_cols; output_cols--) {
                              *(data_col++) = 0;
                           }
                        } else {
                           int input_col = -pad_w + kernel_col * dilation_w;
                           for (int output_col = output_w; output_col; output_col--) {
                              if (is_a_ge_zero_and_a_lt_b(input_col, width)) {
                                 *(data_col++) = data_im[input_dep * width * height + input_row * width + input_col];
                              } else {
                                 *(data_col++) = 0;
                              }
                              input_col += stride_w;
                           }
                        }
                        input_row += stride_h;
                     }
                  }
                  input_dep += stride_d;
               }
            }
         }
      }
   }
}

template <typename Dtype>
void col2im(const Dtype* data_col, const int channels,
    const int height, const int width, const int kernel_h, const int kernel_w,
    const int pad_h, const int pad_w,
    const int stride_h, const int stride_w,
    const int dilation_h, const int dilation_w,
    Dtype* data_im) {
   // note that output data_im needs to be set to zero value!!!!
   std::fill(data_im, data_im + height * width * channels, 0.);
  //caffe_set(height * width * channels, Dtype(0), data_im);
  // data_im must be a zero vector
  //const Dtype * data_col_0 = data_col;
  const int output_h = (height + 2 * pad_h -
    (dilation_h * (kernel_h - 1) + 1)) / stride_h + 1;
  const int output_w = (width + 2 * pad_w -
    (dilation_w * (kernel_w - 1) + 1)) / stride_w + 1;
  const int channel_size = height * width;
  for (int channel = channels; channel--; data_im += channel_size) {
    for (int kernel_row = 0; kernel_row < kernel_h; kernel_row++) {
      for (int kernel_col = 0; kernel_col < kernel_w; kernel_col++) {
        int input_row = -pad_h + kernel_row * dilation_h;
        for (int output_rows = output_h; output_rows; output_rows--) {
          if (!is_a_ge_zero_and_a_lt_b(input_row, height)) {
            data_col += output_w;
          } else {
            int input_col = -pad_w + kernel_col * dilation_w;
            for (int output_col = output_w; output_col; output_col--) {
              if (is_a_ge_zero_and_a_lt_b(input_col, width)) {
                //assert(input_row*width+input_col < height * width * channels);
                //assert(data_col - data_col_0 < output_h*output_w*channels);
               //  std::cout << "COL2IM: input_row" << "  " << input_row << "  " << input_col
               //       << " <---- " << data_col - data_col_0 << " values:  "
               //       << data_im[input_row * width + input_col] << " <--- " << *data_col << std::endl;
                data_im[input_row * width + input_col] += *data_col;
              }
              data_col++;
              input_col += stride_w;
            }
          }
          input_row += stride_h;
        }
      }
    }
  }
  //std::cout << "finishing col2imp" << std::endl;
}

// Used at the end of infer() to fill the return object.
template <class T>
void FillOutput(T const *arr, std::vector<T> &out, std::size_t n)
{
   out.resize(n);
   for (std::size_t i = 0; i < n; ++i) {
      out[i] = arr[i];
   }
}

}  // end namespace UTILITY

namespace BLAS{
extern "C" void sgemm_(const char * transa, const char * transb, const int * m, const int * n, const int * k,
                       const float * alpha, const float * A, const int * lda, const float * B, const int * ldb,
                       const float * beta, float * C, const int * ldc);
}//BLAS


struct GNN_Data {
      RTensor<float> node_data;      // the node feature data, tensor with shape (num_nodes, num_node_features)
      RTensor<float> edge_data;      // the edge feature data, tensor with shape (num_edges, num_edge_features)
      RTensor<float> global_data;    // the global features, tensor with shape (1, num_global_features)
      RTensor<int> edge_index;       // the edge index (receivers and senders for each edge), tensor with shape (2, num_edges)
                                     // edge_index[0,:] are the receivers and edge_index[1,:] are the senders


      // need to have default constructor since RTensor has not one
      GNN_Data(): node_data(RTensor<float>({})), edge_data(RTensor<float>({})), global_data(RTensor<float>({})), edge_index(RTensor<int>({})) {}

};

template<typename T>
TMVA::Experimental::RTensor<T> Concatenate( TMVA::Experimental::RTensor<T> & t1,  TMVA::Experimental::RTensor<T> & t2, int axis = 0)
{
   // concatenate tensor along axis. Shape must be the same except in the dimension of the concatenated axis
   if (t1.GetMemoryLayout() != t2.GetMemoryLayout())
      throw std::runtime_error("TMVA RTensor Concatenate - tensors have different memory layout");
   auto & shape1 = t1.GetShape();
   auto & shape2 = t2.GetShape();
   if (t1.GetSize()/shape1[axis] != t2.GetSize()/shape2[axis]) {
      std::cout << "axis " << axis << " sizes " << t1.GetSize() << " " << t2.GetSize() << "  ";
      std::cout << "shape 1 : " << ConvertShapeToString(t1.GetShape());
      std::cout << " shape 2 : " << ConvertShapeToString(t2.GetShape()) << std::endl;
      throw std::runtime_error("TMVA RTensor Concatenate - tensors have incompatible shapes");
   }
   std::vector<size_t> outShape = shape1;
   outShape[axis] = shape1[axis] + shape2[axis];
   TMVA::Experimental::RTensor<T> tout(outShape, t1.GetMemoryLayout());
   if (t1.GetMemoryLayout() == TMVA::Experimental::MemoryLayout::ColumnMajor) {
      throw std::runtime_error("TMVA RTensor Concatenate is not yet supported for column major tensors");
   }

   auto & stride1 = t1.GetStrides();
   auto & stride2 = t2.GetStrides();
   auto & outStride = tout.GetStrides();

   size_t s1 = (axis > 0) ? stride1[axis-1] : t1.GetSize();  // block size to copy from first tensor
   size_t s2 = (axis > 0) ? stride2[axis-1] : t2.GetSize();  // block size to copy from second tensor
   size_t sout = (axis > 0) ? outStride[axis-1] : tout.GetSize();
   size_t nb = t1.GetSize()/s1;
   for (size_t i = 0; i < nb; i++) {
      std::copy(t1.GetData() + i*s1, t1.GetData() + (i+1)*s1, tout.GetData() + i * sout );
      std::copy(t2.GetData() + i*s2, t2.GetData() + (i+1)*s2, tout.GetData() + i * sout + s1 );
   }

   return tout;
}


inline GNN_Data Concatenate(GNN_Data & data1, GNN_Data & data2, int axis = 0) {
   GNN_Data out;
   out.node_data = Concatenate(data1.node_data,data2.node_data, axis);
   out.edge_data = Concatenate(data1.edge_data,data2.edge_data, axis);
   out.global_data = Concatenate<float>(data1.global_data,data2.global_data, axis-1);
   // assume sender/receivers of data1 and data2 are the same
   out.edge_index = data1.edge_index.Copy();
   return out;
}

inline GNN_Data Copy(const GNN_Data & data) {
   GNN_Data out;
   out.node_data = RTensor<float>(data.node_data.GetShape());
   out.edge_data = RTensor<float>(data.edge_data.GetShape());
   out.global_data = RTensor<float>(data.global_data.GetShape());
   out.edge_index = RTensor<int>(data.edge_index.GetShape());
   std::copy(data.node_data.GetData(), data.node_data.GetData()+ data.node_data.GetSize(), out.node_data.GetData());
   std::copy(data.edge_data.GetData(), data.edge_data.GetData()+ data.edge_data.GetSize(), out.edge_data.GetData());
   std::copy(data.global_data.GetData(), data.global_data.GetData()+ data.global_data.GetSize(), out.global_data.GetData());
   std::copy(data.edge_index.GetData(), data.edge_index.GetData()+ data.edge_index.GetSize(), out.edge_index.GetData());
   return out;
}

inline void Gemm_Call(float *output, bool transa, bool transb, int m, int n, int k, float alpha, const float *A,
                      const float *B, float beta, const float *C)
{
   char ct = 't';
   char cn = 'n';
   const int *lda = transa ? &k : &m;
   const int *ldb = transb ? &n : &k;
   const int *ldc = &m;
   if (C != nullptr) {
      std::copy(C, C + m * n, output);
   }
   TMVA::Experimental::SOFIE::BLAS::sgemm_(transa ? &ct : &cn, transb ? &ct : &cn, &m, &n, &k, &alpha, A, lda, B, ldb,
                                           &beta, output, ldc);
}

template <class T>
void ReadTensorFromStream(std::istream &is, T &target, std::string const &expectedName, std::size_t expectedLength)
{
   std::string name;
   std::size_t length;
   is >> name >> length;
   if (name != expectedName) {
      std::string err_msg =
         "TMVA-SOFIE failed to read the correct tensor name; expected name is " + expectedName + " , read " + name;
      throw std::runtime_error(err_msg);
   }
   if (length != expectedLength) {
      std::string err_msg = "TMVA-SOFIE failed to read the correct tensor size; expected size is " +
                            std::to_string(expectedLength) + " , read " + std::to_string(length);
      throw std::runtime_error(err_msg);
   }
   for (size_t i = 0; i < length; ++i) {
      is >> target[i];
   }
   if (is.fail()) {
      throw std::runtime_error("TMVA-SOFIE failed to read the values for tensor " + expectedName);
   }
}

} // namespace SOFIE
} // namespace Experimental
} // namespace TMVA

#endif //TMVA_SOFIE_COMMON
