#pragma once

#include <ATen/ATen.h>
#include <torch/csrc/python_headers.h>

#include <torch/csrc/utils/python_numbers.h>
#include <torch/csrc/Exceptions.h>

namespace torch { namespace utils {

inline void store_scalar(void* data, at::ScalarType scalarType, PyObject* obj) {
  switch (scalarType) {
    case at::kByte: *(uint8_t*)data = (uint8_t)THPUtils_unpackLong(obj); break;
    case at::kChar: *(int8_t*)data = (int8_t)THPUtils_unpackLong(obj); break;
    case at::kShort: *(int16_t*)data = (int16_t)THPUtils_unpackLong(obj); break;
    case at::kInt: *(int32_t*)data = (int32_t)THPUtils_unpackLong(obj); break;
    case at::kLong: *(int64_t*)data = THPUtils_unpackLong(obj); break;
    case at::kHalf:
      *(at::Half*)data = at::convert<at::Half, double>(THPUtils_unpackDouble(obj));
      break;
    case at::kFloat: *(float*)data = (float)THPUtils_unpackDouble(obj); break;
    case at::kDouble: *(double*)data = THPUtils_unpackDouble(obj); break;
    case at::kComplexHalf: *(c10::complex<at::Half>*)data = (c10::complex<at::Half>)THPUtils_unpackComplexDouble(obj); break;
    case at::kComplexFloat: *(c10::complex<float>*)data = (c10::complex<float>)THPUtils_unpackComplexDouble(obj); break;
    case at::kComplexDouble: *(c10::complex<double>*)data = THPUtils_unpackComplexDouble(obj); break;
    case at::kBool: *(bool*)data = THPUtils_unpackNumberAsBool(obj); break;
    case at::kBFloat16:
      *(at::BFloat16*)data = at::convert<at::BFloat16, double>(THPUtils_unpackDouble(obj));
      break;
    default: throw std::runtime_error("invalid type");
  }
}

inline PyObject* load_scalar(void* data, at::ScalarType scalarType) {
  switch (scalarType) {
    case at::kByte: return THPUtils_packInt64(*(uint8_t*)data);
    case at::kChar: return THPUtils_packInt64(*(int8_t*)data);
    case at::kShort: return THPUtils_packInt64(*(int16_t*)data);
    case at::kInt: return THPUtils_packInt64(*(int32_t*)data);
    case at::kLong: return THPUtils_packInt64(*(int64_t*)data);
    case at::kHalf: return PyFloat_FromDouble(at::convert<double, at::Half>(*(at::Half*)data));
    case at::kFloat: return PyFloat_FromDouble(*(float*)data);
    case at::kDouble: return PyFloat_FromDouble(*(double*)data);
    case at::kComplexHalf: {
      auto data_ = reinterpret_cast<c10::complex<at::Half>*>(data);
      return PyComplex_FromDoubles(data_->real(), data_->imag());
    }
    case at::kComplexFloat: {
      auto data_ = reinterpret_cast<c10::complex<float>*>(data);
      return PyComplex_FromDoubles(data_->real(), data_->imag());
    }
    case at::kComplexDouble: return PyComplex_FromCComplex(*reinterpret_cast<Py_complex *>((c10::complex<double>*)data));
    case at::kBool: return PyBool_FromLong(*(bool*)data);
    case at::kBFloat16: return PyFloat_FromDouble(at::convert<double, at::BFloat16>(*(at::BFloat16*)data));
    default: throw std::runtime_error("invalid type");
  }
}

}}  // namespace torch::utils
