#ifndef TH_GENERIC_FILE
#define TH_GENERIC_FILE "torch/csrc/generic/Storage.cpp"
#else
#include <torch/csrc/utils/python_arg_parser.h>

PyObject *THPStorageClass = nullptr;

PyObject * THPStorage_(New)(c10::intrusive_ptr<c10::StorageImpl> ptr)
{
  AT_ASSERT(ptr);
  PyTypeObject *type = (PyTypeObject *)THPStorageClass;
  PyObject *obj = type->tp_alloc(type, 0);
  if (obj) {
    ((THPStorage *)obj)->cdata = ptr.release();
  }
  return obj;
}

static void THPStorage_(dealloc)(THPStorage* self)
{
  if (self->cdata) {
    c10::raw::intrusive_ptr::decref(self->cdata);
  }
  Py_TYPE(self)->tp_free((PyObject*)self);
}

static PyObject * THPStorage_(pynew)(PyTypeObject *type, PyObject *args, PyObject *kwargs)
{
  HANDLE_TH_ERRORS

  static torch::PythonArgParser parser({
      THPStorageStr "(*, int64_t allocator=None, Device device=None)",
      THPStorageStr "(int64_t size, *, int64_t allocator=None, Device device=None)",
      THPStorageStr "(PyObject* sequence, *, int64_t allocator=None, Device device=None)",
  });
  torch::ParsedArgs<3> parsed_args;
  auto r = parser.parse(args, kwargs, parsed_args);

  int64_t allocator_arg_idx = 0;
  int64_t device_arg_idx = 1;

  if (r.idx > 0) {
    allocator_arg_idx = 1;
    device_arg_idx = 2;
  }

  c10::optional<int64_t> allocator_opt = r.toInt64Optional(allocator_arg_idx);
  c10::optional<at::Device> device_opt = r.deviceOptional(device_arg_idx);

  TORCH_CHECK(!allocator_opt.has_value() || !device_opt.has_value(),
    THPStorageStr, "(): only one or neither of 'allocator' or 'device' can ",
    "be given, but not both");

  THPStoragePtr self((THPStorage *)type->tp_alloc(type, 0));
  THPUtils_assert(self, "failed to allocate a " THPStorageStr " object");
  c10::Allocator* allocator = nullptr;
  at::OptionalDeviceGuard device_guard;

  if (allocator_opt.has_value()) {
    allocator = reinterpret_cast<c10::Allocator*>(allocator_opt.value());
  } else if (device_opt.has_value()) {
    at::Device device = device_opt.value();
    if (device.type() == at::kCPU) {
      allocator = c10::GetDefaultCPUAllocator();
#ifdef USE_CUDA
    } else if (device.type() == at::kCUDA) {
      at::globalContext().lazyInitCUDA();
      allocator = c10::cuda::CUDACachingAllocator::get();
#endif
    } else {
      TORCH_CHECK(false,
        THPStorageStr, "(): Storage device not recognized: ", device.type());
    }
    device_guard.reset_device(device);
  } else {
    allocator = c10::GetDefaultCPUAllocator();
  }

  // torch.Storage(*, ...)
  if (r.idx == 0) {
    self->cdata = c10::make_intrusive<at::StorageImpl>(
      c10::StorageImpl::use_byte_size_t(),
      0,
      allocator,
      /*resizable=*/true).release();
    return (PyObject*)self.release();

  // torch.Storage(size, *, ...)
  } else if (r.idx == 1) {
    int64_t size = r.toInt64(0);
    self->cdata = c10::make_intrusive<at::StorageImpl>(
      c10::StorageImpl::use_byte_size_t(),
      size,
      allocator,
      /*resizable=*/true).release();
    return (PyObject*)self.release();

  // torch.Storage(sequence, *, ...)
  } else if (r.idx == 2) {
    PyObject *sequence = r.pyobject(0);
    Py_ssize_t length = PySequence_Length(sequence);
    TORCH_CHECK(PySequence_Check(sequence),
      THPStorageStr, "(): Expected a sequence type, but got ",
      THPUtils_typename(sequence));
    TORCH_CHECK(length >= 0,
      THPStorageStr, "(): Could not obtain the length of sequence of type ",
      THPUtils_typename(sequence));
    self->cdata = c10::make_intrusive<at::StorageImpl>(
      c10::StorageImpl::use_byte_size_t(),
      length,
      allocator,
      /*resizable=*/true)
      .release();
    THPObjectPtr item;
    try {
      for (Py_ssize_t i = 0; i < length; i++) {
        item = PySequence_GetItem(sequence, i);
        // NOLINTNEXTLINE(cppcoreguidelines-init-variables)
        scalar_t value = THPUtils_(unpackReal)(item.get());
        if (allocator == c10::GetDefaultCPUAllocator()) {
          self->cdata->unsafe_data<scalar_t>()[i] = value;
        } else {
          // TODO: this might be slow - consider batched updates?
          storage_set(
            at::unsafeStorageFromTH(self->cdata, /*retain=*/true),
            i,
            value);
        }
      }
    } catch (const std::exception &e) {
      THPUtils_setError(THPStorageStr
          "(): tried to construct a storage from a sequence (%s), "
          "but one of the items was of type %s instead of %s",
          THPUtils_typename(sequence),
          THPUtils_typename(item.get()),
          THPUtils_typeTraits<scalar_t>::python_type_str);
      return nullptr;
    }
    return (PyObject*)self.release();
  }
  Py_RETURN_NONE;
  END_HANDLE_TH_ERRORS
}

static Py_ssize_t THPStorage_(length)(THPStorage *self)
{
  HANDLE_TH_ERRORS
  return self->cdata->nbytes() / sizeof(scalar_t);
  END_HANDLE_TH_ERRORS_RET(-1)
}

static PyObject * THPStorage_(get)(THPStorage *self, PyObject *index)
{
  HANDLE_TH_ERRORS
  /* Integer index */
  if (THPUtils_checkLong(index)) {
    int64_t nindex = THPUtils_unpackLong(index);
    if (nindex < 0)
      nindex += (self->cdata->nbytes() / sizeof(scalar_t));
    if (nindex < 0 || nindex >= static_cast<int64_t>(self->cdata->nbytes() / sizeof(scalar_t))) {
      PyErr_SetString(PyExc_IndexError, fmt::format(
            "index {} out of range for storage of size {}",
            nindex, self->cdata->nbytes() / sizeof(scalar_t)));
      return nullptr;
    }
    scalar_t value = storage_get(at::unsafeStorageFromTH(self->cdata, /*retain=*/true), nindex);
    return THPUtils_(newReal)(value);
  /* Slice index */
  } else if (PySlice_Check(index)) {
    // NOLINTNEXTLINE(cppcoreguidelines-init-variables)
    Py_ssize_t start, stop, slicelength, step;
    int64_t len = self->cdata->nbytes() / sizeof(scalar_t);
    if (!THPUtils_parseSlice(index, len, &start, &stop, &step, &slicelength))
      return nullptr;
    if (step != 1) {
      THPUtils_setError("Trying to slice with a step of %lld, but only a step of "
          "1 is supported", (long long)step);
      return nullptr;
    }

    scalar_t *data = self->cdata->data<scalar_t>();

    at::StorageImpl* old_storage = self->cdata;
    c10::raw::intrusive_ptr::incref(old_storage);
    auto new_storage = c10::make_intrusive<at::StorageImpl>(
        c10::StorageImpl::use_byte_size_t(),
#ifdef THQUANTIZED
        slicelength * sizeof(quantized_t),
#else
        slicelength * sizeof(scalar_t),
#endif
        at::DataPtr(
            static_cast<void*>(data + start),
            old_storage,
            [](void* s) {
              c10::raw::intrusive_ptr::decref(static_cast<at::StorageImpl*>(s));
            },
            old_storage->device()),
        old_storage->allocator(),
        /* resizable */ false);

    PyObject *_ret = THPStorage_(New)(std::move(new_storage));
    return _ret;
  }
  PyErr_Format(PyExc_TypeError, "can't index a " THPStorageStr " with %s",
      THPUtils_typename(index));
  return nullptr;
  END_HANDLE_TH_ERRORS
}

static int THPStorage_(set)(THPStorage *self, PyObject *index, PyObject *value)
{
  HANDLE_TH_ERRORS
  if (!THPUtils_(checkReal)(value)) {
    THPUtils_setError("can only set storage content with a %s, but got "
        "%s instead", THPUtils_typeTraits<scalar_t>::python_type_str,
        THPUtils_typename(value));
    return -1;
  }

  scalar_t rvalue = THPUtils_(unpackReal)(value);
  if (THPUtils_checkLong(index)) {
    int64_t nindex = THPUtils_unpackLong(index);
    storage_set(
      at::unsafeStorageFromTH(self->cdata, /*retain=*/true),
      nindex,
      rvalue);
    return 0;
  } else if (PySlice_Check(index)) {
    // NOLINTNEXTLINE(cppcoreguidelines-init-variables)
    Py_ssize_t start, stop, slicelength, step;
    int64_t len = self->cdata->nbytes() / sizeof(scalar_t);
    if (!THPUtils_parseSlice(index, len, &start, &stop, &step, &slicelength))
      return -1;
    if (step != 1) {
      THPUtils_setError("Trying to slice with a step of %lld, but only a step of "
          "1 is supported", (long long)step);
      return 0;
    }
    // TODO: check the bounds only once
    // TODO: fill?
    for (;start < stop; start++)
      storage_set(
        at::unsafeStorageFromTH(self->cdata, /*retain=*/true),
        start,
        rvalue);
    return 0;
  }
  THPUtils_setError("can't index a " THPStorageStr " with %s",
      THPUtils_typename(index));
  return -1;
  END_HANDLE_TH_ERRORS_RET(-1)
}

static PyMappingMethods THPStorage_(mappingmethods) = {
  (lenfunc)THPStorage_(length),
  (binaryfunc)THPStorage_(get),
  (objobjargproc)THPStorage_(set)
};

// TODO: implement equality
PyTypeObject THPStorageType = {
  PyVarObject_HEAD_INIT(nullptr, 0)
  "torch._C." THPStorageBaseStr,               /* tp_name */
  sizeof(THPStorage),                          /* tp_basicsize */
  0,                                           /* tp_itemsize */
  (destructor)THPStorage_(dealloc),            /* tp_dealloc */
  0,                                           /* tp_vectorcall_offset */
  nullptr,                                     /* tp_getattr */
  nullptr,                                     /* tp_setattr */
  nullptr,                                     /* tp_reserved */
  nullptr,                                     /* tp_repr */
  nullptr,                                     /* tp_as_number */
  nullptr,                                     /* tp_as_sequence */
  &THPStorage_(mappingmethods),                /* tp_as_mapping */
  nullptr,                                     /* tp_hash  */
  nullptr,                                     /* tp_call */
  nullptr,                                     /* tp_str */
  nullptr,                                     /* tp_getattro */
  nullptr,                                     /* tp_setattro */
  nullptr,                                     /* tp_as_buffer */
  Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,    /* tp_flags */
  nullptr,                                     /* tp_doc */
  nullptr,                                     /* tp_traverse */
  nullptr,                                     /* tp_clear */
  nullptr,                                     /* tp_richcompare */
  0,                                           /* tp_weaklistoffset */
  nullptr,                                     /* tp_iter */
  nullptr,                                     /* tp_iternext */
  nullptr,   /* will be assigned in init */    /* tp_methods */
  nullptr,   /* will be assigned in init */    /* tp_members */
  nullptr,                                     /* tp_getset */
  nullptr,                                     /* tp_base */
  nullptr,                                     /* tp_dict */
  nullptr,                                     /* tp_descr_get */
  nullptr,                                     /* tp_descr_set */
  0,                                           /* tp_dictoffset */
  nullptr,                                     /* tp_init */
  nullptr,                                     /* tp_alloc */
  THPStorage_(pynew),                          /* tp_new */
};

// NOLINTNEXTLINE(cppcoreguidelines-avoid-c-arrays,modernize-avoid-c-arrays,cppcoreguidelines-avoid-non-const-global-variables)
static struct PyMemberDef THPStorage_(members)[] = {
  {(char*)"_cdata", T_ULONGLONG, offsetof(THPStorage, cdata), READONLY, nullptr},
  {nullptr}
};

static PyObject * THPStorage_(device)(THPStorage* self, void *unused) {
  HANDLE_TH_ERRORS
  return THPDevice_New(self->cdata->device());
  END_HANDLE_TH_ERRORS
}

static PyObject * THPStorage_(dtype)(THPStorage *self, void *unused)
{
  HANDLE_TH_ERRORS
  return torch::autograd::utils::wrap(
      torch::getTHPDtype(at::typeMetaToScalarType(
#ifdef THQUANTIZED
          caffe2::TypeMeta::Make<quantized_t>()
#else
          caffe2::TypeMeta::Make<scalar_t>()
#endif
              )));
  END_HANDLE_TH_ERRORS
}

typedef PyObject *(*getter)(PyObject *, void *);

// NOLINTNEXTLINE(cppcoreguidelines-avoid-c-arrays,modernize-avoid-c-arrays,cppcoreguidelines-avoid-non-const-global-variables)
static struct PyGetSetDef THPStorage_(properties)[] = {
  {"device", (getter)THPStorage_(device), nullptr, nullptr, nullptr},
  {nullptr}
};

// NOLINTNEXTLINE(bugprone-suspicious-include)
#include <torch/csrc/generic/StorageMethods.cpp>
// NOLINTNEXTLINE(bugprone-suspicious-include)
#include <torch/csrc/generic/StorageSharing.cpp>

bool THPStorage_(init)(PyObject *module)
{
  static std::vector<PyMethodDef> methods;
  THPUtils_addPyMethodDefs(methods, THPStorage_(methods));
  THPUtils_addPyMethodDefs(methods, THPStorage_(sharingMethods));

  THPStorageType.tp_methods = methods.data();
  THPStorageType.tp_members = THPStorage_(members);
  THPStorageType.tp_getset = THPStorage_(properties);
  if (PyType_Ready(&THPStorageType) < 0)
    return false;
  Py_INCREF(&THPStorageType);
  PyModule_AddObject(module, THPStorageBaseStr, (PyObject *)&THPStorageType);
  return true;
}

void THPStorage_(postInit)(PyObject *module)
{
  THPStorageClass = PyObject_GetAttrString(module, "_UntypedStorage");
  if (!THPStorageClass) throw python_error();
}

#endif