#include <gtest/gtest.h>

#include <torch/tensor.h>

#include <ATen/Context.h>
#include <ATen/Functions.h>
#include <ATen/OptionsGuard.h>
#include <ATen/core/TensorOptions.h>

#include <string>
#include <vector>

using namespace at;

// A macro so we don't lose location information when an assertion fails.
#define REQUIRE_OPTIONS(device_, index_, type_, layout_)                      \
  ASSERT_EQ(options.device().type(), Device((device_), (index_)).type()); \
  ASSERT_TRUE(                                                                \
      options.device().index() == Device((device_), (index_)).index());       \
  ASSERT_EQ(options.dtype(), (type_));                                    \
  ASSERT_TRUE(options.layout() == (layout_))

#define REQUIRE_TENSOR_OPTIONS(device_, index_, type_, layout_)                \
  ASSERT_EQ(tensor.device().type(), Device((device_), (index_)).type());   \
  ASSERT_EQ(tensor.device().index(), Device((device_), (index_)).index()); \
  ASSERT_EQ(tensor.type().scalarType(), (type_));                          \
  ASSERT_TRUE(tensor.type().layout() == (layout_))

TEST(TensorOptionsTest, DefaultsToTheRightValues) {
  TensorOptions options;
  REQUIRE_OPTIONS(kCPU, -1, kFloat, kStrided);
}

TEST(TensorOptionsTest, ReturnsTheCorrectType) {
  auto options = TensorOptions().device(kCPU).dtype(kInt).layout(kSparse);
  ASSERT_TRUE(
      at::getType(options) == getNonVariableType(Backend::SparseCPU, kInt));
}

TEST(TensorOptionsTest, UtilityFunctionsReturnTheRightTensorOptions) {
  auto options = dtype(kInt);
  REQUIRE_OPTIONS(kCPU, -1, kInt, kStrided);

  options = layout(kSparse);
  REQUIRE_OPTIONS(kCPU, -1, kFloat, kSparse);

  options = device({kCUDA, 1});
  REQUIRE_OPTIONS(kCUDA, 1, kFloat, kStrided);

  options = device_index(1);
  REQUIRE_OPTIONS(kCUDA, 1, kFloat, kStrided);

  options = dtype(kByte).layout(kSparse).device(kCUDA, 2).device_index(3);
  REQUIRE_OPTIONS(kCUDA, 3, kByte, kSparse);
}

TEST(TensorOptionsTest, ConstructsWellFromCPUTypes) {
  TensorOptions options;
  REQUIRE_OPTIONS(kCPU, -1, kFloat, kStrided);

  options = TensorOptions({kCPU, 0});
  REQUIRE_OPTIONS(kCPU, 0, kFloat, kStrided);

  options = TensorOptions(kInt);
  REQUIRE_OPTIONS(kCPU, -1, kInt, kStrided);

  options = TensorOptions(getNonVariableType(Backend::SparseCPU, kFloat));
  REQUIRE_OPTIONS(kCPU, -1, kFloat, kSparse);

  options = TensorOptions(getNonVariableType(Backend::SparseCPU, kByte));
  REQUIRE_OPTIONS(kCPU, -1, kByte, kSparse);
}

TEST(TensorOptionsTest, ConstructsWellFromCPUTensors) {
  auto options = empty(5, kDouble).options();
  REQUIRE_OPTIONS(kCPU, -1, kDouble, kStrided);

  options = empty(5, getNonVariableType(Backend::SparseCPU, kByte)).options();
  REQUIRE_OPTIONS(kCPU, -1, kByte, kSparse);
}

TEST(TensorOptionsTest, ConstructsWellFromVariables) {
  auto options = torch::empty(5).options();
  REQUIRE_OPTIONS(kCPU, -1, kFloat, kStrided);
  ASSERT_FALSE(options.requires_grad());

  options = torch::empty(5, at::requires_grad()).options();
  REQUIRE_OPTIONS(kCPU, -1, kFloat, kStrided);
  ASSERT_FALSE(options.requires_grad());
}

TEST(TensorOptionsTest, OptionsGuard) {
  Tensor tensor;
  {
    OptionsGuard guard(TensorOptions{});
    tensor = at::empty({10});
  }
  REQUIRE_TENSOR_OPTIONS(kCPU, -1, kFloat, kStrided);

  {
    OptionsGuard guard(TensorOptions().dtype(kInt));
    tensor = at::empty({10});
  }
  REQUIRE_TENSOR_OPTIONS(kCPU, -1, kInt, kStrided);

  {
    OptionsGuard guard(TensorOptions().dtype(kInt).layout(kSparse));
    tensor = at::empty({10});
  }
  REQUIRE_TENSOR_OPTIONS(kCPU, -1, kInt, kSparse);

  {
    OptionsGuard guard(requires_grad(true));
    tensor = torch::empty({10});
  }
  REQUIRE_TENSOR_OPTIONS(kCPU, -1, kFloat, kStrided);
  ASSERT_TRUE(tensor.requires_grad());
}

TEST(DeviceTest, ParsesCorrectlyFromString) {
  Device device("cpu:0");
  ASSERT_EQ(device, Device(DeviceType::CPU, 0));

  device = Device("cpu");
  ASSERT_EQ(device, Device(DeviceType::CPU));

  device = Device("cuda:123");
  ASSERT_EQ(device, Device(DeviceType::CUDA, 123));

  device = Device("cuda");
  ASSERT_EQ(device, Device(DeviceType::CUDA));

  device = Device("mkldnn");
  ASSERT_EQ(device, Device(DeviceType::MKLDNN));

  device = Device("opengl");
  ASSERT_EQ(device, Device(DeviceType::OPENGL));

  device = Device("opencl");
  ASSERT_EQ(device, Device(DeviceType::OPENCL));

  device = Device("ideep");
  ASSERT_EQ(device, Device(DeviceType::IDEEP));

  device = Device("hip");
  ASSERT_EQ(device, Device(DeviceType::HIP));

  device = Device("hip:321");
  ASSERT_EQ(device, Device(DeviceType::HIP, 321));

  std::vector<std::string> badnesses = {
      "", "cud:1", "cuda:", "cpu::1", ":1", "3", "tpu:4", "??"};
  for (const auto& badness : badnesses) {
    ASSERT_ANY_THROW({ Device d(badness); });
  }
}