// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.

#include "core/common/span_utils.h"
#include "core/framework/data_types.h"

#include "core/graph/onnx_protobuf.h"

#include "core/graph/constants.h"
#include "core/framework/op_kernel.h"
#include "core/framework/sparse_tensor.h"
#include "core/framework/tensorprotoutils.h"
#include "core/framework/sparse_utils.h"
#include "core/framework/data_transfer.h"

#include "core/graph/model.h"
#include "core/session/inference_session.h"
#include "test/providers/provider_test_utils.h"
#include "asserts.h"
#include "test_utils.h"
#include "file_util.h"
#include "default_providers.h"

#include "gtest/gtest.h"
#include "gmock/gmock.h"

#include "core/util/math_cpuonly.h"
#include <Eigen/SparseCore>

using namespace ONNX_NAMESPACE;
using namespace onnxruntime::common;

namespace onnxruntime {
namespace test {

template <typename T>
inline int64_t vector_len(const std::vector<T>& v) {
  return static_cast<int64_t>(v.size());
}

// This file contains sample implementations of several ops with sparse-tensor inputs/outputs.
// Each op is implemented as a struct with the following signature:
// struct SparseOp {
//    static std::string OpName();
//    static ONNX_NAMESPACE::OpSchema OpSchema();
//    class OpKernelImpl final : public OpKernel {...};
//    static KernelDefBuilder KernelDef();
// }

// op SparseFromCOO
struct SparseFromCOO {
  static std::string OpName() { return "SparseFromCOO"; };

  static ONNX_NAMESPACE::OpSchema OpSchema() {
    ONNX_NAMESPACE::OpSchema schema;
    schema.SetDoc(R"DOC(
This operator constructs a sparse tensor from three tensors that provide a COO
(coordinate) representation.
)DOC")
        .Input(
            0,
            "values",
            "A 1-dimensional tensor of shape [NNZ] that holds all non-zero values",
            "T1",
            OpSchema::Single)
        .Input(
            1,
            "indices",
            "A 2-dimensional tensor of shape [NNZ,d] that holds the (d) indices of non-zero values",
            "T2",
            OpSchema::Single)
        .Input(
            2,
            "shape",
            "A 1-dimensional tensor of shape [d] that holds the shape of the underlying dense tensor",
            "T2",
            OpSchema::Single)
        .Output(
            0,
            "sparse_rep",
            "A sparse representation of the tensor",
            "T",
            OpSchema::Single)
        .TypeConstraint(
            "T1",
            {"tensor(int64)"},
            "Type of the values (input tensor)")
        .TypeConstraint(
            "T2",
            {"tensor(int64)"},
            "Type of index tensor and shape")
        .TypeConstraint(
            "T",
            {"sparse_tensor(int64)"},
            "Output type");
    return schema;
  }

  /**
   *  @brief An implementation of the SparseFromCOO op.
   */
  class OpKernelImpl final : public OpKernel {
   public:
    OpKernelImpl(const OpKernelInfo& info) : OpKernel{info} {}

    Status Compute(OpKernelContext* ctx) const override {
      ORT_ENFORCE(ctx->InputCount() == 3, "Expecting 3 inputs");

      const Tensor& values = *ctx->Input<Tensor>(0);
      const Tensor& indices = *ctx->Input<Tensor>(1);
      const Tensor& shape_tensor = *ctx->Input<Tensor>(2);

      // values and indices should be 1-dimensional tensors
      const TensorShape& val_shape = values.Shape();
      const TensorShape& ind_shape = indices.Shape();
      const TensorShape& shape_shape = shape_tensor.Shape();

      const auto nnz = val_shape.Size();

      ORT_ENFORCE(val_shape.NumDimensions() == 1, "Values must be a 1-dimensional tensor.");
      ORT_ENFORCE(ind_shape.NumDimensions() == 1U || ind_shape.NumDimensions() == 2U,
                  "Indices must be a 1-D or 2-D tensor.");
      if (ind_shape.NumDimensions() == 1) {
        ORT_ENFORCE(ind_shape[0] == nnz, "Indices must have [NNZ] shape.");
      } else {
        ORT_ENFORCE(ind_shape[0] == nnz, "Indices must have [NNZ,2] shape.");
        ORT_ENFORCE(ind_shape[1] == 2U, "Indices must have [NNZ,2] shape.");
      }

      ORT_ENFORCE(shape_shape.NumDimensions() == 1, "Shape must be a 1-dimensional tensor.");

      TensorShape shape(shape_tensor.Data<int64_t>(), shape_shape.Size());

#if !defined(DISABLE_SPARSE_TENSORS)
      SparseTensor* output = ctx->OutputSparse(0, shape);
      ORT_ENFORCE(output != nullptr);
      const auto& dtm = Info().GetDataTransferManager();
      const auto* data_transfer = dtm.GetDataTransfer(OrtDevice(), output->Location().device);
      ORT_ENFORCE(data_transfer != nullptr, "Can not find corresponding data transfer");
      ORT_THROW_IF_ERROR(output->MakeCooData(*data_transfer, OrtMemoryInfo(),
                                             static_cast<size_t>(val_shape.Size()),
                                             values.DataRaw(),
                                             indices.DataAsSpan<int64_t>()));
#endif
      return Status::OK();
    }
  };

  static KernelDefBuilder KernelDef() {
    KernelDefBuilder def;
    def.SetName(SparseFromCOO::OpName())
#if !defined(DISABLE_SPARSE_TENSORS)
        .TypeConstraint("T", DataTypeImpl::GetSparseTensorType<int64_t>())
#endif
        .TypeConstraint("T1", DataTypeImpl::GetTensorType<int64_t>())
        .TypeConstraint("T2", DataTypeImpl::GetTensorType<int64_t>());
    return def;
  }
};

// op SparseAbs
struct SparseAbs {
  static const std::string OpName() { return "SparseAbs"; };

  // The ONNX schema for SparseAbs:
  static ONNX_NAMESPACE::OpSchema OpSchema() {
    ONNX_NAMESPACE::OpSchema schema;
    schema.SetDoc(R"DOC(
This operator applies the Abs op element-wise to the input sparse-tensor.
)DOC")
        .Input(
            0,
            "input",
            "Input sparse tensor",
            "T",
            OpSchema::Single)
        .Output(
            0,
            "output",
            "Output sparse tensor",
            "T",
            OpSchema::Single)
        .TypeConstraint(
            "T",
            {"sparse_tensor(int64)"},
            "Input and Output type");
    return schema;
  }

  // A kernel implementation of SparseAbs:
  class OpKernelImpl final : public OpKernel {
   public:
    OpKernelImpl(const OpKernelInfo& info) : OpKernel{info} {}

    Status Compute(OpKernelContext* ctx) const override {
      ORT_ENFORCE(ctx->InputCount() == 1, "Expecting 1 input");

#if !defined(DISABLE_SPARSE_TENSORS)
      const SparseTensor* input = ctx->Input<SparseTensor>(0);
      const auto* input_values = input->Values().Data<int64_t>();
      const auto nnz = input->NumValues();
      const auto& shape = input->DenseShape();

      auto input_coo_view = input->AsCoo();
      // Allocate/get output-tensor:
      SparseTensor* output = ctx->OutputSparse(0, shape);
      auto output_mutator = output->MakeCooData(nnz, static_cast<size_t>(input_coo_view.Indices().Shape().Size()));

      // compute output values:
      auto* output_values = output_mutator.Values().MutableData<int64_t>();

      for (size_t i = 0; i < nnz; ++i)
        output_values[i] = std::abs(input_values[i]);

      // Currently, there is no way to share the indices/shape between two sparse-tensors.
      // So, we copy indices/shape from input to output.
      // TODO: Extend allocation-planner to enable such sharing.
      const auto& input_indices = input_coo_view.Indices();
      memcpy(output_mutator.Indices().MutableData<int64_t>(), input_indices.Data<int64_t>(), input_indices.SizeInBytes());
#endif
      return Status::OK();
    }
  };

  // A KernelDefBuilder for SparseAbs:
  static KernelDefBuilder KernelDef() {
    KernelDefBuilder def;
#if !defined(DISABLE_SPARSE_TENSORS)
    def.SetName(OpName())
        .TypeConstraint("T", DataTypeImpl::GetSparseTensorType<int64_t>());
#endif
    return def;
  }
};

// op SparseToValues
struct SparseToValues {
  static const std::string OpName() { return "SparseToValues"; };

  static ONNX_NAMESPACE::OpSchema OpSchema() {
    ONNX_NAMESPACE::OpSchema schema;
    schema.SetDoc("Return the non-zero values in a sparse tensor (as a dense tensor).")
        .Input(
            0,
            "sparse_rep",
            "Input sparse tensor.",
            "T1",
            OpSchema::Single)
        .Output(
            0,
            "values",
            "A single dimensional tensor that holds non-zero values in the input",
            "T2",
            OpSchema::Single)
        .TypeConstraint(
            "T1",
            {"sparse_tensor(int64)"},
            "Only int64 is allowed")
        .TypeConstraint(
            "T2",
            {"tensor(int64)"},
            "Type of the values component");
    return schema;
  }

  // A kernel implementation of SparseToValues
  class OpKernelImpl final : public OpKernel {
   public:
    OpKernelImpl(const OpKernelInfo& info) : OpKernel{info} {}

    Status Compute(OpKernelContext* ctx) const override {
      ORT_ENFORCE(ctx->InputCount() == 1, "Expecting a single SparseTensorSample input");

#if !defined(DISABLE_SPARSE_TENSORS)
      const SparseTensor* sparse_input = ctx->Input<SparseTensor>(0);
      const auto* values = sparse_input->Values().Data<int64_t>();
      auto nnz = sparse_input->Values().Shape().Size();

      TensorShape output_shape{nnz};

      Tensor* output = ctx->Output(0, output_shape);
      int64_t* output_data = output->MutableData<int64_t>();
      ORT_ENFORCE(output_data != nullptr);

      memcpy(output_data, values, sparse_input->Values().SizeInBytes());
#endif
      return Status::OK();
    }
  };

  // A KernelDefBuilder for SparseToValues
  static KernelDefBuilder KernelDef() {
    KernelDefBuilder def;
#if !defined(DISABLE_SPARSE_TENSORS)
    def.SetName(OpName())
        .TypeConstraint("T1", DataTypeImpl::GetSparseTensorType<int64_t>())
        .TypeConstraint("T2", DataTypeImpl::GetTensorType<int64_t>());
#endif
    return def;
  }
};

using Action = std::function<void(CustomRegistry*)>;

class SparseTensorTests : public testing::Test {
 protected:
  InferenceSession session_object;
  std::shared_ptr<CustomRegistry> registry;
  std::unique_ptr<Model> model;

  std::vector<OpSchema> schemas;
  std::vector<Action> register_actions;
  std::vector<TypeProto> types;

  SparseTensorTests() : session_object(SessionOptions(), GetEnvironment()),
                        registry(std::make_shared<CustomRegistry>()) {
  }

  void SetUp() override {
    ASSERT_STATUS_OK(session_object.RegisterCustomRegistry(registry));
  }

  template <typename Op>
  void Add() {
    auto schema = Op::OpSchema();
    schema.SetName(Op::OpName());
    schema.SetDomain(onnxruntime::kMLDomain);
    schema.SinceVersion(10);
    schemas.push_back(schema);

    Action register_kernel = [](CustomRegistry* registry2) {
      auto kernel_def_builder = Op::KernelDef();
      kernel_def_builder
          .SetDomain(onnxruntime::kMLDomain)
          .SinceVersion(10)
          .Provider(onnxruntime::kCpuExecutionProvider);
      KernelCreateFn kernel_create_fn = [](FuncManager&, const OpKernelInfo& info, std::unique_ptr<OpKernel>& out) { out = std::make_unique<typename Op::OpKernelImpl>(info); return Status::OK(); };
      ASSERT_STATUS_OK(registry2->RegisterCustomKernel(kernel_def_builder, kernel_create_fn));
    };
    register_actions.push_back(register_kernel);
  }

  void RegisterOps() {
    ASSERT_STATUS_OK(registry->RegisterOpSet(schemas, onnxruntime::kMLDomain, 10, 11));
    for (auto& registerop : register_actions)
      registerop(registry.get());
  }

  void BuildModel() {
    IOnnxRuntimeOpSchemaRegistryList custom_schema_registries = {registry->GetOpschemaRegistry()};
    model.reset(new Model("SparseTensorTest", false, ModelMetaData(), PathString(), custom_schema_registries,
                          {}, {}, DefaultLoggingManager().DefaultLogger()));
  }

  void SerializeAndLoad() {
    // Serialize model and deserialize it back
    std::string serialized_model;
    auto model_proto = model->ToProto();
    EXPECT_TRUE(model_proto.SerializeToString(&serialized_model));
    std::stringstream sstr(serialized_model);
    ASSERT_STATUS_OK(session_object.Load(sstr));
    ASSERT_STATUS_OK(session_object.Initialize());
  }

#if !defined(DISABLE_SPARSE_TENSORS)
  NodeArg* Sparse(const std::string& name) {
    types.push_back(*DataTypeImpl::GetSparseTensorType<int64_t>()->GetTypeProto());
    Graph& graph = model->MainGraph();
    auto& arg = graph.GetOrCreateNodeArg(name, &types.back());
    return &arg;
  }
#endif

  NodeArg* Dense(const std::string& name) {
    types.push_back(*DataTypeImpl::GetTensorType<int64_t>()->GetTypeProto());
    Graph& graph = model->MainGraph();
    auto& arg = graph.GetOrCreateNodeArg(name, &types.back());
    return &arg;
  }

  void Node(const std::string& op, const std::vector<NodeArg*> inputs, const std::vector<NodeArg*> outputs) {
    Graph& graph = model->MainGraph();
    auto& node = graph.AddNode("", op, "", inputs, outputs, nullptr, onnxruntime::kMLDomain);
    node.SetExecutionProviderType(onnxruntime::kCpuExecutionProvider);
  }

  OrtValue Constant(const std::vector<int64_t>& elts) {
    const std::vector<int64_t> shape{static_cast<int64_t>(elts.size())};
    return Constant(elts, shape);
  }

  OrtValue Constant(const std::vector<int64_t>& elts, const std::vector<int64_t>& shape) {
    OrtValue mlvalue;
    CreateMLValue<int64_t>(TestCPUExecutionProvider()->CreatePreferredAllocators()[0], shape, elts, &mlvalue);
    return mlvalue;
  }

  NameMLValMap feeds;

  void AddInput(NodeArg* arg, const std::vector<int64_t>& value) {
    feeds[arg->Name()] = Constant(value);
  }

  void AddInput(NodeArg* arg, const std::vector<int64_t>& value, const std::vector<int64_t>& shape) {
    feeds[arg->Name()] = Constant(value, shape);
  }

  void ExpectEq(OrtValue val1, OrtValue val2) {
    // Restricted to case where val1 and val2 are int64_t tensors
    auto& tensor1 = val1.Get<Tensor>();
    auto& tensor2 = val2.Get<Tensor>();
    EXPECT_EQ(tensor1.Shape().Size(), tensor2.Shape().Size());
    auto* data1 = tensor1.Data<int64_t>();
    auto* data2 = tensor2.Data<int64_t>();
    for (int64_t i = 0, limit = tensor1.Shape().Size(); i < limit; ++i) {
      EXPECT_EQ(data1[i], data2[i]);
    }
  }

  void ExpectEq(OrtValue val1, const std::vector<int64_t>& data2) {
    // Restricted to case where val1 is an int64_t tensor
    auto& tensor1 = val1.Get<Tensor>();
    EXPECT_EQ(static_cast<uint64_t>(tensor1.Shape().Size()), data2.size());
    auto* data1 = tensor1.Data<int64_t>();
    for (int64_t i = 0, limit = tensor1.Shape().Size(); i < limit; ++i) {
      EXPECT_EQ(data1[i], data2[i]);
    }
  }

  std::vector<std::string> output_names;
  std::vector<OrtValue> expected_output;

  void ExpectOutput(NodeArg* arg, const std::vector<int64_t>& value) {
    output_names.push_back(arg->Name());
    expected_output.push_back(Constant(value));
  }

  void RunTest() {
    RunOptions run_options;
    std::vector<OrtValue> fetches;

    ASSERT_STATUS_OK(session_object.Run(run_options, feeds, output_names, &fetches));

    ASSERT_EQ(expected_output.size(), fetches.size());
    for (size_t i = 0; i < fetches.size(); ++i) {
      ExpectEq(fetches[i], expected_output[i]);
    }
  }
};

#if !defined(DISABLE_SPARSE_TENSORS)
// Test ops SparseFromCOO, SparseAbs, and SparseToValues.
// Tests 1-dimensional int64 sparse tensor.
TEST_F(SparseTensorTests, Test1) {
  // Register ops
  Add<SparseFromCOO>();
  Add<SparseAbs>();
  Add<SparseToValues>();
  RegisterOps();

  // Build model/graph
  BuildModel();

  // Node: create a sparse tensor from COO components:
  // sparse1 <- SparseFromCOO(values, indices, shape)
  auto values = Dense("values");     // a dense tensor containing non-zero-values
  auto indices = Dense("indices");   // a dense tensor containing indices of non-zero-values
  auto shape = Dense("shape");       // a dense tensor representing shape
  auto sparse1 = Sparse("sparse1");  // a sparse tensor created from above

  Node(SparseFromCOO::OpName(), {values, indices, shape}, {sparse1});

  // Node:apply SparseAbs op
  // sparse2 <- SparseAbs(sparse1)
  auto sparse2 = Sparse("sparse2");
  Node(SparseAbs::OpName(), {sparse1}, {sparse2});

  // Node: Extract non-zero values from sparse2
  // output <- SparseToValues(sparse2)
  auto output = Dense("output");
  Node(SparseToValues::OpName(), {sparse2}, {output});

  // Check graph, serialize it and deserialize it back
  Graph& graph = model->MainGraph();
  ASSERT_STATUS_OK(graph.Resolve());
  SerializeAndLoad();

  // Run the model
  AddInput(values, {-99, 2});
  AddInput(indices, {1, 4}, {2});
  AddInput(shape, {5});
  ExpectOutput(output, {99, 2});
  RunTest();
}

// Test ops SparseFromCOO, SparseAbs, and SparseToValues.
// Tests 2-dimensional int64 sparse tensor.
TEST_F(SparseTensorTests, Test2) {
  // Register ops
  Add<SparseFromCOO>();
  Add<SparseAbs>();
  Add<SparseToValues>();
  RegisterOps();

  // Build model/graph
  BuildModel();

  // Node: create a sparse tensor from COO components:
  // sparse1 <- SparseFromCOO(values, indices, shape)
  auto values = Dense("values");     // a dense tensor containing non-zero-values
  auto indices = Dense("indices");   // a dense tensor containing indices of non-zero-values
  auto shape = Dense("shape");       // a dense tensor representing shape
  auto sparse1 = Sparse("sparse1");  // a sparse tensor created from above

  Node(SparseFromCOO::OpName(), {values, indices, shape}, {sparse1});

  // Node:apply SparseAbs op
  // sparse2 <- SparseAbs(sparse1)
  auto sparse2 = Sparse("sparse2");
  Node(SparseAbs::OpName(), {sparse1}, {sparse2});

  // Node: Extract non-zero values from sparse2
  // output <- SparseToValues(sparse2)
  auto output = Dense("output");
  Node(SparseToValues::OpName(), {sparse2}, {output});

  // Check graph, serialize it and deserialize it back
  Graph& graph = model->MainGraph();
  ASSERT_STATUS_OK(graph.Resolve());
  SerializeAndLoad();

  // Run the model
  AddInput(values, {-99, 2});
  AddInput(indices, {1, 1, 4, 4}, {2, 2});
  AddInput(shape, {5, 5});
  ExpectOutput(output, {99, 2});
  RunTest();
}

TEST(SparseCrcsFormatTests, Test1) {
  // const std::vector<float> input_data = {
  //     0, 1, 2, 0, 0, 0, 3, 4, 5,
  //     6, 7, 8, 0, 0, 0, 9, 10, 11,
  //     12, 13, 14, 0, 0, 0, 15, 16, 17,
  //     0, 0, 0, 18, 19, 20, 21, 22, 23,
  //     0, 0, 0, 24, 25, 26, 27, 28, 29,
  //     0, 0, 0, 30, 31, 32, 33, 34, 35,
  //     36, 37, 38, 39, 40, 41, 0, 0, 0,
  //     42, 43, 44, 45, 46, 47, 0, 0, 0,
  //     48, 49, 50, 51, 52, 53, 0, 0, 0};
  auto* cpu_provider = TestCPUExecutionProvider();
  auto cpu_transfer = cpu_provider->GetDataTransfer();

  TensorShape dense_shape{9, 9};

  std::vector<float> values = {
      1, 2, 3, 4, 5,
      6, 7, 8, 9, 10, 11,
      12, 13, 14, 15, 16, 17,
      18, 19, 20, 21, 22, 23,
      24, 25, 26, 27, 28, 29,
      30, 31, 32, 33, 34, 35,
      36, 37, 38, 39, 40, 41,
      42, 43, 44, 45, 46, 47,
      48, 49, 50, 51, 52, 53};

  TensorShape values_shape{vector_len(values)};

  // Row major
  std::vector<int64_t> inner_indices = {
      1, 2, 6, 7, 8,
      0, 1, 2, 6, 7, 8,
      0, 1, 2, 6, 7, 8,
      3, 4, 5, 6, 7, 8,
      3, 4, 5, 6, 7, 8,
      3, 4, 5, 6, 7, 8,
      0, 1, 2, 3, 4, 5,
      0, 1, 2, 3, 4, 5,
      0, 1, 2, 3, 4, 5};

  ASSERT_EQ(values.size(), inner_indices.size());

  std::vector<int64_t> outer_indices = {
      0, 5, 11, 17, 23, 29, 35, 41, 47, 53};

  ASSERT_EQ(9U + 1U, outer_indices.size());

  // Test owning instance
  auto default_allocator = TestCPUExecutionProvider()->CreatePreferredAllocators()[0];

  SparseTensor tensor_alloc(DataTypeImpl::GetType<float>(), dense_shape, default_allocator);
  ASSERT_EQ(tensor_alloc.DenseShape(), dense_shape);

  ASSERT_STATUS_OK(tensor_alloc.MakeCsrData(*cpu_transfer, OrtMemoryInfo(),
                                            values.size(), values.data(),
                                            gsl::make_span(inner_indices),
                                            gsl::make_span(outer_indices)));

  ASSERT_EQ(values.size(), tensor_alloc.NumValues());
  ASSERT_EQ(0, memcmp(tensor_alloc.Values().Data<float>(), values.data(), tensor_alloc.Values().SizeInBytes()));
  {
    auto csr_view = tensor_alloc.AsCsr();
    const Tensor& inner = csr_view.Inner();
    const Tensor& outer = csr_view.Outer();
    ASSERT_EQ(inner.Shape().Size(), vector_len(inner_indices));
    ASSERT_EQ(outer.Shape().Size(), vector_len(outer_indices));
    ASSERT_EQ(0, memcmp(inner.Data<int64_t>(), inner_indices.data(), inner.SizeInBytes()));
    ASSERT_EQ(0, memcmp(outer.Data<int64_t>(), outer_indices.data(), outer.SizeInBytes()));
  }

  OrtMemoryInfo mem_info;
  SparseTensor tensor_wrap(DataTypeImpl::GetType<float>(), dense_shape, {vector_len(values)}, values.data(), mem_info);
  ASSERT_EQ(tensor_wrap.DenseShape(), dense_shape);
  ASSERT_STATUS_OK(tensor_wrap.UseCsrIndices(gsl::make_span(inner_indices), gsl::make_span(outer_indices)));

  ASSERT_EQ(values.size(), tensor_wrap.NumValues());
  ASSERT_EQ(0, memcmp(tensor_alloc.Values().Data<float>(), tensor_wrap.Values().Data<float>(), values.size() * sizeof(float)));
  auto csr_alloc = tensor_alloc.AsCsr();
  auto csr_wrap = tensor_wrap.AsCsr();
  ASSERT_EQ(0, memcmp(csr_alloc.Inner().Data<int64_t>(),
                      csr_wrap.Inner().Data<int64_t>(),
                      inner_indices.size() * sizeof(int64_t)));
  ASSERT_EQ(0, memcmp(csr_alloc.Outer().Data<int64_t>(),
                      csr_wrap.Outer().Data<int64_t>(),
                      outer_indices.size() * sizeof(int64_t)));
}
#endif  // !defined(DISABLE_SPARSE_TENSORS)

// Code below depends on the values being size 4
template <typename T>
static std::vector<T> CreateValues() {
  return {1, 2, 3, 4};
}

/* std::string support in the future
template <>
std::vector<std::string> CreateValues<std::string>() {
  return {"one", "two", "three", "four"};
}
*/

template <>
std::vector<BFloat16> CreateValues<BFloat16>() {
  return {BFloat16(1.f), BFloat16(2.f), BFloat16(3.f), BFloat16(4.f)};
}

template <>
std::vector<MLFloat16> CreateValues<MLFloat16>() {
  return {MLFloat16(1.f), MLFloat16(2.f), MLFloat16(3.f), MLFloat16(4.f)};
}

template <typename T>
static void CreateTensorWithExternalData(
    TensorProto_DataType type,
    const std::vector<T>& test_data,
    std::basic_string<ORTCHAR_T>& filename,
    TensorProto& tensor_proto) {
  // Create external data
  FILE* fp;
  CreateTestFile(fp, filename);
  size_t size_in_bytes = test_data.size() * sizeof(T);
  ASSERT_EQ(size_in_bytes, fwrite(test_data.data(), 1, size_in_bytes, fp));
  ASSERT_EQ(0, fclose(fp));

  // set the tensor_proto to reference this external data
  onnx::StringStringEntryProto* location = tensor_proto.mutable_external_data()->Add();
  location->set_key("location");
  location->set_value(ToUTF8String(filename));
  tensor_proto.set_data_location(onnx::TensorProto_DataLocation_EXTERNAL);
  tensor_proto.set_data_type(type);
}

namespace {

void insert_indices_data(bool indices_1D,
                         size_t values_size, size_t shape_size,
                         std::vector<int8_t>& indices_data,
                         TensorProto& indices_tp) {
  if (indices_1D) {
    indices_data = {2, 5, 6, 10};
    indices_tp.add_dims(indices_data.size());
  } else {
    // indices are shape {NNZ, rank} so convert flattened values of 2, 5, 6 and 10 to rank 3 values
    indices_tp.add_dims(values_size);
    indices_tp.add_dims(shape_size);
    indices_data = {
        0, 1, 0,
        0, 2, 1,
        1, 0, 0,
        1, 2, 0};
  }
}

template <typename T>
struct InsertIndices {
  void operator()(bool indices_1D, size_t values_size, size_t shape_size, TensorProto& indices_tp) const {
    static_assert(std::is_integral_v<T>, "indices data must be integral data type");
    static_assert(std::is_signed_v<T>, "indices must be signed data type");
    std::vector<int8_t> indices_data;
    insert_indices_data(indices_1D, values_size, shape_size, indices_data, indices_tp);
    indices_tp.set_data_type(utils::ToTensorProtoElementType<T>());
    if constexpr (sizeof(T) == sizeof(int8_t)) {
      indices_tp.mutable_raw_data()->assign(reinterpret_cast<const char*>(indices_data.data()), indices_data.size());
    } else {
      // Conversion on the fly to the target data type
      std::vector<T> indices(indices_data.cbegin(), indices_data.cend());
      indices_tp.mutable_raw_data()->assign(reinterpret_cast<const char*>(indices.data()), indices.size() * sizeof(T));
      if constexpr (endian::native != endian::little) {
        utils::ConvertRawDataInTensorProto(indices_tp);
      }
    }
  }
};

using SupportedIndicesTypeList = onnxruntime::TypeList<int8_t, int16_t, int32_t, int64_t>;

}  // namespace

template <typename T>
static NodeProto CreateConstantNode(bool indices_1D, int32_t indices_type,
                                    std::function<void(const std::vector<T>& values, TensorProto& tp)> inserter,
                                    std::vector<T>& expected_data) {
  NodeProto constant_node;
  constant_node.set_op_type("Constant");
  constant_node.add_output("dense_tensor_output");

  std::vector<T> values = CreateValues<T>();
  std::vector<int64_t> shape{2, 3, 2};

  AttributeProto& attrib = *constant_node.mutable_attribute()->Add();
  attrib.set_name("sparse_value");
  attrib.set_type(AttributeProto_AttributeType_SPARSE_TENSOR);

  SparseTensorProto& stp = *attrib.mutable_sparse_tensor();
  stp.mutable_dims()->Add(shape.cbegin(), shape.cend());

  TensorProto& indices_tp = *stp.mutable_indices();
  utils::MLTypeCallDispatcherFromTypeList<SupportedIndicesTypeList> type_disp(indices_type);
  type_disp.Invoke<InsertIndices>(indices_1D, values.size(), shape.size(), indices_tp);

  expected_data.resize(2 * 3 * 2);
  expected_data[2] = values[0];
  expected_data[5] = values[1];
  expected_data[6] = values[2];
  expected_data[10] = values[3];

  stp.mutable_values()->add_dims(values.size());
  inserter(values, *stp.mutable_values());

  return constant_node;
}

template <typename T>
static NodeProto CreateConstantNodeAllZeros(bool indices_1D, std::vector<T>& expected_data) {
  NodeProto constant_node;
  constant_node.set_op_type("Constant");
  constant_node.add_output("dense_tensor_output");

  std::vector<int64_t> indices;
  std::vector<int64_t> shape{2, 3, 2};

  AttributeProto& attrib = *constant_node.mutable_attribute()->Add();
  attrib.set_name("sparse_value_all_zeros");
  attrib.set_type(AttributeProto_AttributeType_SPARSE_TENSOR);

  SparseTensorProto& stp = *attrib.mutable_sparse_tensor();
  stp.mutable_dims()->Add(shape.cbegin(), shape.cend());

  TensorProto& indices_tp = *stp.mutable_indices();
  if (indices_1D) {
    indices_tp.add_dims(0);
  } else {
    // indices are shape {NNZ, rank} so convert flattened values of 2, 5, 6 and 10 to rank 3 values
    indices_tp.add_dims(0);
    indices_tp.add_dims(0);
  }

  indices_tp.set_data_type(ONNX_NAMESPACE::TensorProto_DataType_INT64);

  // Must be all zeros
  expected_data.resize(2 * 3 * 2);

  auto& mutable_values = *stp.mutable_values();
  mutable_values.set_name("all_zeros");
  mutable_values.set_data_type(utils::ToTensorProtoElementType<T>());
  mutable_values.add_dims(0);

  return constant_node;
}

template <typename T>
static void TestConversion(bool use_1D_indices, int32_t indices_type,
                           std::function<void(const std::vector<T>& values, TensorProto& tp)> inserter,
                           std::function<void(gsl::span<const T> expected, const TensorProto& actual)> checker) {
  std::vector<T> expected;
  auto node = CreateConstantNode<T>(use_1D_indices, indices_type, inserter, expected);

  TensorProto dense;
  // Path is required for loading external data (if any)
  // When path is empty it will look for the data in current dir
  ASSERT_STATUS_OK(utils::ConstantNodeProtoToTensorProto(node, std::filesystem::path(), dense));

  gsl::span<const T> expected_span = gsl::make_span<const T>(expected.data(), expected.size());
  checker(expected_span, dense);
}

template <typename T>
static void TestConversionAllZeros(bool use_1D_indices,
                                   std::function<void(gsl::span<const T> expected, const TensorProto& actual)> checker) {
  std::vector<T> expected;
  auto node = CreateConstantNodeAllZeros<T>(use_1D_indices, expected);

  TensorProto dense;
  // Path is required for loading external data (if any)
  // When path is empty it will look for the data in current dir
  ASSERT_STATUS_OK(utils::ConstantNodeProtoToTensorProto(node, std::filesystem::path(), dense));

  gsl::span<const T> expected_span = gsl::make_span<const T>(expected.data(), expected.size());
  checker(expected_span, dense);
}

template <typename T>
static void TestConversion(
    std::function<void(const std::vector<T>& values, TensorProto& tp)> inserter,
    std::function<void(gsl::span<const T> expected, const TensorProto& actual)> checker) {
  std::vector<TensorProto_DataType> indices_types{
      TensorProto_DataType_INT8,
      TensorProto_DataType_INT16,
      TensorProto_DataType_INT32,
      TensorProto_DataType_INT64};

  for (auto dt : indices_types) {
    TestConversion(true, dt, inserter, checker);
    TestConversion(false, dt, inserter, checker);
  }
  TestConversionAllZeros(true, checker);
  TestConversionAllZeros(false, checker);
}

template <typename T>
static void RawDataWriter(const std::vector<T>& values, TensorProto& tp, TensorProto_DataType datatype) {
  tp.set_data_type(datatype);
  utils::SetRawDataInTensorProto(tp, values.data(), values.size() * sizeof(T));
}

int64_t ActualSize(const TensorProto& actual) {
  int64_t actual_size = 1;
  for (const auto dim : actual.dims()) {
    actual_size *= dim;
  }
  return actual_size;
}

template <typename T>
static void RawDataChecker(gsl::span<const T> expected, const TensorProto& actual) {
  int64_t actual_size = ActualSize(actual);

  const T* raw_data = reinterpret_cast<const T*>(actual.raw_data().data());
  auto actual_span = gsl::make_span<const T>(raw_data, actual_size);

  ASSERT_THAT(actual_span, testing::ContainerEq(expected));
}

template <>
void RawDataChecker<MLFloat16>(gsl::span<const MLFloat16> expected_bfloat, const TensorProto& actual) {
  int64_t actual_size = ActualSize(actual);

  auto expected = ReinterpretAsSpan<const uint16_t>(expected_bfloat);
  const uint16_t* raw_data = reinterpret_cast<const uint16_t*>(actual.raw_data().data());
  auto actual_span = gsl::make_span<const uint16_t>(raw_data, actual_size);

  ASSERT_THAT(actual_span, testing::ContainerEq(expected));
}

template <>
void RawDataChecker<BFloat16>(gsl::span<const BFloat16> expected_bfloat, const TensorProto& actual) {
  int64_t actual_size = ActualSize(actual);

  auto expected = ReinterpretAsSpan<const uint16_t>(expected_bfloat);
  const uint16_t* raw_data = reinterpret_cast<const uint16_t*>(actual.raw_data().data());
  auto actual_span = gsl::make_span<const uint16_t>(raw_data, actual_size);

  ASSERT_THAT(actual_span, testing::ContainerEq(expected));
}

TEST(SparseTensorConversionTests, TestConstantNodeConversion) {
  TestConversion<float>(
      [](const std::vector<float>& values, TensorProto& tp) {
        tp.set_data_type(TensorProto_DataType_FLOAT);
        tp.mutable_float_data()->Add(values.cbegin(), values.cend());
      },
      RawDataChecker<float>);

  TestConversion<double>(
      [](const std::vector<double>& values, TensorProto& tp) {
        tp.set_data_type(TensorProto_DataType_DOUBLE);
        tp.mutable_double_data()->Add(values.cbegin(), values.cend());
      },
      RawDataChecker<double>);

  TestConversion<BFloat16>(
      [](const std::vector<BFloat16>& values, TensorProto& tp) {
        tp.set_data_type(TensorProto_DataType_BFLOAT16);
        for (auto v : values) {
          tp.mutable_int32_data()->Add(v.val);
        }
      },
      RawDataChecker<BFloat16>);

  TestConversion<MLFloat16>(
      [](const std::vector<MLFloat16>& values, TensorProto& tp) {
        tp.set_data_type(TensorProto_DataType_FLOAT16);
        for (auto v : values) {
          tp.mutable_int32_data()->Add(v.val);
        }
      },
      RawDataChecker<MLFloat16>);

  TestConversion<int16_t>(
      [](const std::vector<int16_t>& values, TensorProto& tp) {
        tp.set_data_type(TensorProto_DataType_INT16);
        tp.mutable_int32_data()->Add(values.cbegin(), values.cend());
      },
      RawDataChecker<int16_t>);

  TestConversion<uint16_t>(
      [](const std::vector<uint16_t>& values, TensorProto& tp) {
        tp.set_data_type(TensorProto_DataType_UINT16);
        tp.mutable_int32_data()->Add(values.cbegin(), values.cend());
      },
      RawDataChecker<uint16_t>);

  TestConversion<int32_t>(
      [](const std::vector<int32_t>& values, TensorProto& tp) {
        tp.set_data_type(TensorProto_DataType_INT32);
        tp.mutable_int32_data()->Add(values.cbegin(), values.cend());
      },
      RawDataChecker<int32_t>);

  TestConversion<uint32_t>(
      [](const std::vector<uint32_t>& values, TensorProto& tp) {
        tp.set_data_type(TensorProto_DataType_UINT32);
        tp.mutable_uint64_data()->Add(values.cbegin(), values.cend());
      },
      RawDataChecker<uint32_t>);

  // Test all zeros case
  TestConversion<int64_t>(
      [](const std::vector<int64_t>& values, TensorProto& tp) {
        tp.set_data_type(TensorProto_DataType_INT64);
        tp.mutable_int64_data()->Add(values.cbegin(), values.cend());
      },
      RawDataChecker<int64_t>);

  TestConversion<uint64_t>(
      [](const std::vector<uint64_t>& values, TensorProto& tp) {
        tp.set_data_type(TensorProto_DataType_UINT64);
        tp.mutable_uint64_data()->Add(values.cbegin(), values.cend());
      },
      RawDataChecker<uint64_t>);

  TestConversion<int8_t>(
      [](const std::vector<int8_t>& values, TensorProto& tp) {
        tp.set_data_type(TensorProto_DataType_INT8);
        tp.mutable_int32_data()->Add(values.cbegin(), values.cend());
      },
      RawDataChecker<int8_t>);

  TestConversion<uint8_t>(
      [](const std::vector<uint8_t>& values, TensorProto& tp) {
        RawDataWriter(values, tp, TensorProto_DataType_UINT8);
      },
      RawDataChecker<uint8_t>);

  // Test constant node conversion for SparseTensor with external data
  PathString tensor_filename(ORT_TSTR("tensor_XXXXXX"));
  TestConversion<float>(
      true,
      TensorProto_DataType_INT64,
      [&tensor_filename](const std::vector<float>& values, TensorProto& tp) {
        CreateTensorWithExternalData<float>(TensorProto_DataType_FLOAT, values, tensor_filename, tp);
      },
      RawDataChecker<float>);
  DeleteFileFromDisk(tensor_filename.c_str());
}

/// Dense to Sparse conversion tests
#if !defined(DISABLE_SPARSE_TENSORS)
#if !defined(ORT_MINIMAL_BUILD)

template <typename T>
static std::vector<T> CreateSparseValues(size_t indices_start) {
  std::vector<T> result(indices_start + 2);
  result[indices_start] = 2;
  result[indices_start + 1] = 3;
  return result;
}

/* std::string support in the future
template <>
std::vector<std::string> CreateSparseValues<std::string>() {
  return {"", "two", "three", ""};
}
*/

template <>
std::vector<BFloat16> CreateSparseValues<BFloat16>(size_t indices_start) {
  std::vector<BFloat16> result(indices_start + 2);
  result[indices_start] = BFloat16(2.f);
  result[indices_start + 1] = BFloat16(3.f);
  return result;
}

template <>
std::vector<MLFloat16> CreateSparseValues<MLFloat16>(size_t indices_start) {
  std::vector<MLFloat16> result(indices_start + 2);
  result[indices_start] = MLFloat16(2.f);
  result[indices_start + 1] = MLFloat16(3.f);
  return result;
}

template <typename T>
static std::vector<T> CreateSparseValuesAllZeros() {
  return {0, 0, 0, 0};
}

template <>
std::vector<BFloat16> CreateSparseValuesAllZeros<BFloat16>() {
  return {BFloat16(0.f), BFloat16(0.f), BFloat16(0.f), BFloat16(0.f)};
}

template <>
std::vector<MLFloat16> CreateSparseValuesAllZeros<MLFloat16>() {
  return {MLFloat16(0.f), MLFloat16(0.f), MLFloat16(0.f), MLFloat16(0.f)};
}

template <typename T>
TensorProto CreateDenseTensor(size_t indices_start,
                              std::function<void(const std::vector<T>& values, TensorProto& tp)> inserter,
                              std::vector<T>& expected_values, std::vector<int64_t>& expected_indicies) {
  TensorProto result;
  std::vector<T> values = CreateSparseValues<T>(indices_start);
  auto ind_start = static_cast<int64_t>(indices_start);
  expected_indicies = {ind_start, ind_start + 1};
  for (const auto& ind : expected_indicies) {
    expected_values.push_back(values[ind]);
  }
  inserter(values, result);
  result.add_dims(static_cast<int64_t>(values.size()));
  return result;
}

template <typename T>
TensorProto CreateDenseTensorAllZeros(std::function<void(const std::vector<T>& values, TensorProto& tp)> inserter) {
  TensorProto result;
  std::vector<T> values = CreateSparseValuesAllZeros<T>();
  inserter(values, result);
  result.add_dims(static_cast<int64_t>(values.size()));
  return result;
}

int64_t ActualSize(const SparseTensorProto& actual) {
  int64_t actual_size = 1;
  for (const auto dim : actual.values().dims()) {
    actual_size *= dim;
  }
  return actual_size;
}

template <typename T>
static void RawSparseDataChecker(gsl::span<const T> expected_values,
                                 gsl::span<const int64_t> expected_indicies,
                                 const SparseTensorProto& actual) {
  const int64_t actual_size = ActualSize(actual);

  const T* raw_data = reinterpret_cast<const T*>(actual.values().raw_data().data());
  auto actual_span = gsl::make_span<const T>(raw_data, actual_size);

  ASSERT_THAT(actual_span, testing::ContainerEq(expected_values));

  SparseIndicesChecker(actual.indices(), expected_indicies);
}

template <>
void RawSparseDataChecker<BFloat16>(gsl::span<const BFloat16> expected_bfloat,
                                    gsl::span<const int64_t> expected_indicies,
                                    const SparseTensorProto& actual) {
  const int64_t actual_size = ActualSize(actual);

  static_assert(sizeof(uint16_t) == sizeof(BFloat16), "Expecting equal sizes");
  auto expected = ReinterpretAsSpan<const uint16_t>(expected_bfloat);
  const uint16_t* raw_data = reinterpret_cast<const uint16_t*>(actual.values().raw_data().data());
  auto actual_span = gsl::make_span<const uint16_t>(raw_data, actual_size);

  ASSERT_THAT(actual_span, testing::ContainerEq(expected));
  SparseIndicesChecker(actual.indices(), expected_indicies);
}

template <>
void RawSparseDataChecker<MLFloat16>(gsl::span<const MLFloat16> expected_bfloat,
                                     gsl::span<const int64_t> expected_indicies,
                                     const SparseTensorProto& actual) {
  const int64_t actual_size = ActualSize(actual);

  static_assert(sizeof(uint16_t) == sizeof(MLFloat16), "Expecting equal sizes");
  auto expected = ReinterpretAsSpan<const uint16_t>(expected_bfloat);
  const uint16_t* raw_data = reinterpret_cast<const uint16_t*>(actual.values().raw_data().data());
  auto actual_span = gsl::make_span<const uint16_t>(raw_data, actual_size);

  ASSERT_THAT(actual_span, testing::ContainerEq(expected));
  SparseIndicesChecker(actual.indices(), expected_indicies);
}

template <typename T>
static Status TestDenseToSparseConversionValues(size_t indices_start,
                                                std::function<void(const std::vector<T>& values, TensorProto& tp)> inserter,
                                                std::function<void(gsl::span<const T> expected,
                                                                   gsl::span<const int64_t> expected_indicies,
                                                                   const SparseTensorProto& actual)>
                                                    checker) {
  std::vector<T> expected_values;
  std::vector<int64_t> expected_indicies;
  // Path is required for loading external data
  // Using empty path here since the data is not external
  std::filesystem::path model_path;
  TensorProto dense_tensor = CreateDenseTensor(indices_start, inserter, expected_values, expected_indicies);

  SparseTensorProto sparse_tensor;
  ORT_RETURN_IF_ERROR(utils::DenseTensorToSparseTensorProto(dense_tensor, model_path, sparse_tensor));

  gsl::span<const T>
      expected_values_span = gsl::make_span(expected_values.data(), expected_values.size());
  gsl::span<const int64_t> expected_ind_span = gsl::make_span(expected_indicies.data(), expected_indicies.size());
  checker(expected_values_span, expected_ind_span, sparse_tensor);
  return Status::OK();
}

template <typename T>
static Status TestDenseAllZerosToSparseConversion(
    std::function<void(const std::vector<T>& values, TensorProto& tp)> inserter,
    std::function<void(gsl::span<const T> expected,
                       gsl::span<const int64_t> expected_indicies,
                       const SparseTensorProto& actual)>
        checker) {
  std::vector<T> expected_values;
  std::vector<int64_t> expected_indicies;
  // Path is required for loading external data
  // Using empty path here since the data is not external
  std::filesystem::path model_path;
  TensorProto dense_tensor = CreateDenseTensorAllZeros(inserter);

  SparseTensorProto sparse_tensor;
  ORT_RETURN_IF_ERROR(utils::DenseTensorToSparseTensorProto(dense_tensor, model_path, sparse_tensor));

  gsl::span<const T>
      expected_values_span = gsl::make_span(expected_values.data(), expected_values.size());
  gsl::span<const int64_t> expected_ind_span = gsl::make_span(expected_indicies.data(), expected_indicies.size());
  checker(expected_values_span, expected_ind_span, sparse_tensor);
  return Status::OK();
}

template <typename T>
static Status TestDenseToSparseConversion(size_t indices_start,
                                          std::function<void(const std::vector<T>& values, TensorProto& tp)> inserter,
                                          std::function<void(gsl::span<const T> expected,
                                                             gsl::span<const int64_t> expected_indicies,
                                                             const SparseTensorProto& actual)>
                                              checker) {
  ORT_RETURN_IF_ERROR(TestDenseToSparseConversionValues<T>(indices_start, inserter, checker));
  return TestDenseAllZerosToSparseConversion<T>(inserter, checker);
}

TEST(SparseTensorConversionTests, TestDenseToSparseConversion) {
  // This one will test indices that are less than max int8 value
  // which should result in int8 indices
  ASSERT_STATUS_OK(TestDenseToSparseConversion<float>(
      20U,
      [](const std::vector<float>& values, TensorProto& tp) {
        tp.set_data_type(TensorProto_DataType_FLOAT);
        tp.set_name("dense_float");
        tp.mutable_float_data()->Add(values.cbegin(), values.cend());
      },
      RawSparseDataChecker<float>));

  // This one will test indices that are max(int8) < ind < max(int16) value
  // which should result in int16 indices
  ASSERT_STATUS_OK(TestDenseToSparseConversion<double>(
      static_cast<size_t>(std::numeric_limits<int8_t>::max()) + 20U,
      [](const std::vector<double>& values, TensorProto& tp) {
        tp.set_data_type(TensorProto_DataType_DOUBLE);
        tp.set_name("dense_double");
        tp.mutable_double_data()->Add(values.cbegin(), values.cend());
      },
      RawSparseDataChecker<double>));

  // This one will test indices that are max(int16) < ind < max(int32) value
  // which should result in int32 indices
  ASSERT_STATUS_OK(TestDenseToSparseConversion<BFloat16>(
      static_cast<size_t>(std::numeric_limits<int16_t>::max()) + 20U,
      [](const std::vector<BFloat16>& values, TensorProto& tp) {
        tp.set_data_type(TensorProto_DataType_BFLOAT16);
        tp.set_name("dense_bfloat16");
        for (auto v : values) {
          tp.mutable_int32_data()->Add(v.val);
        }
      },
      RawSparseDataChecker<BFloat16>));

  // Protobuf can not hold anything more than 2Gb and it overflows. Can't test 64-bit indices
  // on conversion unless explicitly created.
  // which should result in int32 indices
  ASSERT_STATUS_OK(TestDenseToSparseConversion<MLFloat16>(
      20U,
      [](const std::vector<MLFloat16>& values, TensorProto& tp) {
        tp.set_data_type(TensorProto_DataType_FLOAT16);
        tp.set_name("dense_float16");
        for (auto v : values) {
          tp.mutable_int32_data()->Add(v.val);
        }
      },
      RawSparseDataChecker<MLFloat16>));

  ASSERT_STATUS_OK(TestDenseToSparseConversion<int16_t>(
      20U,
      [](const std::vector<int16_t>& values, TensorProto& tp) {
        tp.set_name("dense_int16");
        tp.set_data_type(TensorProto_DataType_INT16);
        tp.mutable_int32_data()->Add(values.cbegin(), values.cend());
      },
      RawSparseDataChecker<int16_t>));

  ASSERT_STATUS_OK(TestDenseToSparseConversion<uint16_t>(
      20U,
      [](const std::vector<uint16_t>& values, TensorProto& tp) {
        tp.set_name("dense_uint16");
        tp.set_data_type(TensorProto_DataType_UINT16);
        tp.mutable_int32_data()->Add(values.cbegin(), values.cend());
      },
      RawSparseDataChecker<uint16_t>));

  ASSERT_STATUS_OK(TestDenseToSparseConversion<int32_t>(
      20U,
      [](const std::vector<int32_t>& values, TensorProto& tp) {
        tp.set_name("dense_int32");
        tp.set_data_type(TensorProto_DataType_INT32);
        tp.mutable_int32_data()->Add(values.cbegin(), values.cend());
      },
      RawSparseDataChecker<int32_t>));

  ASSERT_STATUS_OK(TestDenseToSparseConversion<uint32_t>(
      20U,
      [](const std::vector<uint32_t>& values, TensorProto& tp) {
        tp.set_name("dense_uint32");
        tp.set_data_type(TensorProto_DataType_UINT32);
        tp.mutable_uint64_data()->Add(values.cbegin(), values.cend());
      },
      RawSparseDataChecker<uint32_t>));

  ASSERT_STATUS_OK(TestDenseToSparseConversion<int64_t>(
      20U,
      [](const std::vector<int64_t>& values, TensorProto& tp) {
        tp.set_name("dense_int64");
        tp.set_data_type(TensorProto_DataType_INT64);
        tp.mutable_int64_data()->Add(values.cbegin(), values.cend());
      },
      RawSparseDataChecker<int64_t>));

  ASSERT_STATUS_OK(TestDenseToSparseConversion<uint64_t>(
      20U,
      [](const std::vector<uint64_t>& values, TensorProto& tp) {
        tp.set_name("dense_uint64");
        tp.set_data_type(TensorProto_DataType_UINT64);
        tp.mutable_uint64_data()->Add(values.cbegin(), values.cend());
      },
      RawSparseDataChecker<uint64_t>));

  ASSERT_STATUS_OK(TestDenseToSparseConversion<int8_t>(
      20U,
      [](const std::vector<int8_t>& values, TensorProto& tp) {
        tp.set_name("dense_int8");
        tp.set_data_type(TensorProto_DataType_INT8);
        tp.mutable_int32_data()->Add(values.cbegin(), values.cend());
      },
      RawSparseDataChecker<int8_t>));

  ASSERT_STATUS_OK(TestDenseToSparseConversion<uint8_t>(
      20U,
      [](const std::vector<uint8_t>& values, TensorProto& tp) {
        tp.set_name("dense_int64");
        RawDataWriter(values, tp, TensorProto_DataType_UINT8);
      },
      RawSparseDataChecker<uint8_t>));
}

TEST(SparseTensorConversionTests, CsrConversion) {
  auto* cpu_provider = TestCPUExecutionProvider();
  auto cpu_allocator = cpu_provider->CreatePreferredAllocators()[0];

  const TensorShape dense_shape{3, 3};
  std::vector<int32_t> dense_data = {
      0, 0, 1,
      1, 0, 1,
      0, 0, 0};

  std::vector<std::string> dense_data_str = {
      "", "", "1",
      "1", "", "1",
      "", "", ""};

  std::vector<int32_t> dense_data_all_zeros = {
      0, 0, 0,
      0, 0, 0,
      0, 0, 0};

  const std::vector<int32_t> expected_values = {1, 1, 1};
  const std::vector<std::string> expected_values_str = {"1", "1", "1"};
  const char* const strings[] = {"1", "1", "1"};
  const std::vector<int64_t> expected_inner = {2, 0, 2};
  const std::vector<int64_t> expected_outer = {0, 1, 3, 3};

  DataTransferManager dtm;
  {
    auto cpu_transfer = cpu_provider->GetDataTransfer();
    ASSERT_STATUS_OK(dtm.RegisterDataTransfer(std::move(cpu_transfer)));
  }
  {
    {
      // Test CSR initialization of 100% sparse tensor, passing 0 in the shape
      SparseTensor fully_sparse(DataTypeImpl::GetType<int32_t>(), TensorShape{3, 3}, cpu_allocator);
      ASSERT_STATUS_OK(fully_sparse.MakeCsrData(*cpu_provider->GetDataTransfer(), cpu_allocator->Info(),
                                                0U, nullptr, gsl::span<int64_t>(), gsl::span<int64_t>()));
      ASSERT_EQ(fully_sparse.Format(), SparseFormat::kCsrc);
      ASSERT_EQ(0, fully_sparse.RequiredAllocationSize());
      ASSERT_EQ(0U, fully_sparse.NumValues());
      ASSERT_EQ(1U, fully_sparse.Values().Shape().GetDims().size());
      ASSERT_EQ(0, fully_sparse.Values().Shape().Size());
      ASSERT_TRUE(fully_sparse.Values().DataAsSpan<int32_t>().empty());
      auto csr_view = fully_sparse.AsCsr();
      const auto& inner = csr_view.Inner();
      ASSERT_EQ(0, inner.Shape().Size());
      ASSERT_EQ(1U, inner.Shape().GetDims().size());
      ASSERT_TRUE(inner.DataAsSpan<int64_t>().empty());
      const auto& outer = csr_view.Outer();
      ASSERT_EQ(0, outer.Shape().Size());
      ASSERT_EQ(1U, outer.Shape().GetDims().size());
      ASSERT_TRUE(outer.DataAsSpan<int64_t>().empty());
    }
    {
      // Test CSR initialization of 100% sparse tensor, passing 0 in the shape
      SparseTensor fully_sparse(DataTypeImpl::GetType<int32_t>(), TensorShape{3, 3}, TensorShape{0}, nullptr, cpu_allocator->Info());
      ASSERT_STATUS_OK(fully_sparse.UseCsrIndices(gsl::span<int64_t>(), gsl::span<int64_t>()));
      ASSERT_EQ(fully_sparse.Format(), SparseFormat::kCsrc);
      ASSERT_EQ(0, fully_sparse.RequiredAllocationSize());
      ASSERT_EQ(0U, fully_sparse.NumValues());
      ASSERT_EQ(1U, fully_sparse.Values().Shape().GetDims().size());
      ASSERT_EQ(0, fully_sparse.Values().Shape().Size());
      ASSERT_TRUE(fully_sparse.Values().DataAsSpan<int32_t>().empty());
      auto csr_view = fully_sparse.AsCsr();
      const auto& inner = csr_view.Inner();
      ASSERT_EQ(0, inner.Shape().Size());
      ASSERT_EQ(1U, inner.Shape().GetDims().size());
      ASSERT_TRUE(inner.DataAsSpan<int64_t>().empty());
      const auto& outer = csr_view.Outer();
      ASSERT_EQ(0, outer.Shape().Size());
      ASSERT_EQ(1U, outer.Shape().GetDims().size());
      ASSERT_TRUE(outer.DataAsSpan<int64_t>().empty());
    }
  }

  Tensor dense_cpu_src(DataTypeImpl::GetType<int32_t>(), dense_shape, dense_data.data(), cpu_allocator->Info());
  {
    // test where both src and destination are on CPU
    SparseTensor dst;
    ASSERT_STATUS_OK(sparse_utils::DenseTensorToSparseCsr(dtm, dense_cpu_src, cpu_allocator, cpu_allocator, dst));
    ASSERT_EQ(dst.Format(), SparseFormat::kCsrc);
    ASSERT_EQ(dense_cpu_src.DataType(), dst.DataType());
    ASSERT_EQ(dense_cpu_src.Shape(), dst.DenseShape());
    ASSERT_EQ(dst.NumValues(), expected_values.size());
    auto values = dst.Values().DataAsSpan<int32_t>();
    ASSERT_TRUE(std::equal(expected_values.cbegin(), expected_values.cend(), values.begin(), values.end()));

    auto csr_view = dst.AsCsr();
    auto inner = csr_view.Inner().DataAsSpan<int64_t>();
    ASSERT_EQ(expected_inner.size(), inner.size());
    ASSERT_TRUE(std::equal(expected_inner.cbegin(), expected_inner.cend(), inner.begin(), inner.end()));

    auto outer = csr_view.Outer().DataAsSpan<int64_t>();
    ASSERT_EQ(expected_outer.size(), outer.size());
    ASSERT_TRUE(std::equal(expected_outer.cbegin(), expected_outer.cend(), outer.begin(), outer.end()));

    // Let's convert back to make sure we get the original
    Tensor dense_dst;
    const SparseTensor& sparse_src = dst;
    ASSERT_STATUS_OK(sparse_utils::SparseCsrToDenseTensor(dtm, sparse_src, cpu_allocator, cpu_allocator, dense_dst));
    ASSERT_EQ(dense_dst.DataType(), sparse_src.DataType());
    ASSERT_EQ(dense_dst.Shape(), sparse_src.DenseShape());
    ASSERT_EQ(dense_dst.Shape().Size(), vector_len(dense_data));
    auto dense_values_dst = dense_dst.DataAsSpan<int32_t>();
    ASSERT_EQ(dense_values_dst.size(), dense_data.size());
    ASSERT_TRUE(std::equal(dense_values_dst.begin(), dense_values_dst.end(), dense_data.cbegin(), dense_data.cend()));
  }

  // Strings test
  {
    Tensor str_cpu_src(DataTypeImpl::GetType<std::string>(), dense_shape, dense_data_str.data(), cpu_allocator->Info());
    SparseTensor dst;
    ASSERT_STATUS_OK(sparse_utils::DenseTensorToSparseCsr(dtm, str_cpu_src, cpu_allocator, cpu_allocator, dst));
    ASSERT_EQ(dst.Format(), SparseFormat::kCsrc);
    ASSERT_EQ(str_cpu_src.DataType(), dst.DataType());
    ASSERT_EQ(str_cpu_src.Shape(), dst.DenseShape());
    ASSERT_EQ(dst.NumValues(), expected_values_str.size());
    auto values = dst.Values().DataAsSpan<std::string>();
    ASSERT_TRUE(std::equal(expected_values_str.cbegin(), expected_values_str.cend(), values.begin(), values.end()));

    auto csr_view = dst.AsCsr();
    auto inner = csr_view.Inner().DataAsSpan<int64_t>();
    ASSERT_EQ(expected_inner.size(), inner.size());
    ASSERT_TRUE(std::equal(expected_inner.cbegin(), expected_inner.cend(), inner.begin(), inner.end()));

    auto outer = csr_view.Outer().DataAsSpan<int64_t>();
    ASSERT_EQ(expected_outer.size(), outer.size());
    ASSERT_TRUE(std::equal(expected_outer.cbegin(), expected_outer.cend(), outer.begin(), outer.end()));

    // Let's convert back to make sure we get the original
    Tensor dense_dst;
    const SparseTensor& sparse_src = dst;
    ASSERT_STATUS_OK(sparse_utils::SparseCsrToDenseTensor(dtm, sparse_src, cpu_allocator, cpu_allocator, dense_dst));
    ASSERT_EQ(dense_dst.DataType(), sparse_src.DataType());
    ASSERT_EQ(dense_dst.Shape(), sparse_src.DenseShape());
    ASSERT_EQ(dense_dst.Shape().Size(), vector_len(dense_data_str));
    auto dense_values_dst = dense_dst.DataAsSpan<std::string>();
    ASSERT_EQ(dense_values_dst.size(), dense_data.size());
    ASSERT_TRUE(std::equal(dense_values_dst.begin(), dense_values_dst.end(), dense_data_str.cbegin(), dense_data_str.cend()));
  }

  {
    // Use MakeCsrStrings()
    SparseTensor str_cpu_src(DataTypeImpl::GetType<std::string>(), dense_shape, cpu_allocator);
    ASSERT_STATUS_OK(str_cpu_src.MakeCsrStrings(expected_values_str.size(), strings,
                                                gsl::make_span(expected_inner), gsl::make_span(expected_outer)));
    ASSERT_EQ(str_cpu_src.Format(), SparseFormat::kCsrc);
    ASSERT_TRUE(str_cpu_src.IsDataTypeString());
    ASSERT_EQ(str_cpu_src.DenseShape(), dense_shape);
    ASSERT_EQ(str_cpu_src.NumValues(), expected_values_str.size());
    auto values = str_cpu_src.Values().DataAsSpan<std::string>();
    ASSERT_TRUE(std::equal(expected_values_str.cbegin(), expected_values_str.cend(), values.begin(), values.end()));

    auto csr_view = str_cpu_src.AsCsr();
    auto inner = csr_view.Inner().DataAsSpan<int64_t>();
    ASSERT_EQ(expected_inner.size(), inner.size());
    ASSERT_TRUE(std::equal(expected_inner.cbegin(), expected_inner.cend(), inner.begin(), inner.end()));

    auto outer = csr_view.Outer().DataAsSpan<int64_t>();
    ASSERT_EQ(expected_outer.size(), outer.size());
    ASSERT_TRUE(std::equal(expected_outer.cbegin(), expected_outer.cend(), outer.begin(), outer.end()));
  }

#ifdef USE_CUDA
  auto cuda_provider = DefaultCudaExecutionProvider();
  auto cuda_allocator = cuda_provider->CreatePreferredAllocators()[0];
  {
    auto cuda_transfer = cuda_provider->GetDataTransfer();
    ASSERT_STATUS_OK(dtm.RegisterDataTransfer(std::move(cuda_transfer)));
  }
  {
    // test where source is on GPU and destination is on CPU
    SparseTensor sparse_dst;
    ASSERT_STATUS_OK(sparse_utils::DenseTensorToSparseCsr(dtm, dense_cpu_src, cpu_allocator, cuda_allocator, sparse_dst));
    ASSERT_EQ(dense_cpu_src.DataType(), sparse_dst.DataType());
    ASSERT_EQ(dense_cpu_src.Shape(), sparse_dst.DenseShape());

    Tensor gpu_dense_dst;
    ASSERT_STATUS_OK(sparse_utils::SparseCsrToDenseTensor(dtm, sparse_dst, cpu_allocator, cuda_allocator, gpu_dense_dst));
    ASSERT_EQ(gpu_dense_dst.DataType(), sparse_dst.DataType());
    ASSERT_EQ(gpu_dense_dst.Shape(), sparse_dst.DenseShape());

    // Make a copy for examination
    Tensor cpu_dense_dst(gpu_dense_dst.DataType(), gpu_dense_dst.Shape(), cpu_allocator);
    ASSERT_STATUS_OK(dtm.CopyTensor(gpu_dense_dst, cpu_dense_dst));
    ASSERT_EQ(cpu_dense_dst.Shape().Size(), vector_len(dense_data));
    auto dense_dst_data = cpu_dense_dst.DataAsSpan<int32_t>();
    ASSERT_EQ(dense_dst_data.size(), dense_data.size());
    ASSERT_TRUE(std::equal(dense_dst_data.begin(), dense_dst_data.end(), dense_data.cbegin(), dense_data.cend()));
  }
  {
    // Test cases when it is all zeros
    Tensor dense_cpu_src_all_zeros(DataTypeImpl::GetType<int32_t>(), dense_shape, dense_data_all_zeros.data(), cpu_allocator->Info());
    SparseTensor sparse_dst;
    ASSERT_STATUS_OK(sparse_utils::DenseTensorToSparseCsr(dtm, dense_cpu_src_all_zeros, cpu_allocator, cuda_allocator, sparse_dst));
    ASSERT_EQ(sparse_dst.Format(), SparseFormat::kCsrc);
    ASSERT_EQ(dense_cpu_src.DataType(), sparse_dst.DataType());
    ASSERT_EQ(dense_cpu_src.Shape(), sparse_dst.DenseShape());
    auto csr_view = sparse_dst.AsCsr();
    auto inner_indices = csr_view.Inner().DataAsSpan<int64_t>();
    ASSERT_TRUE(inner_indices.empty());
    auto outer_indices = csr_view.Outer().DataAsSpan<int64_t>();
    ASSERT_TRUE(outer_indices.empty());

    Tensor gpu_dense_dst;
    ASSERT_STATUS_OK(sparse_utils::SparseCsrToDenseTensor(dtm, sparse_dst, cpu_allocator, cuda_allocator, gpu_dense_dst));
    ASSERT_EQ(gpu_dense_dst.DataType(), sparse_dst.DataType());
    ASSERT_EQ(gpu_dense_dst.Shape(), sparse_dst.DenseShape());

    // Make a copy for examination
    Tensor cpu_dense_dst(gpu_dense_dst.DataType(), gpu_dense_dst.Shape(), cpu_allocator);
    ASSERT_STATUS_OK(dtm.CopyTensor(gpu_dense_dst, cpu_dense_dst));
    auto dense_dst_data = cpu_dense_dst.DataAsSpan<int32_t>();
    ASSERT_EQ(dense_dst_data.size(), dense_data_all_zeros.size());
    ASSERT_TRUE(std::equal(dense_dst_data.begin(), dense_dst_data.end(), dense_data_all_zeros.cbegin(), dense_data_all_zeros.cend()));
  }
#endif
}

TEST(SparseTensorConversionTests, CooConversion) {
  auto* cpu_provider = TestCPUExecutionProvider();
  auto cpu_allocator = cpu_provider->CreatePreferredAllocators()[0];

  const TensorShapeVector dense_shape{3, 3};
  std::vector<int32_t> dense_data = {
      0, 0, 1,
      1, 0, 1,
      0, 0, 0};

  std::vector<std::string> dense_data_str = {
      "", "", "1",
      "1", "", "1",
      "", "", ""};

  std::vector<int32_t> dense_data_all_zeros = {
      0, 0, 0,
      0, 0, 0,
      0, 0, 0};

  const std::vector<int32_t> expected_values = {1, 1, 1};
  const std::vector<std::string> expected_values_str = {"1", "1", "1"};
  const char* const strings[] = {"1", "1", "1"};
  const std::vector<int64_t> expected_linear_indices = {2, 3, 5};
  const std::vector<int64_t> expected_2d_indices = {0, 2, 1, 0, 1, 2};

  DataTransferManager dtm;
  {
    auto cpu_transfer = cpu_provider->GetDataTransfer();
    ASSERT_STATUS_OK(dtm.RegisterDataTransfer(std::move(cpu_transfer)));
  }

  {
    // Test COO initialization of 100% sparse tensor, passing 0 in the shape
    SparseTensor fully_sparse(DataTypeImpl::GetType<int32_t>(), TensorShape{3, 3}, cpu_allocator);
    ASSERT_STATUS_OK(fully_sparse.MakeCooData(*cpu_provider->GetDataTransfer(), cpu_allocator->Info(), 0, nullptr, gsl::span<int64_t>()));
    ASSERT_EQ(fully_sparse.Format(), SparseFormat::kCoo);
    ASSERT_EQ(0, fully_sparse.RequiredAllocationSize());
    ASSERT_EQ(0U, fully_sparse.NumValues());
    ASSERT_EQ(1U, fully_sparse.Values().Shape().GetDims().size());
    ASSERT_EQ(0, fully_sparse.Values().Shape().Size());
    ASSERT_TRUE(fully_sparse.Values().DataAsSpan<int32_t>().empty());
    auto coo_view = fully_sparse.AsCoo();
    const auto& indices = coo_view.Indices();
    ASSERT_EQ(0, indices.Shape().Size());
    // For fully sparse we assume a 2-D indices.
    ASSERT_EQ(2U, indices.Shape().GetDims().size());
    ASSERT_TRUE(indices.DataAsSpan<int64_t>().empty());
  }

  {
    // Test COO initialization of 100% sparse tensor, passing 0 in the shape
    SparseTensor fully_sparse(DataTypeImpl::GetType<int32_t>(), TensorShape{3, 3}, TensorShape{0}, nullptr, cpu_allocator->Info());
    ASSERT_STATUS_OK(fully_sparse.UseCooIndices(gsl::span<int64_t>()));
    ASSERT_EQ(fully_sparse.Format(), SparseFormat::kCoo);
    ASSERT_EQ(0, fully_sparse.RequiredAllocationSize());
    ASSERT_EQ(0U, fully_sparse.NumValues());
    ASSERT_EQ(1U, fully_sparse.Values().Shape().GetDims().size());
    ASSERT_EQ(0, fully_sparse.Values().Shape().Size());
    ASSERT_TRUE(fully_sparse.Values().DataAsSpan<int32_t>().empty());
    auto coo_view = fully_sparse.AsCoo();
    const auto& indices = coo_view.Indices();
    ASSERT_EQ(0, indices.Shape().Size());
    // For fully sparse we assume a 2-D indices.
    ASSERT_EQ(2U, indices.Shape().GetDims().size());
    ASSERT_TRUE(indices.DataAsSpan<int64_t>().empty());
  }

  Tensor dense_cpu_src(DataTypeImpl::GetType<int32_t>(), dense_shape, dense_data.data(), cpu_allocator->Info());
  {
    // test where both src and destination are on CPU. Linear index.
    SparseTensor dst;
    ASSERT_STATUS_OK(sparse_utils::DenseTensorToSparseCoo(dtm, dense_cpu_src, cpu_allocator, cpu_allocator, true, dst));
    ASSERT_EQ(dst.Format(), SparseFormat::kCoo);
    ASSERT_EQ(dense_cpu_src.DataType(), dst.DataType());
    ASSERT_EQ(dense_cpu_src.Shape(), dst.DenseShape());
    ASSERT_EQ(dst.NumValues(), expected_values.size());
    auto values = dst.Values().DataAsSpan<int32_t>();
    ASSERT_TRUE(std::equal(expected_values.cbegin(), expected_values.cend(), values.begin(), values.end()));
    auto coo_view = dst.AsCoo();
    ASSERT_EQ(coo_view.Indices().Shape().GetDims().size(), 1U);
    auto indices = coo_view.Indices().DataAsSpan<int64_t>();
    ASSERT_EQ(indices.size(), expected_linear_indices.size());
    ASSERT_TRUE(std::equal(indices.begin(), indices.end(), expected_linear_indices.cbegin(), expected_linear_indices.cend()));

    // Now convert back to dense
    Tensor dense_dst;
    const SparseTensor& sparse_src = dst;
    ASSERT_STATUS_OK(sparse_utils::SparseCooToDenseTensor(dtm, sparse_src, cpu_allocator, cpu_allocator, dense_dst));
    ASSERT_EQ(dense_dst.DataType(), sparse_src.DataType());
    ASSERT_EQ(dense_dst.Shape(), sparse_src.DenseShape());
    auto dense_values_dst = dense_dst.DataAsSpan<int32_t>();
    ASSERT_EQ(dense_values_dst.size(), dense_data.size());
    ASSERT_TRUE(std::equal(dense_values_dst.begin(), dense_values_dst.end(), dense_data.cbegin(), dense_data.cend()));
  }

  // String test
  {
    Tensor dense_cpu_str(DataTypeImpl::GetType<std::string>(), dense_shape, dense_data_str.data(), cpu_allocator->Info());
    SparseTensor dst;
    ASSERT_STATUS_OK(sparse_utils::DenseTensorToSparseCoo(dtm, dense_cpu_str, cpu_allocator, cpu_allocator, true, dst));
    ASSERT_EQ(dst.Format(), SparseFormat::kCoo);
    ASSERT_EQ(dense_cpu_str.DataType(), dst.DataType());
    ASSERT_EQ(dense_cpu_str.Shape(), dst.DenseShape());
    ASSERT_EQ(dst.NumValues(), expected_values_str.size());

    auto values = dst.Values().DataAsSpan<std::string>();
    ASSERT_TRUE(std::equal(expected_values_str.cbegin(), expected_values_str.cend(), values.begin(), values.end()));
    auto coo_view = dst.AsCoo();
    ASSERT_EQ(coo_view.Indices().Shape().GetDims().size(), 1U);
    auto indices = coo_view.Indices().DataAsSpan<int64_t>();
    ASSERT_EQ(indices.size(), expected_linear_indices.size());
    ASSERT_TRUE(std::equal(indices.begin(), indices.end(), expected_linear_indices.cbegin(), expected_linear_indices.cend()));

    // Now convert back to dense
    Tensor dense_dst;
    const SparseTensor& sparse_src = dst;
    ASSERT_STATUS_OK(sparse_utils::SparseCooToDenseTensor(dtm, sparse_src, cpu_allocator, cpu_allocator, dense_dst));
    ASSERT_EQ(dense_dst.DataType(), sparse_src.DataType());
    ASSERT_EQ(dense_dst.Shape(), sparse_src.DenseShape());
    auto dense_values_dst = dense_dst.DataAsSpan<std::string>();
    ASSERT_EQ(dense_values_dst.size(), dense_data_str.size());
    ASSERT_TRUE(std::equal(dense_values_dst.begin(), dense_values_dst.end(), dense_data_str.cbegin(), dense_data_str.cend()));
  }

  {
    // Use MakeCooStrings()
    SparseTensor str_cpu_src(DataTypeImpl::GetType<std::string>(), dense_shape, cpu_allocator);
    ASSERT_STATUS_OK(str_cpu_src.MakeCooStrings(expected_values_str.size(), strings,
                                                gsl::make_span(expected_linear_indices)));
    ASSERT_EQ(str_cpu_src.Format(), SparseFormat::kCoo);
    ASSERT_TRUE(str_cpu_src.IsDataTypeString());
    ASSERT_EQ(str_cpu_src.DenseShape(), TensorShape(dense_shape));
    ASSERT_EQ(str_cpu_src.NumValues(), expected_values_str.size());
    auto values = str_cpu_src.Values().DataAsSpan<std::string>();
    ASSERT_TRUE(std::equal(expected_values_str.cbegin(), expected_values_str.cend(), values.begin(), values.end()));

    auto coo_view = str_cpu_src.AsCoo();
    auto indices = coo_view.Indices().DataAsSpan<int64_t>();
    ASSERT_EQ(expected_linear_indices.size(), indices.size());
    ASSERT_TRUE(std::equal(expected_linear_indices.cbegin(), expected_linear_indices.cend(), indices.begin(), indices.end()));
  }

  {
    // test where both src and destination are on CPU. 2-D index
    SparseTensor dst;
    ASSERT_STATUS_OK(sparse_utils::DenseTensorToSparseCoo(dtm, dense_cpu_src, cpu_allocator, cpu_allocator, false, dst));
    ASSERT_EQ(dst.Format(), SparseFormat::kCoo);
    ASSERT_EQ(dense_cpu_src.DataType(), dst.DataType());
    ASSERT_EQ(dense_cpu_src.Shape(), dst.DenseShape());
    ASSERT_EQ(dst.NumValues(), expected_values.size());
    auto values = dst.Values().DataAsSpan<int32_t>();
    ASSERT_TRUE(std::equal(expected_values.cbegin(), expected_values.cend(), values.begin(), values.end()));

    auto coo_view = dst.AsCoo();
    ASSERT_EQ(coo_view.Indices().Shape().GetDims().size(), 2U);
    auto indices = coo_view.Indices().DataAsSpan<int64_t>();
    ASSERT_EQ(indices.size(), expected_2d_indices.size());
    ASSERT_TRUE(std::equal(indices.begin(), indices.end(), expected_2d_indices.cbegin(), expected_2d_indices.cend()));

    // Now convert back to dense
    Tensor dense_dst;
    const SparseTensor& sparse_src = dst;
    ASSERT_STATUS_OK(sparse_utils::SparseCooToDenseTensor(dtm, sparse_src, cpu_allocator, cpu_allocator, dense_dst));
    ASSERT_EQ(dense_dst.DataType(), sparse_src.DataType());
    ASSERT_EQ(dense_dst.Shape(), sparse_src.DenseShape());
    auto dense_values_dst = dense_dst.DataAsSpan<int32_t>();
    ASSERT_EQ(dense_values_dst.size(), dense_data.size());
    ASSERT_TRUE(std::equal(dense_values_dst.begin(), dense_values_dst.end(), dense_data.cbegin(), dense_data.cend()));
  }

#ifdef USE_CUDA
  auto cuda_provider = DefaultCudaExecutionProvider();
  auto cuda_allocator = cuda_provider->CreatePreferredAllocators()[0];
  {
    auto cuda_transfer = cuda_provider->GetDataTransfer();
    ASSERT_STATUS_OK(dtm.RegisterDataTransfer(std::move(cuda_transfer)));
  }
  {
    // test where source is on GPU and destination is on GPU
    SparseTensor sparse_dst;
    ASSERT_STATUS_OK(sparse_utils::DenseTensorToSparseCoo(dtm, dense_cpu_src, cpu_allocator, cuda_allocator, false, sparse_dst));
    ASSERT_EQ(sparse_dst.Format(), SparseFormat::kCoo);
    ASSERT_EQ(dense_cpu_src.DataType(), sparse_dst.DataType());
    ASSERT_EQ(dense_cpu_src.Shape(), sparse_dst.DenseShape());
    auto coo_view = sparse_dst.AsCoo();
    ASSERT_EQ(coo_view.Indices().Shape().GetDims().size(), 2U);
    auto indices = coo_view.Indices().DataAsSpan<int64_t>();
    ASSERT_EQ(indices.size(), expected_2d_indices.size());

    Tensor gpu_dense_dst;
    ASSERT_STATUS_OK(sparse_utils::SparseCooToDenseTensor(dtm, sparse_dst, cpu_allocator, cuda_allocator, gpu_dense_dst));
    ASSERT_EQ(gpu_dense_dst.DataType(), sparse_dst.DataType());
    ASSERT_EQ(gpu_dense_dst.Shape(), sparse_dst.DenseShape());
    // Make a copy for examination
    Tensor cpu_dense_dst(gpu_dense_dst.DataType(), gpu_dense_dst.Shape(), cpu_allocator);
    ASSERT_STATUS_OK(dtm.CopyTensor(gpu_dense_dst, cpu_dense_dst));
    auto dense_dst_data = cpu_dense_dst.DataAsSpan<int32_t>();
    ASSERT_EQ(dense_dst_data.size(), dense_data.size());
    ASSERT_TRUE(std::equal(dense_dst_data.begin(), dense_dst_data.end(), dense_data.cbegin(), dense_data.cend()));
  }

  {
    // Test cases when it is all zeros
    Tensor dense_cpu_src_all_zeros(DataTypeImpl::GetType<int32_t>(), dense_shape, dense_data_all_zeros.data(), cpu_allocator->Info());
    SparseTensor sparse_dst;
    ASSERT_STATUS_OK(sparse_utils::DenseTensorToSparseCoo(dtm, dense_cpu_src_all_zeros, cpu_allocator, cuda_allocator, false, sparse_dst));
    ASSERT_EQ(sparse_dst.Format(), SparseFormat::kCoo);
    ASSERT_EQ(dense_cpu_src.DataType(), sparse_dst.DataType());
    ASSERT_EQ(dense_cpu_src.Shape(), sparse_dst.DenseShape());
    auto coo_view = sparse_dst.AsCoo();
    ASSERT_EQ(coo_view.Indices().Shape().GetDims().size(), 2U);
    auto indices = coo_view.Indices().DataAsSpan<int64_t>();
    ASSERT_TRUE(indices.empty());

    Tensor gpu_dense_dst;
    ASSERT_STATUS_OK(sparse_utils::SparseCooToDenseTensor(dtm, sparse_dst, cpu_allocator, cuda_allocator, gpu_dense_dst));
    ASSERT_EQ(gpu_dense_dst.DataType(), sparse_dst.DataType());
    ASSERT_EQ(gpu_dense_dst.Shape(), sparse_dst.DenseShape());

    // Make a copy for examination
    Tensor cpu_dense_dst(gpu_dense_dst.DataType(), gpu_dense_dst.Shape(), cpu_allocator);
    ASSERT_STATUS_OK(dtm.CopyTensor(gpu_dense_dst, cpu_dense_dst));
    auto dense_dst_data = cpu_dense_dst.DataAsSpan<int32_t>();
    ASSERT_EQ(dense_dst_data.size(), dense_data_all_zeros.size());
    ASSERT_TRUE(std::equal(dense_dst_data.begin(), dense_dst_data.end(), dense_data_all_zeros.cbegin(), dense_data_all_zeros.cend()));
  }
#endif
}
#endif  // !ORT_MINIMAL_BUILD

TEST(SparseTensorConversionTests, BlockSparse) {
  auto* cpu_provider = TestCPUExecutionProvider();
  auto cpu_allocator = cpu_provider->CreatePreferredAllocators()[0];

  DataTransferManager dtm;
  {
    auto cpu_transfer = cpu_provider->GetDataTransfer();
    ASSERT_STATUS_OK(dtm.RegisterDataTransfer(std::move(cpu_transfer)));
  }

  {
    // Fully sparse
    SparseTensor fully_sparse(DataTypeImpl::GetType<int32_t>(), TensorShape{3, 3}, cpu_allocator);
    ASSERT_STATUS_OK(fully_sparse.MakeBlockSparseData(*cpu_provider->GetDataTransfer(), cpu_allocator->Info(),
                                                      TensorShape{0}, nullptr, TensorShape{0}, nullptr));
    ASSERT_EQ(fully_sparse.Format(), SparseFormat::kBlockSparse);
    ASSERT_EQ(0, fully_sparse.RequiredAllocationSize());
    ASSERT_EQ(0U, fully_sparse.NumValues());
    ASSERT_EQ(1U, fully_sparse.Values().Shape().GetDims().size());
    ASSERT_EQ(0, fully_sparse.Values().Shape().Size());
    ASSERT_TRUE(fully_sparse.Values().DataAsSpan<int32_t>().empty());
    auto blocksparse_view = fully_sparse.AsBlockSparse();
    const auto& indices = blocksparse_view.Indices();
    ASSERT_EQ(0, indices.Shape().Size());
    ASSERT_EQ(1U, indices.Shape().GetDims().size());
    ASSERT_TRUE(indices.DataAsSpan<int32_t>().empty());
  }

  {
    // Fully sparse
    SparseTensor fully_sparse(DataTypeImpl::GetType<int32_t>(), TensorShape{3, 3},
                              TensorShape{0}, nullptr, cpu_allocator->Info());
    ASSERT_STATUS_OK(fully_sparse.UseBlockSparseIndices(TensorShape{0}, nullptr));
    ASSERT_EQ(fully_sparse.Format(), SparseFormat::kBlockSparse);
    ASSERT_EQ(0, fully_sparse.RequiredAllocationSize());
    ASSERT_EQ(0U, fully_sparse.NumValues());
    ASSERT_EQ(1U, fully_sparse.Values().Shape().GetDims().size());
    ASSERT_EQ(0, fully_sparse.Values().Shape().Size());
    ASSERT_TRUE(fully_sparse.Values().DataAsSpan<int32_t>().empty());
    auto blocksparse_view = fully_sparse.AsBlockSparse();
    const auto& indices = blocksparse_view.Indices();
    ASSERT_EQ(0, indices.Shape().Size());
    ASSERT_EQ(1U, indices.Shape().GetDims().size());
    ASSERT_TRUE(indices.DataAsSpan<int32_t>().empty());
  }

  const TensorShape dense_shape{8, 8};
  constexpr int64_t block_size = 2;
  const TensorShape values_shape{2, block_size, block_size};
  // Two dense blocks
  std::vector<int32_t> data_blocks{
      1, 2, 3, 4, 5, 6, 7, 8};

  const char* const strings[] = {
      "1", "2", "3", "4", "5", "6", "7", "8"};

  const std::string expected_strings[] = {
      "1", "2", "3", "4", "5", "6", "7", "8"};

  const TensorShape indices_shape{2, 2};  // two blocks by two coordinates
  // (0, 0), (0,1)
  std::vector<int32_t> blocksparse_indices = {
      0, 0, 0, 1};

  {
    // Test instantiation only
    SparseTensor own_buffer_tensor(DataTypeImpl::GetType<int32_t>(), dense_shape, cpu_allocator);
    ASSERT_STATUS_OK(own_buffer_tensor.MakeBlockSparseData(*cpu_provider->GetDataTransfer(), cpu_allocator->Info(),
                                                           values_shape, data_blocks.data(),
                                                           indices_shape, blocksparse_indices.data()));
    ASSERT_EQ(own_buffer_tensor.Format(), SparseFormat::kBlockSparse);
    ASSERT_EQ(dense_shape, own_buffer_tensor.DenseShape());
    ASSERT_EQ(data_blocks.size(), own_buffer_tensor.NumValues());
    ASSERT_EQ(values_shape, own_buffer_tensor.Values().Shape());
    auto data_span = own_buffer_tensor.Values().DataAsSpan<int32_t>();
    ASSERT_EQ(data_blocks.size(), data_span.size());
    ASSERT_TRUE(std::equal(data_blocks.cbegin(), data_blocks.cend(), data_span.begin(), data_span.end()));

    auto block_sparse = own_buffer_tensor.AsBlockSparse();
    const auto& indices = block_sparse.Indices();
    ASSERT_EQ(indices_shape, indices.Shape());
    auto indices_span = indices.DataAsSpan<int32_t>();
    ASSERT_TRUE(std::equal(blocksparse_indices.cbegin(), blocksparse_indices.cend(),
                           indices_span.begin(), indices_span.end()));
  }

  {
    // Test instantiation only
    SparseTensor user_buffer_tensor(DataTypeImpl::GetType<int32_t>(), dense_shape, values_shape, data_blocks.data(), cpu_allocator->Info());
    ASSERT_STATUS_OK(user_buffer_tensor.UseBlockSparseIndices(indices_shape, blocksparse_indices.data()));
    ASSERT_EQ(user_buffer_tensor.Format(), SparseFormat::kBlockSparse);
    ASSERT_EQ(dense_shape, user_buffer_tensor.DenseShape());
    ASSERT_EQ(data_blocks.size(), user_buffer_tensor.NumValues());
    ASSERT_EQ(values_shape, user_buffer_tensor.Values().Shape());
    auto data_span = user_buffer_tensor.Values().DataAsSpan<int32_t>();
    ASSERT_EQ(data_blocks.size(), data_span.size());
    ASSERT_TRUE(std::equal(data_blocks.cbegin(), data_blocks.cend(), data_span.begin(), data_span.end()));

    auto block_sparse = user_buffer_tensor.AsBlockSparse();
    const auto& indices = block_sparse.Indices();
    ASSERT_EQ(indices_shape, indices.Shape());
    auto indices_span = indices.DataAsSpan<int32_t>();
    ASSERT_TRUE(std::equal(blocksparse_indices.cbegin(), blocksparse_indices.cend(),
                           indices_span.begin(), indices_span.end()));
  }

  {
    // Use MakeBlockSparseStrings()
    SparseTensor own_buffer_tensor(DataTypeImpl::GetType<std::string>(), dense_shape, cpu_allocator);
    ASSERT_STATUS_OK(own_buffer_tensor.MakeBlockSparseStrings(values_shape, strings, indices_shape, blocksparse_indices.data()));
    ASSERT_TRUE(own_buffer_tensor.IsDataTypeString());
    ASSERT_EQ(own_buffer_tensor.Format(), SparseFormat::kBlockSparse);
    ASSERT_EQ(dense_shape, own_buffer_tensor.DenseShape());
    ASSERT_EQ(data_blocks.size(), own_buffer_tensor.NumValues());
    ASSERT_EQ(values_shape, own_buffer_tensor.Values().Shape());
    auto data_span = own_buffer_tensor.Values().DataAsSpan<std::string>();
    auto expected_span = gsl::make_span(expected_strings);
    ASSERT_EQ(expected_span.size(), data_span.size());
    ASSERT_TRUE(std::equal(expected_span.begin(), expected_span.end(), data_span.begin(), data_span.end()));

    auto block_sparse = own_buffer_tensor.AsBlockSparse();
    const auto& indices = block_sparse.Indices();
    ASSERT_EQ(indices_shape, indices.Shape());
    auto indices_span = indices.DataAsSpan<int32_t>();
    ASSERT_TRUE(std::equal(blocksparse_indices.cbegin(), blocksparse_indices.cend(),
                           indices_span.begin(), indices_span.end()));
  }
}
#endif  // !defined(DISABLE_SPARSE_TENSORS)

}  // namespace test
}  // namespace onnxruntime
