// SPDX-FileCopyrightText: 2017 - 2024 The Ginkgo authors
//
// SPDX-License-Identifier: BSD-3-Clause

#include <ginkgo/core/matrix/batch_ell.hpp>


#include <algorithm>
#include <type_traits>


#include <ginkgo/core/base/array.hpp>
#include <ginkgo/core/base/exception.hpp>
#include <ginkgo/core/base/exception_helpers.hpp>
#include <ginkgo/core/base/executor.hpp>
#include <ginkgo/core/base/math.hpp>
#include <ginkgo/core/base/utils.hpp>
#include <ginkgo/core/matrix/ell.hpp>


#include "core/matrix/batch_ell_kernels.hpp"
#include "core/matrix/csr_kernels.hpp"


namespace gko {
namespace batch {
namespace matrix {
namespace ell {
namespace {


GKO_REGISTER_OPERATION(simple_apply, batch_ell::simple_apply);
GKO_REGISTER_OPERATION(advanced_apply, batch_ell::advanced_apply);
GKO_REGISTER_OPERATION(scale, batch_ell::scale);
GKO_REGISTER_OPERATION(check_diagonal_entries,
                       csr::check_diagonal_entries_exist);
GKO_REGISTER_OPERATION(add_scaled_identity, batch_ell::add_scaled_identity);


}  // namespace
}  // namespace ell


template <typename ValueType, typename IndexType>
std::unique_ptr<gko::matrix::Ell<ValueType, IndexType>>
Ell<ValueType, IndexType>::create_view_for_item(size_type item_id)
{
    auto exec = this->get_executor();
    auto num_rows = this->get_common_size()[0];
    auto stride = this->get_common_size()[0];
    auto mat = unbatch_type::create(
        exec, this->get_common_size(),
        make_array_view(exec, this->get_num_elements_per_item(),
                        this->get_values_for_item(item_id)),
        make_array_view(exec, this->get_num_elements_per_item(),
                        this->get_col_idxs()),
        this->get_num_stored_elements_per_row(), stride);
    return mat;
}


template <typename ValueType, typename IndexType>
std::unique_ptr<const gko::matrix::Ell<ValueType, IndexType>>
Ell<ValueType, IndexType>::create_const_view_for_item(size_type item_id) const
{
    auto exec = this->get_executor();
    auto num_rows = this->get_common_size()[0];
    auto stride = this->get_common_size()[0];
    auto mat = unbatch_type::create_const(
        exec, this->get_common_size(),
        make_const_array_view(exec, this->get_num_elements_per_item(),
                              this->get_const_values_for_item(item_id)),
        make_const_array_view(exec, this->get_num_elements_per_item(),
                              this->get_const_col_idxs()),
        this->get_num_stored_elements_per_row(), stride);
    return mat;
}


template <typename ValueType, typename IndexType>
std::unique_ptr<Ell<ValueType, IndexType>> Ell<ValueType, IndexType>::create(
    std::shared_ptr<const Executor> exec, const batch_dim<2>& size,
    const IndexType num_elems_per_row)
{
    return std::unique_ptr<Ell>{new Ell{exec, size, num_elems_per_row}};
}


template <typename ValueType, typename IndexType>
std::unique_ptr<Ell<ValueType, IndexType>> Ell<ValueType, IndexType>::create(
    std::shared_ptr<const Executor> exec, const batch_dim<2>& size,
    const IndexType num_elems_per_row, array<value_type> values,
    array<index_type> col_idxs)
{
    return std::unique_ptr<Ell>{new Ell{
        exec, size, num_elems_per_row, std::move(values), std::move(col_idxs)}};
}


template <typename ValueType, typename IndexType>
std::unique_ptr<const Ell<ValueType, IndexType>>
Ell<ValueType, IndexType>::create_const(
    std::shared_ptr<const Executor> exec, const batch_dim<2>& sizes,
    const IndexType num_elems_per_row,
    gko::detail::const_array_view<ValueType>&& values,
    gko::detail::const_array_view<IndexType>&& col_idxs)
{
    // cast const-ness away, but return a const object afterwards,
    // so we can ensure that no modifications take place.
    return std::unique_ptr<const Ell>(
        new Ell{exec, sizes, num_elems_per_row,
                gko::detail::array_const_cast(std::move(values)),
                gko::detail::array_const_cast(std::move(col_idxs))});
}


template <typename ValueType, typename IndexType>
Ell<ValueType, IndexType>::Ell(std::shared_ptr<const Executor> exec,
                               const batch_dim<2>& size,
                               IndexType num_elems_per_row)
    : EnableBatchLinOp<Ell<ValueType, IndexType>>(exec, size),
      num_elems_per_row_(num_elems_per_row == 0 ? size.get_common_size()[1]
                                                : num_elems_per_row),
      values_(exec, compute_num_elems(size, num_elems_per_row_)),
      col_idxs_(exec, this->get_common_size()[0] * num_elems_per_row_)
{}


template <typename ValueType, typename IndexType>
Ell<ValueType, IndexType>::Ell(std::shared_ptr<const Executor> exec,
                               const batch_dim<2>& size,
                               const IndexType num_elems_per_row,
                               array<value_type> values,
                               array<index_type> col_idxs)
    : EnableBatchLinOp<Ell>(exec, size),
      num_elems_per_row_{num_elems_per_row},
      values_{exec, std::move(values)},
      col_idxs_{exec, std::move(col_idxs)}
{
    // Ensure that the value and col_idxs arrays have the correct size
    auto num_elems = this->get_common_size()[0] * num_elems_per_row *
                     this->get_num_batch_items();
    GKO_ASSERT_EQ(num_elems, values_.get_size());
    GKO_ASSERT_EQ(this->get_num_elements_per_item(), col_idxs_.get_size());
}


template <typename ValueType, typename IndexType>
Ell<ValueType, IndexType>* Ell<ValueType, IndexType>::apply(
    ptr_param<const MultiVector<ValueType>> b,
    ptr_param<MultiVector<ValueType>> x)
{
    this->validate_application_parameters(b.get(), x.get());
    auto exec = this->get_executor();
    this->apply_impl(make_temporary_clone(exec, b).get(),
                     make_temporary_clone(exec, x).get());
    return this;
}


template <typename ValueType, typename IndexType>
const Ell<ValueType, IndexType>* Ell<ValueType, IndexType>::apply(
    ptr_param<const MultiVector<ValueType>> b,
    ptr_param<MultiVector<ValueType>> x) const
{
    this->validate_application_parameters(b.get(), x.get());
    auto exec = this->get_executor();
    this->apply_impl(make_temporary_clone(exec, b).get(),
                     make_temporary_clone(exec, x).get());
    return this;
}


template <typename ValueType, typename IndexType>
Ell<ValueType, IndexType>* Ell<ValueType, IndexType>::apply(
    ptr_param<const MultiVector<ValueType>> alpha,
    ptr_param<const MultiVector<ValueType>> b,
    ptr_param<const MultiVector<ValueType>> beta,
    ptr_param<MultiVector<ValueType>> x)
{
    this->validate_application_parameters(alpha.get(), b.get(), beta.get(),
                                          x.get());
    auto exec = this->get_executor();
    this->apply_impl(make_temporary_clone(exec, alpha).get(),
                     make_temporary_clone(exec, b).get(),
                     make_temporary_clone(exec, beta).get(),
                     make_temporary_clone(exec, x).get());
    return this;
}


template <typename ValueType, typename IndexType>
const Ell<ValueType, IndexType>* Ell<ValueType, IndexType>::apply(
    ptr_param<const MultiVector<ValueType>> alpha,
    ptr_param<const MultiVector<ValueType>> b,
    ptr_param<const MultiVector<ValueType>> beta,
    ptr_param<MultiVector<ValueType>> x) const
{
    this->validate_application_parameters(alpha.get(), b.get(), beta.get(),
                                          x.get());
    auto exec = this->get_executor();
    this->apply_impl(make_temporary_clone(exec, alpha).get(),
                     make_temporary_clone(exec, b).get(),
                     make_temporary_clone(exec, beta).get(),
                     make_temporary_clone(exec, x).get());
    return this;
}


template <typename ValueType, typename IndexType>
void Ell<ValueType, IndexType>::apply_impl(const MultiVector<ValueType>* b,
                                           MultiVector<ValueType>* x) const
{
    this->get_executor()->run(ell::make_simple_apply(this, b, x));
}


template <typename ValueType, typename IndexType>
void Ell<ValueType, IndexType>::apply_impl(const MultiVector<ValueType>* alpha,
                                           const MultiVector<ValueType>* b,
                                           const MultiVector<ValueType>* beta,
                                           MultiVector<ValueType>* x) const
{
    this->get_executor()->run(
        ell::make_advanced_apply(alpha, this, b, beta, x));
}


template <typename ValueType, typename IndexType>
void Ell<ValueType, IndexType>::scale(const array<ValueType>& row_scale,
                                      const array<ValueType>& col_scale)
{
    GKO_ASSERT_EQ(col_scale.get_size(),
                  (this->get_common_size()[1] * this->get_num_batch_items()));
    GKO_ASSERT_EQ(row_scale.get_size(),
                  (this->get_common_size()[0] * this->get_num_batch_items()));
    auto exec = this->get_executor();
    exec->run(ell::make_scale(make_temporary_clone(exec, &col_scale).get(),
                              make_temporary_clone(exec, &row_scale).get(),
                              this));
}


template <typename ValueType, typename IndexType>
void Ell<ValueType, IndexType>::add_scaled_identity(
    ptr_param<const MultiVector<ValueType>> alpha,
    ptr_param<const MultiVector<ValueType>> beta)
{
    GKO_ASSERT_BATCH_EQUAL_NUM_ITEMS(alpha, beta);
    GKO_ASSERT_BATCH_EQUAL_NUM_ITEMS(this, beta);
    GKO_ASSERT_EQUAL_DIMENSIONS(alpha->get_common_size(), gko::dim<2>(1, 1));
    GKO_ASSERT_EQUAL_DIMENSIONS(beta->get_common_size(), gko::dim<2>(1, 1));
    auto exec = this->get_executor();

    auto csr_mat = gko::matrix::Csr<ValueType, IndexType>::create(exec);
    this->create_const_view_for_item(0)->convert_to(csr_mat);

    bool has_all_diags{false};
    exec->run(ell::make_check_diagonal_entries(csr_mat.get(), has_all_diags));
    if (!has_all_diags) {
        GKO_UNSUPPORTED_MATRIX_PROPERTY(
            "The matrix is missing one or more diagonal entries!");
    }
    exec->run(ell::make_add_scaled_identity(
        make_temporary_clone(exec, alpha).get(),
        make_temporary_clone(exec, beta).get(), this));
}


template <typename ValueType, typename IndexType>
void Ell<ValueType, IndexType>::convert_to(
    Ell<next_precision<ValueType>, IndexType>* result) const
{
    result->values_ = this->values_;
    result->col_idxs_ = this->col_idxs_;
    result->num_elems_per_row_ = this->num_elems_per_row_;
    result->set_size(this->get_size());
}


template <typename ValueType, typename IndexType>
void Ell<ValueType, IndexType>::move_to(
    Ell<next_precision<ValueType>, IndexType>* result)
{
    this->convert_to(result);
}


#define GKO_DECLARE_BATCH_ELL_MATRIX(ValueType) class Ell<ValueType, int32>
GKO_INSTANTIATE_FOR_EACH_VALUE_TYPE(GKO_DECLARE_BATCH_ELL_MATRIX);


}  // namespace matrix
}  // namespace batch
}  // namespace gko
