// Copyright (C) 2018-2026 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
//

#pragma once

#include <cstddef>
#include <memory>
#include <string>
#include <vector>

#include "openvino/op/op.hpp"
#include "openvino/op/util/activation_functions.hpp"
#include "openvino/op/util/rnn_cell_base.hpp"

namespace ov {
namespace op {
enum class LSTMWeightsFormat {
    FICO,  // IE
    ICOF,  // PyTorch
    IFCO,  // DNNL, TF, MxNet
    IFOC,  // Caffe
    IOFC,  // ONNX
};

ov::op::util::LSTMWeightsFormat convert_lstm_weights_enums(LSTMWeightsFormat format);

namespace v0 {
///
/// \brief      Class for single lstm cell node.
///
/// \note       Following implementation supports:
///             \li \c peepholes Gers & Schmidhuber (2000)
///             https://ieeexplore.ieee.org/document/861302
///             \li Coupling input and forget gates.
///
/// \note       It calculates following equations:
///
///             it = f(Xt*(Wi^T) + Ht-1*(Ri^T) + Pi (.) Ct-1 + Wbi + Rbi)
///             ft = f(Xt*(Wf^T) + Ht-1*(Rf^T) + Pf (.) Ct-1 + Wbf + Rbf)
///             ct = g(Xt*(Wc^T) + Ht-1*(Rc^T) + Wbc + Rbc)
///             Ct = ft (.) Ct-1 + it (.) ct
///             ot = f(Xt*(Wo^T) + Ht-1*(Ro^T) + Po (.) Ct + Wbo + Rbo)
///             Ht = ot (.) h(Ct)
///
///             *       - Is a dot product,
///             (.)     - is a Hadamard product (element-wise),
///             f, g, h - are activation functions.
///
/// \note       This class represents only single *cell* (for current time step) and not
///             the whole LSTM Sequence layer
///
/// \sa         LSTMSequence, RNNCell, GRUCell
///
/// \ingroup ov_ops_cpp_api
class OPENVINO_API LSTMCell : public util::RNNCellBase {
public:
    OPENVINO_OP("LSTMCell", "opset1", op::util::RNNCellBase);

    LSTMCell();
    ///
    /// \brief      Constructs LSTMCell node.
    ///
    /// \param[in]  X                     The input tensor with shape: [batch_size,
    ///                                   input_size].
    /// \param[in]  initial_hidden_state  The hidden state tensor at current time step
    ///                                   with shape: [batch_size, hidden_size].
    /// \param[in]  initial_cell_state    The cell state tensor at current time step
    ///                                   with shape: [batch_size, hidden_size].
    /// \param[in]  W                     The gate weights tensor with shape:
    ///                                   [4*hidden_size, input_size].
    /// \param[in]  R                     The recurrence weights tensor with shape:
    ///                                   [4*hidden_size, hidden_size].
    /// \param[in]  hidden_size           The number of hidden units for recurrent cell.
    /// \param[in]  weights_format        The order of gates in weights tensors. The
    ///                                   default format is IFCO since it is used by
    ///                                   DNNL.
    /// \param[in]  activations           The vector of activation functions used inside
    ///                                   recurrent cell.
    /// \param[in]  activations_alpha     The vector of alpha parameters for activation
    ///                                   functions in order respective to activation
    ///                                   list.
    /// \param[in]  activations_beta      The vector of beta parameters for activation
    ///                                   functions in order respective to activation
    ///                                   list.
    /// \param[in]  clip                  The value defining clipping range [-clip,
    ///                                   clip] on input of activation functions.
    /// \param[in]  input_forget          Controls coupling input and forget gates.
    ///
    LSTMCell(const Output<Node>& X,
             const Output<Node>& initial_hidden_state,
             const Output<Node>& initial_cell_state,
             const Output<Node>& W,
             const Output<Node>& R,
             std::size_t hidden_size,
             LSTMWeightsFormat weights_format = LSTMWeightsFormat::IFCO,
             const std::vector<std::string>& activations = std::vector<std::string>{"sigmoid", "tanh", "tanh"},
             const std::vector<float>& activations_alpha = {},
             const std::vector<float>& activations_beta = {},
             float clip = 0.f,
             bool input_forget = false);

    ///
    /// \brief      Constructs LSTMCell node.
    ///
    /// \param[in]  X                     The input tensor with shape: [batch_size,
    ///                                   input_size].
    /// \param[in]  initial_hidden_state  The hidden state tensor at current time step
    ///                                   with shape: [batch_size, hidden_size].
    /// \param[in]  initial_cell_state    The cell state tensor at current time step
    ///                                   with shape: [batch_size, hidden_size].
    /// \param[in]  W                     The weight tensor with shape: [4*hidden_size,
    ///                                   input_size].
    /// \param[in]  R                     The recurrence weight tensor with shape:
    ///                                   [4*hidden_size, hidden_size].
    /// \param[in]  B                     The bias tensor for gates with shape:
    ///                                   [4*hidden_size].
    /// \param[in]  hidden_size           The number of hidden units for recurrent cell.
    /// \param[in]  weights_format        The order of gates in weights tensors. The
    ///                                   default format is IFCO since it is used by
    ///                                   DNNL.
    /// \param[in]  activations           The vector of activation functions used inside
    ///                                   recurrent cell.
    /// \param[in]  activations_alpha     The vector of alpha parameters for activation
    ///                                   functions in order respective to activation
    ///                                   list.
    /// \param[in]  activations_beta      The vector of beta parameters for activation
    ///                                   functions in order respective to activation
    ///                                   list.
    /// \param[in]  clip                  The value defining clipping range [-clip,
    ///                                   clip] on input of activation functions.
    /// \param[in]  input_forget          Controls coupling input and forget gates.
    ///
    LSTMCell(const Output<Node>& X,
             const Output<Node>& initial_hidden_state,
             const Output<Node>& initial_cell_state,
             const Output<Node>& W,
             const Output<Node>& R,
             const Output<Node>& B,
             std::size_t hidden_size,
             LSTMWeightsFormat weights_format = LSTMWeightsFormat::IFCO,
             const std::vector<std::string>& activations = std::vector<std::string>{"sigmoid", "tanh", "tanh"},
             const std::vector<float>& activations_alpha = {},
             const std::vector<float>& activations_beta = {},
             float clip = 0.f,
             bool input_forget = false);

    ///
    /// \brief      Constructs LSTMCell node.
    ///
    /// \param[in]  X                     The input tensor with shape: [batch_size,
    ///                                   input_size].
    /// \param[in]  initial_hidden_state  The hidden state tensor at current time step
    ///                                   with shape: [batch_size, hidden_size].
    /// \param[in]  initial_cell_state    The cell state tensor at current time step
    ///                                   with shape: [batch_size, hidden_size].
    /// \param[in]  W                     The weight tensor with shape: [4*hidden_size,
    ///                                   input_size].
    /// \param[in]  R                     The recurrence weight tensor with shape:
    ///                                   [4*hidden_size, hidden_size].
    /// \param[in]  B                     The bias tensor for gates with shape:
    ///                                   [4*hidden_size].
    /// \param[in]  P                     The weight tensor for peepholes with shape:
    ///                                   [3*hidden_size] - 3 equals to only iof gates.
    ///                                   The order is: input, output, forget gates.
    /// \param[in]  hidden_size           The number of hidden units for recurrent cell.
    /// \param[in]  weights_format        The order of gates in weights tensors. The
    ///                                   default format is IFCO since it is used by
    ///                                   DNNL.
    /// \param[in]  activations           The vector of activation functions used inside
    ///                                   recurrent cell.
    /// \param[in]  activations_alpha     The vector of alpha parameters for activation
    ///                                   functions in order respective to activation
    ///                                   list.
    /// \param[in]  activations_beta      The vector of beta parameters for activation
    ///                                   functions in order respective to activation
    ///                                   list.
    /// \param[in]  clip                  The value defining clipping range [-clip,
    ///                                   clip] on input of activation functions.
    /// \param[in]  input_forget          Controls coupling input and forget gates.
    ///
    LSTMCell(const Output<Node>& X,
             const Output<Node>& initial_hidden_state,
             const Output<Node>& initial_cell_state,
             const Output<Node>& W,
             const Output<Node>& R,
             const Output<Node>& B,
             const Output<Node>& P,
             std::size_t hidden_size,
             LSTMWeightsFormat weights_format = LSTMWeightsFormat::IFCO,
             const std::vector<std::string>& activations = std::vector<std::string>{"sigmoid", "tanh", "tanh"},
             const std::vector<float>& activations_alpha = {},
             const std::vector<float>& activations_beta = {},
             float clip = 0.f,
             bool input_forget = false);

    void validate_and_infer_types() override;
    bool visit_attributes(AttributeVisitor& visitor) override;
    std::shared_ptr<Node> clone_with_new_inputs(const OutputVector& new_args) const override;

    bool get_input_forget() const {
        return m_input_forget;
    }
    LSTMWeightsFormat get_weights_format() const {
        return m_weights_format;
    }

private:
    ///
    /// \brief      Creates the default bias input initialized with zeros.
    ///
    /// \return     The object of Output class.
    ///
    Output<Node> get_default_bias_input() const;

    ///
    /// \brief      Creates the default peepholes input initialized with zeros.
    ///
    /// \return     The object of Output class.
    ///
    Output<Node> get_default_peepholes_input() const;
    ///
    /// \brief The Activation function f.
    ///
    util::ActivationFunction m_activation_f;
    ///
    /// \brief The Activation function g.
    ///
    util::ActivationFunction m_activation_g;
    ///
    /// \brief The Activation function h.
    ///
    util::ActivationFunction m_activation_h;
    ///
    /// \brief      Controls whether to couple input and forget gates.
    ///
    bool m_input_forget = false;

    ///
    /// \brief The order of gates in weights tensors.
    ///
    LSTMWeightsFormat m_weights_format;
};
}  // namespace v0

namespace v4 {
///
/// \brief      Class for single lstm cell node.
///
/// \note       Following implementation supports:
///             \li \c peepholes Gers & Schmidhuber (2000)
///             https://ieeexplore.ieee.org/document/861302
///             \li Coupling input and forget gates.
///
/// \note       It calculates following equations:
///
///             it = f(Xt*(Wi^T) + Ht-1*(Ri^T) + Wbi + Rbi)
///             ft = f(Xt*(Wf^T) + Ht-1*(Rf^T)  + Wbf + Rbf)
///             ct = g(Xt*(Wc^T) + Ht-1*(Rc^T) + Wbc + Rbc)
///             Ct = ft (.) Ct-1 + it (.) ct
///             ot = f(Xt*(Wo^T) + Ht-1*(Ro^T) + Wbo + Rbo)
///             Ht = ot (.) h(Ct)
///
///             *       - Is a dot product,
///             (.)     - is a Hadamard product (element-wise),
///             f, g, h - are activation functions.
///
/// \note       This class represents only single *cell* (for current time step) and not
///             the whole LSTM Sequence layer
///
/// \sa         LSTMSequence, RNNCell, GRUCell
///
/// \ingroup ov_ops_cpp_api
class OPENVINO_API LSTMCell : public util::RNNCellBase {
public:
    OPENVINO_OP("LSTMCell", "opset4", op::util::RNNCellBase);

    LSTMCell();
    ///
    /// \brief      Constructs LSTMCell node.
    ///
    /// \param[in]  X                     The input tensor with shape: [batch_size,
    ///                                   input_size].
    /// \param[in]  initial_hidden_state  The hidden state tensor at current time step
    ///                                   with shape: [batch_size, hidden_size].
    /// \param[in]  initial_cell_state    The cell state tensor at current time step
    ///                                   with shape: [batch_size, hidden_size].
    /// \param[in]  W                     The gate weights tensor with shape:
    ///                                   [4*hidden_size, input_size].
    /// \param[in]  R                     The recurrence weights tensor with shape:
    ///                                   [4*hidden_size, hidden_size].
    /// \param[in]  hidden_size           The number of hidden units for recurrent cell.
    /// \param[in]  activations           The vector of activation functions used inside
    ///                                   recurrent cell.
    /// \param[in]  activations_alpha     The vector of alpha parameters for activation
    ///                                   functions in order respective to activation
    ///                                   list.
    /// \param[in]  activations_beta      The vector of beta parameters for activation
    ///                                   functions in order respective to activation
    ///                                   list.
    /// \param[in]  clip                  The value defining clipping range [-clip,
    ///                                   clip] on input of activation functions.
    LSTMCell(const Output<Node>& X,
             const Output<Node>& initial_hidden_state,
             const Output<Node>& initial_cell_state,
             const Output<Node>& W,
             const Output<Node>& R,
             std::size_t hidden_size,
             const std::vector<std::string>& activations = std::vector<std::string>{"sigmoid", "tanh", "tanh"},
             const std::vector<float>& activations_alpha = {},
             const std::vector<float>& activations_beta = {},
             float clip = 0.f);

    ///
    /// \brief      Constructs LSTMCell node.
    ///
    /// \param[in]  X                     The input tensor with shape: [batch_size,
    ///                                   input_size].
    /// \param[in]  initial_hidden_state  The hidden state tensor at current time step
    ///                                   with shape: [batch_size, hidden_size].
    /// \param[in]  initial_cell_state    The cell state tensor at current time step
    ///                                   with shape: [batch_size, hidden_size].
    /// \param[in]  W                     The weight tensor with shape: [4*hidden_size,
    ///                                   input_size].
    /// \param[in]  R                     The recurrence weight tensor with shape:
    ///                                   [4*hidden_size, hidden_size].
    /// \param[in]  B                     The bias tensor for gates with shape:
    ///                                   [4*hidden_size].
    /// \param[in]  hidden_size           The number of hidden units for recurrent cell.
    /// \param[in]  activations           The vector of activation functions used inside
    ///                                   recurrent cell.
    /// \param[in]  activations_alpha     The vector of alpha parameters for activation
    ///                                   functions in order respective to activation
    ///                                   list.
    /// \param[in]  activations_beta      The vector of beta parameters for activation
    ///                                   functions in order respective to activation
    ///                                   list.
    /// \param[in]  clip                  The value defining clipping range [-clip,
    ///                                   clip] on input of activation functions.
    ///
    LSTMCell(const Output<Node>& X,
             const Output<Node>& initial_hidden_state,
             const Output<Node>& initial_cell_state,
             const Output<Node>& W,
             const Output<Node>& R,
             const Output<Node>& B,
             std::size_t hidden_size,
             const std::vector<std::string>& activations = std::vector<std::string>{"sigmoid", "tanh", "tanh"},
             const std::vector<float>& activations_alpha = {},
             const std::vector<float>& activations_beta = {},
             float clip = 0.f);

    void validate_and_infer_types() override;

    bool visit_attributes(AttributeVisitor& visitor) override;
    std::shared_ptr<Node> clone_with_new_inputs(const OutputVector& new_args) const override;

private:
    ///
    /// \brief      Creates the default bias input initialized with zeros.
    ///
    /// \return     The object of Output class.
    ///
    Output<Node> get_default_bias_input() const;

    ///
    /// \brief The Activation function f.
    ///
    util::ActivationFunction m_activation_f;
    ///
    /// \brief The Activation function g.
    ///
    util::ActivationFunction m_activation_g;
    ///
    /// \brief The Activation function h.
    ///
    util::ActivationFunction m_activation_h;
};
}  // namespace v4
}  // namespace op

OPENVINO_API
std::ostream& operator<<(std::ostream& s, const op::LSTMWeightsFormat& type);

template <>
class OPENVINO_API AttributeAdapter<op::LSTMWeightsFormat> : public EnumAttributeAdapterBase<op::LSTMWeightsFormat> {
public:
    AttributeAdapter(op::LSTMWeightsFormat& value) : EnumAttributeAdapterBase<op::LSTMWeightsFormat>(value) {}

    OPENVINO_RTTI("AttributeAdapter<ov::op::LSTMWeightsFormat>");
    ~AttributeAdapter() override;
};

}  // namespace ov
