///////////////////////////////////////////////////////////////////////////////

// BSD 3-Clause License

//

// Copyright (C) 2019-2024, LAAS-CNRS, University of Edinburgh,

//                          Heriot-Watt University

// Copyright note valid unless otherwise stated in individual files.

// All rights reserved.

///////////////////////////////////////////////////////////////////////////////

#ifndef CROCODDYL_CORE_RESIDUALS_CONTROL_HPP_

#define CROCODDYL_CORE_RESIDUALS_CONTROL_HPP_

#include "crocoddyl/core/fwd.hpp"

#include "crocoddyl/core/residual-base.hpp"

namespace crocoddyl {

/**

 * @brief Define a control residual

 *

 * This residual function is defined as

 * \f$\mathbf{r}=\mathbf{u}-\mathbf{u}^*\f$, where

 * \f$\mathbf{u},\mathbf{u}^*\in~\mathbb{R}^{nu}\f$ are the current and

 * reference control inputs, respectively. Note that the dimension of the

 * residual vector is obtained from `nu`.

 *

 * Both residual and residual Jacobians are computed analytically.

 *

 * As described in ResidualModelAbstractTpl(), the residual value and its

 * Jacobians are calculated by `calc` and `calcDiff`, respectively.

 *

 * \sa `ResidualModelAbstractTpl`, `calc()`, `calcDiff()`, `createData()`

 */

template <typename _Scalar>

class ResidualModelControlTpl : public ResidualModelAbstractTpl<_Scalar> {

 public:

  typedef _Scalar Scalar;

  typedef MathBaseTpl<Scalar> MathBase;

  typedef ResidualModelAbstractTpl<Scalar> Base;

  typedef ResidualDataAbstractTpl<Scalar> ResidualDataAbstract;

  typedef DataCollectorAbstractTpl<Scalar> DataCollectorAbstract;

  typedef typename MathBase::VectorXs VectorXs;

  typedef typename MathBase::MatrixXs MatrixXs;

  /**

   * @brief Initialize the control residual model

   *

   * The default `nu` value is obtained from `StateAbstractTpl::get_nv()`.

   *

   * @param[in] state  State of the multibody system

   * @param[in] uref   Reference control input

   */

  ResidualModelControlTpl(boost::shared_ptr<typename Base::StateAbstract> state,

                          const VectorXs& uref);

  /**

   * @brief Initialize the control residual model

   *

   * The default `nu` value is obtained from `StateAbstractTpl::get_nv()`.

   *

   * @param[in] state  State of the multibody system

   * @param[in] nu     Dimension of the control vector

   */

  ResidualModelControlTpl(boost::shared_ptr<typename Base::StateAbstract> state,

                          const std::size_t nu);

  /**

   * @brief Initialize the control residual model

   *

   * The default reference control is obtained from

   * `MathBaseTpl<>::VectorXs::Zero(nu)`.

   *

   * @param[in] state  State of the multibody system

   */

  explicit ResidualModelControlTpl(

      boost::shared_ptr<typename Base::StateAbstract> state);

  virtual ~ResidualModelControlTpl();

  /**

   * @brief Compute the control residual

   *

   * @param[in] data  Control residual data

   * @param[in] x     State point \f$\mathbf{x}\in\mathbb{R}^{ndx}\f$

   * @param[in] u     Control input \f$\mathbf{u}\in\mathbb{R}^{nu}\f$

   */

  virtual void calc(const boost::shared_ptr<ResidualDataAbstract>& data,

                    const Eigen::Ref<const VectorXs>& x,

                    const Eigen::Ref<const VectorXs>& u);

  /**

   * @brief @copydoc Base::calc(const boost::shared_ptr<ResidualDataAbstract>&

   * data, const Eigen::Ref<const VectorXs>& x)

   */

  virtual void calc(const boost::shared_ptr<ResidualDataAbstract>& data,

                    const Eigen::Ref<const VectorXs>& x);

  /**

   * @brief Compute the derivatives of the control residual

   *

   * @param[in] data  Control residual data

   * @param[in] x     State point \f$\mathbf{x}\in\mathbb{R}^{ndx}\f$

   * @param[in] u     Control input \f$\mathbf{u}\in\mathbb{R}^{nu}\f$

   */

  virtual void calcDiff(const boost::shared_ptr<ResidualDataAbstract>& data,

                        const Eigen::Ref<const VectorXs>& x,

                        const Eigen::Ref<const VectorXs>& u);

  /**

   * @brief Create the control residual data

   */

  virtual boost::shared_ptr<ResidualDataAbstract> createData(

      DataCollectorAbstract* const data);

  /**

   * @brief Compute the derivative of the control-cost function

   *

   * This function assumes that the derivatives of the activation and residual

   * are computed via calcDiff functions.

   *

   * @param cdata     Cost data

   * @param rdata     Residual data

   * @param adata     Activation data

   * @param update_u  Update the derivative of the cost function w.r.t. to the

   * control if True.

   */

  virtual void calcCostDiff(

      const boost::shared_ptr<CostDataAbstract>& cdata,

      const boost::shared_ptr<ResidualDataAbstract>& rdata,

      const boost::shared_ptr<ActivationDataAbstract>& adata,

      const bool update_u = true);

  /**

   * @brief Return the reference control vector

   */

  const VectorXs& get_reference() const;

  /**

   * @brief Modify the reference control vector

   */

  void set_reference(const VectorXs& reference);

  /**

   * @brief Print relevant information of the control residual

   *

   * @param[out] os  Output stream object

   */

  virtual void print(std::ostream& os) const;

 protected:

  using Base::nu_;

  using Base::state_;

 private:

  VectorXs uref_;  //!< Reference control input

};

}  // namespace crocoddyl

/* --- Details -------------------------------------------------------------- */

/* --- Details -------------------------------------------------------------- */

/* --- Details -------------------------------------------------------------- */

#include "crocoddyl/core/residuals/control.hxx"

#endif  // CROCODDYL_CORE_RESIDUALS_CONTROL_HPP_