/*
 *    This file is part of CasADi.
 *
 *    CasADi -- A symbolic framework for dynamic optimization.
 *    Copyright (C) 2010-2023 Joel Andersson, Joris Gillis, Moritz Diehl,
 *                            KU Leuven. All rights reserved.
 *    Copyright (C) 2011-2014 Greg Horn
 *
 *    CasADi is free software; you can redistribute it and/or
 *    modify it under the terms of the GNU Lesser General Public
 *    License as published by the Free Software Foundation; either
 *    version 3 of the License, or (at your option) any later version.
 *
 *    CasADi is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *    Lesser General Public License for more details.
 *
 *    You should have received a copy of the GNU Lesser General Public
 *    License along with CasADi; if not, write to the Free Software
 *    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */


#ifndef CASADI_NLPSOL_IMPL_HPP
#define CASADI_NLPSOL_IMPL_HPP

#include "nlpsol.hpp"
#include "oracle_function.hpp"
#include "plugin_interface.hpp"


/// \cond INTERNAL
namespace casadi {

  /** \brief Integrator memory

      \identifier{1ni} */
  struct CASADI_EXPORT NlpsolMemory : public OracleMemory {
    // Problem data structure
    casadi_nlpsol_data<double> d_nlp;
    // number of iterations
    casadi_int n_iter;
    // Success?
    bool success;
    // Return status
    UnifiedReturnStatus unified_return_status;
  };

  /** \brief NLP solver storage class

      @copydoc Nlpsol_doc
      \author Joel Andersson
      \date 2010-2013

      \identifier{1nj} */
  class CASADI_EXPORT
  Nlpsol : public OracleFunction, public PluginInterface<Nlpsol> {
  public:

    // Memory structure
    casadi_nlpsol_prob<double> p_nlp_;

    /// Number of variables
    casadi_int nx_;

    /// Number of constraints
    casadi_int ng_;

    /// Number of parameters
    casadi_int np_;

    /// callback function, executed at each iteration
    Function fcallback_;

    /// Execute the callback function only after this amount of iterations
    casadi_int callback_step_;

    /// Linear solver and options
    std::string sens_linsol_;
    Dict sens_linsol_options_;

    std::vector<char> detect_simple_bounds_is_simple_;
    Function detect_simple_bounds_parts_;
    std::vector<casadi_int> detect_simple_bounds_target_x_;
    std::vector<casadi_int> detect_simple_bounds_target_g_;

    ///@{
    /** \brief Options

        \identifier{1nk} */
    bool eval_errors_fatal_;
    bool warn_initial_bounds_;
    bool iteration_callback_ignore_errors_;
    bool calc_multipliers_;
    bool calc_lam_x_, calc_lam_p_, calc_f_, calc_g_;
    bool bound_consistency_;
    double min_lam_;
    bool no_nlp_grad_;
    std::vector<bool> discrete_;
    std::vector<bool> equality_;
    ///@}

    // Mixed integer problem?
    bool mi_;

    /// Cache for KKT function
    mutable WeakRef kkt_;

#ifdef CASADI_WITH_THREADSAFE_SYMBOLICS
    /// Mutex for thread safety
    mutable std::mutex kkt_mtx_;
#endif // CASADI_WITH_THREADSAFE_SYMBOLICS

    /** \brief Serialize an object without type information

        \identifier{1nl} */
    void serialize_body(SerializingStream &s) const override;
    /** \brief Serialize type information

        \identifier{1nm} */
    void serialize_type(SerializingStream &s) const override;

    /** \brief Deserialize into MX

        \identifier{1nn} */
    static ProtoFunction* deserialize(DeserializingStream& s);

    /** \brief String used to identify the immediate FunctionInternal subclass

        \identifier{1no} */
    std::string serialize_base_function() const override { return "Nlpsol"; }

    /// Constructor
    Nlpsol(const std::string& name, const Function& oracle);

    /// Destructor
    ~Nlpsol() override = 0;

    ///@{
    /** \brief Number of function inputs and outputs

        \identifier{1np} */
    size_t get_n_in() override { return NLPSOL_NUM_IN;}
    size_t get_n_out() override { return NLPSOL_NUM_OUT;}
    ///@}

    /// @{
    /** \brief Sparsities of function inputs and outputs

        \identifier{1nq} */
    Sparsity get_sparsity_in(casadi_int i) override;
    Sparsity get_sparsity_out(casadi_int i) override;
    /// @}

    ///@{
    /** \brief Names of function input and outputs

        \identifier{1nr} */
    std::string get_name_in(casadi_int i) override { return nlpsol_in(i);}
    std::string get_name_out(casadi_int i) override { return nlpsol_out(i);}
    /// @}

    ///@{
    /** \brief Options

        \identifier{1ns} */
    static const Options options_;
    const Options& get_options() const override { return options_;}
    ///@}

    /** \brief  Print description

        \identifier{1nt} */
    void disp_more(std::ostream& stream) const override;

    /// Initialize
    void init(const Dict& opts) override;

    /** \brief Create memory block

        \identifier{1nu} */
    void* alloc_mem() const override { return new NlpsolMemory();}

    /** \brief Initalize memory block

        \identifier{1nv} */
    int init_mem(void* mem) const override;

    /** \brief Free memory block

        \identifier{1nw} */
    void free_mem(void *mem) const override { delete static_cast<NlpsolMemory*>(mem);}

    /** \brief Check if the inputs correspond to a well-posed problem

        \identifier{1nx} */
    virtual void check_inputs(void* mem) const;

    /** \brief Get default input value

        \identifier{1ny} */
    double get_default_in(casadi_int ind) const override { return nlpsol_default_in(ind);}

    /// Can discrete variables be treated
    virtual bool integer_support() const { return false;}

    /** \brief Set the (persistent) work vectors

        \identifier{1nz} */
    void set_work(void* mem, const double**& arg, double**& res,
                          casadi_int*& iw, double*& w) const override;

    // Evaluate numerically
    int eval(const double** arg, double** res, casadi_int* iw, double* w, void* mem) const final;

    // Solve the NLP
    virtual int solve(void* mem) const = 0;

    /** \brief Generate code for the declarations of the C function

        \identifier{27j} */
    void codegen_declarations(CodeGenerator& g) const override;

    /** \brief Generate code for the function body

        \identifier{1o0} */
    void codegen_body_enter(CodeGenerator& g) const override;

    /** \brief Generate code for the function body

        \identifier{27k} */
    void codegen_body_exit(CodeGenerator& g) const override;

    /** \brief Do the derivative functions need nondifferentiated outputs?

        \identifier{1o1} */
    bool uses_output() const override {return true;}

    /// Get all statistics
    Dict get_stats(void* mem) const override;

    ///@{
    /** \brief Generate a function that calculates forward mode derivatives

        \identifier{1o2} */
    bool has_forward(casadi_int nfwd) const override { return true;}
    Function get_forward(casadi_int nfwd, const std::string& name,
                         const std::vector<std::string>& inames,
                         const std::vector<std::string>& onames,
                         const Dict& opts) const override;
    ///@}

    ///@{
    /** \brief Generate a function that calculates reverse mode derivatives

        \identifier{1o3} */
    bool has_reverse(casadi_int nadj) const override { return true;}
    Function get_reverse(casadi_int nadj, const std::string& name,
                         const std::vector<std::string>& inames,
                         const std::vector<std::string>& onames,
                         const Dict& opts) const override;
    ///@}

    // Call the callback function
    int callback(NlpsolMemory* m) const;

    // Get KKT function
    Function kkt() const;

    // Make sure primal-dual solution is consistent with bounds
    static void bound_consistency(casadi_int n, double* z, double* lam,
                                  const double* lbz, const double* ubz);

    // Creator function for internal class
    typedef Nlpsol* (*Creator)(const std::string& name, const Function& oracle);

    // No static functions exposed
    struct Exposed{ };

    /// Collection of solvers
    static std::map<std::string, Plugin> solvers_;

#ifdef CASADI_WITH_THREADSAFE_SYMBOLICS
    static std::mutex mutex_solvers_;
#endif // CASADI_WITH_THREADSAFE_SYMBOLICS

    /// Infix
    static const std::string infix_;

    /// Short name
    static std::string shortname() { return "nlpsol";}

    /** \brief Get type name

        \identifier{1o4} */
    std::string class_name() const override {return "Nlpsol";}

    /** \brief Check if the function is of a particular type

        \identifier{1o5} */
    bool is_a(const std::string& type, bool recursive) const override;

    // Get reduced Hessian
    virtual DM getReducedHessian();

    /// Read options from parameter xml
    virtual void setOptionsFromFile(const std::string & file);

    /// WORKAROUND: Add an element to an std::vector stored in a GenericType:
    template<typename Type> static void append_to_vec(GenericType& t, Type el) {
      std::vector<Type> v = t;
      v.push_back(el);
      t = v;
    }

    /// Convert dictionary to Problem
    template<typename XType>
      static Function create_oracle(const std::map<std::string, XType>& d,
                                    const Dict& opts);

  protected:
    /** \brief Deserializing constructor

        \identifier{1o6} */
    explicit Nlpsol(DeserializingStream& s);
  private:
    void set_nlpsol_prob();
  };

} // namespace casadi
/// \endcond
#endif // CASADI_NLPSOL_IMPL_HPP
