////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2012-2022 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Octave 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if ! defined (octave_cdef_object_h)
#define octave_cdef_object_h 1

#include "octave-config.h"

#include <map>
#include <string>

#include "oct-refcount.h"

#include "cdef-fwd.h"
#include "error.h"
#include "oct-map.h"
#include "ov.h"
#include "ovl.h"

OCTAVE_BEGIN_NAMESPACE(octave)

// This is mainly a bootstrap class to declare the expected interface.
// The actual base class is cdef_class_base, which is declared after
// cdef_object, such that it can contain cdef_object objects.

class
OCTINTERP_API
cdef_object_rep
{
public:

  friend class cdef_object;

  cdef_object_rep (void) : m_count (1) { }

  cdef_object_rep& operator = (const cdef_object_rep&) = delete;

  virtual ~cdef_object_rep (void) = default;

  virtual cdef_class get_class (void) const;

  virtual void set_class (const cdef_class&)
  {
    err_invalid_object ("set_class");
  }

  virtual cdef_object_rep * clone (void) const
  {
    err_invalid_object ("clone");
  }

  virtual cdef_object_rep * empty_clone (void) const
  {
    err_invalid_object ("empty_clone");
  }

  virtual cdef_object_rep * copy (void) const
  {
    err_invalid_object ("copy");
  }

  virtual cdef_object_rep * make_array (void) const
  {
    err_invalid_object ("make_array");
  }

  virtual bool is_array (void) const { return false; }

  virtual bool is_value_object (void) const { return false; }

  virtual bool is_handle_object (void) const { return false; }

  virtual bool is_meta_object (void) const { return false; }

  virtual Array<cdef_object> array_value (void) const
  {
    err_invalid_object ("array_value");
  }

  virtual void put (const std::string&, const octave_value&)
  { err_invalid_object ("put"); }

  virtual octave_value get (const std::string&) const
  {
    err_invalid_object ("get");
  }

  virtual void set_property (octave_idx_type, const std::string&,
                             const octave_value&)
  {
    err_invalid_object ("set_property");
  }

  virtual octave_value get_property (octave_idx_type, const std::string&) const
  {
    err_invalid_object ("get_property");
  }

  virtual void break_closure_cycles (const std::shared_ptr<stack_frame>&)
  {
    err_invalid_object ("break_closure_cycles");
  }

  virtual octave_value_list
  subsref (const std::string&, const std::list<octave_value_list>&,
           int, std::size_t&, const cdef_class&, bool)
  {
    err_invalid_object ("subsref");
  }

  virtual octave_value
  subsasgn (const std::string&, const std::list<octave_value_list>&,
            const octave_value&)
  {
    err_invalid_object ("subsasgn");
  }

  virtual string_vector map_keys (void) const;

  virtual bool is_valid (void) const { return false; }

  OCTINTERP_API std::string class_name (void) const;

  virtual void mark_for_construction (const cdef_class&)
  {
    err_invalid_object ("mark_for_construction");
  }

  virtual bool is_constructed_for (const cdef_class&) const
  {
    err_invalid_object ("is_constructed_for");
  }

  virtual bool is_partially_constructed_for (const cdef_class&) const
  {
    err_invalid_object ("is_partially_constructed_for");
  }

  virtual void mark_as_constructed (void)
  {
    err_invalid_object ("mark_as_constructed");
  }

  virtual void mark_as_constructed (const cdef_class&)
  {
    err_invalid_object ("mark_as_constructed");
  }

  virtual bool is_constructed (void) const
  {
    err_invalid_object ("is_constructed");
  }

  virtual octave_idx_type static_count (void) const { return 0; }

  virtual void destroy (void) { delete this; }

  OCTINTERP_API void release (const cdef_object& obj);

  virtual dim_vector dims (void) const { return dim_vector (); }

protected:

  // Reference count
  refcount<octave_idx_type> m_count;

  // Restricted copying.

  cdef_object_rep (const cdef_object_rep&) : m_count (1) { }

private:

  OCTAVE_NORETURN void err_invalid_object (const char *who) const
  {
    error ("%s: invalid object", who);
  }
};

class
OCTINTERP_API
cdef_object
{
public:

  // FIXME: use a null object?
  cdef_object (void) : m_rep (new cdef_object_rep ()) { }

  cdef_object (const cdef_object& obj) : m_rep (obj.m_rep)
  { m_rep->m_count++; }

  cdef_object (cdef_object_rep *r) : m_rep (r) { }

  virtual ~cdef_object (void) { m_rep->release (*this); }

  cdef_object& operator = (const cdef_object& obj)
  {
    if (m_rep != obj.m_rep)
      {
        m_rep->release (*this);

        m_rep = obj.m_rep;
        m_rep->m_count++;
      }

    return *this;
  }

  OCTINTERP_API cdef_class get_class (void) const;

  void set_class (const cdef_class& cls) { m_rep->set_class (cls); }

  std::string class_name (void) const { return m_rep->class_name (); }

  cdef_object clone (void) const { return cdef_object (m_rep->clone ()); }

  cdef_object empty_clone (void) const
  {
    return cdef_object (m_rep->empty_clone ());
  }

  dim_vector dims (void) const { return m_rep->dims (); }

  cdef_object make_array (void) const
  {
    return cdef_object (m_rep->make_array ());
  }

  cdef_object copy (void) const { return cdef_object (m_rep->copy ()); }

  bool is_array (void) const { return m_rep->is_array (); }

  bool is_value_object (void) const { return m_rep->is_value_object (); }

  bool is_handle_object (void) const { return m_rep->is_handle_object (); }

  bool is_meta_object (void) const { return m_rep->is_meta_object (); }

  Array<cdef_object> array_value (void) const
  { return m_rep->array_value (); }

  void put (const std::string& pname, const octave_value& val)
  {
    m_rep->put (pname, val);
  }

  octave_value get (const std::string& pname) const
  {
    return m_rep->get (pname);
  }

  void set_property (octave_idx_type idx, const std::string& pname,
                     const octave_value& pval)
  {
    return m_rep->set_property (idx, pname, pval);
  }

  octave_value
  get_property (octave_idx_type idx, const std::string& pname) const
  {
    return m_rep->get_property (idx, pname);
  }

  void break_closure_cycles (const std::shared_ptr<stack_frame>& frame)
  {
    m_rep->break_closure_cycles (frame);
  }

  octave_value_list
  subsref (const std::string& type, const std::list<octave_value_list>& idx,
           int nargout, std::size_t& skip, const cdef_class& context,
           bool auto_add = false)
  {
    return m_rep->subsref (type, idx, nargout, skip, context, auto_add);
  }

  octave_value
  subsasgn (const std::string& type, const std::list<octave_value_list>& idx,
            const octave_value& rhs, int ignore_copies = 0)
  {
    make_unique (ignore_copies);
    return m_rep->subsasgn (type, idx, rhs);
  }

  string_vector map_keys (void) const { return m_rep->map_keys (); }

  OCTINTERP_API octave_map map_value (void) const;

  const cdef_object_rep * get_rep (void) const { return m_rep; }

  bool ok (void) const { return m_rep->is_valid (); }

  void mark_for_construction (const cdef_class& cls)
  {
    m_rep->mark_for_construction (cls);
  }

  bool is_constructed (void) const { return m_rep->is_constructed (); }

  bool is_constructed_for (const cdef_class& cls) const
  {
    return m_rep->is_constructed_for (cls);
  }

  bool is_partially_constructed_for (const cdef_class& cls) const
  {
    return m_rep->is_partially_constructed_for (cls);
  }

  void mark_as_constructed (void) { m_rep->mark_as_constructed (); }

  void mark_as_constructed (const cdef_class& cls)
  { m_rep->mark_as_constructed (cls); }

  bool is (const cdef_object& obj) const { return m_rep == obj.m_rep; }

protected:

  cdef_object_rep * get_rep (void) { return m_rep; }

  void make_unique (int ignore_copies)
  {
    if (m_rep->m_count > ignore_copies + 1)
      *this = clone ();
  }

private:

  cdef_object_rep *m_rep;
};

class
OCTINTERP_API
cdef_object_base : public cdef_object_rep
{
public:

  cdef_object_base (void)
    : cdef_object_rep (), m_klass ()
  { }

  cdef_object_base& operator = (const cdef_object_base&) = delete;

  ~cdef_object_base (void) { }

  OCTINTERP_API cdef_class get_class (void) const;

  OCTINTERP_API void set_class (const cdef_class& cls);

  cdef_object_rep * empty_clone (void) const
  {
    return new cdef_object_base (*this);
  }

  OCTINTERP_API cdef_object_rep * make_array (void) const;

protected:

  // Restricted copying!
  cdef_object_base (const cdef_object_base& obj)
    : cdef_object_rep (obj), m_klass (obj.m_klass)
  { }

private:

  // The class of the object
  cdef_object m_klass;
};

class
OCTINTERP_API
cdef_object_array : public cdef_object_base
{
public:

  cdef_object_array (void) : cdef_object_base () { }

  cdef_object_array (const Array<cdef_object>& a)
    : cdef_object_base (), m_array (a)
  { }

  cdef_object_array& operator = (const cdef_object_array&) = delete;

  ~cdef_object_array (void) = default;

  cdef_object_rep * clone (void) const
  {
    return new cdef_object_array (*this);
  }

  dim_vector dims (void) const { return m_array.dims (); }

  bool is_valid (void) const { return true; }

  bool is_array (void) const { return true; }

  Array<cdef_object> array_value (void) const { return m_array; }

  OCTINTERP_API octave_value_list
  subsref (const std::string& type, const std::list<octave_value_list>& idx,
           int nargout, std::size_t& skip, const cdef_class& context,
           bool auto_add);

  OCTINTERP_API octave_value
  subsasgn (const std::string& type, const std::list<octave_value_list>& idx,
            const octave_value& rhs);

  void set_property (octave_idx_type idx, const std::string& pname,
                     const octave_value& pval)
  {
    cdef_object& tmp = m_array.elem (idx);

    return tmp.put (pname, pval);
  }

  octave_value
  get_property (octave_idx_type idx, const std::string& pname) const
  {
    cdef_object tmp = m_array.elem (idx);

    return tmp.get (pname);
  }

private:

  Array<cdef_object> m_array;

  void fill_empty_values (void) { fill_empty_values (m_array); }

  OCTINTERP_API void fill_empty_values (Array<cdef_object>& arr);

  // Private copying!
  cdef_object_array (const cdef_object_array& obj)
    : cdef_object_base (obj), m_array (obj.m_array)
  { }
};

class
OCTINTERP_API
cdef_object_scalar : public cdef_object_base
{
public:

  cdef_object_scalar (void) : cdef_object_base () { }

  cdef_object_scalar& operator = (const cdef_object_scalar&) = delete;

  ~cdef_object_scalar (void) = default;

  dim_vector dims (void) const { return dim_vector (1, 1); }

  void break_closure_cycles (const std::shared_ptr<stack_frame>& frame);

  void put (const std::string& pname, const octave_value& val)
  {
    m_map.assign (pname, val);
  }

  octave_value get (const std::string& pname) const
  {
    Cell val = m_map.contents (pname);

    if (val.numel () < 1)
      error ("get: unknown slot: %s", pname.c_str ());

    return val(0, 0);
  }

  void set_property (octave_idx_type idx, const std::string& pname,
                     const octave_value& pval)
  {
    if (idx != 0)
      error ("invalid index");  // FIXME

    put (pname, pval);
  }

  octave_value
  get_property (octave_idx_type idx, const std::string& pname) const
  {
    if (idx != 0)
      error ("invalid index");  // FIXME

    return get (pname);
  }

  OCTINTERP_API octave_value_list
  subsref (const std::string& type, const std::list<octave_value_list>& idx,
           int nargout, std::size_t& skip, const cdef_class& context,
           bool auto_add);

  OCTINTERP_API octave_value
  subsasgn (const std::string& type, const std::list<octave_value_list>& idx,
            const octave_value& rhs);

  OCTINTERP_API void mark_for_construction (const cdef_class&);

  OCTINTERP_API bool is_constructed_for (const cdef_class& cls) const;

  OCTINTERP_API bool
  is_partially_constructed_for (const cdef_class& cls) const;

  void mark_as_constructed (void) { m_ctor_list.clear (); }

  OCTINTERP_API void mark_as_constructed (const cdef_class& cls);

  bool is_constructed (void) const { return m_ctor_list.empty (); }

protected:

  // Object property values
  octave_scalar_map m_map;

  // Internal/temporary structure used during object construction
  std::map< cdef_class, std::list<cdef_class>> m_ctor_list;

protected:

  // Restricted object copying!
  cdef_object_scalar (const cdef_object_scalar& obj)
    : cdef_object_base (obj), m_map (obj.m_map), m_ctor_list (obj.m_ctor_list)
  { }
};

class
OCTINTERP_API
handle_cdef_object : public cdef_object_scalar
{
public:

  handle_cdef_object (void) : cdef_object_scalar () { }

  handle_cdef_object& operator = (const handle_cdef_object&) = delete;

  OCTINTERP_API ~handle_cdef_object (void);

  cdef_object_rep * clone (void) const
  {
    handle_cdef_object *obj = const_cast<handle_cdef_object *> (this);
    obj->m_count++;
    return obj;
  }

  cdef_object_rep * copy (void) const
  {
    return new handle_cdef_object (*this);
  }

  bool is_valid (void) const { return true; }

  bool is_handle_object (void) const { return true; }

protected:

  // Restricted copying!
  handle_cdef_object (const handle_cdef_object& obj)
    : cdef_object_scalar (obj)
  { }
};

class
OCTINTERP_API
value_cdef_object : public cdef_object_scalar
{
public:

  value_cdef_object (void) : cdef_object_scalar () { }

  value_cdef_object& operator = (const value_cdef_object&) = delete;

  OCTINTERP_API ~value_cdef_object (void);

  cdef_object_rep * clone (void) const
  {
    return new value_cdef_object (*this);
  }

  cdef_object_rep * copy (void) const { return clone (); }

  bool is_valid (void) const { return true; }

  bool is_value_object (void) const { return true; }

private:

  // Private copying!
  value_cdef_object (const value_cdef_object& obj)
    : cdef_object_scalar (obj)
  { }
};

class
OCTINTERP_API
cdef_meta_object_rep : public handle_cdef_object
{
public:

  cdef_meta_object_rep (void) : handle_cdef_object () { }

  cdef_meta_object_rep& operator = (const cdef_meta_object_rep&) = delete;

  ~cdef_meta_object_rep (void) = default;

  cdef_object_rep * copy (void) const
  { return new cdef_meta_object_rep (*this); }

  bool is_meta_object (void) const { return true; }

  virtual bool is_class (void) const { return false; }

  virtual bool is_property (void) const { return false; }

  virtual bool is_method (void) const { return false; }

  virtual bool is_package (void) const { return false; }

  virtual octave_value_list
  meta_subsref (const std::string& /* type */,
                const std::list<octave_value_list>& /* idx */,
                int /* nargout */)
  {
    error ("subsref: invalid meta object");
  }

  virtual void meta_release (void) { }

  virtual bool meta_accepts_postfix_index (char /* type */) const
  {
    return false;
  }

protected:

  // Restricted copying!
  cdef_meta_object_rep (const cdef_meta_object_rep& obj)
    : handle_cdef_object (obj)
  { }
};

class
OCTINTERP_API
cdef_meta_object : public cdef_object
{
public:

  cdef_meta_object (void) : cdef_object () { }

  // Object consistency is checked in sub-classes.
  cdef_meta_object (const cdef_meta_object& obj) : cdef_object (obj) { }

  cdef_meta_object (cdef_meta_object_rep *r) : cdef_object (r) { }

  cdef_meta_object (const cdef_object& obj) : cdef_object (obj) { }

  cdef_meta_object& operator = (const cdef_object&) = delete;

  ~cdef_meta_object (void) = default;

  bool is_class (void) const { return get_rep ()->is_class (); }

  bool is_property (void) const { return get_rep ()->is_property (); }

  bool is_method (void) const { return get_rep ()->is_method (); }

  bool is_package (void) const { return get_rep ()->is_package (); }

  octave_value_list
  meta_subsref (const std::string& type,
                const std::list<octave_value_list>& idx, int nargout)
  {
    return get_rep ()->meta_subsref (type, idx, nargout);
  }

  void meta_release (void) { get_rep ()->meta_release (); }

  bool meta_accepts_postfix_index (char type) const
  {
    return get_rep ()->meta_accepts_postfix_index (type);
  }

private:

  cdef_meta_object_rep * get_rep (void)
  {
    return dynamic_cast<cdef_meta_object_rep *> (cdef_object::get_rep ());
  }

  const cdef_meta_object_rep * get_rep (void) const
  {
    return dynamic_cast<const cdef_meta_object_rep *> (cdef_object::get_rep ());
  }
};

OCTAVE_END_NAMESPACE(octave)

#endif