////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 1993-2021 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/>.
//
////////////////////////////////////////////////////////////////////////

// Use the GNU readline library for command line editing and history.

#if ! defined (octave_input_h)
#define octave_input_h 1

#include "octave-config.h"

#include <cstdio>

#include <memory>
#include <string>
#include <unordered_map>

#include "hook-fcn.h"
#include "oct-time.h"
#include "ovl.h"
#include "pager.h"

// TRUE after a call to completion_matches.
extern bool octave_completion_matches_called;

// TRUE if the plotting system has requested a call to drawnow at
// the next user prompt.
extern OCTINTERP_API bool Vdrawnow_requested;

extern OCTINTERP_API octave::sys::time Vlast_prompt_time;

class octave_value;

OCTAVE_NAMESPACE_BEGIN

  class interpreter;

  class input_system
  {
  public:

    input_system (interpreter& interp);

    void initialize (bool line_editing);

    octave_value PS1 (const octave_value_list& args, int nargout);

    std::string PS1 (void) const { return m_PS1; }

    std::string PS1 (const std::string& s)
    {
      std::string val = m_PS1;
      m_PS1 = s;
      return val;
    }

    void set_PS1 (const std::string& s) { m_PS1 = s; }

    octave_value PS2 (const octave_value_list& args, int nargout);

    std::string PS2 (void) const { return m_PS2; }

    std::string PS2 (const std::string& s)
    {
      std::string val = m_PS2;
      m_PS2 = s;
      return val;
    }

    void set_PS2 (const std::string& s) { m_PS2 = s; }

    std::string last_debugging_command (void) const
    {
      return m_last_debugging_command;
    }

    std::string last_debugging_command (const std::string& s)
    {
      std::string val = m_last_debugging_command;
      m_last_debugging_command = s;
      return val;
    }

    octave_value
    completion_append_char (const octave_value_list& args, int nargout);

    char completion_append_char (void) const
    {
      return m_completion_append_char;
    }

    char completion_append_char (char c)
    {
      char val = m_completion_append_char;
      m_completion_append_char = c;
      return val;
    }

    void set_completion_append_char (char c) { m_completion_append_char = c; }

    octave_value gud_mode (const octave_value_list& args, int nargout);

    bool gud_mode (void) const { return m_gud_mode; }

    bool gud_mode (bool flag)
    {
      bool val = m_gud_mode;
      m_gud_mode = flag;
      return val;
    }

    void set_gud_mode (bool flag) { m_gud_mode = flag; }

    octave_value mfile_encoding (const octave_value_list& args, int nargout);

    std::string mfile_encoding (void) const { return m_mfile_encoding; }

    std::string mfile_encoding (const std::string& s)
    {
      std::string val = m_mfile_encoding;
      m_mfile_encoding = s;
      return val;
    }

    void set_mfile_encoding (const std::string& s) { m_mfile_encoding = s; }

    std::string dir_encoding (const std::string& dir);

    void set_dir_encoding (const std::string& dir, std::string& enc);

    octave_value
    auto_repeat_debug_command (const octave_value_list& args, int nargout);

    bool auto_repeat_debug_command (void) const
    {
      return m_auto_repeat_debug_command;
    }

    bool auto_repeat_debug_command (bool val)
    {
      bool old_val = m_auto_repeat_debug_command;
      m_auto_repeat_debug_command = val;
      return old_val;
    }

    bool yes_or_no (const std::string& prompt);

    std::string interactive_input (const std::string& s, bool& eof);

    octave_value_list
    get_user_input (const octave_value_list& args, int nargout);

    bool have_input_event_hooks (void) const;

    void add_input_event_hook (const hook_function& hook_fcn);

    bool remove_input_event_hook (const std::string& hook_fcn_id);

    void clear_input_event_hooks (void);

    void run_input_event_hooks (void);

  private:

    interpreter& m_interpreter;

    // Primary prompt string.
    std::string m_PS1;

    // Secondary prompt string.
    std::string m_PS2;

    // Character to append after successful command-line completion
    // attempts.
    char m_completion_append_char;

    // TRUE if we are running in the Emacs GUD mode.
    bool m_gud_mode;

    // Codepage which is used to read .m files
    std::string m_mfile_encoding;

    // map of directories -> used mfile encoding
    std::unordered_map<std::string, std::string> m_dir_encoding;

    // TRUE means repeat last debug command if the user just types RET.
    bool m_auto_repeat_debug_command;

    // If we are in debugging mode, this is the last command entered,
    // so that we can repeat the previous command if the user just
    // types RET.
    std::string m_last_debugging_command;

    hook_function_list m_input_event_hook_functions;

    bool m_initialized;

    std::string gnu_readline (const std::string& s, bool& eof) const;
  };

  class base_reader
  {
  public:

    friend class input_reader;

    base_reader (interpreter& interp)
      : m_interpreter (interp)
    { }

    base_reader (const base_reader& x)
      : m_interpreter (x.m_interpreter)
    { }

    virtual ~base_reader (void) = default;

    virtual std::string get_input (const std::string& prompt, bool& eof) = 0;

    virtual std::string input_source (void) const { return s_in_src; }

    std::string octave_gets (const std::string& prompt, bool& eof);

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

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

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

  protected:

    interpreter& m_interpreter;

  private:

    static const std::string s_in_src;
  };

  class input_reader
  {
  public:

    input_reader (interpreter& interp);

    input_reader (interpreter& interp, FILE *file);

    input_reader (interpreter& interp, FILE *file, const std::string& enc);

    input_reader (interpreter& interp, const std::string& str);

    input_reader (const input_reader& ir) = default;

    input_reader& operator = (const input_reader& ir) = default;

    ~input_reader (void) = default;

    std::string get_input (const std::string& prompt, bool& eof)
    {
      return m_rep->get_input (prompt, eof);
    }

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

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

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

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

  private:

    std::shared_ptr<base_reader> m_rep;
  };

OCTAVE_NAMESPACE_END

#endif