////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 1996-2022 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 (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <cstring>

#include <fstream>
#include <sstream>
#include <string>

#include "cmd-edit.h"
#include "cmd-hist.h"
#include "file-ops.h"
#include "lo-error.h"
#include "lo-sysdep.h"
#include "singleton-cleanup.h"
#include "str-vec.h"

#if defined (USE_READLINE)
#include <cstdlib>

#include "oct-rl-hist.h"

#include "file-ops.h"
#include "file-stat.h"
#endif

OCTAVE_BEGIN_NAMESPACE(octave)

command_history *command_history::s_instance = nullptr;

#if defined (USE_READLINE)

class
gnu_history : public command_history
{
public:

  gnu_history (void)
    : command_history (), mark (0) { }

  ~gnu_history (void) = default;

  void do_process_histcontrol (const std::string&);

  std::string do_histcontrol (void) const;

  bool do_add (const std::string&);

  void do_remove (int);

  void do_clear (void);

  int do_where (void) const;

  int do_length (void) const;

  int do_max_input_history (void) const;

  int do_base (void) const;

  int do_current_number (void) const;

  void do_stifle (int);

  int do_unstifle (void);

  int do_is_stifled (void) const;

  void do_set_mark (int);

  int do_goto_mark (void);

  void do_read (const std::string&, bool);

  void do_read_range (const std::string&, int, int, bool);

  void do_write (const std::string&) const;

  void do_append (const std::string&);

  void do_truncate_file (const std::string&, int) const;

  string_vector do_list (int, bool) const;

  std::string do_get_entry (int) const;

  void do_replace_entry (int, const std::string&);

  void do_clean_up_and_save (const std::string&, int);

private:

  int mark;
};

void
gnu_history::do_process_histcontrol (const std::string& control_arg)
{
  m_history_control = 0;

  std::size_t len = control_arg.length ();
  std::size_t beg = 0;

  while (beg < len)
    {
      if (control_arg[beg] == ':')
        beg++;
      else
        {
          std::size_t end = control_arg.find (':', beg);

          if (end == std::string::npos)
            end = len;

          std::string tmp = control_arg.substr (beg, end-beg);

          if (tmp == "erasedups")
            m_history_control |= HC_ERASEDUPS;
          else if (tmp == "ignoreboth")
            m_history_control |= (HC_IGNDUPS | HC_IGNSPACE);
          else if (tmp == "ignoredups")
            m_history_control |= HC_IGNDUPS;
          else if (tmp == "ignorespace")
            m_history_control |= HC_IGNSPACE;
          else
            (*current_liboctave_warning_with_id_handler)
              ("Octave:history-control",
               "unknown histcontrol directive %s", tmp.c_str ());

          if (end != std::string::npos)
            beg = end + 1;
        }
    }
}

std::string
gnu_history::do_histcontrol (void) const
{
  // FIXME: instead of reconstructing this value, should we just save
  // the string we were given when constructing the command_history object?

  std::string retval;

  if (m_history_control & HC_IGNSPACE)
    retval.append ("ignorespace");

  if (m_history_control & HC_IGNDUPS)
    {
      if (retval.length () > 0)
        retval += ':';

      retval.append ("ignoredups");
    }

  if (m_history_control & HC_ERASEDUPS)
    {
      if (retval.length () > 0)
        retval += ':';

      retval.append ("erasedups");
    }

  return retval;
}

bool
gnu_history::do_add (const std::string& s)
{
  if (! do_ignoring_entries ())
    {
      if (s.empty ()
          || (s.length () == 1 && (s[0] == '\r' || s[0] == '\n')))
        return false;

      // Strip newline before adding to list
      std::string stmp = s;
      if (stmp.back () == '\n')
        stmp.pop_back ();

      int added = ::octave_add_history (stmp.c_str (), m_history_control);
      m_lines_this_session += added;
      return added > 0 ? true : false;
    }
  return false;
}

void
gnu_history::do_remove (int n)
{
  ::octave_remove_history (n);
}

void
gnu_history::do_clear (void)
{
  ::octave_clear_history ();
}

int
gnu_history::do_where (void) const
{
  return ::octave_where_history ();
}

int
gnu_history::do_length (void) const
{
  return ::octave_history_length ();
}

int
gnu_history::do_max_input_history (void) const
{
  return ::octave_max_input_history ();
}

int
gnu_history::do_base (void) const
{
  return ::octave_history_base ();
}

int
gnu_history::do_current_number (void) const
{
  return m_size > 0 ? do_base () + do_where () : -1;
}

void
gnu_history::do_stifle (int n)
{
  ::octave_stifle_history (n);
}

int
gnu_history::do_unstifle (void)
{
  return ::octave_unstifle_history ();
}

int
gnu_history::do_is_stifled (void) const
{
  return ::octave_history_is_stifled ();
}

void
gnu_history::do_set_mark (int n)
{
  mark = n;
}

int
gnu_history::do_goto_mark (void)
{
  if (mark)
    {
      char *line = ::octave_history_goto_mark (mark);

      if (line)
        {
          command_editor::insert_text (line);

          command_editor::clear_undo_list ();
        }
    }

  mark = 0;

  // FIXME: for operate_and_get_next.
  command_editor::remove_startup_hook (command_history::goto_mark);

  return 0;
}

void
gnu_history::do_read (const std::string& f, bool must_exist)
{
  if (! f.empty ())
    {
      int status = ::octave_read_history (f.c_str ());

      if (status != 0 && must_exist)
        {
          std::string msg = "reading file '" + f + "'";

          error (status, msg);
        }
      else
        {
          m_lines_in_file = do_where ();

          ::octave_using_history ();
        }
    }
  else
    error ("gnu_history::read: missing filename");
}

void
gnu_history::do_read_range (const std::string& f, int from, int to,
                            bool must_exist)
{
  if (from < 0)
    from = m_lines_in_file;

  if (! f.empty ())
    {
      int status = ::octave_read_history_range (f.c_str (), from, to);

      if (status != 0 && must_exist)
        {
          std::ostringstream buf;
          buf << "reading lines " << from << " to " << to
              << " from file '" << f << "'";

          error (status, buf.str ());
        }
      else
        {
          m_lines_in_file = do_where ();

          ::octave_using_history ();
        }
    }
  else
    error ("gnu_history::read_range: missing filename");
}

void
gnu_history::do_write (const std::string& f_arg) const
{
  if (m_initialized)
    {
      std::string f = f_arg;

      if (f.empty ())
        f = m_file;

      if (! f.empty ())
        {
          // Try to create the folder if it does not exist
          std::string hist_dir = sys::file_ops::dirname (f);
          if (! hist_dir.empty ())
            {
              sys::file_stat fs (hist_dir);
              if (! fs.is_dir ()
                  && (sys::recursive_mkdir (hist_dir, 0777) < 0))
                (*current_liboctave_error_handler)
                  ("%s: Could not create directory \"%s\" for history",
                   "gnu_history::do_write", hist_dir.c_str ());
            }

          int status = ::octave_write_history (f.c_str ());

          if (status != 0)
            {
              std::string msg = "writing file '" + f + "'";

              error (status, msg);
            }
        }
      else
        error ("gnu_history::write: missing filename");
    }
}

void
gnu_history::do_append (const std::string& f_arg)
{
  if (m_initialized)
    {
      if (m_lines_this_session)
        {
          if (m_lines_this_session < do_where ())
            {
              // Create file if it doesn't already exist.

              std::string f = f_arg;

              if (f.empty ())
                f = m_file;

              if (! f.empty ())
                {
                  sys::file_stat fs (f);

                  if (! fs)
                    {
                      std::ofstream tmp = sys::ofstream (f, std::ios::out);
                      tmp.close ();
                    }

                  int status
                    = ::octave_append_history (m_lines_this_session, f.c_str ());

                  if (status != 0)
                    {
                      std::string msg = "appending to file '" + f_arg + "'";

                      error (status, msg);
                    }
                  else
                    m_lines_in_file += m_lines_this_session;

                  m_lines_this_session = 0;
                }
              else
                error ("gnu_history::append: missing filename");
            }
        }
    }
}

void
gnu_history::do_truncate_file (const std::string& f_arg, int n) const
{
  if (m_initialized)
    {
      std::string f = f_arg;

      if (f.empty ())
        f = m_file;

      if (! f.empty ())
        ::octave_history_truncate_file (f.c_str (), n);
      else
        error ("gnu_history::truncate_file: missing filename");
    }
}

string_vector
gnu_history::do_list (int limit, bool number_lines) const
{
  string_vector retval;

  if (limit)
    retval = ::octave_history_list (limit, number_lines);

  return retval;
}

std::string
gnu_history::do_get_entry (int n) const
{
  std::string retval;

  char *line = ::octave_history_get (do_base () + n);

  if (line)
    retval = line;

  return retval;
}

void
gnu_history::do_replace_entry (int which, const std::string& line)
{
  ::octave_replace_history_entry (which, line.c_str ());
}

void
gnu_history::do_clean_up_and_save (const std::string& f_arg, int n)
{
  if (m_initialized)
    {
      std::string f = f_arg;

      if (f.empty ())
        f = m_file;

      if (! f.empty ())
        {
          if (n < 0)
            n = m_size;

          stifle (n);

          do_write (f.c_str ());
        }
      else
        error ("gnu_history::clean_up_and_save: missing filename");
    }
}

#endif

bool
command_history::instance_ok (void)
{
  bool retval = true;

  if (! s_instance)
    {
      make_command_history ();

      if (s_instance)
        singleton_cleanup_list::add (cleanup_instance);
    }

  if (! s_instance)
    (*current_liboctave_error_handler)
      ("unable to create command history object!");

  return retval;
}

void
command_history::make_command_history (void)
{
#if defined (USE_READLINE)
  s_instance = new gnu_history ();
#else
  s_instance = new command_history ();
#endif
}

void
command_history::initialize (bool read_history_file,
                             const std::string& f_arg, int sz,
                             const std::string& control_arg)
{
  if (instance_ok ())
    s_instance->do_initialize (read_history_file, f_arg, sz, control_arg);
}

bool
command_history::is_initialized (void)
{
  // We just want to check the status of an existing instance, not
  // create one.
  return s_instance && s_instance->do_is_initialized ();
}

void
command_history::set_file (const std::string& f_arg)
{
  if (instance_ok ())
    {
      std::string f = sys::file_ops::tilde_expand (f_arg);

      s_instance->do_set_file (f);
    }
}

std::string
command_history::file (void)
{
  return instance_ok () ? s_instance->do_file () : "";
}

void
command_history::process_histcontrol (const std::string& control_arg)
{
  if (instance_ok ())
    s_instance->do_process_histcontrol (control_arg);
}

std::string
command_history::histcontrol (void)
{
  return instance_ok () ? s_instance->do_histcontrol () : "";
}

void
command_history::set_size (int n)
{
  if (instance_ok ())
    s_instance->do_set_size (n);
}

int
command_history::size (void)
{
  return instance_ok () ? s_instance->do_size () : 0;
}

void
command_history::ignore_entries (bool flag)
{
  if (instance_ok ())
    s_instance->do_ignore_entries (flag);
}

bool
command_history::ignoring_entries (void)
{
  return instance_ok () ? s_instance->do_ignoring_entries () : false;
}

bool
command_history::add (const std::string& s)
{
  if (instance_ok ())
    return s_instance->do_add (s);
  return false;
}

void
command_history::remove (int n)
{
  if (instance_ok ())
    s_instance->do_remove (n);
}

void
command_history::clear (void)
{
  if (instance_ok ())
    s_instance->do_clear ();
}

int
command_history::where (void)
{
  return instance_ok () ? s_instance->do_where () : 0;
}

int
command_history::length (void)
{
  return instance_ok () ? s_instance->do_length () : 0;
}

int
command_history::max_input_history (void)
{
  return instance_ok () ? s_instance->do_max_input_history () : 0;
}

int
command_history::base (void)
{
  return instance_ok () ? s_instance->do_base () : 0;
}

int
command_history::current_number (void)
{
  return instance_ok () ? s_instance->do_current_number () : 0;
}

void
command_history::stifle (int n)
{
  if (instance_ok ())
    s_instance->do_stifle (n);
}

int
command_history::unstifle (void)
{
  return instance_ok () ? s_instance->do_unstifle () : 0;
}

int
command_history::is_stifled (void)
{
  return instance_ok () ? s_instance->do_is_stifled () : 0;
}

void
command_history::set_mark (int n)
{
  if (instance_ok ())
    s_instance->do_set_mark (n);
}

int
command_history::goto_mark (void)
{
  return instance_ok () ? s_instance->do_goto_mark () : 0;
}

void
command_history::read (bool must_exist)
{
  read (file (), must_exist);
}

void
command_history::read (const std::string& f, bool must_exist)
{
  if (instance_ok ())
    s_instance->do_read (f, must_exist);
}

void
command_history::read_range (int from, int to, bool must_exist)
{
  read_range (file (), from, to, must_exist);
}

void
command_history::read_range (const std::string& f, int from, int to,
                             bool must_exist)
{
  if (instance_ok ())
    s_instance->do_read_range (f, from, to, must_exist);
}

void
command_history::write (const std::string& f)
{
  if (instance_ok ())
    s_instance->do_write (f);
}

void
command_history::append (const std::string& f)
{
  if (instance_ok ())
    s_instance->do_append (f);
}

void
command_history::truncate_file (const std::string& f, int n)
{
  if (instance_ok ())
    s_instance->do_truncate_file (f, n);
}

string_vector
command_history::list (int limit, bool number_lines)
{
  return (instance_ok ()
          ? s_instance->do_list (limit, number_lines) : string_vector ());
}

std::string
command_history::get_entry (int n)
{
  return instance_ok () ? s_instance->do_get_entry (n) : "";
}

void
command_history::replace_entry (int which, const std::string& line)
{
  if (instance_ok ())
    s_instance->do_replace_entry (which, line);
}

void
command_history::clean_up_and_save (const std::string& f, int n)
{
  if (instance_ok ())
    s_instance->do_clean_up_and_save (f, n);
}

void
command_history::do_process_histcontrol (const std::string&)
{ }

void
command_history::do_initialize (bool read_history_file,
                                const std::string& f_arg, int sz,
                                const std::string& control_arg)
{
  command_history::set_file (f_arg);
  command_history::set_size (sz);
  command_history::process_histcontrol (control_arg);

  if (read_history_file)
    command_history::read (false);

  m_initialized = true;
}

bool
command_history::do_is_initialized (void) const
{
  return m_initialized;
}

void
command_history::do_set_file (const std::string& f)
{
  m_file = f;
}

std::string
command_history::do_file (void)
{
  return m_file;
}

void
command_history::do_set_size (int n)
{
  m_size = n;
}

int
command_history::do_size (void) const
{
  return m_size;
}

void
command_history::do_ignore_entries (bool flag)
{
  m_ignoring_additions = flag;
}

bool
command_history::do_ignoring_entries (void) const
{
  return m_ignoring_additions;
}

bool
command_history::do_add (const std::string&)
{
  return false;
}

void
command_history::do_remove (int)
{ }

void
command_history::do_clear (void)
{ }

int
command_history::do_where (void) const
{
  return 0;
}

int
command_history::do_length (void) const
{
  return 0;
}

int
command_history::do_max_input_history (void) const
{
  return 0;
}

int
command_history::do_base (void) const
{
  return 0;
}

int
command_history::do_current_number (void) const
{
  return m_size > 0 ? do_base () + do_where () : -1;
}

void
command_history::do_stifle (int)
{ }

int
command_history::do_unstifle (void)
{
  return -1;
}

int
command_history::do_is_stifled (void) const
{
  return 0;
}

void
command_history::do_set_mark (int)
{ }

int
command_history::do_goto_mark (void)
{
  return 0;
}

void
command_history::do_read (const std::string& f, bool)
{
  if (f.empty ())
    error ("command_history::read: missing filename");
}

void
command_history::do_read_range (const std::string& f, int, int, bool)
{
  if (f.empty ())
    error ("command_history::read_range: missing filename");
}

void
command_history::do_write (const std::string& f_arg) const
{
  if (m_initialized)
    {
      std::string f = f_arg;

      if (f.empty ())
        f = m_file;

      if (f.empty ())
        error ("command_history::write: missing filename");
    }
}

void
command_history::do_append (const std::string& f_arg)
{
  if (m_initialized)
    {
      if (m_lines_this_session)
        {
          if (m_lines_this_session < do_where ())
            {
              // Create file if it doesn't already exist.

              std::string f = f_arg;

              if (f.empty ())
                f = m_file;

              if (f.empty ())
                error ("command_history::append: missing filename");
            }
        }
    }
}

void
command_history::do_truncate_file (const std::string& f_arg, int) const
{
  if (m_initialized)
    {
      std::string f = f_arg;

      if (f.empty ())
        f = m_file;

      if (f.empty ())
        error ("command_history::truncate_file: missing filename");
    }
}

string_vector
command_history::do_list (int, bool) const
{
  return string_vector ();
}

std::string
command_history::do_get_entry (int) const
{
  return "";
}

void
command_history::do_replace_entry (int, const std::string&)
{ }

void
command_history::do_clean_up_and_save (const std::string& f_arg, int)
{
  if (m_initialized)
    {
      std::string f = f_arg;

      if (f.empty ())
        f = m_file;

      if (f.empty ())
        error ("command_history::clean_up_and_save: missing filename");
    }
}

void
command_history::error (int err_num, const std::string& msg) const
{
  if (msg.empty ())
    (*current_liboctave_error_handler) ("%s", std::strerror (err_num));
  else
    (*current_liboctave_error_handler) ("%s: %s", msg.c_str (),
                                        std::strerror (err_num));
}

void
command_history::error (const std::string& s) const
{
  (*current_liboctave_error_handler) ("%s", s.c_str ());
}

OCTAVE_END_NAMESPACE(octave)