/* TUI Interpreter definitions for GDB, the GNU debugger.

   Copyright (C) 2003-2022 Free Software Foundation, Inc.

   This file is part of GDB.

   This program 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.

   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "cli/cli-interp.h"
#include "interps.h"
#include "top.h"
#include "event-top.h"
#include "gdbsupport/event-loop.h"
#include "ui-out.h"
#include "cli-out.h"
#include "tui/tui-data.h"
#include "tui/tui-win.h"
#include "tui/tui.h"
#include "tui/tui-io.h"
#include "infrun.h"
#include "observable.h"
#include "gdbthread.h"
#include "inferior.h"
#include "main.h"

/* Set to true when the TUI mode must be activated when we first start
   gdb.  */
static bool tui_start_enabled = false;

class tui_interp final : public cli_interp_base
{
public:
  explicit tui_interp (const char *name)
    : cli_interp_base (name)
  {}

  void init (bool top_level) override;
  void resume () override;
  void suspend () override;
  gdb_exception exec (const char *command_str) override;
  ui_out *interp_ui_out () override;
};

/* Returns the INTERP if the INTERP is a TUI, and returns NULL
   otherwise.  */

static tui_interp *
as_tui_interp (struct interp *interp)
{
  return dynamic_cast<tui_interp *> (interp);
}

/* Cleanup the tui before exiting.  */

static void
tui_exit (void)
{
  /* Disable the tui.  Curses mode is left leaving the screen in a
     clean state (see endwin()).  */
  tui_disable ();
}

/* Observers for several run control events.  If the interpreter is
   quiet (i.e., another interpreter is being run with
   interpreter-exec), print nothing.  */

/* Observer for the normal_stop notification.  */

static void
tui_on_normal_stop (struct bpstat *bs, int print_frame)
{
  if (!print_frame)
    return;

  /* This event is suppressed.  */
  if (cli_suppress_notification.normal_stop)
    return;

  SWITCH_THRU_ALL_UIS ()
    {
      struct interp *interp = top_level_interpreter ();
      struct interp *tui = as_tui_interp (interp);
      struct thread_info *thread;

      if (tui == NULL)
	continue;

      thread = inferior_thread ();
      if (should_print_stop_to_console (interp, thread))
	print_stop_event (tui->interp_ui_out ());
    }
}

/* Observer for the signal_received notification.  */

static void
tui_on_signal_received (enum gdb_signal siggnal)
{
  SWITCH_THRU_ALL_UIS ()
    {
      struct interp *tui = as_tui_interp (top_level_interpreter ());

      if (tui == NULL)
	continue;

      print_signal_received_reason (tui->interp_ui_out (), siggnal);
    }
}

/* Observer for the end_stepping_range notification.  */

static void
tui_on_end_stepping_range (void)
{
  SWITCH_THRU_ALL_UIS ()
    {
      struct interp *tui = as_tui_interp (top_level_interpreter ());

      if (tui == NULL)
	continue;

      print_end_stepping_range_reason (tui->interp_ui_out ());
    }
}

/* Observer for the signal_exited notification.  */

static void
tui_on_signal_exited (enum gdb_signal siggnal)
{
  SWITCH_THRU_ALL_UIS ()
    {
      struct interp *tui = as_tui_interp (top_level_interpreter ());

      if (tui == NULL)
	continue;

      print_signal_exited_reason (tui->interp_ui_out (), siggnal);
    }
}

/* Observer for the exited notification.  */

static void
tui_on_exited (int exitstatus)
{
  SWITCH_THRU_ALL_UIS ()
    {
      struct interp *tui = as_tui_interp (top_level_interpreter ());

      if (tui == NULL)
	continue;

      print_exited_reason (tui->interp_ui_out (), exitstatus);
    }
}

/* Observer for the no_history notification.  */

static void
tui_on_no_history (void)
{
  SWITCH_THRU_ALL_UIS ()
    {
      struct interp *tui = as_tui_interp (top_level_interpreter ());

      if (tui == NULL)
	continue;

      print_no_history_reason (tui->interp_ui_out ());
    }
}

/* Observer for the sync_execution_done notification.  */

static void
tui_on_sync_execution_done (void)
{
  struct interp *tui = as_tui_interp (top_level_interpreter ());

  if (tui == NULL)
    return;

  display_gdb_prompt (NULL);
}

/* Observer for the command_error notification.  */

static void
tui_on_command_error (void)
{
  struct interp *tui = as_tui_interp (top_level_interpreter ());

  if (tui == NULL)
    return;

  display_gdb_prompt (NULL);
}

/* Observer for the user_selected_context_changed notification.  */

static void
tui_on_user_selected_context_changed (user_selected_what selection)
{
  /* This event is suppressed.  */
  if (cli_suppress_notification.user_selected_context)
    return;

  thread_info *tp = inferior_ptid != null_ptid ? inferior_thread () : NULL;

  SWITCH_THRU_ALL_UIS ()
    {
      struct interp *tui = as_tui_interp (top_level_interpreter ());

      if (tui == NULL)
	continue;

      if (selection & USER_SELECTED_INFERIOR)
	print_selected_inferior (tui->interp_ui_out ());

      if (tp != NULL
	  && ((selection & (USER_SELECTED_THREAD | USER_SELECTED_FRAME))))
	print_selected_thread_frame (tui->interp_ui_out (), selection);

    }
}

/* These implement the TUI interpreter.  */

void
tui_interp::init (bool top_level)
{
  /* Install exit handler to leave the screen in a good shape.  */
  atexit (tui_exit);

  tui_initialize_io ();
  if (gdb_stdout->isatty ())
    {
      tui_ensure_readline_initialized ();

      /* This installs the SIGWINCH signal handler.  The handler needs to do
	 readline calls (to rl_resize_terminal), so it must not be installed
	 unless readline is properly initialized.  */
      tui_initialize_win ();
    }
}

/* Used as the command handler for the tui.  */

static void
tui_command_line_handler (gdb::unique_xmalloc_ptr<char> &&rl)
{
  /* When a tui enabled GDB is running in either tui mode or cli mode then
     it is always the tui interpreter that is in use.  As a result we end
     up in here even in standard cli mode.

     We only need to do any special actions when the tui is in use
     though.  When the tui is active the users return is not echoed to the
     screen as a result the display will not automatically move us to the
     next line.  Here we manually insert a newline character and move the
     cursor.  */
  if (tui_active)
    tui_inject_newline_into_command_window ();

  /* Now perform GDB's standard CLI command line handling.  */
  command_line_handler (std::move (rl));
}

void
tui_interp::resume ()
{
  struct ui *ui = current_ui;
  struct ui_file *stream;

  /* gdb_setup_readline will change gdb_stdout.  If the TUI was
     previously writing to gdb_stdout, then set it to the new
     gdb_stdout afterwards.  */

  stream = tui_old_uiout->set_stream (gdb_stdout);
  if (stream != gdb_stdout)
    {
      tui_old_uiout->set_stream (stream);
      stream = NULL;
    }

  gdb_setup_readline (1);

  ui->input_handler = tui_command_line_handler;

  if (stream != NULL)
    tui_old_uiout->set_stream (gdb_stdout);

  if (tui_start_enabled)
    tui_enable ();
}

void
tui_interp::suspend ()
{
  tui_start_enabled = tui_active;
  tui_disable ();
}

ui_out *
tui_interp::interp_ui_out ()
{
  if (tui_active)
    return tui_out;
  else
    return tui_old_uiout;
}

gdb_exception
tui_interp::exec (const char *command_str)
{
  internal_error (__FILE__, __LINE__, _("tui_exec called"));
}


/* Factory for TUI interpreters.  */

static struct interp *
tui_interp_factory (const char *name)
{
  return new tui_interp (name);
}

void _initialize_tui_interp ();
void
_initialize_tui_interp ()
{
  interp_factory_register (INTERP_TUI, tui_interp_factory);

  if (interpreter_p && strcmp (interpreter_p, INTERP_TUI) == 0)
    tui_start_enabled = true;

  if (interpreter_p && strcmp (interpreter_p, INTERP_CONSOLE) == 0)
    {
      xfree (interpreter_p);
      interpreter_p = xstrdup (INTERP_TUI);
    }

  /* If changing this, remember to update cli-interp.c as well.  */
  gdb::observers::normal_stop.attach (tui_on_normal_stop, "tui-interp");
  gdb::observers::signal_received.attach (tui_on_signal_received, "tui-interp");
  gdb::observers::end_stepping_range.attach (tui_on_end_stepping_range,
					     "tui-interp");
  gdb::observers::signal_exited.attach (tui_on_signal_exited, "tui-interp");
  gdb::observers::exited.attach (tui_on_exited, "tui-interp");
  gdb::observers::no_history.attach (tui_on_no_history, "tui-interp");
  gdb::observers::sync_execution_done.attach (tui_on_sync_execution_done,
					      "tui-interp");
  gdb::observers::command_error.attach (tui_on_command_error, "tui-interp");
  gdb::observers::user_selected_context_changed.attach
    (tui_on_user_selected_context_changed, "tui-interp");
}