/* Haiku window system support
   Copyright (C) 2021 Free Software Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs 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.

GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */

#include <config.h>

#include "lisp.h"
#include "frame.h"
#include "keyboard.h"
#include "menu.h"
#include "buffer.h"
#include "blockinput.h"

#include "haikuterm.h"
#include "haiku_support.h"

static Lisp_Object *volatile menu_item_selection;

int popup_activated_p = 0;

struct submenu_stack_cell
{
  void *parent_menu;
  void *pane;
};

static void
digest_menu_items (void *first_menu, int start, int menu_items_used,
		   int mbar_p)
{
  void **menus, **panes;
  ssize_t menu_len = (menu_items_used + 1 - start) * sizeof *menus;
  ssize_t pane_len = (menu_items_used + 1 - start) * sizeof *panes;

  menus = alloca (menu_len);
  panes = alloca (pane_len);

  int i = start, menu_depth = 0;

  memset (menus, 0, menu_len);
  memset (panes, 0, pane_len);

  void *menu = first_menu;

  menus[0] = first_menu;

  void *window = NULL;
  if (FRAMEP (Vmenu_updating_frame) &&
      FRAME_LIVE_P (XFRAME (Vmenu_updating_frame)) &&
      FRAME_HAIKU_P (XFRAME (Vmenu_updating_frame)))
    window = FRAME_HAIKU_WINDOW (XFRAME (Vmenu_updating_frame));

  while (i < menu_items_used)
    {
      if (NILP (AREF (menu_items, i)))
	{
	  menus[++menu_depth] = menu;
	  i++;
	}
      else if (EQ (AREF (menu_items, i), Qlambda))
	{
	  panes[menu_depth] = NULL;
	  menu = panes[--menu_depth] ? panes[menu_depth] : menus[menu_depth];
	  i++;
	}
      else if (EQ (AREF (menu_items, i), Qquote))
	i += 1;
      else if (EQ (AREF (menu_items, i), Qt))
	{
	  Lisp_Object pane_name, prefix;
	  const char *pane_string;

	  if (menu_items_n_panes == 1)
	    {
	      i += MENU_ITEMS_PANE_LENGTH;
	      continue;
	    }

	  pane_name = AREF (menu_items, i + MENU_ITEMS_PANE_NAME);
	  prefix = AREF (menu_items, i + MENU_ITEMS_PANE_PREFIX);

	  if (STRINGP (pane_name) && STRING_MULTIBYTE (pane_name))
	    {
	      pane_name = ENCODE_UTF_8 (pane_name);
	      ASET (menu_items, i + MENU_ITEMS_PANE_NAME, pane_name);
	    }

	  pane_string = (NILP (pane_name)
			 ? "" : SSDATA (pane_name));
	  if (!NILP (prefix))
	    pane_string++;

	  if (strcmp (pane_string, ""))
	    {
	      panes[menu_depth] =
		menu = BMenu_new_submenu (menus[menu_depth], pane_string, 1);
	    }

	  i += MENU_ITEMS_PANE_LENGTH;
	}
      else
	{
	  Lisp_Object item_name, enable, descrip, def, selected;
	  item_name = AREF (menu_items, i + MENU_ITEMS_ITEM_NAME);
	  enable = AREF (menu_items, i + MENU_ITEMS_ITEM_ENABLE);
	  descrip = AREF (menu_items, i + MENU_ITEMS_ITEM_EQUIV_KEY);
	  def = AREF (menu_items, i + MENU_ITEMS_ITEM_DEFINITION);
	  selected = AREF (menu_items, i + MENU_ITEMS_ITEM_SELECTED);

	  if (STRINGP (item_name) && STRING_MULTIBYTE (item_name))
	    {
	      item_name = ENCODE_UTF_8 (item_name);
	      ASET (menu_items, i + MENU_ITEMS_ITEM_NAME, item_name);
	    }

	  if (STRINGP (descrip) && STRING_MULTIBYTE (descrip))
	    {
	      descrip = ENCODE_UTF_8 (descrip);
	      ASET (menu_items, i + MENU_ITEMS_ITEM_EQUIV_KEY, descrip);
	    }

	  if (i + MENU_ITEMS_ITEM_LENGTH < menu_items_used &&
	      NILP (AREF (menu_items, i + MENU_ITEMS_ITEM_LENGTH)))
	    menu = BMenu_new_submenu (menu, SSDATA (item_name), !NILP (enable));
	  else if (NILP (def) && menu_separator_name_p (SSDATA (item_name)))
	    BMenu_add_separator (menu);
	  else if (!mbar_p)
	    BMenu_add_item (menu, SSDATA (item_name),
			    !NILP (def) ? aref_addr (menu_items, i) : NULL,
			    !NILP (enable), !NILP (selected), 0, window,
			    !NILP (descrip) ? SSDATA (descrip) : NULL);
	  else
	    BMenu_add_item (menu, SSDATA (item_name),
			    !NILP (def) ? (void *) (intptr_t) i : NULL,
			    !NILP (enable), !NILP (selected), 1, window,
			    !NILP (descrip) ? SSDATA (descrip) : NULL);

	  i += MENU_ITEMS_ITEM_LENGTH;
	}
    }
}

static Lisp_Object
haiku_dialog_show (struct frame *f, Lisp_Object title,
		   Lisp_Object header, const char **error_name)
{
  int i, nb_buttons = 0;

  *error_name = NULL;

  if (menu_items_n_panes > 1)
    {
      *error_name = "Multiple panes in dialog box";
      return Qnil;
    }

  Lisp_Object pane_name = AREF (menu_items, MENU_ITEMS_PANE_NAME);
  i = MENU_ITEMS_PANE_LENGTH;

  if (STRING_MULTIBYTE (pane_name))
    pane_name = ENCODE_UTF_8 (pane_name);

  block_input ();
  void *alert = BAlert_new (SSDATA (pane_name), NILP (header) ? HAIKU_INFO_ALERT :
			    HAIKU_IDEA_ALERT);

  Lisp_Object vals[10];

  while (i < menu_items_used)
    {
      Lisp_Object item_name, enable, descrip, value;
      item_name = AREF (menu_items, i + MENU_ITEMS_ITEM_NAME);
      enable = AREF (menu_items, i + MENU_ITEMS_ITEM_ENABLE);
      descrip = AREF (menu_items, i + MENU_ITEMS_ITEM_EQUIV_KEY);
      value = AREF (menu_items, i + MENU_ITEMS_ITEM_VALUE);

      if (NILP (item_name))
	{
	  BAlert_delete (alert);
	  *error_name = "Submenu in dialog items";
	  unblock_input ();
	  return Qnil;
	}

      if (EQ (item_name, Qquote))
	{
	  i++;
	}

      if (nb_buttons >= 9)
	{
	  BAlert_delete (alert);
	  *error_name = "Too many dialog items";
	  unblock_input ();
	  return Qnil;
	}

      if (STRING_MULTIBYTE (item_name))
	item_name = ENCODE_UTF_8 (item_name);
      if (!NILP (descrip) && STRING_MULTIBYTE (descrip))
	descrip = ENCODE_UTF_8 (descrip);

      void *button = BAlert_add_button (alert, SSDATA (item_name));

      BButton_set_enabled (button, !NILP (enable));
      if (!NILP (descrip))
	BView_set_tooltip (button, SSDATA (descrip));

      vals[nb_buttons] = value;
      ++nb_buttons;
      i += MENU_ITEMS_ITEM_LENGTH;
    }

  int32_t val = BAlert_go (alert);
  unblock_input ();

  if (val < 0)
    quit ();
  else
    return vals[val];

  return Qnil;
}

Lisp_Object
haiku_popup_dialog (struct frame *f, Lisp_Object header, Lisp_Object contents)
{
  Lisp_Object title;
  const char *error_name = NULL;
  Lisp_Object selection;
  ptrdiff_t specpdl_count = SPECPDL_INDEX ();

  check_window_system (f);

  /* Decode the dialog items from what was specified.  */
  title = Fcar (contents);
  CHECK_STRING (title);
  record_unwind_protect_void (unuse_menu_items);

  if (NILP (Fcar (Fcdr (contents))))
    /* No buttons specified, add an "Ok" button so users can pop down
       the dialog.  Also, the lesstif/motif version crashes if there are
       no buttons.  */
    contents = list2 (title, Fcons (build_string ("Ok"), Qt));

  list_of_panes (list1 (contents));

  /* Display them in a dialog box.  */
  block_input ();
  selection = haiku_dialog_show (f, title, header, &error_name);
  unblock_input ();

  unbind_to (specpdl_count, Qnil);
  discard_menu_items ();

  if (error_name)
    error ("%s", error_name);
  return selection;
}

Lisp_Object
haiku_menu_show (struct frame *f, int x, int y, int menuflags,
		 Lisp_Object title, const char **error_name)
{
  int i = 0, submenu_depth = 0;
  void *view = FRAME_HAIKU_VIEW (f);
  void *menu;

  Lisp_Object *subprefix_stack =
    alloca (menu_items_used * sizeof (Lisp_Object));

  eassert (FRAME_HAIKU_P (f));

  *error_name = NULL;

  if (menu_items_used <= MENU_ITEMS_PANE_LENGTH)
    {
      *error_name = "Empty menu";
      return Qnil;
    }

  block_input ();
  if (STRINGP (title) && STRING_MULTIBYTE (title))
    title = ENCODE_UTF_8 (title);

  menu = BPopUpMenu_new (STRINGP (title) ? SSDATA (title) : NULL);
  digest_menu_items (menu, 0, menu_items_used, 0);
  BView_convert_to_screen (view, &x, &y);
  unblock_input ();

  menu_item_selection = BMenu_run (menu, x, y);

  FRAME_DISPLAY_INFO (f)->grabbed = 0;

  if (menu_item_selection)
    {
      Lisp_Object prefix, entry;

      prefix = entry = Qnil;
      i = 0;
      while (i < menu_items_used)
	{
	  if (NILP (AREF (menu_items, i)))
	    {
	      subprefix_stack[submenu_depth++] = prefix;
	      prefix = entry;
	      i++;
	    }
	  else if (EQ (AREF (menu_items, i), Qlambda))
	    {
	      prefix = subprefix_stack[--submenu_depth];
	      i++;
	    }
	  else if (EQ (AREF (menu_items, i), Qt))
	    {
	      prefix
		= AREF (menu_items, i + MENU_ITEMS_PANE_PREFIX);
	      i += MENU_ITEMS_PANE_LENGTH;
	    }
	  /* Ignore a nil in the item list.
	     It's meaningful only for dialog boxes.  */
	  else if (EQ (AREF (menu_items, i), Qquote))
	    i += 1;
	  else
	    {
	      entry
		= AREF (menu_items, i + MENU_ITEMS_ITEM_VALUE);
	      if (menu_item_selection == aref_addr (menu_items, i))
		{
		  if (menuflags & MENU_KEYMAPS)
		    {
		      int j;

		      entry = list1 (entry);
		      if (!NILP (prefix))
			entry = Fcons (prefix, entry);
		      for (j = submenu_depth - 1; j >= 0; j--)
			if (!NILP (subprefix_stack[j]))
			  entry = Fcons (subprefix_stack[j], entry);
		    }
		  BPopUpMenu_delete (menu);
		  return entry;
		}
	      i += MENU_ITEMS_ITEM_LENGTH;
	    }
	}
    }
  else if (!(menuflags & MENU_FOR_CLICK))
    {
      BPopUpMenu_delete (menu);
      quit ();
    }
  BPopUpMenu_delete (menu);
  return Qnil;
}

void
free_frame_menubar (struct frame *f)
{
  FRAME_MENU_BAR_LINES (f) = 0;
  FRAME_MENU_BAR_HEIGHT (f) = 0;
  FRAME_EXTERNAL_MENU_BAR (f) = 0;

  block_input ();
  void *mbar = FRAME_HAIKU_MENU_BAR (f);
  if (mbar)
    BMenuBar_delete (mbar);
  if (FRAME_OUTPUT_DATA (f)->menu_bar_open_p)
    --popup_activated_p;
  FRAME_OUTPUT_DATA (f)->menu_bar_open_p = 0;
  unblock_input ();

  adjust_frame_size (f, -1, -1, 2, false, Qmenu_bar_lines);
}

void
initialize_frame_menubar (struct frame *f)
{
  /* This function is called before the first chance to redisplay
     the frame.  It has to be, so the frame will have the right size.  */
  fset_menu_bar_items (f, menu_bar_items (FRAME_MENU_BAR_ITEMS (f)));
  set_frame_menubar (f, true);
}

void
set_frame_menubar (struct frame *f, bool deep_p)
{
  void *mbar = FRAME_HAIKU_MENU_BAR (f);
  void *view = FRAME_HAIKU_VIEW (f);

  int first_time_p = 0;

  if (!mbar)
    {
      mbar = FRAME_HAIKU_MENU_BAR (f) = BMenuBar_new (view);
      first_time_p = 1;
    }

  Lisp_Object items;
  struct buffer *prev = current_buffer;
  Lisp_Object buffer;
  ptrdiff_t specpdl_count = SPECPDL_INDEX ();
  int previous_menu_items_used = f->menu_bar_items_used;
  Lisp_Object *previous_items
    = alloca (previous_menu_items_used * sizeof *previous_items);

  XSETFRAME (Vmenu_updating_frame, f);

  if (!deep_p)
    {
      FRAME_OUTPUT_DATA (f)->menu_up_to_date_p = 0;
      items = FRAME_MENU_BAR_ITEMS (f);
      Lisp_Object string;

      block_input ();
      int count = BMenu_count_items (mbar);

      int i;
      for (i = 0; i < ASIZE (items); i += 4)
	{
	  string = AREF (items, i + 1);

	  if (!STRINGP (string))
	    break;

	  if (STRING_MULTIBYTE (string))
	    string = ENCODE_UTF_8 (string);

	  if (i / 4 < count)
	    {
	      void *it = BMenu_item_at (mbar, i / 4);
	      BMenu_item_set_label (it, SSDATA (string));
	    }
	  else
	    BMenu_new_menu_bar_submenu (mbar, SSDATA (string));
	}

      if (i / 4 < count)
	BMenu_delete_from (mbar, i / 4, count - i / 4 + 1);
      unblock_input ();

      f->menu_bar_items_used = 0;
    }
  else
    {
      /* If we are making a new widget, its contents are empty,
	 do always reinitialize them.  */
      if (first_time_p)
	previous_menu_items_used = 0;
      buffer = XWINDOW (FRAME_SELECTED_WINDOW (f))->contents;
      specbind (Qinhibit_quit, Qt);
      /* Don't let the debugger step into this code
	 because it is not reentrant.  */
      specbind (Qdebug_on_next_call, Qnil);

      record_unwind_save_match_data ();
      if (NILP (Voverriding_local_map_menu_flag))
	{
	  specbind (Qoverriding_terminal_local_map, Qnil);
	  specbind (Qoverriding_local_map, Qnil);
	}

      set_buffer_internal_1 (XBUFFER (buffer));

      /* Run the Lucid hook.  */
      safe_run_hooks (Qactivate_menubar_hook);

      /* If it has changed current-menubar from previous value,
	 really recompute the menubar from the value.  */
      if (! NILP (Vlucid_menu_bar_dirty_flag))
	call0 (Qrecompute_lucid_menubar);
      safe_run_hooks (Qmenu_bar_update_hook);
      fset_menu_bar_items (f, menu_bar_items (FRAME_MENU_BAR_ITEMS (f)));

      items = FRAME_MENU_BAR_ITEMS (f);

      /* Save the frame's previous menu bar contents data.  */
      if (previous_menu_items_used)
	memcpy (previous_items, xvector_contents (f->menu_bar_vector),
		previous_menu_items_used * word_size);

      /* Fill in menu_items with the current menu bar contents.
	 This can evaluate Lisp code.  */
      save_menu_items ();
      menu_items = f->menu_bar_vector;
      menu_items_allocated = VECTORP (menu_items) ? ASIZE (menu_items) : 0;
      init_menu_items ();
      int i;
      int count = BMenu_count_items (mbar);
      int subitems = ASIZE (items) / 4;

      int *submenu_start, *submenu_end,	*submenu_n_panes;
      Lisp_Object *submenu_names;

      submenu_start = alloca ((subitems + 1) * sizeof *submenu_start);
      submenu_end = alloca (subitems * sizeof *submenu_end);
      submenu_n_panes = alloca (subitems * sizeof *submenu_n_panes);
      submenu_names = alloca (subitems * sizeof (Lisp_Object));

      for (i = 0; i < subitems; ++i)
	{
	  Lisp_Object key, string, maps;

	  key = AREF (items, i * 4);
	  string = AREF (items, i * 4 + 1);
	  maps = AREF (items, i * 4 + 2);

	  if (NILP (string))
	    break;

	  if (STRINGP (string) && STRING_MULTIBYTE (string))
	    string = ENCODE_UTF_8 (string);

	  submenu_start[i] = menu_items_used;
	  menu_items_n_panes = 0;
	  parse_single_submenu (key, string, maps);
	  submenu_n_panes[i] = menu_items_n_panes;
	  submenu_end[i] = menu_items_used;
	  submenu_names[i] = string;
	}
      finish_menu_items ();
      submenu_start[i] = -1;

      block_input ();
      for (i = 0; submenu_start[i] >= 0; ++i)
	{
	  void *mn = NULL;
	  if (i < count)
	    mn = BMenu_item_get_menu (BMenu_item_at (mbar, i));
	  if (mn)
	    BMenu_delete_all (mn);
	  else
	    mn = BMenu_new_menu_bar_submenu (mbar, SSDATA (submenu_names[i]));

	  menu_items_n_panes = submenu_n_panes[i];
	  digest_menu_items (mn, submenu_start[i], submenu_end[i], 1);
	}
      unblock_input ();

      set_buffer_internal_1 (prev);

      FRAME_OUTPUT_DATA (f)->menu_up_to_date_p = 1;
      fset_menu_bar_vector (f, menu_items);
      f->menu_bar_items_used = menu_items_used;
    }
  unbind_to (specpdl_count, Qnil);
}

void
run_menu_bar_help_event (struct frame *f, int mb_idx)
{
  Lisp_Object frame;
  Lisp_Object vec;
  Lisp_Object help;

  if (!FRAME_OUTPUT_DATA (f)->menu_up_to_date_p)
    return;

  block_input ();
  XSETFRAME (frame, f);

  if (mb_idx < 0)
    {
      kbd_buffer_store_help_event (frame, Qnil);
      unblock_input ();
      return;
    }

  vec = f->menu_bar_vector;
  if (mb_idx >= ASIZE (vec))
    emacs_abort ();

  help = AREF (vec, mb_idx + MENU_ITEMS_ITEM_HELP);
  if (STRINGP (help) || NILP (help))
    kbd_buffer_store_help_event (frame, help);
  unblock_input ();
}

DEFUN ("menu-or-popup-active-p", Fmenu_or_popup_active_p, Smenu_or_popup_active_p,
       0, 0, 0, doc: /* SKIP: real doc in xmenu.c. */)
  (void)
{
  return popup_activated_p ? Qt : Qnil;
}

DEFUN ("haiku-menu-bar-open", Fhaiku_menu_bar_open, Shaiku_menu_bar_open, 0, 1, "i",
       doc: /* Show the menu bar in FRAME.

Move the mouse pointer onto the first element of FRAME's menu bar, and
cause it to be opened.  If FRAME is nil or not given, use the selected
frame.  If FRAME has no menu bar, a pop-up is displayed at the position
of the last non-menu event instead. */)
  (Lisp_Object frame)
{
  struct frame *f = decode_window_system_frame (frame);

  if (FRAME_EXTERNAL_MENU_BAR (f))
    {
      if (!FRAME_OUTPUT_DATA (f)->menu_up_to_date_p)
	set_frame_menubar (f, 1);
    }
  else
    {
      return call2 (Qpopup_menu, call0 (Qmouse_menu_bar_map),
		    last_nonmenu_event);
    }

  block_input ();
  BMenuBar_start_tracking (FRAME_HAIKU_MENU_BAR (f));
  unblock_input ();

  return Qnil;
}

void
syms_of_haikumenu (void)
{
  DEFSYM (Qdebug_on_next_call, "debug-on-next-call");
  DEFSYM (Qpopup_menu, "popup-menu");
  DEFSYM (Qmouse_menu_bar_map, "mouse-menu-bar-map");

  defsubr (&Smenu_or_popup_active_p);
  defsubr (&Shaiku_menu_bar_open);
  return;
}