/* Copyright (C) 1994, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
   2007, 2009 Free Software Foundation, Inc.

   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 2 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, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

/** \file menu.c
 *  \brief Source: pulldown menu code
 */

#include <config.h>

#include <ctype.h>
#include <stdarg.h>
#include <string.h>
#include <sys/types.h>

#include "global.h"

#include "../src/tty/tty.h"
#include "../src/skin/skin.h"
#include "../src/tty/mouse.h"
#include "../src/tty/key.h"	/* key macros */

#include "menu.h"
#include "help.h"
#include "dialog.h"
#include "widget.h"
#include "main.h"		/* is_right */
#include "strutil.h"

int menubar_visible = 1;	/* This is the new default */

menu_entry_t *
menu_entry_create (const char *name, menu_exec_fn cmd)
{
    menu_entry_t *entry;

    entry = g_new (menu_entry_t, 1);
    entry->first_letter = ' ';
    entry->text = parse_hotkey (name);
    entry->callback = cmd;

    return entry;
}

void
menu_entry_free (menu_entry_t *entry)
{
    if (entry != NULL) {
	release_hotkey (entry->text);
	g_free (entry);
    }
}

static void
menu_arrange (Menu* menu)
{
    if (menu != NULL) {
	unsigned int i;

	for (i = 0; i < menu->entries->len; i++) {
	    menu_entry_t *entry;
	    size_t len;

	    entry = g_ptr_array_index (menu->entries, i);

	    if (entry != NULL) {
		len = (size_t) hotkey_width (entry->text);
		menu->max_entry_len = max (menu->max_entry_len, len);
	    }
	}
    }
}

Menu *
create_menu (const char *name, GPtrArray *entries, const char *help_node)
{
    Menu *menu;

    menu = g_new (Menu, 1);
    menu->start_x = 0;
    menu->text = parse_hotkey (name);
    menu->entries = entries;
    menu->max_entry_len = 1;
    menu->selected = 0;
    menu->help_node = g_strdup (help_node);
    menu_arrange (menu);

    return menu;
}

void
destroy_menu (Menu *menu)
{
    release_hotkey (menu->text);
    g_ptr_array_foreach (menu->entries, (GFunc) menu_entry_free, NULL);
    g_ptr_array_free (menu->entries, TRUE);
    g_free (menu->help_node);
    g_free (menu);
}

void
menu_add_entry (Menu *menu, const char *name, menu_exec_fn cmd)
{
    if (menu->entries == NULL)
	menu->entries = g_ptr_array_new ();
    g_ptr_array_add (menu->entries,
			menu_entry_create (name, cmd));
    menu_arrange (menu);
}

void
menu_add_separator (Menu *menu)
{
    if (menu->entries == NULL)
	menu->entries = g_ptr_array_new ();
    g_ptr_array_add (menu->entries, menu_separator_create ());
}

static void
menubar_paint_idx (WMenuBar *menubar, unsigned int idx, int color)
{
    const Menu *menu = g_ptr_array_index (menubar->menu, menubar->selected);
    const menu_entry_t *entry = g_ptr_array_index (menu->entries, idx);
    const int y = 2 + idx;
    int x = menu->start_x;

    if (x + menu->max_entry_len + 3 > menubar->widget.cols)
	x = menubar->widget.cols - menu->max_entry_len - 3;

    if (entry == NULL) {
	/* menu separator */
	tty_setcolor (MENU_ENTRY_COLOR);

	widget_move (&menubar->widget, y, x - 1);
	tty_print_alt_char (ACS_LTEE);

	tty_draw_hline (menubar->widget.y + y, menubar->widget.x + x,
			    ACS_HLINE, menu->max_entry_len + 2);

	widget_move (&menubar->widget, y, x + menu->max_entry_len + 2);
	tty_print_alt_char (ACS_RTEE);
    } else {
	/* menu text */
	tty_setcolor (color);
	widget_move (&menubar->widget, y, x);
	tty_print_char ((unsigned char) entry->first_letter);
	tty_draw_hline (-1, -1, ' ', menu->max_entry_len + 1); /* clear line */
	tty_print_string (entry->text.start);

	if (entry->text.hotkey != NULL) {
	    tty_setcolor (color == MENU_SELECTED_COLOR ?
			    MENU_HOTSEL_COLOR : MENU_HOT_COLOR);
	    tty_print_string (entry->text.hotkey);
	    tty_setcolor (color);
	}

	if (entry->text.end != NULL)
	    tty_print_string (entry->text.end);

	/* move cursor to the start of entry text */
	widget_move (&menubar->widget, y, x + 1);
    }
}

static void
menubar_draw_drop (WMenuBar *menubar)
{
    const Menu *menu = g_ptr_array_index (menubar->menu, menubar->selected);
    const unsigned int count = menu->entries->len;
    int column = menu->start_x - 1;
    unsigned int i;

    if (column + menu->max_entry_len + 4 > menubar->widget.cols)
	column = menubar->widget.cols - menu->max_entry_len - 4;

    tty_setcolor (MENU_ENTRY_COLOR);
    draw_box (menubar->widget.parent,
		 menubar->widget.y + 1, menubar->widget.x + column,
		 count + 2, menu->max_entry_len + 4);

    /* draw items except selected */
    for (i = 0; i < count; i++)
	if (i != menu->selected)
	    menubar_paint_idx (menubar, i, MENU_ENTRY_COLOR);

    /* draw selected item at last to move cursor to the nice location */
    menubar_paint_idx (menubar, menu->selected, MENU_SELECTED_COLOR);
}

static void
menubar_set_color (WMenuBar *menubar, int current, gboolean hotkey)
{
    if (!menubar->is_active)
	tty_setcolor (hotkey ? COLOR_HOT_FOCUS : SELECTED_COLOR);
    else if (current == menubar->selected)
	tty_setcolor (hotkey ? MENU_HOTSEL_COLOR : MENU_SELECTED_COLOR);
    else
	tty_setcolor (hotkey ? MENU_HOT_COLOR : MENU_ENTRY_COLOR);
}

static void
menubar_draw (WMenuBar *menubar)
{
    unsigned int i;

    /* First draw the complete menubar */
    tty_setcolor (menubar->is_active ? MENU_ENTRY_COLOR : SELECTED_COLOR);
    tty_draw_hline (menubar->widget.y, menubar->widget.x, ' ', menubar->widget.cols);

    /* Now each one of the entries */
    for (i = 0; i < menubar->menu->len; i++) {
	Menu *menu = g_ptr_array_index (menubar->menu, i);

	menubar_set_color (menubar, i, FALSE);
	widget_move (&menubar->widget, 0, menu->start_x);

	tty_print_string (menu->text.start);

	if (menu->text.hotkey != NULL) {
	    menubar_set_color (menubar, i, TRUE);
	    tty_print_string (menu->text.hotkey);
	    menubar_set_color (menubar, i, FALSE);
	}

	if (menu->text.end != NULL)
	    tty_print_string (menu->text.end);
    }

    if (menubar->is_dropped)
	menubar_draw_drop (menubar);
    else
	widget_move (&menubar->widget, 0,
			((Menu *) g_ptr_array_index (menubar->menu,
					menubar->selected))->start_x);
}

static void
menubar_remove (WMenuBar *menubar)
{
    if (menubar->is_dropped) {
	menubar->is_dropped = FALSE;
	do_refresh ();
	menubar->is_dropped = TRUE;
    }
}

static void
menubar_left (WMenuBar *menubar)
{
    menubar_remove (menubar);
    if (menubar->selected == 0)
	menubar->selected = menubar->menu->len - 1;
    else
	menubar->selected--;
    menubar_draw (menubar);
}

static void
menubar_right (WMenuBar *menubar)
{
    menubar_remove (menubar);
    menubar->selected = (menubar->selected + 1) % menubar->menu->len;
    menubar_draw (menubar);
}

static void
menubar_finish (WMenuBar *menubar)
{
    menubar->is_dropped = FALSE;
    menubar->is_active = FALSE;
    menubar->widget.lines = 1;
    widget_want_hotkey (menubar->widget, 0);

    dlg_select_by_id (menubar->widget.parent, menubar->previous_widget);
    do_refresh ();
}

static void
menubar_drop (WMenuBar *menubar, unsigned int selected)
{
    menubar->is_dropped = TRUE;
    menubar->selected = selected;
    menubar_draw (menubar);
}

static void
menubar_execute (WMenuBar *menubar, unsigned int idx)
{
    const Menu *menu = g_ptr_array_index (menubar->menu, menubar->selected);
    const menu_entry_t *entry = g_ptr_array_index (menu->entries, idx);

    if ((entry == NULL) || (entry->callback == NULL))
	return;

    is_right = (menubar->selected != 0);

    /* This used to be the other way round, i.e. first callback and 
       then menubar_finish. The new order (hack?) is needed to make 
       change_panel () work which is used in quick_view_cmd () -- Norbert
    */
    menubar_finish (menubar);
    (*entry->callback) ();
    do_refresh ();
}

static void
menubar_down (WMenuBar *menubar)
{
    Menu *menu = g_ptr_array_index (menubar->menu, menubar->selected);
    menu_entry_t *entry;

    menubar_paint_idx (menubar, menu->selected, MENU_ENTRY_COLOR);

    do {
	menu->selected = (menu->selected + 1) % menu->entries->len;
	entry = (menu_entry_t *) g_ptr_array_index (menu->entries, menu->selected);
    } while ((entry == NULL) || (entry->callback == NULL));

    menubar_paint_idx (menubar, menu->selected, MENU_SELECTED_COLOR);
}

static void
menubar_up (WMenuBar *menubar)
{
    Menu *menu = g_ptr_array_index (menubar->menu, menubar->selected);
    menu_entry_t *entry;

    menubar_paint_idx (menubar, menu->selected, MENU_ENTRY_COLOR);

    do {
	if (menu->selected == 0)
	    menu->selected = menu->entries->len - 1;
	else
	    menu->selected--;
	entry = (menu_entry_t *) g_ptr_array_index (menu->entries, menu->selected);
    } while ((entry == NULL) || (entry->callback == NULL));

    menubar_paint_idx (menubar, menu->selected, MENU_SELECTED_COLOR);
}

static int
menubar_handle_key (WMenuBar *menubar, int key)
{
    /* Lowercase */
    if (isascii (key))
	key = g_ascii_tolower (key);

    if (is_abort_char (key)) {
	menubar_finish (menubar);
	return 1;
    }

    /* menubar help or menubar navigation */
    switch (key) {
    case KEY_F(1):
	if (menubar->is_dropped)
	    interactive_display (NULL,
		    ((Menu *) g_ptr_array_index (menubar->menu,
					menubar->selected))->help_node);
	else
	    interactive_display (NULL, "[Menu Bar]");
	menubar_draw (menubar);
	return 1;

    case KEY_LEFT:
    case XCTRL('b'):
	menubar_left (menubar);
	return 1;

    case KEY_RIGHT:
    case XCTRL ('f'):
	menubar_right (menubar);
	return 1;
    }

    if (!menubar->is_dropped) {
	unsigned int i;

	/* drop menu by hotkey */
	for (i = 0; i < menubar->menu->len; i++) {
	    Menu *menu = g_ptr_array_index (menubar->menu, i);

	    if ((menu->text.hotkey != NULL)
		&& (key == g_ascii_tolower (menu->text.hotkey[0]))) {
		    menubar_drop (menubar, i);
		    return 1;
	    }
	}

	/* drop menu by Enter or Dowwn key */
	if (key == KEY_ENTER || key == XCTRL ('n')
	    || key == KEY_DOWN || key == '\n')
	    menubar_drop (menubar, menubar->selected);

	return 1;
    }

    {
	const Menu *menu = g_ptr_array_index (menubar->menu, menubar->selected);
	unsigned int i;

	/* execute menu callback by hotkey */
        for (i = 0; i < menu->entries->len; i++) {
	    const menu_entry_t *entry = g_ptr_array_index (menu->entries, i);

	    if ((entry != NULL) && (entry->callback != NULL)
		&& (entry->text.hotkey != NULL)
		&& (key == g_ascii_tolower (entry->text.hotkey[0]))) {
		menubar_execute (menubar, i);
		return 1;
	    }
        }

	/* menu execute by Enter or menu navigation */
	switch (key) {
	case KEY_ENTER:
	case '\n':
	    menubar_execute (menubar, menu->selected);
	    return 1;

	case KEY_DOWN:
	case XCTRL ('n'):
	    menubar_down (menubar);
	    break;

	case KEY_UP:
	case XCTRL ('p'):
	    menubar_up (menubar);
	    break;
	}
    }

    return 0;
}

static cb_ret_t
menubar_callback (Widget *w, widget_msg_t msg, int parm)
{
    WMenuBar *menubar = (WMenuBar *) w;

    switch (msg) {
	/* We do not want the focus unless we have been activated */
    case WIDGET_FOCUS:
	if (!menubar->is_active)
	    return MSG_NOT_HANDLED;

	widget_want_cursor (menubar->widget, 1);

	/* Trick to get all the mouse events */
	menubar->widget.lines = LINES;

	/* Trick to get all of the hotkeys */
	widget_want_hotkey (menubar->widget, 1);
	menubar_draw (menubar);
	return MSG_HANDLED;

	/* We don't want the buttonbar to activate while using the menubar */
    case WIDGET_HOTKEY:
    case WIDGET_KEY:
	if (menubar->is_active) {
	    menubar_handle_key (menubar, parm);
	    return MSG_HANDLED;
	}
	return MSG_NOT_HANDLED;

    case WIDGET_CURSOR:
	/* Put the cursor in a suitable place */
	return MSG_NOT_HANDLED;

    case WIDGET_UNFOCUS:
	if (menubar->is_active)
	    return MSG_NOT_HANDLED;
	
	widget_want_cursor (menubar->widget, 0);
	return MSG_HANDLED;

    case WIDGET_DRAW:
	if (menubar_visible) {
	    menubar_draw (menubar);
	    return MSG_HANDLED;
	}
	/* fall through */

    case WIDGET_RESIZED:
	/* try show menu after screen resize */
	send_message (w, WIDGET_FOCUS, 0);
	return MSG_HANDLED;
	

    case WIDGET_DESTROY:
	menubar_set_menu (menubar, NULL);
	return MSG_HANDLED;

    default:
	return default_proc (msg, parm);
    }
}

static int
menubar_event (Gpm_Event *event, void *data)
{
    WMenuBar *menubar = data;
    gboolean was_active = TRUE;
    int left_x, right_x, bottom_y;
    Menu *menu;

    /* ignore unsupported events */
    if ((event->type & (GPM_UP | GPM_DOWN | GPM_DRAG)) == 0)
	return MOU_NORMAL;

    /* ignore wheel events if menu is inactive */
    if (!menubar->is_active
	    && ((event->buttons & (GPM_B_MIDDLE | GPM_B_UP | GPM_B_DOWN)) != 0))
	return MOU_NORMAL;

    if (!menubar->is_dropped) {
	menubar->previous_widget = menubar->widget.parent->current->dlg_id;
	menubar->is_active = TRUE;
	menubar->is_dropped = TRUE;
	was_active = FALSE;
    }

    /* Mouse operations on the menubar */
    if (event->y == 1 || !was_active) {
	if ((event->type & GPM_UP) != 0)
	    return MOU_NORMAL;

	/* wheel events on menubar */
	if (event->buttons & GPM_B_UP)
	    menubar_left (menubar);
	else if (event->buttons & GPM_B_DOWN)
	    menubar_right (menubar);
	else {
	    int new_selection = 0;

	    while ((new_selection < menubar->menu->len)
		    && (event->x > ((Menu *) g_ptr_array_index (menubar->menu,
							new_selection))->start_x))
		new_selection++;

	    if (new_selection != 0) /* Don't set the invalid value -1 */
		new_selection--;
	
	    if (!was_active) {
		menubar->selected = new_selection;
		dlg_select_widget (menubar);
	    } else {
		menubar_remove (menubar);
		menubar->selected = new_selection;
	    }
	    menubar_draw (menubar);
	}
	return MOU_NORMAL;
    }

    if (!menubar->is_dropped || (event->y < 2))
	return MOU_NORMAL;

    /* middle click -- everywhere */
    if (((event->buttons & GPM_B_MIDDLE) != 0)
	    && ((event->type & GPM_DOWN) != 0)) {
	Menu *menu = (Menu *) g_ptr_array_index (menubar->menu, menubar->selected);
	menubar_execute (menubar, menu->selected);
	return MOU_NORMAL;
    }

    /* the mouse operation is on the menus or it is not */
    menu = (Menu *) g_ptr_array_index (menubar->menu, menubar->selected);
    left_x = menu->start_x;
    right_x = left_x + menu->max_entry_len + 3;
    if (right_x > menubar->widget.cols) {
	left_x = menubar->widget.cols - menu->max_entry_len - 3;
	right_x = menubar->widget.cols;
    }

    bottom_y = menu->entries->len + 3;

    if ((event->x >= left_x) && (event->x <= right_x) && (event->y <= bottom_y)){
	int pos = event->y - 3;
	const menu_entry_t *entry = g_ptr_array_index (menu->entries, pos);

	/* mouse wheel */
	if ((event->buttons & GPM_B_UP) && (event->type & GPM_DOWN)) {
	    menubar_up (menubar);
	    return MOU_NORMAL;
	}
	if ((event->buttons & GPM_B_DOWN) && (event->type & GPM_DOWN)) {
	    menubar_down (menubar);
	    return MOU_NORMAL;
	}

	/* ignore events above and below dropped down menu */
	if  ((pos < 0) || (pos >= menu->entries->len))
	    return MOU_NORMAL;

	if ((entry != NULL) && (entry->callback != NULL)) {
	    menubar_paint_idx (menubar, menu->selected, MENU_ENTRY_COLOR);
	    menu->selected = pos;
	    menubar_paint_idx (menubar, menu->selected, MENU_SELECTED_COLOR);

	    if ((event->type & GPM_UP) != 0)
		menubar_execute (menubar, pos);
	}
    } else
	/* use click not wheel to close menu */
	if (((event->type & GPM_DOWN) != 0)
		 && ((event->buttons & (GPM_B_UP | GPM_B_DOWN)) == 0))
	    menubar_finish (menubar);

    return MOU_NORMAL;
}

WMenuBar *
menubar_new (int y, int x, int cols, GPtrArray *menu)
{
    WMenuBar *menubar = g_new0 (WMenuBar, 1);

    init_widget (&menubar->widget, y, x, 1, cols,
		 menubar_callback, menubar_event);
    widget_want_cursor (menubar->widget, 0);
    menubar_set_menu (menubar, menu);
    return menubar;
}

void
menubar_set_menu (WMenuBar *menubar, GPtrArray *menu)
{
    /* delete previous menu */
    if (menubar->menu != NULL) {
	g_ptr_array_foreach (menubar->menu, (GFunc) destroy_menu, NULL);
	g_ptr_array_free (menubar->menu, TRUE);
    }
    /* add new menu */
    menubar->is_active = FALSE;
    menubar->is_dropped = FALSE;
    menubar->menu = menu;
    menubar->selected = 0;
    menubar_arrange (menubar);
}

void
menubar_add_menu (WMenuBar *menubar, Menu *menu)
{
    if (menubar->menu == NULL)
	menubar->menu = g_ptr_array_new ();

    if (menu != NULL)
	g_ptr_array_add (menubar->menu, menu);

    menubar_arrange (menubar);
}

/*
 * Properly space menubar items. Should be called when menubar is created
 * and also when widget width is changed (i.e. upon xterm resize).
 */
void
menubar_arrange (WMenuBar* menubar)
{
    int start_x = 1;
    unsigned int i;
    int gap;

    if ((menubar->menu == NULL) || (menubar->menu->len == 0))
	return;

#ifndef RESIZABLE_MENUBAR
    gap = 3;

    for (i = 0; i < menubar->menu->len; i++) {
	Menu *menu = g_ptr_array_index (menubar->menu, i);
	int len = hotkey_width (menu->text);

	menu->start_x = start_x;
	start_x += len + gap;
    }
#else /* RESIZABLE_MENUBAR */
    gap = menubar->widget.cols - 2;

    /* First, calculate gap between items... */
    for (i = 0; i < menubar->menu->len; i++) {
	Menu *menu = g_ptr_array_index (menubar->menu, i);
	/* preserve length here, to be used below */
	menu->start_x = hotkey_width (menu->text);
	gap -= menu->start_x;
    }

    gap /= (menubar->menu->len - 1);

    if (gap <= 0) {
	/* We are out of luck - window is too narrow... */
	gap = 1;
    }

    /* ...and now fix start positions of menubar items */
    for (i = 0; i < menubar->menu->len; i++) {
	Menu *menu = g_ptr_array_index (menubar->menu, i);
	int len = menu->start_x;

	menu->start_x = start_x;
	start_x += len + gap;
    }
#endif /* RESIZABLE_MENUBAR */
}