/*  menubox.c -- implements the menu box
 *
 *  ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk)
 *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcapw@cfw.com)
 *
 *  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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 *  Changes by Clifford Wolf (god@clifford.at)
 *
 *  [ 1998-06-13 ]
 *
 *    *)  A bugfix for the Page-Down problem
 *
 *    *)  Formerly when I used Page Down and Page Up, the cursor would be set 
 *        to the first position in the menu box.  Now lxdialog is a bit
 *        smarter and works more like other menu systems (just have a look at
 *        it).
 *
 *    *)  Formerly if I selected something my scrolling would be broken because
 *        lxdialog is re-invoked by the Menuconfig shell script, can't
 *        remember the last scrolling position, and just sets it so that the
 *        cursor is at the bottom of the box.  Now it writes the temporary file
 *        lxdialog.scrltmp which contains this information. The file is
 *        deleted by lxdialog if the user leaves a submenu or enters a new
 *        one, but it would be nice if Menuconfig could make another "rm -f"
 *        just to be sure.  Just try it out - you will recognise a difference!
 *
 *  [ 1998-06-14 ]
 *
 *    *)  Now lxdialog is crash-safe against broken "lxdialog.scrltmp" files
 *        and menus change their size on the fly.
 *
 *    *)  If for some reason the last scrolling position is not saved by
 *        lxdialog, it sets the scrolling so that the selected item is in the
 *        middle of the menu box, not at the bottom.
 */

#include "dialog.h"

static int menu_width, item_x;

/*
 * Print menu item
 */
static void print_item(WINDOW * win, const char *item, int choice,
		       int selected, int hotkey)
{
    char menu_item[menu_width + 1];
    int i, j;

    strncpy(menu_item, item, menu_width);
    menu_item[menu_width] = 0;
    j = first_alpha(menu_item, "YyNnMm");

    /* Clear 'residue' of last item */
    wattrset(win, menubox_attr);
    wmove(win, choice, 0);
    for (i = 0; i < menu_width; i++)
	waddch(win, ' ');
    wattrset(win, selected ? item_selected_attr : item_attr);
    mvwaddstr(win, choice, item_x, menu_item);
    if (hotkey) {
	wattrset(win, selected ? tag_key_selected_attr : tag_key_attr);
	mvwaddch(win, choice, item_x + j, menu_item[j]);
    }
}

/*
 * Print the scroll indicators.
 */
static void print_arrows(WINDOW * win, int item_no, int scroll, int y, int x,
			 int height)
{
    int cur_y, cur_x;

    getyx(win, cur_y, cur_x);

    wmove(win, y, x);

    if (scroll > 0) {
	wattrset(win, uarrow_attr);
	waddch(win, ACS_UARROW);
	waddstr(win, "(-)");
    } else {
	wattrset(win, menubox_attr);
	waddch(win, ACS_HLINE);
	waddch(win, ACS_HLINE);
	waddch(win, ACS_HLINE);
	waddch(win, ACS_HLINE);
    }

    y = y + height + 1;
    wmove(win, y, x);

    if ((height < item_no) && (scroll + height < item_no)) {
	wattrset(win, darrow_attr);
	waddch(win, ACS_DARROW);
	waddstr(win, "(+)");
    } else {
	wattrset(win, menubox_border_attr);
	waddch(win, ACS_HLINE);
	waddch(win, ACS_HLINE);
	waddch(win, ACS_HLINE);
	waddch(win, ACS_HLINE);
    }

    wmove(win, cur_y, cur_x);
}

/*
 * Display the termination buttons.
 */
static void print_buttons(WINDOW * win, int height, int width, int selected)
{
    int x = width / 2 - 16, y = height - 2;

    print_button(win, "Select", y, x, selected == 0);
    print_button(win, " Exit ", y, x + 12, selected == 1);
    print_button(win, " Help ", y, x + 24, selected == 2);

    wmove(win, y, x + 1 + 12 * selected);
    wrefresh(win);
}

/*
 * Display a menu for choosing among a number of options
 */
int dialog_menu(const char *title, const char *prompt, int height, int width,
		int menu_height, const char *current, int item_no,
		const char *const *items)
{
    WINDOW *dialog, *menu;
    FILE *f;
    int key = 0, button = 0, scroll = 0, choice = 0, first_item = 0;
    int i, j, x, y, box_x, box_y, max_choice;

    max_choice = MIN(menu_height, item_no);

    /* center dialog box on screen */
    x = (COLS - width) / 2;
    y = (LINES - height) / 2;

    draw_shadow(stdscr, y, x, height, width);

    dialog = newwin(height, width, y, x);
    keypad(dialog, TRUE);

    draw_box(dialog, 0, 0, height, width, dialog_attr, border_attr);
    wattrset(dialog, border_attr);
    mvwaddch(dialog, height - 3, 0, ACS_LTEE);
    for (i = 0; i < width - 2; i++)
	waddch(dialog, ACS_HLINE);
    wattrset(dialog, dialog_attr);
    waddch(dialog, ACS_RTEE);

    if (title != NULL) {
	wattrset(dialog, title_attr);
	mvwaddch(dialog, 0, (width - strlen(title)) / 2 - 1, ' ');
	waddstr(dialog, (char *) title);
	waddch(dialog, ' ');
    }

    wattrset(dialog, dialog_attr);
    print_autowrap(dialog, prompt, width - 2, 1, 3);

    menu_width = width - 6;
    box_y = height - menu_height - 5;
    box_x = (width - menu_width) / 2 - 1;

    /* create new window for the menu */
    menu = subwin(dialog, menu_height, menu_width,
		  y + box_y + 1, x + box_x + 1);
    keypad(menu, TRUE);

    /* draw a box around the menu items */
    draw_box(dialog, box_y, box_x, menu_height + 2, menu_width + 2,
	     menubox_border_attr, menubox_attr);

    /*
     * Find length of longest item in order to center menu.
     * Set 'choice' to default item. 
     */
    item_x = 0;
    for (i = 0; i < item_no; i++) {
	item_x = MAX(item_x, MIN(menu_width, strlen(items[i * 2 + 1]) + 2));
	if (strcmp(current, items[i * 2]) == 0)
	    choice = i;
    }

    item_x = (menu_width - item_x) / 2;

    /* get the scroll info from the temp file */
    if ((f = fopen("lxdialog.scrltmp", "r")) != NULL) {
	if ((fscanf(f, "%d\n", &scroll) == 1) && (scroll <= choice) &&
	    (scroll + max_choice > choice) && (scroll >= 0) &&
	    (scroll + max_choice <= item_no)) {
	    first_item = scroll;
	    choice = choice - scroll;
	    fclose(f);
	} else {
	    remove("lxdialog.scrltmp");
	    fclose(f);
	    f = NULL;
	}
    }
    if ((choice >= max_choice) || (f == NULL && choice >= max_choice / 2)) {
	if (choice >= item_no - max_choice / 2)
	    scroll = first_item = item_no - max_choice;
	else
	    scroll = first_item = choice - max_choice / 2;
	choice = choice - scroll;
    }

    /* Print the menu */
    for (i = 0; i < max_choice; i++)
	print_item(menu, items[(first_item + i) * 2 + 1], i, i == choice,
		   (items[(first_item + i) * 2][0] != ':'));

    wnoutrefresh(menu);

    print_arrows(dialog, item_no, scroll,
		 box_y, box_x + item_x + 1, menu_height);

    print_buttons(dialog, height, width, 0);

    while (key != ESC) {
	key = wgetch(dialog);

	if (key < 256 && isalpha(key))
	    key = tolower(key);

	if (strchr("ynm", key))
	    i = max_choice;
	else {
	    for (i = choice + 1; i < max_choice; i++) {
		j = first_alpha(items[(scroll + i) * 2 + 1], "YyNnMm");
		if (key == tolower(items[(scroll + i) * 2 + 1][j]))
		    break;
	    }
	    if (i == max_choice)
		for (i = 0; i < max_choice; i++) {
		    j = first_alpha(items[(scroll + i) * 2 + 1], "YyNnMm");
		    if (key == tolower(items[(scroll + i) * 2 + 1][j]))
			break;
		}
	}

	if (i < max_choice ||
	    key == KEY_UP || key == KEY_DOWN ||
	    key == '-' || key == '+' || key == KEY_PPAGE || key == KEY_NPAGE) {

	    print_item(menu, items[(scroll + choice) * 2 + 1], choice, FALSE,
		       (items[(scroll + choice) * 2][0] != ':'));

	    if (key == KEY_UP || key == '-') {
		if (choice < 2 && scroll) {
		    /* Scroll menu down */
		    scrollok(menu, TRUE);
		    wscrl(menu, -1);
		    scrollok(menu, FALSE);

		    scroll--;

		    print_item(menu, items[scroll * 2 + 1], 0, FALSE,
			       (items[scroll * 2][0] != ':'));
		} else
		    choice = MAX(choice - 1, 0);

	    } else if (key == KEY_DOWN || key == '+') {

		print_item(menu, items[(scroll + choice) * 2 + 1], choice,
			   FALSE, (items[(scroll + choice) * 2][0] != ':'));

		if ((choice > max_choice - 3) &&
		    (scroll + max_choice < item_no)) {
		    /* Scroll menu up */
		    scrollok(menu, TRUE);
		    scroll(menu);
		    scrollok(menu, FALSE);

		    scroll++;

		    print_item(menu, items[(scroll + max_choice - 1) * 2 + 1],
			       max_choice - 1, FALSE,
			       (items[(scroll + max_choice - 1) * 2][0] !=
				':'));
		} else
		    choice = MIN(choice + 1, max_choice - 1);

	    } else if (key == KEY_PPAGE) {
		scrollok(menu, TRUE);
		for (i = 0; (i < max_choice); i++) {
		    if (scroll > 0) {
			wscrl(menu, -1);
			scroll--;
			print_item(menu, items[scroll * 2 + 1], 0, FALSE,
				   (items[scroll * 2][0] != ':'));
		    } else {
			if (choice > 0)
			    choice--;
		    }
		}
		scrollok(menu, FALSE);

	    } else if (key == KEY_NPAGE) {
		for (i = 0; (i < max_choice); i++) {
		    if (scroll + max_choice < item_no) {
			scrollok(menu, TRUE);
			scroll(menu);
			scrollok(menu, FALSE);
			scroll++;
			print_item(menu,
				   items[(scroll + max_choice - 1) * 2 + 1],
				   max_choice - 1, FALSE,
				   (items[(scroll + max_choice - 1) * 2][0] !=
				    ':'));
		    } else {
			if (choice + 1 < max_choice)
			    choice++;
		    }
		}

	    } else
		choice = i;

	    print_item(menu, items[(scroll + choice) * 2 + 1], choice, TRUE,
		       (items[(scroll + choice) * 2][0] != ':'));

	    print_arrows(dialog, item_no, scroll,
			 box_y, box_x + item_x + 1, menu_height);

	    wnoutrefresh(menu);
	    wrefresh(dialog);

	    continue;		/* wait for another key press */
	}

	switch (key) {
	case KEY_LEFT:
	case TAB:
	case KEY_RIGHT:
	    button = ((key == KEY_LEFT ? --button : ++button) < 0)
		? 2 : (button > 2 ? 0 : button);

	    print_buttons(dialog, height, width, button);
	    wrefresh(dialog);
	    break;
	case ' ':
	case 's':
	case 'y':
	case 'n':
	case 'm':
	    /* save scroll info */
	    if ((f = fopen("lxdialog.scrltmp", "w")) != NULL) {
		fprintf(f, "%d\n", scroll);
		fclose(f);
	    }
	    delwin(dialog);
	    fprintf(stderr, "%s\n", items[(scroll + choice) * 2]);
	    switch (key) {
	    case 's':
		return 3;
	    case 'y':
		return 3;
	    case 'n':
		return 4;
	    case 'm':
		return 5;
	    case ' ':
		return 6;
	    }
	    return 0;
	case 'h':
	case '?':
	    button = 2;
	case '\n':
	    delwin(dialog);
	    if (button == 2)
		fprintf(stderr, "%s \"%s\"\n",
			items[(scroll + choice) * 2],
			items[(scroll + choice) * 2 + 1] +
			first_alpha(items[(scroll + choice) * 2 + 1], ""));
	    else
		fprintf(stderr, "%s\n", items[(scroll + choice) * 2]);

	    remove("lxdialog.scrltmp");
	    return button;
	case 'e':
	case 'x':
	    key = ESC;
	case ESC:
	    break;
	}
    }

    delwin(dialog);
    remove("lxdialog.scrltmp");

    return -1;			/* ESC pressed */
}
