/*
 *  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.
 *
 * 02 January 1999, Michael Elizabeth Chastain (mec@shout.net)
 * Reset 'scroll' to 0 if the value from lxdialog.scrltmp is bogus.
 * This fixes a bug in Menuconfig where using ' ' to descend into menus
 * would leave mis-synchronized lxdialog.scrltmp files lying around,
 * fscanf would read in 'scroll', and eventually that value would get used.
 */

#include "dialog.h"

static int menu_width, item_x;

/*
 * Print menu item
 */
static void do_print_item(WINDOW * win, const char *item, int line_y,
                          int selected, int hotkey)
{
    int j;

    char *menu_item = malloc(menu_width + 1);

    strncpy(menu_item, item, menu_width - item_x);
    menu_item[menu_width - item_x] = '\0';
    j = first_alpha(menu_item, "YyNnMmHh");

    /*
     * Clear 'residue' of last item 
     */
    wattrset(win, dlg.menubox.atr);
    wmove(win, line_y, 0);
#if OLD_NCURSES
    {
        int i;

        for (i = 0; i < menu_width; i++)
            waddch(win, ' ');
    }
#else
    wclrtoeol(win);
#endif
    wattrset(win, selected ? dlg.item_selected.atr : dlg.item.atr);
    mvwaddstr(win, line_y, item_x, menu_item);
    if (hotkey) {
        wattrset(win, selected ? dlg.tag_key_selected.atr : dlg.tag_key.atr);
        mvwaddch(win, line_y, item_x + j, menu_item[j]);
    }
    if (selected) {
        wmove(win, line_y, item_x + 1);
    }
    free(menu_item);
    wrefresh(win);
}

#define print_item(index, choice, selected)				\
do {									\
	item_set(index);						\
	do_print_item(menu, item_str(), choice, selected, !item_is_tag(':')); \
} while (0)

/*
 * 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, dlg.uarrow.atr);
        waddch(win, ACS_UARROW);
        waddstr(win, "(-)");
    } else {
        wattrset(win, dlg.menubox.atr);
        waddch(win, ACS_HLINE);
        waddch(win, ACS_HLINE);
        waddch(win, ACS_HLINE);
        waddch(win, ACS_HLINE);
    }

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

    if ((height < item_no) && (scroll + height < item_no)) {
        wattrset(win, dlg.darrow.atr);
        waddch(win, ACS_DARROW);
        waddstr(win, "(+)");
    } else {
        wattrset(win, dlg.menubox_border.atr);
        waddch(win, ACS_HLINE);
        waddch(win, ACS_HLINE);
        waddch(win, ACS_HLINE);
        waddch(win, ACS_HLINE);
    }

    wmove(win, cur_y, cur_x);
    wrefresh(win);
}

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

    int y = height - 2;

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

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

/* scroll up n lines (n may be negative) */
static void do_scroll(WINDOW * win, int *scroll, int n)
{
    /*
     * Scroll menu up 
     */
    scrollok(win, TRUE);
    wscrl(win, n);
    scrollok(win, FALSE);
    *scroll = *scroll + n;
    wrefresh(win);
}

/*
 * Display a menu for choosing among a number of options
 */
int dialog_menu(const char *title, const char *prompt,
                const void *selected, int *s_scroll)
{
    int i, j, x, y, box_x, box_y;

    int height, width, menu_height;

    int key = 0, button = 0, scroll = 0, choice = 0;

    int first_item = 0, max_choice;

    WINDOW *dialog, *menu;

 do_resize:
    height = getmaxy(stdscr);
    width = getmaxx(stdscr);
    if (height < 15 || width < 65)
        return -ERRDISPLAYTOOSMALL;

    height -= 4;
    width -= 5;
    menu_height = height - 10;

    max_choice = MIN(menu_height, item_count());

    /*
     * 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, dlg.dialog.atr, dlg.border.atr);
    wattrset(dialog, dlg.border.atr);
    mvwaddch(dialog, height - 3, 0, ACS_LTEE);
    for (i = 0; i < width - 2; i++)
        waddch(dialog, ACS_HLINE);
    wattrset(dialog, dlg.dialog.atr);
    wbkgdset(dialog, dlg.dialog.atr & A_COLOR);
    waddch(dialog, ACS_RTEE);

    print_title(dialog, title, width);

    wattrset(dialog, dlg.dialog.atr);
    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,
             dlg.menubox_border.atr, dlg.menubox.atr);

    if (menu_width >= 80)
        item_x = (menu_width - 70) / 2;
    else
        item_x = 4;

    /*
     * Set choice to default item 
     */
    item_foreach()
        if (selected && (selected == item_data()))
        choice = item_n();
    /*
     * get the saved scroll info 
     */
    scroll = *s_scroll;
    if ((scroll <= choice) && (scroll + max_choice > choice) &&
        (scroll >= 0) && (scroll + max_choice <= item_count())) {
        first_item = scroll;
        choice = choice - scroll;
    } else {
        scroll = 0;
    }
    if ((choice >= max_choice)) {
        if (choice >= item_count() - max_choice / 2)
            scroll = first_item = item_count() - 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(first_item + i, i, i == choice);
    }

    wnoutrefresh(menu);

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

    print_buttons(dialog, height, width, 0);
    wmove(menu, choice, item_x + 1);
    wrefresh(menu);

    while (key != KEY_ESC) {
        key = wgetch(menu);

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

        if (strchr("ynmh", key))
            i = max_choice;
        else {
            for (i = choice + 1; i < max_choice; i++) {
                item_set(scroll + i);
                j = first_alpha(item_str(), "YyNnMmHh");
                if (key == tolower(item_str()[j]))
                    break;
            }
            if (i == max_choice)
                for (i = 0; i < max_choice; i++) {
                    item_set(scroll + i);
                    j = first_alpha(item_str(), "YyNnMmHh");
                    if (key == tolower(item_str()[j]))
                        break;
                }
        }

        if (i < max_choice ||
            key == KEY_UP || key == KEY_DOWN ||
            key == '-' || key == '+' || key == KEY_PPAGE || key == KEY_NPAGE) {
            /*
             * Remove highligt of current item 
             */
            print_item(scroll + choice, choice, FALSE);

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

                    print_item(scroll, 0, FALSE);
                } else
                    choice = MAX(choice - 1, 0);

            } else if (key == KEY_DOWN || key == '+') {
                print_item(scroll + choice, choice, FALSE);

                if ((choice > max_choice - 3) &&
                    (scroll + max_choice < item_count())) {
                    /*
                     * Scroll menu up 
                     */
                    do_scroll(menu, &scroll, 1);

                    print_item(scroll + max_choice - 1, max_choice - 1, FALSE);
                } 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) {
                        do_scroll(menu, &scroll, -1);
                        print_item(scroll, 0, FALSE);
                    } else {
                        if (choice > 0)
                            choice--;
                    }
                }

            } else if (key == KEY_NPAGE) {
                for (i = 0; (i < max_choice); i++) {
                    if (scroll + max_choice < item_count()) {
                        do_scroll(menu, &scroll, 1);
                        print_item(scroll + max_choice - 1,
                                   max_choice - 1, FALSE);
                    } else {
                        if (choice + 1 < max_choice)
                            choice++;
                    }
                }
            } else
                choice = i;

            print_item(scroll + choice, choice, TRUE);

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

            wnoutrefresh(dialog);
            wrefresh(menu);

            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(menu);
            break;
        case ' ':
        case 's':
        case 'y':
        case 'n':
        case 'm':
        case '/':
            /*
             * save scroll info 
             */
            *s_scroll = scroll;
            delwin(menu);
            delwin(dialog);
            item_set(scroll + choice);
            item_set_selected(1);
            switch (key) {
            case 's':
                return 3;
            case 'y':
                return 3;
            case 'n':
                return 4;
            case 'm':
                return 5;
            case ' ':
                return 6;
            case '/':
                return 7;
            }
            return 0;
        case 'h':
        case '?':
            button = 2;
        case '\n':
            *s_scroll = scroll;
            delwin(menu);
            delwin(dialog);
            item_set(scroll + choice);
            item_set_selected(1);
            return button;
        case 'e':
        case 'x':
            key = KEY_ESC;
            break;
        case KEY_ESC:
            key = on_key_esc(menu);
            break;
        case KEY_RESIZE:
            on_key_resize();
            delwin(menu);
            delwin(dialog);
            goto do_resize;
        }
    }
    delwin(menu);
    delwin(dialog);
    return key;                 /* ESC pressed */
}
