/*
 *  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 */
}