#!/usr/bin/python

import curses
from curses import panel

class Menu(object):
    def __init__(self, stdscreen, items):
        self.window = stdscreen.subwin(0, 0)
        self.window.keypad(1)
        self.panel = panel.new_panel(self.window)
        self.panel.hide()
        panel.update_panels()

        self.position = 0
        self.items = items
        self.items.append(('exit', 'exit'))

    def navigate(self, n):
        self.position += n
        self.position %= len(self.items)

    def display(self):
        self.panel.top()
        self.panel.show()
        self.window.clear()

        while True:
            self.window.refresh()
            curses.doupdate()
            for index, item in enumerate(self.items):
                if index == self.position:
                    mode = curses.A_REVERSE
                else:
                    mode = curses.A_NORMAL

                msg = '%d. %s' % (index, item[0])
                self.window.addstr(1+index, 1, msg, mode)

            key = self.window.getch()

            if key in [curses.KEY_ENTER, ord('\n')]:
                if self.position == len(self.items)-1:
                    break
                else:
                    self.items[self.position][1]()

            elif key == curses.KEY_UP:
                self.navigate(-1)

            elif key == curses.KEY_DOWN:
                self.navigate(1)

        self.window.clear()
        self.panel.hide()
        panel.update_panels()
        curses.doupdate()
    
class App(object):
    def __init__(self, stdscreen):
        self.screen = stdscreen
        curses.curs_set(0)

        submenu_items = [
            ('beep', curses.beep),
            ('flash', curses.flash)
        ]
        submenu = Menu(self.screen, submenu_items)

        main_menu_items = [
            ('beep', curses.beep),
            ('flash', curses.flash),
            ('submenu', submenu.display)
        ]
        main_menu = Menu(self.screen, main_menu_items)
        main_menu.display()

if __name__ == '__main__':
    curses.wrapper(App)