from pony.orm import *

db = Database()
db.bind(provider='postgres', user='alex', password='', host='localhost', port='5432', database='menu_db')

set_sql_debug(False)


class Menu(db.Entity):
    id = PrimaryKey(int, auto=True)
    name = Required(str)
    menu = Optional('Menu', reverse='menus')
    menus = Set('Menu', reverse='menu')
    commands = Set('Command')


class Command(db.Entity):
    id = PrimaryKey(int, auto=True)
    name = Required(str)
    text = Required(str)
    menu = Optional(Menu)


db.generate_mapping(create_tables=True)

with db_session:

    # menu_1 = Menu(name='menu_1')
    # command_1 = Command(name='command_1', text='command_1 called', menu=menu_1)
    # command_2 = Command(name='command_2', text='command_2 called', menu=menu_1)
    #
    # menu_2 = Menu(name='menu_2', menu=menu_1)
    # command_3 = Command(name='command_3', text='command_3 called', menu=menu_2)

    current_menu = None
    action_name = None

    while True:

        for menu in Menu.select(lambda m: m.menu == current_menu):
            print('> ' + menu.name)

        for command in Command.select(lambda c: c.menu == current_menu):
            print('* ' + command.name)

        if current_menu:
            print('* back')

        action_name = input()

        if not action_name.strip():
            print('please type action')
            continue

        if current_menu and action_name == 'back':
            current_menu = current_menu.menu
            continue

        menu = Menu.get(menu=current_menu, name=action_name)

        if menu:
            current_menu = menu
        else:
            command = Command.get(menu=current_menu, name=action_name)
            print(command.text if command else 'action not found')