cic-stack/apps/cic-ussd/cic_ussd/menu/ussd_menu.py
2021-08-06 16:29:01 +00:00

104 lines
4.0 KiB
Python

# standard imports
import logging
from typing import Optional
# third party imports
from tinydb import Query
from tinydb.table import Document, Table
# define logger.
logg = logging.getLogger()
class UssdMenu:
"""
This class defines the USSD menu object that is called whenever a user makes transitions in the menu.
:cvar ussd_menu_db: The tinydb database object.
:type ussd_menu_db: Table
"""
ussd_menu_db = None
Menu = Query()
def __init__(self,
name: str,
description: str,
parent: Optional[str],
country: Optional[str] = 'Kenya',
gateway: Optional[str] = 'USSD'):
"""
This function is called whenever a USSD menu object is created and saves the instance to a JSON DB.
:param name: The name of the menu and is used as it's unique identifier.
:type name: str.
:param description: A brief explanation of what the menu does.
:type description: str.
:param parent: The menu from which the current menu is called. Transitions move from parent to child menus.
:type parent: str.
:param country: The country from which the menu is created for and being used. Defaults to Kenya.
:type country: str
:param gateway: The gateway through which the menu is used. Defaults to USSD.
:type gateway: str.
:raises ValueError: If menu already exists.
"""
self.name = name
self.description = description
self.parent = parent
self.display_key = f'{gateway.lower()}.{country.lower()}.{name}'
menu = self.ussd_menu_db.get(UssdMenu.Menu.name == name)
if menu:
raise ValueError('Menu already exists!')
self.ussd_menu_db.insert({
'name': self.name,
'description': self.description,
'parent': self.parent,
'display_key': self.display_key
})
@staticmethod
def find_by_name(name: str) -> Document:
"""
This function attempts to fetch a menu from the JSON DB using the unique name.
:param name: The name of the menu that is being searched for.
:type name: str.
:return: The function returns the queried menu in JSON format if found,
else it returns the menu item for invalid requests.
:rtype: Document.
"""
menu = UssdMenu.ussd_menu_db.get(UssdMenu.Menu.name == name)
if menu:
return menu
logg.error("No USSD Menu with name {}".format(name))
return UssdMenu.ussd_menu_db.get(UssdMenu.Menu.name == 'exit_invalid_request')
@staticmethod
def set_description(name: str, description: str):
"""
This function updates the description for a specific menu in the JSON DB.
:param name: The name of the menu whose description should be updated.
:type name: str.
:param description: The new menu description. On success it should overwrite the menu's previous description.
:type description: str.
"""
menu = UssdMenu.find_by_name(name=name)
UssdMenu.ussd_menu_db.update({'description': description}, UssdMenu.Menu.name == menu['name'])
@staticmethod
def parent_menu(menu_name: str) -> Document:
"""
This function fetches the parent menu of the menu instance it has been called on.
:param menu_name: The name of the menu whose parent is to be returned.
:type menu_name: str
:return: This function returns the menu's parent menu in JSON format.
:rtype: Document.
"""
ussd_menu = UssdMenu.find_by_name(name=menu_name)
return UssdMenu.find_by_name(ussd_menu.get('parent'))
def __repr__(self) -> str:
"""
This method return the object representation of the menu.
:return: This function returns a string containing the object representation of the menu.
:rtype: str.
"""
return f"<UssdMenu {self.name} - {self.description}>"