108 lines
3.9 KiB
Python
108 lines
3.9 KiB
Python
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# standard imports
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import logging
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from typing import Optional
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import json
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# third party imports
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from redis import Redis
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logg = logging.getLogger()
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class UssdSession:
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"""
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This class defines the USSD session object that is called whenever a user interacts with the system.
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:cvar redis_cache: The in-memory redis cache.
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:type redis_cache: Redis
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"""
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redis_cache: Redis = None
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def __init__(self,
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external_session_id: str,
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service_code: str,
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msisdn: str,
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user_input: str,
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state: str,
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session_data: Optional[dict] = None):
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"""
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This function is called whenever a USSD session object is created and saves the instance to a JSON DB.
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:param external_session_id: The Africa's Talking session ID.
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:type external_session_id: str.
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:param service_code: The USSD service code from which the user used to gain access to the system.
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:type service_code: str.
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:param msisdn: The user's phone number.
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:type msisdn: str.
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:param user_input: The data or choice the user has made while interacting with the system.
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:type user_input: str.
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:param state: The name of the USSD menu that the user was interacting with.
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:type state: str.
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:param session_data: Any additional data that was persisted during the user's interaction with the system.
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:type session_data: dict.
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"""
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self.external_session_id = external_session_id
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self.service_code = service_code
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self.msisdn = msisdn
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self.user_input = user_input
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self.state = state
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self.session_data = session_data
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session = self.redis_cache.get(external_session_id)
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if session:
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session = json.loads(session)
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self.version = session.get('version') + 1
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else:
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self.version = 1
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self.session = {
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'external_session_id': self.external_session_id,
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'service_code': self.service_code,
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'msisdn': self.msisdn,
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'user_input': self.user_input,
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'state': self.state,
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'session_data': self.session_data,
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'version': self.version
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}
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self.redis_cache.set(self.external_session_id, json.dumps(self.session))
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self.redis_cache.persist(self.external_session_id)
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def set_data(self, key: str, value: str) -> None:
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"""
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This function adds or updates data to the session data.
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:param key: The name used to identify the data.
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:type key: str.
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:param value: The actual data to be stored in the session data.
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:type value: str.
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"""
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if self.session_data is None:
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self.session_data = {}
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self.session_data[key] = value
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self.redis_cache.set(self.external_session_id, json.dumps(self.session))
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def get_data(self, key: str) -> Optional[str]:
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"""
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This function attempts to fetch data from the session data using the identifier for the specific data.
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:param key: The name used as the identifier for the specific data.
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:type key: str.
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:return: This function returns the queried data if found, else it doesn't return any value.
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:rtype: str.
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"""
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if self.session_data is not None:
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return self.session_data.get(key)
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else:
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return None
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def to_json(self):
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""" This function serializes the in memory ussd session object to a JSON object
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:return: A JSON object of a ussd session in memory
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:rtype: dict
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"""
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return {
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"external_session_id": self.external_session_id,
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"service_code": self.service_code,
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"msisdn": self.msisdn,
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"user_input": self.user_input,
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"state": self.state,
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"session_data": self.session_data,
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"version": self.version
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}
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