Refactors balance.py

- Moves it into account package
- Makes functions names cic-compliant.
- Adds docstrings.

apps/cic-ussd/cic_ussd/account/balance.py

@@ -33,12 +33,12 @@ class BalanceManager:
     def get_balances(self, asynchronous: bool = False) -> Union[celery.Task, dict]:
         """
         This function queries cic-eth for an account's balances, It provides a means to receive the balance either
-        asynchronously or synchronously depending on the provided value for teh asynchronous parameter. It returns a
-        dictionary containing network, outgoing and incoming balances.
+        asynchronously or synchronously depending on the provided asynchronous value from the function's caller. It
+        returns a dictionary containing network, outgoing and incoming balances when synchronously called.
         :param asynchronous: Boolean value checking whether to return balances asynchronously
         :type asynchronous: bool
-        :return:
-        :rtype:
+        :return: dict containing network, outgoing and incoming balances | an async result object from celery.
+        :rtype: dict|celery.Task
         """
         if asynchronous:
             cic_eth_api = Api(
@@ -47,7 +47,7 @@ class BalanceManager:
                 callback_task='cic_ussd.tasks.callback_handler.process_balances_callback',
                 callback_param=''
             )
-            cic_eth_api.balance(address=self.address, token_symbol=self.token_symbol)
+            return cic_eth_api.balance(address=self.address, token_symbol=self.token_symbol)
         else:
             cic_eth_api = Api(chain_str=self.chain_str)
             balance_request_task = cic_eth_api.balance(
@@ -56,27 +56,30 @@ class BalanceManager:
             return balance_request_task.get()[0]
 
 
-def compute_operational_balance(balances: dict) -> float:
-    """This function calculates the right balance given incoming and outgoing
-    :param balances:
-    :type balances:
-    :return:
-    :rtype:
+def operational_balance(balances: dict) -> float:
+    """This function computes the operational balance at an instance in the system by providing the difference of the
+    outgoing balance from the sum of incoming and network balances.
+    :param balances: A dictionary containing incoming, outgoing and network balances.
+    :type balances: dict
+    :return: The operational balance of the account at the instance of querying.
+    :rtype: float
     """
     incoming_balance = balances.get('balance_incoming')
     outgoing_balance = balances.get('balance_outgoing')
     network_balance = balances.get('balance_network')
 
-    operational_balance = (network_balance + incoming_balance) - outgoing_balance
-    return from_wei(value=operational_balance)
+    balance = (network_balance + incoming_balance) - outgoing_balance
+    return from_wei(value=balance)
 
 
-def get_cached_operational_balance(blockchain_address: str):
-    """
-    :param blockchain_address:
-    :type blockchain_address:
-    :return:
-    :rtype:
+def cached_operational_balance(blockchain_address: str) -> float:
+    """This function retrieves the cached balances data from redis cache and computes the operational balance from
+    the cached data.
+    :param blockchain_address: Ethereum address of the account whose balance data is being retrieved.
+    :type blockchain_address: str, 0x-hex
+    :return: The operational balance of the account as per cached balance data.
+    :rtype: float
+    :raises CachedDataNotFoundError
     """
     key = create_cached_data_key(
         identifier=bytes.fromhex(blockchain_address[2:]),
@@ -84,7 +87,7 @@ def get_cached_operational_balance(blockchain_address: str):
     )
     cached_balance = get_cached_data(key=key)
     if cached_balance:
-        operational_balance = compute_operational_balance(balances=json.loads(cached_balance))
-        return operational_balance
+        balance = operational_balance(balances=json.loads(cached_balance))
+        return balance
     else:
         raise CachedDataNotFoundError('Cached operational balance not found.')