Adds token helper functions.

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

@@ -1,4 +1,5 @@
 # standard imports
+import hashlib
 import json
 import logging
 from typing import Dict, Optional
@@ -10,12 +11,34 @@ from cic_types.condiments import MetadataPointer
 # local imports
 from cic_ussd.account.chain import Chain
 from cic_ussd.cache import cache_data_key, get_cached_data
-from cic_ussd.error import SeppukuError
+from cic_ussd.error import CachedDataNotFoundError, SeppukuError
+from cic_ussd.metadata.tokens import query_token_info, query_token_metadata
 
 
 logg = logging.getLogger(__name__)
 
 
+def collate_token_metadata(token_info: dict, token_metadata: dict) -> dict:
+    """
+    :param token_info:
+    :type token_info:
+    :param token_metadata:
+    :type token_metadata:
+    :return:
+    :rtype:
+    """
+    description = token_info.get('description')
+    issuer = token_info.get('issuer')
+    location = token_metadata.get('location')
+    contact = token_metadata.get('contact')
+    return {
+        'description': description,
+        'issuer': issuer,
+        'location': location,
+        'contact': contact
+    }
+
+
 def get_cached_default_token(chain_str: str) -> Optional[str]:
     """This function attempts to retrieve the default token's data from the redis cache.
     :param chain_str: chain name and network id.
@@ -49,6 +72,33 @@ def get_default_token_symbol():
             raise SeppukuError(f'Could not retrieve default token for: {chain_str}')
 
 
+def hashed_token_proof(token_proof: dict) -> str:
+    """
+    :param token_proof:
+    :type token_proof:
+    :return:
+    :rtype:
+    """
+
+    hash_object = hashlib.new("sha256")
+    hash_object.update(json.dumps(token_proof))
+    return hash_object.digest().hex()
+
+
+def process_token_data(token_symbol: str):
+    """
+    :param token_symbol:
+    :type token_symbol:
+    :return:
+    :rtype:
+    """
+    identifier = token_symbol.encode('utf-8')
+    query_token_metadata(identifier=identifier)
+    token_info = query_token_info(identifier=identifier)
+    hashed_token_info = hashed_token_proof(token_proof=token_info)
+    query_token_data(hashed_proofs=[hashed_token_info], token_symbols=[token_symbol])
+
+
 def query_default_token(chain_str: str):
     """This function synchronously queries cic-eth for the deployed system's default token.
     :param chain_str: Chain name and network id.
@@ -60,3 +110,19 @@ def query_default_token(chain_str: str):
     cic_eth_api = Api(chain_str=chain_str)
     default_token_request_task = cic_eth_api.default_token()
     return default_token_request_task.get()
+
+
+def query_token_data(hashed_proofs: list, token_symbols: list):
+    """
+    :param hashed_proofs:
+    :type hashed_proofs:
+    :param token_symbols:
+    :type token_symbols:
+    :return:
+    :rtype:
+    """
+    api = Api(callback_param='',
+              callback_queue='cic-ussd',
+              chain_str=Chain.spec.__str__(),
+              callback_task='cic_ussd.tasks.callback_handler.token_data_callback')
+    api.tokens(token_symbols=token_symbols, proof=hashed_proofs)