Optional allowance detection for TokenAgency to ease stake init on the same address multiple times.

nucypher/blockchain/eth/actors.py

@@ -32,7 +32,8 @@ from constant_sorrow.constants import (
     NO_FUNDING_ACCOUNT
 )
 from eth_tester.exceptions import TransactionFailed
-from eth_utils import keccak, is_checksum_address
+from eth_utils import is_checksum_address
+from eth_utils import keccak
 from twisted.logger import Logger
 from web3 import Web3
 
@@ -724,9 +725,21 @@ class StakeHolder(BaseConfiguration):
 
         self.__get_accounts()
 
-        if sync_now:
+        if sync_now and not offline_mode:
             self.read_onchain_stakes()  # Stakes
 
+    def __str__(self) -> str:
+        r = f'{self.__class__.__name__}(funding_account={self.funding_account})'
+        return r
+
+    def __repr__(self) -> str:
+        r = f'{self.__class__.__name__}(funding_account={self.funding_account})'
+        return r
+
+    #
+    # Configuration
+    #
+
     def static_payload(self) -> dict:
         """Values to read/write from stakeholder JSON configuration files"""
         payload = dict(provider_uri=self.blockchain.provider_uri,
@@ -757,6 +770,18 @@ class StakeHolder(BaseConfiguration):
             self.__transacting_powers[checksum_address] = transacting_power
         transacting_power.activate(password=password)
 
+    def to_configuration_file(self, *args, **kwargs) -> str:
+        filepath = super().to_configuration_file(modifier=self.funding_account, *args, **kwargs)
+        return filepath
+
+    def connect(self, blockchain: BlockchainInterface = None) -> None:
+        """Go Online"""
+        if not self.staking_agent:
+            self.staking_agent = StakingEscrowAgent(blockchain=blockchain)
+        if not self.token_agent:
+            self.token_agent = NucypherTokenAgent(blockchain=blockchain)
+        self.blockchain = self.token_agent.blockchain
+
     #
     # Account Utilities
     #
@@ -916,7 +941,9 @@ class StakeHolder(BaseConfiguration):
         # Send new staker account NU
         _result = self.token_agent.transfer(amount=amount.to_nunits(),
                                             sender_address=self.funding_account,
-                                            target_address=staker.checksum_address)
+                                            target_address=staker.checksum_address,
+                                            auto_approve=True)
+        return staker
 
     def initialize_stake(self,
                          amount: NU,
@@ -967,6 +994,13 @@ class StakeHolder(BaseConfiguration):
         self.to_configuration_file(override=True)
         return receipts
 
+    def calculate_rewards(self) -> dict:
+        rewards = dict()
+        for staker in self.stakers:
+            reward = staker.calculate_reward()
+            rewards[staker.checksum_address] = reward
+        return rewards
+
     def collect_rewards(self,
                         staker_address: str,
                         password: str,

nucypher/blockchain/eth/agents.py

@@ -124,6 +124,12 @@ class NucypherTokenAgent(EthereumContractAgent, metaclass=Agency):
         address = address if address is not None else self.contract_address
         return self.contract.functions.balanceOf(address).call()
 
+    def increase_allowance(self, sender_address: str, target_address: str, increase: int):
+        contract_function = self.contract.functions.increaseAllowance(target_address, increase)
+        receipt = self.blockchain.send_transaction(transaction_function=contract_function,
+                                                   sender_address=sender_address)
+        return receipt
+
     def approve_transfer(self, amount: int, target_address: str, sender_address: str):
         """Approve the transfer of token from the sender address to the target address."""
         payload = {'gas': 500_000}  # TODO #413: gas needed for use with geth.
@@ -133,8 +139,16 @@ class NucypherTokenAgent(EthereumContractAgent, metaclass=Agency):
                                                    sender_address=sender_address)
         return receipt
 
-    def transfer(self, amount: int, target_address: str, sender_address: str):
-        self.approve_transfer(amount=amount, target_address=target_address, sender_address=sender_address)
+    def transfer(self, amount: int, target_address: str, sender_address: str, auto_approve: bool = True):
+        if auto_approve:
+            allowance = self.contract.functions.allowance(sender_address, target_address).call()
+            if allowance != 0:
+                delta = int(amount) - int(allowance)
+                self.increase_allowance(sender_address=sender_address,
+                                        target_address=target_address,
+                                        increase=delta)
+            else:
+                self.approve_transfer(amount=amount, target_address=target_address, sender_address=sender_address)
         contract_function = self.contract.functions.transfer(target_address, amount)
         receipt = self.blockchain.send_transaction(contract_function=contract_function, sender_address=sender_address)
         return receipt