From 09b825808fe97b2f7da60641cbd55a86d406d401 Mon Sep 17 00:00:00 2001
From: lash <dev@holbrook.no>
Date: Fri, 10 Feb 2023 13:45:29 +0000
Subject: [PATCH] Freeze accounts balances at expiry

---
 python/erc20_demurrage_token/expiry.py | 22 +++++++
 python/erc20_demurrage_token/seal.py   | 21 ++++++
 python/tests/test_expiry.py            | 89 ++++++++++++++++++++++++++
 3 files changed, 132 insertions(+)
 create mode 100644 python/erc20_demurrage_token/expiry.py
 create mode 100644 python/erc20_demurrage_token/seal.py
 create mode 100644 python/tests/test_expiry.py

diff --git a/python/erc20_demurrage_token/expiry.py b/python/erc20_demurrage_token/expiry.py
new file mode 100644
index 0000000..7e0d5a2
--- /dev/null
+++ b/python/erc20_demurrage_token/expiry.py
@@ -0,0 +1,22 @@
+# external imports
+from chainlib.eth.tx import (
+        TxFactory,
+        TxFormat,
+        )
+from chainlib.eth.contract import (
+        ABIContractEncoder,
+        ABIContractType,
+        )
+
+class ExpiryContract(TxFactory):
+
+    def set_expires(self, contract_address, sender_address, expire_timestamp, tx_format=TxFormat.JSONRPC):
+        enc = ABIContractEncoder()
+        enc.method('setExpires')
+        enc.typ(ABIContractType.UINT256)
+        enc.uint256(expire_timestamp)
+        data = enc.get()
+        tx = self.template(sender_address, contract_address, use_nonce=True)
+        tx = self.set_code(tx, data)
+        tx = self.finalize(tx, tx_format)
+        return tx
diff --git a/python/erc20_demurrage_token/seal.py b/python/erc20_demurrage_token/seal.py
new file mode 100644
index 0000000..a318e38
--- /dev/null
+++ b/python/erc20_demurrage_token/seal.py
@@ -0,0 +1,21 @@
+# external imports
+from chainlib.eth.tx import (
+        TxFactory,
+        TxFormat,
+        )
+from chainlib.eth.contract import (
+        ABIContractEncoder,
+        )
+
+class SealedContract(TxFactory):
+
+    def set_state(self, contract_address, sender_address, seal, tx_format=TxFormat.JSONRPC):
+        enc = ABIContractEncoder()
+        enc.method('seal')
+        enc.typ(ABIContractType.UINT256)
+        enc.uint256(seal)
+        data = enc.get()
+        tx = self.template(sender_address, contract_address, use_nonce=True)
+        tx = self.set_code(tx, data)
+        tx = self.finalize(tx, tx_format)
+        return tx
diff --git a/python/tests/test_expiry.py b/python/tests/test_expiry.py
new file mode 100644
index 0000000..8cb7220
--- /dev/null
+++ b/python/tests/test_expiry.py
@@ -0,0 +1,89 @@
+# standard imports
+import os
+import unittest
+import json
+import logging
+import datetime
+
+# external imports
+from chainlib.eth.constant import ZERO_ADDRESS
+from chainlib.eth.nonce import RPCNonceOracle
+from chainlib.eth.tx import receipt
+from chainlib.eth.block import (
+        block_latest,
+        block_by_number,
+    )
+
+# local imports
+from erc20_demurrage_token import DemurrageToken
+
+# test imports
+from erc20_demurrage_token.unittest import TestDemurrageDefault
+
+logging.basicConfig(level=logging.DEBUG)
+logg = logging.getLogger()
+
+testdir = os.path.dirname(__file__)
+
+
+class TestExpire(TestDemurrageDefault):
+
+    def test_expires(self):
+        mint_amount = self.default_supply
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        for i in range(3):
+            (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[i+1], mint_amount)
+            r = self.rpc.do(o)
+
+        targetish_time = self.start_time + (self.period_seconds * 2)
+        (tx_hash, o) = c.set_expires(self.address, self.accounts[0], targetish_time)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        self.backend.time_travel(targetish_time + 60)
+        o = block_latest()
+        r = self.rpc.do(o)
+        o = block_by_number(r)
+        r = self.rpc.do(o)
+        self.assertGreaterEqual(r['timestamp'], targetish_time)
+        
+        nonce_oracle = RPCNonceOracle(self.sink_address, self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+        (tx_hash, o) = c.transfer(self.address, self.sink_address, self.accounts[2], 1)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        o = c.balance_of(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance(r)
+        self.assert_within(balance, 0.9604 * mint_amount, 1)
+
+        o = c.total_supply(self.address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        supply = c.parse_balance(r)
+
+        (tx_hash, o) = c.change_period(self.address, self.sink_address)
+        r = self.rpc.do(o)
+        o = receipt(tx_hash)
+        r = self.rpc.do(o)
+        self.assertEqual(r['status'], 1)
+
+        o = c.balance_of(self.address, self.sink_address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        balance = c.parse_balance(r)
+
+        o = c.decay_by(self.address, supply, int((targetish_time - self.start_time) / 60), sender_address=self.sink_address)
+        r = self.rpc.do(o)
+        target_balance = c.parse_balance(r)
+
+        self.assert_within_lower(balance, supply - target_balance, 0.0001)
+
+
+if __name__ == '__main__':
+    unittest.main()