commit 8e60539245e230e4c8e7bd0c1901fe2744f0f256
Author: nolash <dev@holbrook.no>
Date:   Tue Feb 2 11:26:44 2021 +0100

    Initial commit

diff --git a/python/tests/test_basic.py b/python/tests/test_basic.py
new file mode 100644
index 0000000..8304b3f
--- /dev/null
+++ b/python/tests/test_basic.py
@@ -0,0 +1,82 @@
+# standard imports
+import os
+import unittest
+import json
+import logging
+
+# third-party imports
+import web3
+import eth_tester
+import eth_abi
+
+logging.basicConfig(level=logging.DEBUG)
+logg = logging.getLogger()
+
+logging.getLogger('web3').setLevel(logging.WARNING)
+logging.getLogger('eth.vm').setLevel(logging.WARNING)
+
+testdir = os.path.dirname(__file__)
+
+#BLOCKTIME = 5 # seconds
+TAX_LEVEL = 10000 * 2 # 2%
+#PERIOD = int(60/BLOCKTIME) * 60 * 24 * 30 # month
+PERIOD = 2
+
+class Test(unittest.TestCase):
+
+    contract = None
+
+    def setUp(self):
+        eth_params = eth_tester.backends.pyevm.main.get_default_genesis_params({
+            'gas_limit': 9000000,
+            })
+
+        f = open(os.path.join(testdir, '../../solidity/RedistributedDemurrageToken.bin'), 'r')
+        self.bytecode = f.read()
+        f.close()
+
+        f = open(os.path.join(testdir, '../../solidity/RedistributedDemurrageToken.json'), 'r')
+        self.abi = json.load(f)
+        f.close()
+
+        backend = eth_tester.PyEVMBackend(eth_params)
+        self.eth_tester =  eth_tester.EthereumTester(backend)
+        provider = web3.Web3.EthereumTesterProvider(self.eth_tester)
+        self.w3 = web3.Web3(provider)
+        c = self.w3.eth.contract(abi=self.abi, bytecode=self.bytecode)
+        tx_hash = c.constructor('Foo Token', 'FOO', TAX_LEVEL, PERIOD).transact({'from': self.w3.eth.accounts[0]})
+
+        r = self.w3.eth.getTransactionReceipt(tx_hash)
+        self.contract = self.w3.eth.contract(abi=self.abi, address=r.contractAddress)
+
+        self.start_block = self.w3.eth.blockNumber
+
+    def tearDown(self):
+        pass
+
+
+    def test_period(self):
+        self.assertEqual(self.contract.functions.actualPeriod().call(), 0)
+        self.eth_tester.mine_blocks(PERIOD)
+        self.assertEqual(self.contract.functions.actualPeriod().call(), 1)
+
+    def test_apply_tax(self):
+        tx = self.contract.functions.noop().buildTransaction()
+        logg.debug('gas {}'.format(self.w3.eth.estimateGas(tx)))
+
+        self.eth_tester.mine_blocks(PERIOD)
+        tx_hash = self.contract.functions.applyTax().transact();
+        r = self.w3.eth.getTransactionReceipt(tx_hash);
+        self.assertEqual(self.contract.functions.redistributionCount().call(), 2);
+        self.assertEqual(self.contract.functions.demurrageModifier().call(), TAX_LEVEL);
+
+        self.eth_tester.mine_blocks(PERIOD)
+        tx_hash = self.contract.functions.applyTax().transact();
+        r = self.w3.eth.getTransactionReceipt(tx_hash);
+        self.assertEqual(self.contract.functions.redistributionCount().call(), 3);
+        self.assertEqual(self.contract.functions.demurrageModifier().call(), TAX_LEVEL * 2);
+
+if __name__ == '__main__':
+    unittest.main()
+
+    
diff --git a/solidity/Makefile b/solidity/Makefile
new file mode 100644
index 0000000..cee7eb3
--- /dev/null
+++ b/solidity/Makefile
@@ -0,0 +1,14 @@
+SOLC = /usr/bin/solc
+
+all:
+	$(SOLC) RedistributedDemurrageToken.sol --abi --evm-version byzantium | awk 'NR>3' > RedistributedDemurrageToken.json
+	$(SOLC) RedistributedDemurrageToken.sol --bin --evm-version byzantium | awk 'NR>3' > RedistributedDemurrageToken.bin
+	truncate -s -1 RedistributedDemurrageToken.bin
+
+test: all
+	python ../python/tests/test_basic.py
+
+install: all
+	cp -v RedistributedDemurrageToken.{json,bin} ../python/eth_address_declarator/data/
+	
+.PHONY: test install
diff --git a/solidity/RedistributedDemurrageToken.sol b/solidity/RedistributedDemurrageToken.sol
new file mode 100644
index 0000000..c2d5576
--- /dev/null
+++ b/solidity/RedistributedDemurrageToken.sol
@@ -0,0 +1,81 @@
+pragma solidity > 0.6.11;
+
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+contract RedistributedDemurrageToken {
+
+	address public owner;
+	uint256 public decimals;
+	string public name;
+	string public symbol;
+	uint256 public totalSupply;
+
+	uint256 public periodStart;
+	uint256 public periodDuration;
+	uint32 public taxLevel;
+	uint256 public demurrageModifier;
+
+	bytes32[] redistributions; // uint40(participants) uint160(value) uint56(period) 
+
+	event Transfer(address indexed _from, address indexed _to, uint256 _value);
+	event Approval(address indexed _owner, address indexed _spender, uint256 _value);
+
+	constructor(string memory _name, string memory _symbol, uint32 _taxLevel, uint256 _period) {
+		owner = msg.sender;
+		periodStart = block.number;
+		periodDuration = _period;
+		taxLevel = _taxLevel;
+		name = _name;
+		symbol = _symbol;
+		decimals = 6;
+		bytes32 initialRedistribution = toRedistribution(0, 1, 0);
+		redistributions.push(initialRedistribution);
+	}
+
+	function toRedistribution(uint256 _participants, uint256 _value, uint256 _period) private pure returns(bytes32) {
+		bytes32 redistribution;
+		redistribution |= bytes32((_participants & 0xffffffffff) << 215);
+		redistribution |= bytes32((_value & 0xffffffffffffffffffffffff) << 55);
+		redistribution |= bytes32((_period & 0xffffffffffffff) << 55);
+		return redistribution;
+	}
+
+	function toRedistributionPeriod(bytes32 redistribution) public pure returns (uint256) {
+		return uint256(redistribution & bytes7(0xffffffffffffff));
+	}
+
+	function redistributionCount() public view returns (uint256) {
+		return redistributions.length;
+	}
+
+	function actualPeriod() public view returns (uint256) {
+		return (block.number - periodStart) / periodDuration;
+	}
+
+	function checkPeriod() private view returns (bytes32) {
+		bytes32 lastRedistribution = redistributions[redistributions.length-1];
+		uint256 currentPeriod = this.actualPeriod();
+		if (currentPeriod < toRedistributionPeriod(lastRedistribution)) {
+			return bytes32(0x00);
+		}
+		return lastRedistribution;
+	}
+
+	function applyTax() public returns (uint256) {
+		bytes32 pendingRedistribution;
+		bytes32 nextRedistribution;
+
+		pendingRedistribution = checkPeriod();
+		if (pendingRedistribution == bytes32(0x00)) {
+			return demurrageModifier;	
+		}
+		demurrageModifier += taxLevel;
+		nextRedistribution = toRedistribution(0, actualPeriod(), 0);
+		redistributions.push(nextRedistribution);
+		return demurrageModifier;
+	}
+
+	function noop() public returns (uint256) {
+		return 0;
+	}
+}