From 00bb87e3ec9ab2af34e04a8f35a21c2b45d5f8b7 Mon Sep 17 00:00:00 2001
From: nolash <dev@holbrook.no>
Date: Fri, 2 Jul 2021 15:29:56 +0200
Subject: [PATCH] Add python demurrage calculator

---
 python/erc20_demurrage_token/demurrage.py | 38 +++++++++++++++++++++++
 python/setup.cfg                          |  2 +-
 python/test.sh                            | 33 --------------------
 python/tests/test_demurrage_ext.py        | 23 ++++++++++++++
 4 files changed, 62 insertions(+), 34 deletions(-)
 create mode 100644 python/erc20_demurrage_token/demurrage.py
 delete mode 100644 python/test.sh
 create mode 100644 python/tests/test_demurrage_ext.py

diff --git a/python/erc20_demurrage_token/demurrage.py b/python/erc20_demurrage_token/demurrage.py
new file mode 100644
index 0000000..e97e769
--- /dev/null
+++ b/python/erc20_demurrage_token/demurrage.py
@@ -0,0 +1,38 @@
+#
+import logging
+import datetime
+import math
+
+logging.basicConfig(level=logging.DEBUG)
+logg = logging.getLogger()
+
+
+class DemurrageCalculator:
+
+    def __init__(self, interest_f_minute):
+
+        self.r_min = interest_f_minute
+        self.r_hour = 1 - ((1 -self.r_min) ** 60)
+        self.r_day = 1 - ((1 -self.r_hour) ** 24)
+        #self.r_week = interest_f_day ** 7
+        logg.info('demurrage calculator set with min {:.32f} hour {:.32f} day {:.32f}'.format(self.r_min, self.r_hour, self.r_day))
+
+
+    def amount_since(self, amount, timestamp):
+        delta = datetime.datetime.utcnow() - datetime.datetime.fromtimestamp(timestamp)
+        adjusted_amount = amount * ((1 - self.r_day) ** (delta.days))
+        logg.debug('adjusted for {} days {} -> {}'.format(delta.days, amount, adjusted_amount))
+
+        remainder = delta.seconds
+        remainder_hours = math.floor(remainder / (60 * 60))
+        adjusted_delta = adjusted_amount * ((1 - self.r_hour) ** remainder_hours)
+        adjusted_amount -= (adjusted_amount - adjusted_delta)
+        logg.debug('adjusted for {} hours {} -> {} delta {}'.format(remainder_hours, amount, adjusted_amount, adjusted_delta))
+
+        remainder -= (remainder_hours * (60 * 60))
+        remainder_minutes = math.floor(remainder / 60)
+        adjusted_delta = adjusted_amount * ((1 - self.r_min) ** remainder_minutes)
+        adjusted_amount -= (adjusted_amount - adjusted_delta)
+        logg.debug('adjusted for {} hours {} -> {} delta {}'.format(remainder_minutes, amount, adjusted_amount, adjusted_delta))
+
+        return adjusted_amount
diff --git a/python/setup.cfg b/python/setup.cfg
index d8edfae..7185900 100644
--- a/python/setup.cfg
+++ b/python/setup.cfg
@@ -4,7 +4,7 @@ version = 0.0.2a1
 description = ERC20 token with redistributed continual demurrage
 author = Louis Holbrook
 author_email = dev@holbrook.no
-url = https://gitlab.com/grassrootseconomics/sarafu-token
+url = https://gitlab.com/ccicnet/erc20-demurrage-token
 keywords =
 	ethereum
 	blockchain
diff --git a/python/test.sh b/python/test.sh
deleted file mode 100644
index 9bea348..0000000
--- a/python/test.sh
+++ /dev/null
@@ -1,33 +0,0 @@
-#!/bin/bash
-
-set -e
-
-export PYTHONPATH=.
-
-#modes=(MultiNocap MultiCap SingleCap SingleNocap)
-modes=(SingleCap SingleNocap) # other contracts need to be updted
-for m in ${modes[@]}; do
-	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_basic.py
-	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_growth.py
-	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_amounts.py
-	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_single.py
-done
-
-modes=(SingleCap) # other contracts need to be updted
-for m in ${modes[@]}; do
-	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_period.py
-	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_redistribution_unit.py
-done
-
-modes=(MultiCap SingleCap)
-for m in ${modes[@]}; do
-	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_cap.py
-done
-
-#modes=(MultiCap MultiNocap)
-#for m in ${modes[@]}; do
-#	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_remainder.py
-#	ERC20_DEMURRAGE_TOKEN_TEST_MODE=$m python tests/test_redistribution.py
-#done
-
-set +e
diff --git a/python/tests/test_demurrage_ext.py b/python/tests/test_demurrage_ext.py
new file mode 100644
index 0000000..2090a6f
--- /dev/null
+++ b/python/tests/test_demurrage_ext.py
@@ -0,0 +1,23 @@
+# standard imports
+import datetime
+import unittest
+
+# local imports
+from erc20_demurrage_token.demurrage import DemurrageCalculator
+
+# test imports
+from tests.base import TestDemurrage
+
+
+class TestEmulate(TestDemurrage):
+
+    def test_amount_since(self):
+
+        d = datetime.datetime.utcnow() - datetime.timedelta(seconds=29, hours=5, minutes=3, days=4)
+        c = DemurrageCalculator(0.00000050105908373373)
+        a = c.amount_since(100, d.timestamp())
+        self.assert_within_lower(a, 99.69667, 0.1)
+
+
+if __name__ == '__main__':
+    unittest.main()