From 96f1529af1ad725f0658084128585c2c8b4b844e Mon Sep 17 00:00:00 2001
From: Derek Sonnenberg <derek@ardrive.io>
Date: Tue, 5 Nov 2024 16:34:54 -0600
Subject: [PATCH] feat: init arns discount elgibility and fee caclulation
 PE-7060

---
 src/arns.lua      | 26 +++++++++++++++++++++-----
 src/constants.lua |  3 +++
 src/gar.lua       | 18 ++++++++++++++++++
 3 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/src/arns.lua b/src/arns.lua
index 0865b5c..44f0d59 100644
--- a/src/arns.lua
+++ b/src/arns.lua
@@ -5,6 +5,7 @@ local balances = require("balances")
 local demand = require("demand")
 local arns = {}
 local Auction = require("auctions")
+local gar = require("gar")
 
 NameRegistry = NameRegistry or {
 	reserved = {},
@@ -25,8 +26,15 @@ function arns.buyRecord(name, purchaseType, years, from, timestamp, processId)
 
 	local baseRegistrationFee = demand.baseFeeForNameLength(#name)
 
-	local totalRegistrationFee =
-		arns.calculateRegistrationFee(purchaseType, baseRegistrationFee, years, demand.getDemandFactor())
+	local eligibleForArNSDiscount = gar.isEligibleForArNSDiscount(from)
+
+	local totalRegistrationFee = arns.calculateRegistrationFee(
+		purchaseType,
+		baseRegistrationFee,
+		years,
+		demand.getDemandFactor(),
+		eligibleForArNSDiscount
+	)
 
 	if balances.getBalance(from) < totalRegistrationFee then
 		error("Insufficient balance")
@@ -252,12 +260,20 @@ function arns.calculatePermabuyFee(baseFee, demandFactor)
 	return math.floor(demandFactor * permabuyPrice)
 end
 
-function arns.calculateRegistrationFee(purchaseType, baseFee, years, demandFactor)
+function arns.calculateRegistrationFee(purchaseType, baseFee, years, demandFactor, isEligibleForArNSDiscount)
+	local fee = 0
 	if purchaseType == "lease" then
-		return arns.calculateLeaseFee(baseFee, years, demandFactor)
+		fee = arns.calculateLeaseFee(baseFee, years, demandFactor)
 	elseif purchaseType == "permabuy" then
-		return arns.calculatePermabuyFee(baseFee, demandFactor)
+		fee = arns.calculatePermabuyFee(baseFee, demandFactor)
 	end
+
+	if isEligibleForArNSDiscount then
+		local discount = math.floor(fee * constants.ARNS_DISCOUNT_PERCENTAGE)
+		fee = fee - discount
+	end
+
+	return fee
 end
 
 function arns.calculateUndernameCost(baseFee, increaseQty, registrationType, years, demandFactor)
diff --git a/src/constants.lua b/src/constants.lua
index e29771d..a5b264d 100644
--- a/src/constants.lua
+++ b/src/constants.lua
@@ -21,6 +21,9 @@ constants.UNDERNAME_PERMABUY_FEE_PERCENTAGE = 0.005
 constants.oneYearMs = 31536000 * 1000
 constants.gracePeriodMs = 14 * 24 * 60 * 60 * 1000 -- 2 weeks
 constants.maxLeaseLengthYears = 5
+constants.ARNS_DISCOUNT_PERCENTAGE = 0.2
+constants.ARNS_DISCOUNT_TENURE_WEIGHT_ELIGIBILITY_FACTOR = 1
+constants.ARNS_DISCOUNT_GATEWAY_PERFORMANCE_RATIO_ELIGIBILITY_FACTOR = 0.85
 
 -- DEMAND
 constants.demandSettings = {
diff --git a/src/gar.lua b/src/gar.lua
index e2f9b9b..db9535b 100644
--- a/src/gar.lua
+++ b/src/gar.lua
@@ -503,6 +503,7 @@ function gar.isGatewayActiveBeforeTimestamp(startTimestamp, gateway)
 	local isNotLeaving = not gar.isGatewayLeaving(gateway)
 	return didStartBeforeEpoch and isNotLeaving
 end
+
 function gar.getActiveGatewaysBeforeTimestamp(startTimestamp)
 	local gateways = gar.getGateways()
 	local activeGatewayAddresses = {}
@@ -981,4 +982,21 @@ function gar.instantOperatorWithdrawal(from, vaultId, currentTimestamp)
 	}
 end
 
+function gar.isEligibleForArNSDiscount(from)
+	local gateway = gar.getGateway(from)
+	if gateway == nil then
+		return false
+	end
+
+	if gateway.weights == nil then
+		return false
+	end
+
+	local tenureWeight = gateway.weights.tenureWeight
+	local gatewayPerformanceRatio = gateway.weights.gatewayRewardRatioWeight
+
+	return tenureWeight >= constants.ARNS_DISCOUNT_TENURE_WEIGHT_ELIGIBILITY_FACTOR
+		and gatewayPerformanceRatio >= constants.ARNS_DISCOUNT_GATEWAY_PERFORMANCE_RATIO_ELIGIBILITY_FACTOR
+end
+
 return gar