From f9b630b0f4dd894347635d8483bccd73b907fbbc Mon Sep 17 00:00:00 2001
From: TungHoang <sontunghoang@gmail.com>
Date: Thu, 18 Nov 2021 00:26:21 +0100
Subject: [PATCH] Fix monthly earning estimation (#4282)

---
 private/date/utils.go                         |  7 +++++
 .../estimatedpayouts/estimatedpayouts.go      | 26 +++++++++----------
 .../estimatedpayouts/estimatedpayouts_test.go | 12 ++++-----
 3 files changed, 25 insertions(+), 20 deletions(-)

diff --git a/private/date/utils.go b/private/date/utils.go
index a33693868..ecbc53daa 100644
--- a/private/date/utils.go
+++ b/private/date/utils.go
@@ -58,3 +58,10 @@ func UTCEndOfMonth(now time.Time) time.Time {
 	y, m, _ := now.Date()
 	return time.Date(y, m+1, 1, 0, 0, 0, 0, &time.Location{}).Add(-time.Nanosecond)
 }
+
+// UTCBeginOfMonth returns utc begin of month (f.e. to get first day in month at 00h00m).
+func UTCBeginOfMonth(now time.Time) time.Time {
+	now = now.UTC()
+	y, m, _ := now.Date()
+	return time.Date(y, m, 1, 0, 0, 0, 0, &time.Location{})
+}
diff --git a/storagenode/payouts/estimatedpayouts/estimatedpayouts.go b/storagenode/payouts/estimatedpayouts/estimatedpayouts.go
index 616798e1a..a46d24b85 100644
--- a/storagenode/payouts/estimatedpayouts/estimatedpayouts.go
+++ b/storagenode/payouts/estimatedpayouts/estimatedpayouts.go
@@ -82,24 +82,22 @@ func (estimatedPayout *EstimatedPayout) Set(current, previous PayoutMonthly, now
 	estimatedPayout.CurrentMonth = current
 	estimatedPayout.PreviousMonth = previous
 
-	daysPerMonth := float64(date.UTCEndOfMonth(now).Day())
-	daysSinceJoined := now.Sub(joinedAt).Hours() / 24
-	if daysSinceJoined < 1 {
-		daysSinceJoined = 1
-	}
+	beginOfMonth := date.UTCBeginOfMonth(now)
+	endOfMonth := date.UTCEndOfMonth(now)
 
-	if daysSinceJoined >= float64(now.Day()) {
-		daysPast := float64(now.Day()) - 1
-		if daysPast < 1 {
-			daysPast = 1
-		}
+	// Joined before the first day of this month
+	if joinedAt.Before(beginOfMonth) {
+		minutesPast := now.Sub(beginOfMonth).Minutes()
+		estimatedMinutesJoinedCurrentMonth := endOfMonth.Sub(beginOfMonth).Minutes()
 
-		payoutPerDay := estimatedPayout.CurrentMonth.Payout / daysPast
-		estimatedPayout.CurrentMonthExpectations += int64(payoutPerDay * daysPerMonth)
+		payoutPerMin := estimatedPayout.CurrentMonth.Payout / minutesPast
+		estimatedPayout.CurrentMonthExpectations += int64(payoutPerMin * estimatedMinutesJoinedCurrentMonth)
 		return
 	}
-
-	estimatedPayout.CurrentMonthExpectations += int64(estimatedPayout.CurrentMonth.Payout / math.Round(daysSinceJoined) * daysPerMonth)
+	// Joined this month
+	minutesSinceJoined := now.Sub(joinedAt).Minutes()
+	estimatedMinutesJoinedCurrentMonth := endOfMonth.Sub(joinedAt).Minutes()
+	estimatedPayout.CurrentMonthExpectations += int64(estimatedPayout.CurrentMonth.Payout / minutesSinceJoined * estimatedMinutesJoinedCurrentMonth)
 }
 
 // Add adds estimate into the receiver.
diff --git a/storagenode/payouts/estimatedpayouts/estimatedpayouts_test.go b/storagenode/payouts/estimatedpayouts/estimatedpayouts_test.go
index c0c34c28e..307262627 100644
--- a/storagenode/payouts/estimatedpayouts/estimatedpayouts_test.go
+++ b/storagenode/payouts/estimatedpayouts/estimatedpayouts_test.go
@@ -24,7 +24,7 @@ func TestCurrentMonthExpectations(t *testing.T) {
 	}
 	tests := []test{
 		// 28 days in month
-		{time.Date(2021, 2, 1, 16, 0, 0, 0, time.UTC), 2800.00, time.Date(2021, 1, 1, 12, 0, 0, 0, time.UTC),
+		{time.Date(2021, 2, 1, 16, 0, 0, 0, time.UTC), 4199.00, time.Date(2021, 1, 1, 12, 0, 0, 0, time.UTC),
 			estimatedpayouts.EstimatedPayout{},
 			estimatedpayouts.PayoutMonthly{
 				EgressBandwidth:         123,
@@ -48,7 +48,7 @@ func TestCurrentMonthExpectations(t *testing.T) {
 				Payout:                  payout,
 				Held:                    901,
 			}},
-		{time.Date(2021, 2, 28, 10, 0, 0, 0, time.UTC), 103, time.Date(2021, 1, 26, 10, 0, 0, 0, time.UTC),
+		{time.Date(2021, 2, 28, 10, 0, 0, 0, time.UTC), 102, time.Date(2021, 1, 26, 10, 0, 0, 0, time.UTC),
 			estimatedpayouts.EstimatedPayout{},
 			estimatedpayouts.PayoutMonthly{
 				EgressBandwidth:         123,
@@ -72,7 +72,7 @@ func TestCurrentMonthExpectations(t *testing.T) {
 				Payout:                  payout,
 				Held:                    901,
 			}},
-		{time.Date(2021, 2, 28, 10, 0, 0, 0, time.UTC), 215, time.Date(2021, 2, 15, 10, 0, 0, 0, time.UTC),
+		{time.Date(2021, 2, 28, 10, 0, 0, 0, time.UTC), 104, time.Date(2021, 2, 15, 10, 0, 0, 0, time.UTC),
 			estimatedpayouts.EstimatedPayout{},
 			estimatedpayouts.PayoutMonthly{
 				EgressBandwidth:         123,
@@ -97,7 +97,7 @@ func TestCurrentMonthExpectations(t *testing.T) {
 				Held:                    901,
 			}},
 		// 31 days in month
-		{time.Date(2021, 3, 1, 19, 0, 0, 0, time.UTC), 3100.0, time.Date(2021, 1, 1, 19, 0, 0, 0, time.UTC),
+		{time.Date(2021, 3, 1, 19, 0, 0, 0, time.UTC), 3915.0, time.Date(2021, 1, 1, 19, 0, 0, 0, time.UTC),
 			estimatedpayouts.EstimatedPayout{},
 			estimatedpayouts.PayoutMonthly{
 				EgressBandwidth:         123,
@@ -121,7 +121,7 @@ func TestCurrentMonthExpectations(t *testing.T) {
 				Payout:                  payout,
 				Held:                    901,
 			}},
-		{time.Date(2021, 3, 31, 21, 0, 0, 0, time.UTC), 103, time.Date(2021, 1, 31, 21, 0, 0, 0, time.UTC),
+		{time.Date(2021, 3, 31, 21, 0, 0, 0, time.UTC), 100, time.Date(2021, 1, 31, 21, 0, 0, 0, time.UTC),
 			estimatedpayouts.EstimatedPayout{},
 			estimatedpayouts.PayoutMonthly{
 				EgressBandwidth:         123,
@@ -145,7 +145,7 @@ func TestCurrentMonthExpectations(t *testing.T) {
 				Payout:                  payout,
 				Held:                    901,
 			}},
-		{time.Date(2021, 3, 31, 21, 0, 0, 0, time.UTC), 193, time.Date(2021, 3, 15, 21, 0, 0, 0, time.UTC),
+		{time.Date(2021, 3, 31, 21, 0, 0, 0, time.UTC), 100, time.Date(2021, 3, 15, 21, 0, 0, 0, time.UTC),
 			estimatedpayouts.EstimatedPayout{},
 			estimatedpayouts.PayoutMonthly{
 				EgressBandwidth:         123,