[server] Increase expiry time for free subscriptions (#3124)

## Description
For existing users, the expiry time is random date in future: Tuesday,
July 2, 2120
## Tests
Locally, made the change to show expiry time for free plan and verified
that
- for existing account, new expiry time was shown.
 - For new account, the expiry time was 100 years from now.

server/ente/billing.go

@@ -16,8 +16,8 @@ const (
 	FreePlanProductID = "free"
 	// FreePlanTransactionID is the dummy transaction ID for the free plan
 	FreePlanTransactionID = "none"
-	// TrialPeriodDuration is the duration of the free trial
-	TrialPeriodDuration = 365
+	// TrialPeriodDuration is the duration (in years) of the free trial
+	TrialPeriodDuration = 100
 	// TrialPeriod is the unit for the duration of the free trial
 	TrialPeriod = "days"
 

server/migrations/91_increase_free_validity.down.sql

@@ -0,0 +1 @@
+-- no-op

server/migrations/91_increase_free_validity.up.sql

@@ -0,0 +1 @@
+UPDATE subscriptions SET expiry_time = 4749355117000000 where storage = 5368709120 and product_id = 'free' and original_transaction_id ='none';

server/pkg/utils/billing/billing.go

@@ -108,7 +108,7 @@ func GetFreeSubscription(userID int64) ente.Subscription {
 		ProductID:             ente.FreePlanProductID,
 		OriginalTransactionID: ente.FreePlanTransactionID,
 		Storage:               ente.FreePlanStorage,
-		ExpiryTime:            time.NDaysFromNow(ente.TrialPeriodDuration),
+		ExpiryTime:            time.NYearsFromNow(ente.TrialPeriodDuration),
 	}
 }
 

server/pkg/utils/time/time.go

@@ -48,6 +48,10 @@ func NDaysFromNow(n int) int64 {
 	return time.Now().AddDate(0, 0, n).UnixNano() / 1000
 }
 
+func NYearsFromNow(n int) int64 {
+	return time.Now().AddDate(n, 0, 0).UnixNano() / 1000
+}
+
 // NMinFromNow returns the time n min from now in micro seconds
 func NMinFromNow(n int64) int64 {
 	return time.Now().Add(time.Minute*time.Duration(n)).UnixNano() / 1000