Update subscription item with usage

* Convert the usage report so that it contains one entry for each team
  that registered usage during the billing period.
* For each team, query Stripe to find the corresponding Customer.
* Update each Customer's subscription with their used credits.

Author: Andrew Farries

components/usage/pkg/controller/reconciler.go

@@ -132,18 +132,13 @@ func (u *UsageReconciler) ReconcileTimeRange(ctx context.Context, from, to time.
 }
 
 func submitUsageReport(report []TeamUsage) {
-	var teamIdSet = make(map[string]bool)
-
-	// Convert the usage report into a set of teamIds occurring in the report
+	// Convert the usage report to sum all entries for the same team.
+	var summedReport = make(map[string]int64)
 	for _, usageEntry := range report {
-		teamIdSet[usageEntry.TeamID] = true
-	}
-	teamIds := make([]string, 0, len(teamIdSet))
-	for k := range teamIdSet {
-		teamIds = append(teamIds, k)
+		summedReport[usageEntry.TeamID] += usageEntry.WorkspaceSeconds
 	}
 
-	stripe.FindCustomersForTeamIds(teamIds)
+	stripe.UpdateUsage(summedReport)
 }
 
 func generateUsageReport(teams []teamWithWorkspaces, maxStopTime time.Time) ([]TeamUsage, error) {

components/usage/pkg/stripe/stripe.go

@@ -13,6 +13,7 @@ import (
 	"github.com/gitpod-io/gitpod/common-go/log"
 	"github.com/stripe/stripe-go/v72"
 	"github.com/stripe/stripe-go/v72/customer"
+	"github.com/stripe/stripe-go/v72/usagerecord"
 )
 
 type stripeKeys struct {
@@ -37,19 +38,54 @@ func Authenticate(apiKeyFile string) error {
 	return nil
 }
 
-// FindCustomersForTeamIds queries the stripe API to find all customers with a teamId in `teamIds`.
-func FindCustomersForTeamIds(teamIds []string) {
+// UpdateUsage updates teams' Stripe subscriptions with usage data
+// `usageForTeam` is a map from team name to total workspace seconds used within a billing period.
+func UpdateUsage(usageForTeam map[string]int64) error {
+	teamIds := make([]string, 0, len(usageForTeam))
+	for k := range usageForTeam {
+		teamIds = append(teamIds, k)
+	}
 	queries := queriesForCustomersWithTeamIds(teamIds)
 
 	for _, query := range queries {
 		log.Infof("about to make query %q", query)
-		params := &stripe.CustomerSearchParams{SearchParams: stripe.SearchParams{Query: query}}
+		params := &stripe.CustomerSearchParams{
+			SearchParams: stripe.SearchParams{
+				Query:  query,
+				Expand: []*string{stripe.String("data.subscriptions")},
+			},
+		}
 		iter := customer.Search(params)
 		for iter.Next() {
 			customer := iter.Customer()
 			log.Infof("found customer %q for teamId %q", customer.Name, customer.Metadata["teamId"])
+			subscriptions := customer.Subscriptions.Data
+			if len(subscriptions) != 1 {
+				log.Errorf("customer has an unexpected number of subscriptions (expected 1, got %d)", len(subscriptions))
+				continue
+			}
+			subscription := customer.Subscriptions.Data[0]
+
+			log.Infof("customer has subscription: %q", subscription.ID)
+			if len(subscription.Items.Data) != 1 {
+				log.Errorf("this subscription has an unexpected number of subscriptionItems (expected 1, got %d)", len(subscription.Items.Data))
+				continue
+			}
+
+			creditsUsed := workspaceSecondsToCredits(usageForTeam[customer.Metadata["teamId"]])
+
+			subscriptionItemId := subscription.Items.Data[0].ID
+			log.Infof("registering usage against subscriptionItem %q", subscriptionItemId)
+			_, err := usagerecord.New(&stripe.UsageRecordParams{
+				SubscriptionItem: stripe.String(subscriptionItemId),
+				Quantity:         stripe.Int64(creditsUsed),
+			})
+			if err != nil {
+				log.WithError(err).Errorf("failed to register usage for customer %q", customer.Name)
+			}
 		}
 	}
+	return nil
 }
 
 // queriesForCustomersWithTeamIds constructs Stripe query strings to find the Stripe Customer for each teamId
@@ -73,3 +109,8 @@ func queriesForCustomersWithTeamIds(teamIds []string) []string {
 
 	return queries
 }
+
+// workspaceSecondsToCredits converts seconds (of workspace usage) into Stripe credits.
+func workspaceSecondsToCredits(seconds int64) int64 {
+	return (seconds + 59) / 60
+}

components/usage/pkg/stripe/stripe_test.go

@@ -83,3 +83,50 @@ func TestCustomerQueriesForTeamIds_MultipleQueries(t *testing.T) {
 		})
 	}
 }
+
+func TestWorkspaceSecondsToCreditsCalcuation(t *testing.T) {
+	testCases := []struct {
+		Name            string
+		Seconds         int64
+		ExpectedCredits int64
+	}{
+		{
+			Name:            "0 seconds",
+			Seconds:         0,
+			ExpectedCredits: 0,
+		},
+		{
+			Name:            "1 second",
+			Seconds:         1,
+			ExpectedCredits: 1,
+		},
+		{
+			Name:            "60 seconds",
+			Seconds:         60,
+			ExpectedCredits: 1,
+		},
+		{
+			Name:            "61 seconds",
+			Seconds:         61,
+			ExpectedCredits: 2,
+		},
+		{
+			Name:            "90 seconds",
+			Seconds:         90,
+			ExpectedCredits: 2,
+		},
+		{
+			Name:            "1 hour",
+			Seconds:         3600,
+			ExpectedCredits: 60,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.Name, func(t *testing.T) {
+			actualCredits := workspaceSecondsToCredits(tc.Seconds)
+
+			require.Equal(t, tc.ExpectedCredits, actualCredits)
+		})
+	}
+}