fix: [code-2912]: minor improvements, requested changes (#3197)

* minor improvements, requested changes

app/api/controller/space/usage.go

@@ -20,6 +20,7 @@ import (
 
 	"github.com/harness/gitness/app/auth"
 	"github.com/harness/gitness/app/paths"
+	"github.com/harness/gitness/errors"
 	"github.com/harness/gitness/types"
 	"github.com/harness/gitness/types/enum"
 )
@@ -32,7 +33,13 @@ func (c *Controller) GetUsageMetrics(
 	startDate int64,
 	endDate int64,
 ) (*types.UsageMetric, error) {
-	rootSpaceRef, _, err := paths.DisectRoot(spaceRef)
+	rootSpaceRef, sub, err := paths.DisectRoot(spaceRef)
+	if sub != "" {
+		return nil, errors.InvalidArgument(
+			"metric api can be used only within %q space: please remove %q part",
+			rootSpaceRef, sub,
+		)
+	}
 	if err != nil {
 		return nil, fmt.Errorf("could not find root space: %w", err)
 	}

app/api/handler/space/usage.go

@@ -37,16 +37,19 @@ func HandleUsageMetric(spaceCtrl *space.Controller) http.HandlerFunc {
 		now := time.Now()
 		start := now.Add(-30 * 24 * time.Hour).UnixMilli()
 
-		startDate, ok, _ := request.QueryParamAsPositiveInt64(r, "start_date")
-		if !ok {
-			startDate = start
-		}
-		endDate, ok, _ := request.QueryParamAsPositiveInt64(r, "start_date")
-		if !ok {
-			endDate = now.UnixMilli()
-		}
+		startDate := request.QueryParamAsUnixMillisOrDefault(
+			r,
+			request.QueryParamStartTime,
+			start,
+		)
 
-		rule, err := spaceCtrl.GetUsageMetrics(
+		endDate := request.QueryParamAsUnixMillisOrDefault(
+			r,
+			request.QueryParamEndTime,
+			now.UnixMilli(),
+		)
+
+		metric, err := spaceCtrl.GetUsageMetrics(
 			ctx,
 			session,
 			spaceRef,
@@ -58,6 +61,6 @@ func HandleUsageMetric(spaceCtrl *space.Controller) http.HandlerFunc {
 			return
 		}
 
-		render.JSON(w, http.StatusOK, rule)
+		render.JSON(w, http.StatusOK, metric)
 	}
 }

app/api/request/time.go

@@ -0,0 +1,34 @@
+// Copyright 2023 Harness, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package request
+
+import "net/http"
+
+const (
+	QueryParamStartTime = "start_time"
+	QueryParamEndTime   = "end_time"
+)
+
+func QueryParamAsUnixMillisOrDefault(
+	r *http.Request,
+	param string,
+	defaultValue int64,
+) int64 {
+	millis, ok, _ := QueryParamAsPositiveInt64(r, param)
+	if !ok {
+		return defaultValue
+	}
+	return millis
+}