From d7c082b51575f86bc3be029107beea62f05004f6 Mon Sep 17 00:00:00 2001
From: Todd Gruben <todd@molecula.com>
Date: Mon, 31 Jan 2022 12:32:05 -0600
Subject: [PATCH] add timestamp formating to type FieldRow used in GroupBy

---
 executor.go      | 25 ++++++++++++++++++-------
 executor_test.go | 22 ++++++++++++++++++++++
 2 files changed, 40 insertions(+), 7 deletions(-)

diff --git a/executor.go b/executor.go
index 24e36af61..4409637a0 100644
--- a/executor.go
+++ b/executor.go
@@ -3189,13 +3189,24 @@ func (fr *FieldRow) Clone() (clone *FieldRow) {
 // either a Key or an ID is included.
 func (fr FieldRow) MarshalJSON() ([]byte, error) {
 	if fr.Value != nil {
-		return json.Marshal(struct {
-			Field string `json:"field"`
-			Value int64  `json:"value"`
-		}{
-			Field: fr.Field,
-			Value: *fr.Value,
-		})
+		if fr.FieldOptions.Type == FieldTypeTimestamp {
+			ts := FormatTimestampNano(int64(*fr.Value), fr.FieldOptions.Base, fr.FieldOptions.TimeUnit)
+			return json.Marshal(struct {
+				Field string `json:"field"`
+				Value string `json:"value"`
+			}{
+				Field: fr.Field,
+				Value: ts,
+			})
+		} else {
+			return json.Marshal(struct {
+				Field string `json:"field"`
+				Value int64  `json:"value"`
+			}{
+				Field: fr.Field,
+				Value: *fr.Value,
+			})
+		}
 	}
 
 	if fr.RowKey != "" {
diff --git a/executor_test.go b/executor_test.go
index 15d792987..1c534ac52 100644
--- a/executor_test.go
+++ b/executor_test.go
@@ -3490,6 +3490,28 @@ func TestExecutor_Execute_Remote_Row(t *testing.T) {
 		}
 	})
 
+	t.Run("json format groupBy on timestamps", func(t *testing.T) {
+		//SUP-138
+		c.CreateField(t, "t", pilosa.IndexOptions{TrackExistence: true}, "timestamp", pilosa.OptFieldTypeTimestamp(pilosa.DefaultEpoch, pilosa.TimeUnitSeconds))
+		c.Query(t, "t", `
+		Set(8, timestamp='2021-01-27T08:00:00Z')
+		Set(9, timestamp='2000-01-27T09:00:00Z')
+		Set(10, timestamp='2000-01-27T10:00:00Z')
+	`)
+		if res, err := c.GetNode(0).API.Query(context.Background(), &pilosa.QueryRequest{
+			Index: "t",
+			Query: `GroupBy(Rows(timestamp))`,
+		}); err != nil {
+			t.Fatalf("GroupBy querying: %v", err)
+		} else {
+			b, _ := res.MarshalJSON()
+			expected := `{"results":[[{"group":[{"field":"timestamp","value":"2000-01-27T09:00:00Z"}],"count":1},{"group":[{"field":"timestamp","value":"2000-01-27T10:00:00Z"}],"count":1},{"group":[{"field":"timestamp","value":"2021-01-27T08:00:00Z"}],"count":1}]]}`
+			if string(b) != expected {
+				t.Fatalf("JSON FORMAT not as expected: %v", err)
+			}
+		}
+	})
+
 	t.Run("remote groupBy on ints", func(t *testing.T) {
 		_, err = c.GetPrimary().API.CreateField(context.Background(), "i", "fint", pilosa.OptFieldTypeInt(-1000, 1000))
 		if err != nil {