feat: Reimplement time.Time to display a timestamp in JSON response a…

…nd body

gcloud/helpers/spanner/time.go

@@ -0,0 +1,94 @@
+package spanner
+
+import (
+	"strconv"
+	"time"
+
+	"cloud.google.com/go/spanner"
+)
+
+// Time overrides the spanner.Time to produce a unix milli timestamp when marshalled to json
+type Time time.Time
+
+// MarshalJSON implements the json.Marshaler interface to produce a unix milli timestamp
+func (nt Time) MarshalJSON() ([]byte, error) {
+	casted := time.Time(nt)
+
+	return []byte(strconv.FormatInt(casted.UnixMilli(), 10)), nil
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface to handle a unix milli timestamp and convert it to a Time
+func (nt *Time) UnmarshalJSON(b []byte) error {
+	i, err := strconv.ParseInt(string(b), 10, 64)
+	if err == nil {
+		*nt = Time(time.UnixMilli(i))
+		return nil
+	}
+
+	// if it's not a unix timestamp try decoding as time this is useful for json object created by spanner TO_JSON()
+	if b[0] == '"' {
+		b = b[1 : len(b)-1]
+	}
+
+	date, errT := time.Parse(time.RFC3339Nano, string(b))
+	if errT != nil {
+		return errT
+	}
+
+	*nt = Time(date)
+	return nil
+}
+
+// CommitTimestamp returns a spanner.CommitTimestamp cast to a models.Time
+func CommitTimestamp() Time {
+	return Time(spanner.CommitTimestamp)
+}
+
+// NullTime overrides the spanner.NullTime to produce a unix milli timestamp when marshalled to json
+type NullTime spanner.NullTime
+
+// MarshalJSON implements the json.Marshaler interface to produce a unix milli timestamp
+func (nt NullTime) MarshalJSON() ([]byte, error) {
+	if nt.Valid {
+		return []byte(strconv.FormatInt(nt.Time.UnixMilli(), 10)), nil
+	}
+
+	return []byte("0"), nil
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface to handle a unix milli timestamp and convert it to a NullTime
+func (nt *NullTime) UnmarshalJSON(b []byte) error {
+	if string(b) == "0" {
+		nt.Valid = false
+		return nil
+	}
+
+	i, err := strconv.ParseInt(string(b), 10, 64)
+	if err == nil {
+		*nt = NullTime(spanner.NullTime{Valid: true, Time: time.UnixMilli(i)})
+		return nil
+	}
+
+	// if it's not a unix timestamp try decoding as time this is useful for json object created by spanner TO_JSON()
+	if b[0] == '"' {
+		b = b[1 : len(b)-1]
+	}
+	date, errT := time.Parse(time.RFC3339Nano, string(b))
+	if errT != nil {
+		return errT
+	}
+
+	*nt = NullTime{
+		Time:  date,
+		Valid: true,
+	}
+	return nil
+}
+
+// NullCommitTimestamp returns a spanner.CommitTimestamp casted to a models.NullTime
+func NullCommitTimestamp() NullTime {
+	return NullTime{
+		Time:  spanner.CommitTimestamp,
+		Valid: true,
+	}
+}