fix: don't use tft timestamp

integration/loki/loki.go

@@ -151,9 +151,16 @@ func (l *Loki) Write(payload mpv2.Payload[any]) {
 			l.l.Warn("buffer size reached", zap.Int("size", l.bufferSize))
 		}
 
+		var timestamp time.Time
+		if payload.TimestampMicros > 0 {
+			timestamp = time.UnixMicro(payload.TimestampMicros)
+		} else {
+			timestamp = time.Now()
+		}
+
 		l.entries <- logproto.Entry{
 			Line:      string(lineBytes),
-			Timestamp: time.UnixMicro(payload.TimestampMicros),
+			Timestamp: timestamp,
 			StructuredMetadata: push.LabelsAdapter{
 				{
 					Name:  "event_name",

pkg/encoding/gtag/sst.go

@@ -13,7 +13,7 @@ type SST struct {
 	GCSub *string `json:"gcsub,omitempty" gtag:"gcsub,omitempty"`
 	// Example: DE
 	UC *string `json:"uc,omitempty" gtag:"uc,omitempty"`
-	// Example: 1708250245344
+	// Session start time, time first seen. Example: 1708250245344
 	TFT *string `json:"tft,omitempty" gtag:"tft,omitempty"`
 	// Example: 13l3l3l3l1
 	GCD *string `json:"gcd,omitempty" gtag:"gcd,omitempty"`

pkg/encoding/gtagencode/mpv2.go

@@ -29,9 +29,6 @@ func MPv2(source gtag.Payload, target any) error {
 		"non_personalized_ads": source.NonPersonalizedAds,
 		"debug_mode":           source.IsDebug,
 	}
-	if source.SST != nil && source.SST.TFT != nil {
-		targetData["timestamp_micros"] = gtag.Get(source.SST.TFT) + "000"
-	}
 
 	// combine user properties
 	targetUserProperties := map[string]any{}

pkg/event/params/pageview.go

@@ -3,5 +3,6 @@ package params
 // PageView https://developers.google.com/analytics/devguides/collection/ga4/views?client_type=gtag#manually_send_page_view_events
 type PageView struct {
 	PageTitle    string `json:"page_title,omitempty"`
+	PageReferrer string `json:"page_referrer,omitempty"`
 	PageLocation string `json:"page_location,omitempty"`
 }