add duration seconds reporting (#1528)

* add duration seconds reporting

* Create tidy-goats-marry.md

* tidy

* typo

Author: paulwe

.changeset/tidy-goats-marry.md

@@ -0,0 +1,5 @@
+---
+"@livekit/protocol": patch
+---
+
+add duration seconds reporting

observability/agentsobs/gen_reporter.go

@@ -1,27 +1,53 @@
 package observability
 
-import "time"
+import (
+	"time"
+
+	"github.com/livekit/protocol/utils/options"
+)
 
 type SessionTimer struct {
 	lastMilli int64
+	lastSec   int64
 	lastMin   int64
+	minSecs   int64
+	minMins   int64
+}
+
+type SessionTimerOption func(*SessionTimer)
+
+// WithMinSeconds ensures the first Advance that produces a non-zero secs
+// return reports at least n seconds. Subsequent advances behave normally.
+func WithMinSeconds(n int64) SessionTimerOption {
+	return func(h *SessionTimer) { h.minSecs = n }
 }
 
-func NewSessionTimer(startTime time.Time) *SessionTimer {
+// WithMinMinutes ensures the first Advance that produces a non-zero mins
+// return reports at least n minutes. Subsequent advances behave normally.
+func WithMinMinutes(n int64) SessionTimerOption {
+	return func(h *SessionTimer) { h.minMins = n }
+}
+
+func NewSessionTimer(startTime time.Time, opts ...SessionTimerOption) *SessionTimer {
 	ts := startTime.UnixMilli()
-	return &SessionTimer{ts, ts}
+	return options.Apply(&SessionTimer{lastMilli: ts, lastSec: ts, lastMin: ts}, opts)
 }
 
-func (h *SessionTimer) Advance(now time.Time) (millis, mins int64) {
+func (h *SessionTimer) Advance(now time.Time) (millis, secs, mins int64) {
 	ts := now.UnixMilli()
 	if ts > h.lastMilli {
 		millis = ts - h.lastMilli
 		h.lastMilli = ts
 	}
+	if ts > h.lastSec {
+		secs = max((ts-h.lastSec+999)/1000, h.minSecs)
+		h.minSecs = 0
+		h.lastSec += secs * 1000
+	}
 	if ts > h.lastMin {
-		n := (ts - h.lastMin + 59999) / 60000
-		mins += n
-		h.lastMin += n * 60000
+		mins = max((ts-h.lastMin+59999)/60000, h.minMins)
+		h.minMins = 0
+		h.lastMin += mins * 60000
 	}
 	return
 }