package main

import (
	"context"
	"testing"
	"time"
)

func TestCallbackQueueMetricsTrackWaitingAndProcessing(t *testing.T) {
	metrics := &callbackQueueMetrics{}
	metrics.enqueue()
	metrics.enqueue()
	metrics.startCallback(time.Now().Add(-10 * time.Millisecond))

	snapshot := metrics.snapshot()
	if snapshot.Current != 1 || snapshot.Processing != 1 || snapshot.Maximum != 2 || snapshot.Enqueued != 2 {
		t.Fatalf("unexpected active queue snapshot: %+v", snapshot)
	}
	if snapshot.WaitSecondsTotal <= 0 || snapshot.WaitSecondsMax <= 0 || metrics.isDrained() {
		t.Fatalf("wait or drain state not tracked: %+v", snapshot)
	}

	metrics.finishCallback()
	metrics.startCallback(time.Now())
	metrics.finishCallback()
	if snapshot = metrics.snapshot(); snapshot.Current != 0 || snapshot.Processing != 0 || snapshot.Completed != 2 || !metrics.isDrained() {
		t.Fatalf("unexpected drained queue snapshot: %+v", snapshot)
	}
}

func TestWaitForCallbackQueueWaitsForProcessingCallback(t *testing.T) {
	metrics := &callbackQueueMetrics{}
	metrics.enqueue()
	metrics.startCallback(time.Now())
	go func() {
		time.Sleep(20 * time.Millisecond)
		metrics.finishCallback()
	}()

	started := time.Now()
	if err := waitForCallbackQueue(context.Background(), metrics, time.Second); err != nil {
		t.Fatal(err)
	}
	if time.Since(started) < 15*time.Millisecond {
		t.Fatal("wait returned before the callback finished")
	}
}