package syncengine

import (
	"context"
	"net"
	"sync/atomic"
	"testing"
	"time"

	"github.com/syncserver/internal/wol"
)

func TestIsReachable(t *testing.T) {
	ln, err := net.ListenTCP("tcp4", &net.TCPAddr{IP: net.ParseIP("127.0.0.1"), Port: 0})
	if err != nil {
		t.Skipf("skipping test (no TCP listener available): %v", err)
	}
	defer ln.Close()
	addr := ln.Addr().(*net.TCPAddr)

	ctx := context.Background()

	if !wol.IsReachable(ctx, "127.0.0.1", addr.Port, 500*time.Millisecond) {
		t.Error("expected reachable on listening port")
	}
	if wol.IsReachable(ctx, "127.0.0.1", addr.Port+1, 500*time.Millisecond) {
		t.Error("expected unreachable on non-listening port")
	}
}

func TestIsReachableTimeout(t *testing.T) {
	ctx := context.Background()
	start := time.Now()
	if wol.IsReachable(ctx, "192.0.2.1", 12345, 500*time.Millisecond) {
		t.Error("expected unreachable for non-routable IP")
	}
	if d := time.Since(start); d < 400*time.Millisecond {
		t.Errorf("IsReachable returned too early: %v", d)
	}
}

func TestProbeThrottle(t *testing.T) {
	e := &Engine{lastProbeAt: atomic.Int64{}}

	e.lastProbeAt.Store(time.Now().UnixNano())

	now := time.Now().UnixNano()
	last := e.lastProbeAt.Load()
	if now-last < int64(probeThrottleSeconds*time.Second) {
		return
	}
	t.Error("throttle check did not run as expected")
}

func TestProbeConstants(t *testing.T) {
	if probeThrottleSeconds != 10 {
		t.Errorf("probeThrottleSeconds = %d, want 10", probeThrottleSeconds)
	}
	if probeTimeout != 1500*time.Millisecond {
		t.Errorf("probeTimeout = %v, want 1500ms", probeTimeout)
	}
	if probeMaxConcurrent != 20 {
		t.Errorf("probeMaxConcurrent = %d, want 20", probeMaxConcurrent)
	}
}