package service

import (
	"os"
	"path/filepath"
	"testing"

	"vpn-platform/backend/internal/model"
)

func TestInstanceSnapshotRestore(t *testing.T) {
	base := t.TempDir()
	t.Setenv("VPN_DATA_DIR", base)
	tunnel := &model.Tunnel{ID: 42, Protocol: "openvpn"}
	if _, err := WriteConfig(tunnel, "server.conf", "old-config"); err != nil {
		t.Fatal(err)
	}
	backup, err := SnapshotInstance(tunnel)
	if err != nil {
		t.Fatal(err)
	}
	defer CleanupInstanceSnapshot(backup)
	if _, err := WriteConfig(tunnel, "server.conf", "new-config"); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(InstanceDir(tunnel), "temporary"), []byte("new"), 0o600); err != nil {
		t.Fatal(err)
	}
	if err := RestoreInstanceSnapshot(tunnel, backup); err != nil {
		t.Fatal(err)
	}
	got, err := os.ReadFile(filepath.Join(InstanceDir(tunnel), "server.conf"))
	if err != nil || string(got) != "old-config" {
		t.Fatalf("restored config = %q, err=%v", got, err)
	}
	if _, err := os.Stat(filepath.Join(InstanceDir(tunnel), "temporary")); !os.IsNotExist(err) {
		t.Fatalf("temporary file remained after restore: %v", err)
	}
}