feat: current online users count (resolve #798)

Author: muety

coverage/coverage.out

@@ -74,6 +74,11 @@ func (m *UserServiceMock) Count() (int64, error) {
 	return int64(args.Int(0)), args.Error(1)
 }
 
+func (m *UserServiceMock) CountCurrentlyOnline() (int, error) {
+	args := m.Called()
+	return args.Int(0), args.Error(1)
+}
+
 func (m *UserServiceMock) CreateOrGet(signup *models.Signup, isAdmin bool) (*models.User, bool, error) {
 	args := m.Called(signup, isAdmin)
 	return args.Get(0).(*models.User), args.Bool(1), args.Error(2)

mocks/user_service.go

@@ -7,9 +7,10 @@ type Newsbox struct {
 
 type HomeViewModel struct {
 	SharedViewModel
-	TotalHours int
-	TotalUsers int
-	Newsbox    *Newsbox
+	TotalHours      int
+	TotalUsers      int
+	CurrentlyOnline int
+	Newsbox         *Newsbox
 }
 
 func (s *HomeViewModel) WithSuccess(m string) *HomeViewModel {

models/view/home.go

@@ -59,9 +59,12 @@ func (h *HomeHandler) GetIndex(w http.ResponseWriter, r *http.Request) {
 }
 
 func (h *HomeHandler) buildViewModel(r *http.Request, w http.ResponseWriter) *view.HomeViewModel {
-	var totalHours int
-	var totalUsers int
-	var newsbox view.Newsbox
+	var (
+		totalHours      int
+		totalUsers      int
+		currentlyOnline int
+		newsbox         view.Newsbox
+	)
 
 	if kv, err := h.keyValueSrvc.GetString(conf.KeyLatestTotalTime); err == nil && kv != nil && kv.Value != "" {
 		if d, err := time.ParseDuration(kv.Value); err == nil {
@@ -81,12 +84,19 @@ func (h *HomeHandler) buildViewModel(r *http.Request, w http.ResponseWriter) *vi
 		}
 	}
 
+	if c, err := h.userSrvc.CountCurrentlyOnline(); err == nil {
+		currentlyOnline = c
+	} else {
+		conf.Log().Request(r).Error("failed to count currently online users", "error", err)
+	}
+
 	sharedVm := view.NewSharedViewModel(h.config, nil)
 	sharedVm.LeaderboardEnabled = sharedVm.LeaderboardEnabled && !h.config.App.LeaderboardRequireAuth // logged in users will never actually see the home route's view
 	vm := &view.HomeViewModel{
 		SharedViewModel: sharedVm,
 		TotalHours:      totalHours,
 		TotalUsers:      totalUsers,
+		CurrentlyOnline: currentlyOnline,
 		Newsbox:         &newsbox,
 	}
 	return routeutils.WithSessionMessages(vm, r, w)

routes/home.go

@@ -37,6 +37,7 @@ func TestHomeHandler_Get_NotLoggedIn(t *testing.T) {
 
 	userServiceMock := new(mocks.UserServiceMock)
 	userServiceMock.On("GetUserById", user1.ID).Return(&user1, nil)
+	userServiceMock.On("CountCurrentlyOnline").Return(0, nil)
 
 	keyValueServiceMock := new(mocks.KeyValueServiceMock)
 	keyValueServiceMock.On("GetString", config.KeyLatestTotalTime).Return(&models.KeyStringValue{Key: config.KeyLatestTotalTime, Value: "0"}, nil)

routes/home_test.go

@@ -149,6 +149,7 @@ type IUserService interface {
 	GetAllByLeaderboard(bool) ([]*models.User, error)
 	GetActive(bool) ([]*models.User, error)
 	Count() (int64, error)
+	CountCurrentlyOnline() (int, error)
 	CreateOrGet(*models.Signup, bool) (*models.User, bool, error)
 	Update(*models.User) (*models.User, error)
 	Delete(*models.User) error

services/services.go

@@ -14,26 +14,30 @@ import (
 	"github.com/patrickmn/go-cache"
 	"log/slog"
 	"strings"
+	"sync/atomic"
 	"time"
 )
 
 type UserService struct {
-	config          *config.Config
-	cache           *cache.Cache
-	eventBus        *hub.Hub
-	keyValueService IKeyValueService
-	mailService     IMailService
-	repository      repositories.IUserRepository
+	config              *config.Config
+	cache               *cache.Cache
+	eventBus            *hub.Hub
+	keyValueService     IKeyValueService
+	mailService         IMailService
+	repository          repositories.IUserRepository
+	currentOnlineUsers  *cache.Cache
+	countersInitialized atomic.Bool
 }
 
 func NewUserService(keyValueService IKeyValueService, mailService IMailService, userRepo repositories.IUserRepository) *UserService {
 	srv := &UserService{
-		config:          config.Get(),
-		eventBus:        config.EventBus(),
-		cache:           cache.New(1*time.Hour, 2*time.Hour),
-		keyValueService: keyValueService,
-		mailService:     mailService,
-		repository:      userRepo,
+		config:             config.Get(),
+		eventBus:           config.EventBus(),
+		cache:              cache.New(1*time.Hour, 2*time.Hour),
+		keyValueService:    keyValueService,
+		mailService:        mailService,
+		repository:         userRepo,
+		currentOnlineUsers: cache.New(models.DefaultHeartbeatsTimeout, 1*time.Minute),
 	}
 
 	sub1 := srv.eventBus.Subscribe(0, config.EventWakatimeFailure)
@@ -58,6 +62,18 @@ func NewUserService(keyValueService IKeyValueService, mailService IMailService,
 		}
 	}(&sub1)
 
+	sub2 := srv.eventBus.Subscribe(0, config.EventHeartbeatCreate)
+	go func(sub *hub.Subscription) {
+		for m := range sub.Receiver {
+			heartbeat := m.Fields[config.FieldPayload].(*models.Heartbeat)
+			if time.Now().Sub(heartbeat.Time.T()) > models.DefaultHeartbeatsTimeout {
+				continue
+			}
+			srv.currentOnlineUsers.SetDefault(heartbeat.UserID, true)
+			slog.Info("user became active again", "timeout", models.DefaultHeartbeatsTimeout, "user", heartbeat.UserID)
+		}
+	}(&sub2)
+
 	return srv
 }
 
@@ -174,6 +190,22 @@ func (srv *UserService) Count() (int64, error) {
 	return srv.repository.Count()
 }
 
+func (srv *UserService) CountCurrentlyOnline() (int, error) {
+	if !srv.countersInitialized.Load() {
+		minDate := time.Now().Add(-1 * models.DefaultHeartbeatsTimeout)
+		result, err := srv.repository.GetByLastActiveAfter(minDate)
+		if err != nil {
+			return 0, err
+		}
+		for _, r := range result {
+			srv.currentOnlineUsers.SetDefault(r.ID, true)
+		}
+		srv.countersInitialized.Store(true)
+	}
+
+	return srv.currentOnlineUsers.ItemCount(), nil
+}
+
 func (srv *UserService) CreateOrGet(signup *models.Signup, isAdmin bool) (*models.User, bool, error) {
 	u := &models.User{
 		ID:        signup.Username,

services/user.go

@@ -199,6 +199,31 @@ main {
 .wi-min {
     width: min-content !important;
 }
+
+#online-indicator {
+}
+
+.live-indicator {
+    width: 10px;
+    height: 10px;
+    border-radius: 50%;
+    background-color: #047857;
+    display: inline-block;
+    animation: pulse 2s infinite;
+}
+
+@keyframes pulse {
+    0% {
+        opacity: 0.5;
+    }
+    50% {
+        opacity: 1;
+    }
+    100% {
+        opacity: 0.5;
+    }
+}
+
 @media print {
 
     /* Avoid the element from being breaked */