Compute statistics on time for each widget.

src/backend-api/src/main/kotlin/org/icpclive/api/WidgetUsageStatistics.kt

@@ -0,0 +1,27 @@
+package org.icpclive.api
+
+import kotlinx.serialization.*
+import org.icpclive.cds.api.TeamId
+import org.icpclive.cds.util.serializers.DurationInSecondsSerializer
+import kotlin.time.*
+
+@Serializable
+data class WidgetUsageStatistics(
+    val entries: MutableMap<String, WidgetUsageStatisticsEntry>
+)
+
+@Serializable
+sealed class WidgetUsageStatisticsEntry {
+    @Serializable
+    @SerialName("simple")
+    data class Simple(
+        @Transient val shownSince: TimeSource.Monotonic.ValueTimeMark? = null,
+        @Transient val shownCount: Int = 0,
+        @Serializable(with = DurationInSecondsSerializer::class)
+        @SerialName("totalShownTimeSeconds")
+        val totalShownTime: Duration
+    ) : WidgetUsageStatisticsEntry()
+    @Serializable
+    @SerialName("per_team")
+    data class PerTeam(val byTeam: Map<TeamId, WidgetUsageStatisticsEntry>): WidgetUsageStatisticsEntry()
+}

src/backend-api/src/main/kotlin/org/icpclive/api/Widgets.kt

@@ -25,14 +25,16 @@ fun getLocationOrDefault(widgetPrefix: String, defaultLocationRectangle: Locatio
 @Serializable
 sealed class Widget(
     @SerialName("widgetId") override val id: String,
-    val location: LocationRectangle
+    val location: LocationRectangle,
+    val statisticsId: String,
 ) : TypeWithId
 
 @Serializable
 @SerialName("AdvertisementWidget")
 class AdvertisementWidget(val advertisement: AdvertisementSettings) : Widget(
     generateId(WIDGET_ID_PREFIX),
-    getLocationOrDefault(WIDGET_ID_PREFIX, location)
+    getLocationOrDefault(WIDGET_ID_PREFIX, location),
+    WIDGET_ID_PREFIX,
 ) {
     companion object {
         const val WIDGET_ID_PREFIX = "advertisement"
@@ -44,7 +46,8 @@ class AdvertisementWidget(val advertisement: AdvertisementSettings) : Widget(
 @SerialName("PictureWidget")
 class PictureWidget(val picture: PictureSettings) : Widget(
     generateId(WIDGET_ID_PREFIX),
-    getLocationOrDefault(WIDGET_ID_PREFIX, location)
+    getLocationOrDefault(WIDGET_ID_PREFIX, location),
+    WIDGET_ID_PREFIX
 ) {
     companion object {
         const val WIDGET_ID_PREFIX = "picture"
@@ -56,7 +59,8 @@ class PictureWidget(val picture: PictureSettings) : Widget(
 @SerialName("SvgWidget")
 class SvgWidget(val content: String) : Widget(
     generateId(WIDGET_ID_PREFIX),
-    getLocationOrDefault(WIDGET_ID_PREFIX, location)
+    getLocationOrDefault(WIDGET_ID_PREFIX, location),
+    WIDGET_ID_PREFIX
 ) {
     companion object {
         const val WIDGET_ID_PREFIX = "svg"
@@ -68,7 +72,8 @@ class SvgWidget(val content: String) : Widget(
 @SerialName("QueueWidget")
 class QueueWidget(val settings: QueueSettings) : Widget(
     WIDGET_ID,
-    getLocationOrDefault(WIDGET_ID, location)
+    getLocationOrDefault(WIDGET_ID, location),
+    WIDGET_ID,
 ) {
     companion object {
         const val WIDGET_ID = "queue"
@@ -80,7 +85,8 @@ class QueueWidget(val settings: QueueSettings) : Widget(
 @SerialName("ScoreboardWidget")
 class ScoreboardWidget(val settings: ScoreboardSettings) : Widget(
     WIDGET_ID,
-    getLocationOrDefault(WIDGET_ID, location)
+    getLocationOrDefault(WIDGET_ID, location),
+    WIDGET_ID,
 ) {
     companion object {
         const val WIDGET_ID = "scoreboard"
@@ -92,7 +98,8 @@ class ScoreboardWidget(val settings: ScoreboardSettings) : Widget(
 @SerialName("StatisticsWidget")
 class StatisticsWidget(val settings: StatisticsSettings) : Widget(
     WIDGET_ID,
-    getLocationOrDefault(WIDGET_ID, location)
+    getLocationOrDefault(WIDGET_ID, location),
+    WIDGET_ID
 ) {
     companion object {
         const val WIDGET_ID = "statistics"
@@ -104,7 +111,8 @@ class StatisticsWidget(val settings: StatisticsSettings) : Widget(
 @SerialName("TickerWidget")
 class TickerWidget(val settings: TickerSettings) : Widget(
     WIDGET_ID,
-    getLocationOrDefault(WIDGET_ID, location)
+    getLocationOrDefault(WIDGET_ID, location),
+    WIDGET_ID
 ) {
     companion object {
         const val WIDGET_ID = "ticker"
@@ -117,16 +125,19 @@ enum class TeamViewPosition {
     SINGLE_TOP_RIGHT, PVP_TOP, PVP_BOTTOM, TOP_LEFT, TOP_RIGHT, BOTTOM_LEFT, BOTTOM_RIGHT
 }
 
+
 @Serializable
 @SerialName("TeamViewWidget")
 class TeamViewWidget(
     val settings: OverlayTeamViewSettings
 ) : Widget(
     getWidgetId(settings.position),
-    getLocationOrDefault(getWidgetId(settings.position), getLocation(settings.position))
+    getLocationOrDefault(getWidgetId(settings.position), getLocation(settings.position)),
+    WIDGET_ID_PREFIX
 ) {
     companion object {
-        fun getWidgetId(position: TeamViewPosition) = "teamview." + position.name
+        private const val WIDGET_ID_PREFIX = "teamview"
+        fun getWidgetId(position: TeamViewPosition) = "$WIDGET_ID_PREFIX.${position.name}"
         fun getLocation(position: TeamViewPosition) = when (position) {
             TeamViewPosition.SINGLE_TOP_RIGHT -> LocationRectangle(16, 16, 1488, 984)
             TeamViewPosition.PVP_TOP -> LocationRectangle(16, 16, 1488, 984 / 2 + 16)
@@ -143,7 +154,8 @@ class TeamViewWidget(
 @SerialName("FullScreenClockWidget")
 class FullScreenClockWidget(val settings: FullScreenClockSettings) : Widget(
     WIDGET_ID,
-    getLocationOrDefault(WIDGET_ID, location)
+    getLocationOrDefault(WIDGET_ID, location),
+    WIDGET_ID
 ) {
     companion object {
         const val WIDGET_ID = "fullScreenClock"
@@ -156,6 +168,7 @@ class FullScreenClockWidget(val settings: FullScreenClockSettings) : Widget(
 class TeamLocatorWidget(val settings: TeamLocatorSettings) : Widget(
     WIDGET_ID,
     getLocationOrDefault(WIDGET_ID, location),
+    WIDGET_ID,
 ) {
     companion object {
         const val WIDGET_ID = "teamLocator"

src/backend/src/main/kotlin/org/icpclive/admin/Routing.kt

@@ -148,6 +148,9 @@ fun Route.configureAdminApiRouting() {
                 }
             }
         }
+        get("/usage_stats") {
+            call.respond(Controllers.getWidgetStats())
+        }
     }
     route("/social") {
         setupSocial()

src/backend/src/main/kotlin/org/icpclive/controllers/LocatorWidgetController.kt

@@ -6,7 +6,7 @@ import org.icpclive.api.*
 import org.icpclive.cds.api.ContestInfo
 import org.icpclive.data.*
 
-class LocatorWidgetController(manager: Manager<TeamLocatorWidget>) :
+class LocatorWidgetController(manager: Manager<in TeamLocatorWidget>) :
     SingleWidgetController<ExternalTeamLocatorSettings, TeamLocatorWidget>(ExternalTeamLocatorSettings(), manager) {
     override suspend fun onDelete(id: Int) {}
 

src/backend/src/main/kotlin/org/icpclive/controllers/SingleWidgetController.kt

@@ -13,7 +13,7 @@ import org.icpclive.data.Manager
 
 abstract class SingleWidgetController<SettingsType : ObjectSettings, DataType : TypeWithId>(
     private var settings: SettingsType,
-    private val manager: Manager<DataType>,
+    private val manager: Manager<in DataType>,
     val id: Int? = null,
 ) {
     private val mutex = Mutex()

src/backend/src/main/kotlin/org/icpclive/controllers/TeamViewController.kt

@@ -1,14 +1,12 @@
 package org.icpclive.controllers
 
 import kotlinx.coroutines.delay
-import kotlinx.coroutines.flow.first
 import org.icpclive.api.*
-import org.icpclive.cds.api.MediaType
 import org.icpclive.cds.api.TeamMediaType
 import org.icpclive.data.*
 import kotlin.time.Duration.Companion.seconds
 
-class TeamViewController(manager: Manager<TeamViewWidget>, val position: TeamViewPosition) :
+class TeamViewController(manager: Manager<in TeamViewWidget>, val position: TeamViewPosition) :
     SingleWidgetController<ExternalTeamViewSettings, TeamViewWidget>(ExternalTeamViewSettings(), manager) {
     override suspend fun onDelete(id: Int) {}
 

src/backend/src/main/kotlin/org/icpclive/data/Controllers.kt

@@ -31,4 +31,6 @@ object Controllers {
     }
     val tickerMessage = PresetsController(presetsPath("ticker"), TickerManager, TickerMessageSettings::toMessage)
     val userController = Config.createUsersController()
+
+    suspend fun getWidgetStats() = WidgetManager.getUsageStatistics()
 }

src/backend/src/main/kotlin/org/icpclive/data/Manager.kt

@@ -6,12 +6,12 @@ import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
 import org.icpclive.api.TypeWithId
 
-abstract class Manager<in T> {
+abstract class Manager<T> {
     abstract suspend fun add(item: T)
     abstract suspend fun remove(itemId: String)
 }
 
-abstract class ManagerWithEvents<in T : TypeWithId, E> : Manager<T>() {
+abstract class ManagerWithEvents<T : TypeWithId, E> : Manager<T>() {
     private val mutex = Mutex()
     private var timer = 0L
     private val items = mutableListOf<T>()
@@ -24,15 +24,31 @@ abstract class ManagerWithEvents<in T : TypeWithId, E> : Manager<T>() {
     protected abstract fun createAddEvent(item: T): E
     protected abstract fun createRemoveEvent(id: String): E
     protected abstract fun createSnapshotEvent(items: List<T>): E
+    protected open fun onItemAdd(item: T) {}
+    protected open fun onItemRemove(item: T) {}
+
+    protected suspend fun traverse(block: (T) -> Unit) = mutex.withLock {
+        items.forEach(block)
+    }
+
+    private fun removeById(id: String) : Boolean {
+        val myItems = items.filter { it.id == id }
+        for (item in myItems) {
+            onItemRemove(item)
+        }
+        items.removeAll(myItems)
+        return myItems.isNotEmpty()
+    }
 
     override suspend fun add(item: T) = mutex.withLock {
-        items.removeIf { it.id == item.id } // We don't need the remove event, as create considered as the set on frontend.
+        removeById(item.id) // We don't need the remove event, as create considered as the set on frontend.
         items.add(item)
+        onItemAdd(item)
         sendEvent(createAddEvent(item))
     }
 
     override suspend fun remove(itemId: String) = mutex.withLock {
-        if (items.removeIf { it.id == itemId }) {
+        if (removeById(itemId)) {
             sendEvent(createRemoveEvent(itemId))
         }
     }

src/backend/src/main/kotlin/org/icpclive/data/WidgetManager.kt

@@ -1,13 +1,100 @@
 package org.icpclive.data
 
 import org.icpclive.api.*
+import org.icpclive.cds.util.getLogger
 import org.icpclive.util.completeOrThrow
+import kotlin.time.Duration
+import kotlin.time.TimeSource
+
+private val logger by getLogger()
+
+private fun WidgetUsageStatisticsEntry.Simple?.updateStatsRemove(item: Widget) =
+    when {
+        this == null -> {
+            logger.warning { "Suspicious statistics for widget ${item.statisticsId}: removed, but wasn't added" }
+            WidgetUsageStatisticsEntry.Simple(
+                shownSince = null,
+                shownCount = 0,
+                totalShownTime = Duration.ZERO
+            )
+        }
+        else -> {
+            if (shownCount == 0) {
+                logger.warning { "Suspicious statistics for widget ${item.statisticsId}: removed, but shown count was zero" }
+            }
+            WidgetUsageStatisticsEntry.Simple(
+                shownSince = if (this.shownCount == 1) null else shownSince,
+                shownCount = shownCount - 1,
+                totalShownTime = totalShownTime + if (this.shownCount == 1) shownSince!!.elapsedNow() else Duration.ZERO,
+            )
+        }
+    }
+
+private fun WidgetUsageStatisticsEntry.Simple?.updateStatsAdd(item: Widget) : WidgetUsageStatisticsEntry.Simple =
+    WidgetUsageStatisticsEntry.Simple(
+        shownSince = this?.shownSince ?: TimeSource.Monotonic.markNow(),
+        shownCount = (this?.shownCount ?: 0) + 1,
+        totalShownTime = (this?.totalShownTime ?: Duration.ZERO)
+    )
+
+
+private fun WidgetUsageStatisticsEntry?.updateStatsRemove(item: Widget) : WidgetUsageStatisticsEntry = when (item) {
+    is TeamViewWidget -> {
+        require(this is WidgetUsageStatisticsEntry.PerTeam?)
+        val res = this ?: WidgetUsageStatisticsEntry.PerTeam(mutableMapOf())
+        val newEntry = (res.byTeam[item.settings.teamId] as WidgetUsageStatisticsEntry.Simple?).updateStatsRemove(item)
+        WidgetUsageStatisticsEntry.PerTeam(
+            res.byTeam  + (item.settings.teamId to newEntry)
+        )
+    }
+    else -> {
+        require(this is WidgetUsageStatisticsEntry.Simple?)
+        updateStatsRemove(item)
+    }
+}
+
+private fun WidgetUsageStatisticsEntry?.updateStatsAdd(item: Widget): WidgetUsageStatisticsEntry = when (item) {
+    is TeamViewWidget -> {
+        require(this is WidgetUsageStatisticsEntry.PerTeam?)
+        val res = this ?: WidgetUsageStatisticsEntry.PerTeam(mutableMapOf())
+        val newEntry = (res.byTeam[item.settings.teamId] as WidgetUsageStatisticsEntry.Simple?).updateStatsAdd(item)
+        WidgetUsageStatisticsEntry.PerTeam(
+            res.byTeam  + (item.settings.teamId to newEntry)
+        )
+    }
+    else -> {
+        require(this is WidgetUsageStatisticsEntry.Simple?)
+        updateStatsAdd(item)
+    }
+}
+
 
 class WidgetManager : ManagerWithEvents<Widget, MainScreenEvent>() {
+    private val statistics = WidgetUsageStatistics(mutableMapOf())
+
     override fun createAddEvent(item: Widget) = ShowWidgetEvent(item)
     override fun createRemoveEvent(id: String) = HideWidgetEvent(id)
     override fun createSnapshotEvent(items: List<Widget>) = MainScreenSnapshotEvent(items)
 
+    override fun onItemRemove(item: Widget) {
+        statistics.entries[item.statisticsId] = statistics.entries[item.statisticsId].updateStatsRemove(item)
+        super.onItemRemove(item)
+    }
+
+    override fun onItemAdd(item: Widget) {
+        statistics.entries[item.statisticsId] = statistics.entries[item.statisticsId].updateStatsAdd(item)
+        super.onItemRemove(item)
+    }
+
+    suspend fun getUsageStatistics() : WidgetUsageStatistics {
+        val statisticsCopy = WidgetUsageStatistics(statistics.entries.toMutableMap())
+        traverse {
+            statisticsCopy.entries[it.statisticsId] = statisticsCopy.entries[it.statisticsId].updateStatsRemove(it)
+        }
+        return statisticsCopy
+    }
+
+
     init {
         DataBus.mainScreenFlow.completeOrThrow(flow)
     }