Add another performance check for cold start time until the cached room list is displayed

appnav/src/main/kotlin/io/element/android/appnav/NotLoggedInFlowNode.kt

@@ -24,6 +24,7 @@ import dev.zacsweers.metro.AppScope
 import dev.zacsweers.metro.Assisted
 import dev.zacsweers.metro.AssistedInject
 import io.element.android.annotations.ContributesNode
+import io.element.android.appnav.analytics.AnalyticsColdStartWatcher
 import io.element.android.features.login.api.LoginEntryPoint
 import io.element.android.features.login.api.LoginParams
 import io.element.android.libraries.architecture.BackstackView
@@ -43,6 +44,7 @@ class NotLoggedInFlowNode(
     @Assisted plugins: List<Plugin>,
     private val loginEntryPoint: LoginEntryPoint,
     private val imageLoaderHolder: ImageLoaderHolder,
+    private val analyticsColdStartWatcher: AnalyticsColdStartWatcher,
 ) : BaseFlowNode<NotLoggedInFlowNode.NavTarget>(
     backstack = BackStack(
         initialElement = NavTarget.Root,
@@ -65,6 +67,7 @@ class NotLoggedInFlowNode(
 
     override fun onBuilt() {
         super.onBuilt()
+        analyticsColdStartWatcher.whenLoggingIn()
         lifecycle.subscribe(
             onResume = {
                 SingletonImageLoader.setUnsafe(imageLoaderHolder.get())

appnav/src/main/kotlin/io/element/android/appnav/RootFlowNode.kt

@@ -29,6 +29,7 @@ import dev.zacsweers.metro.Assisted
 import dev.zacsweers.metro.AssistedInject
 import im.vector.app.features.analytics.plan.JoinedRoom
 import io.element.android.annotations.ContributesNode
+import io.element.android.appnav.analytics.AnalyticsColdStartWatcher
 import io.element.android.appnav.di.MatrixSessionCache
 import io.element.android.appnav.intent.IntentResolver
 import io.element.android.appnav.intent.ResolvedIntent
@@ -89,6 +90,7 @@ class RootFlowNode(
     private val featureFlagService: FeatureFlagService,
     private val announcementService: AnnouncementService,
     private val analyticsService: AnalyticsService,
+    private val analyticsColdStartWatcher: AnalyticsColdStartWatcher,
 ) : BaseFlowNode<RootFlowNode.NavTarget>(
     backstack = BackStack(
         initialElement = NavTarget.SplashScreen,
@@ -98,6 +100,7 @@ class RootFlowNode(
     plugins = plugins
 ) {
     override fun onBuilt() {
+        analyticsColdStartWatcher.start()
         matrixSessionCache.restoreWithSavedState(buildContext.savedStateMap)
         super.onBuilt()
         observeNavState()

appnav/src/main/kotlin/io/element/android/appnav/analytics/AnalyticsColdStartWatcher.kt

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2025 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.appnav.analytics
+
+import dev.zacsweers.metro.AppScope
+import dev.zacsweers.metro.ContributesBinding
+import dev.zacsweers.metro.SingleIn
+import io.element.android.libraries.di.annotations.AppCoroutineScope
+import io.element.android.services.analytics.api.AnalyticsLongRunningTransaction
+import io.element.android.services.analytics.api.AnalyticsService
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.catch
+import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.onEach
+import timber.log.Timber
+import java.util.concurrent.atomic.AtomicBoolean
+
+/**
+ * Adds a performance check transaction measuring the time between a cold start (or, after we read the user consent after a cold start)
+ * until the cached room list is displayed. This check only takes place in a cold app start after the user is authenticated.
+ */
+interface AnalyticsColdStartWatcher {
+    fun start()
+    fun whenLoggingIn()
+    fun onRoomListVisible()
+}
+
+@SingleIn(AppScope::class)
+@ContributesBinding(AppScope::class)
+class DefaultAnalyticsColdStartWatcher(
+    private val analyticsService: AnalyticsService,
+    @AppCoroutineScope private val appCoroutineScope: CoroutineScope,
+) : AnalyticsColdStartWatcher {
+    private val isColdStart = AtomicBoolean(true)
+
+    override fun start() {
+        analyticsService.userConsentFlow
+            .onEach { hasConsent ->
+                if (hasConsent) {
+                    if (isColdStart.get()) {
+                        Timber.d("Starting cold start check")
+                        analyticsService.startLongRunningTransaction(AnalyticsLongRunningTransaction.ColdStartUntilCachedRoomList)
+                    } else {
+                        error("The app is no longer in a cold start state")
+                    }
+                }
+            }
+            .catch { Timber.w(it.message) }
+            .launchIn(appCoroutineScope)
+    }
+
+    override fun whenLoggingIn() {
+        if (isColdStart.getAndSet(false)) {
+            Timber.d("Canceled cold start check: user is logging in")
+        }
+    }
+
+    override fun onRoomListVisible() {
+        if (isColdStart.getAndSet(false)) {
+            Timber.d("Room list is visible, finishing cold start check")
+            analyticsService.removeLongRunningTransaction(AnalyticsLongRunningTransaction.ColdStartUntilCachedRoomList)?.finish()
+        }
+    }
+}