Add WinBackPromptEvaluator to re-engage users who were previously default browser

app/src/main/java/com/duckduckgo/app/browser/defaultbrowsing/DefaultBrowserObserver.kt

@@ -35,7 +35,6 @@ class DefaultBrowserObserver(
             appInstallStore.defaultBrowser = isDefaultBrowser
             when {
                 isDefaultBrowser -> {
-                    appInstallStore.wasEverDefaultBrowser = true
                     val params = mapOf(
                         PixelParameter.DEFAULT_BROWSER_SET_FROM_ONBOARDING to false.toString(),
                     )

app/src/main/java/com/duckduckgo/app/browser/defaultbrowsing/prompts/AdditionalDefaultBrowserPromptsImpl.kt

@@ -109,7 +109,7 @@ class AdditionalDefaultBrowserPromptsImpl @Inject constructor(
     moshi: Moshi,
 ) : AdditionalDefaultBrowserPrompts, ModalEvaluator, PrivacyConfigCallbackPlugin {
 
-    override val priority: Int = 2
+    override val priority: Int = 3
     override val evaluatorId: String = "additional_default_browser_prompts"
 
     private val evaluationMutex = Mutex()

app/src/main/java/com/duckduckgo/app/global/install/AppInstallStore.kt

@@ -37,8 +37,9 @@ interface AppInstallStore : MainProcessLifecycleObserver {
 
     var widgetInstalled: Boolean
 
+    /** Setting to `true` also flips [wasEverDefaultBrowser] to `true` permanently. */
     var defaultBrowser: Boolean
-    var wasEverDefaultBrowser: Boolean
+    val wasEverDefaultBrowser: Boolean
 
     var defaultBrowserChangedSurveyDone: Boolean
 
@@ -66,11 +67,15 @@ class AppInstallSharedPreferences @Inject constructor(
 
     override var defaultBrowser: Boolean
         get() = preferences.getBoolean(KEY_DEFAULT_BROWSER, false)
-        set(defaultBrowser) = preferences.edit { putBoolean(KEY_DEFAULT_BROWSER, defaultBrowser) }
+        set(defaultBrowser) = preferences.edit {
+            putBoolean(KEY_DEFAULT_BROWSER, defaultBrowser)
+            if (defaultBrowser) {
+                putBoolean(KEY_WAS_EVER_DEFAULT_BROWSER, true)
+            }
+        }
 
-    override var wasEverDefaultBrowser: Boolean
+    override val wasEverDefaultBrowser: Boolean
         get() = preferences.getBoolean(KEY_WAS_EVER_DEFAULT_BROWSER, false)
-        set(value) = preferences.edit { putBoolean(KEY_WAS_EVER_DEFAULT_BROWSER, value) }
 
     override var defaultBrowserChangedSurveyDone: Boolean
         get() = preferences.getBoolean(KEY_DEFAULT_BROWSER_CHANGED_SURVEY_DONE, false)

app/src/main/java/com/duckduckgo/app/global/store/AndroidUserBrowserProperties.kt

@@ -61,6 +61,10 @@ class AndroidUserBrowserProperties(
         return appInstallStore.defaultBrowser
     }
 
+    override suspend fun wasEverDefaultBrowser(): Boolean {
+        return appInstallStore.wasEverDefaultBrowser
+    }
+
     override fun emailEnabled(): Boolean {
         return emailManager.isSignedIn()
     }

app/src/main/java/com/duckduckgo/app/onboarding/ui/page/BrandDesignUpdatePageViewModel.kt

@@ -298,7 +298,6 @@ class BrandDesignUpdatePageViewModel @Inject constructor(
     fun onDefaultBrowserSet() {
         defaultRoleBrowserDialog.dialogShown()
         appInstallStore.defaultBrowser = true
-        appInstallStore.wasEverDefaultBrowser = true
         pixel.fire(AppPixelName.DEFAULT_BROWSER_SET, mapOf(PixelParameter.DEFAULT_BROWSER_SET_FROM_ONBOARDING to true.toString()))
         viewModelScope.launch {
             _viewState.update { it.copy(showSplitOption = isSplitOmnibarEnabled()) }

app/src/main/java/com/duckduckgo/app/onboarding/ui/page/DefaultBrowserPageViewModel.kt

@@ -154,7 +154,6 @@ class DefaultBrowserPageViewModel @Inject constructor(
         timesPressedJustOnce = 0
         if (defaultBrowserDetector.isDefaultBrowser()) {
             installStore.defaultBrowser = true
-            installStore.wasEverDefaultBrowser = true
             val params = mapOf(
                 Pixel.PixelParameter.DEFAULT_BROWSER_SET_FROM_ONBOARDING to true.toString(),
                 Pixel.PixelParameter.DEFAULT_BROWSER_SET_ORIGIN to originValue,

app/src/main/java/com/duckduckgo/app/onboarding/ui/page/WelcomePageViewModel.kt

@@ -346,7 +346,6 @@ class WelcomePageViewModel @Inject constructor(
     fun onDefaultBrowserSet() {
         defaultRoleBrowserDialog.dialogShown()
         appInstallStore.defaultBrowser = true
-        appInstallStore.wasEverDefaultBrowser = true
         pixel.fire(AppPixelName.DEFAULT_BROWSER_SET, mapOf(PixelParameter.DEFAULT_BROWSER_SET_FROM_ONBOARDING to true.toString()))
 
         viewModelScope.launch {

app/src/test/java/com/duckduckgo/app/browser/defaultbrowsing/DefaultBrowserObserverTest.kt

@@ -65,36 +65,6 @@ class DefaultBrowserObserverTest {
         verify(mockPixel).fire(AppPixelName.DEFAULT_BROWSER_SET, params)
     }
 
-    @Test
-    fun whenDDGBecomesDefaultBrowserThenWasEverDefaultSetToTrue() {
-        whenever(mockDefaultBrowserDetector.isDefaultBrowser()).thenReturn(true)
-        whenever(mockAppInstallStore.defaultBrowser).thenReturn(false)
-
-        testee.onResume(mockOwner)
-
-        verify(mockAppInstallStore).wasEverDefaultBrowser = true
-    }
-
-    @Test
-    fun whenDDGIsNotDefaultBrowserThenWasEverDefaultNotChanged() {
-        whenever(mockDefaultBrowserDetector.isDefaultBrowser()).thenReturn(false)
-        whenever(mockAppInstallStore.defaultBrowser).thenReturn(false)
-
-        testee.onResume(mockOwner)
-
-        verify(mockAppInstallStore, never()).wasEverDefaultBrowser = any()
-    }
-
-    @Test
-    fun whenDDGRemainsDefaultBrowserThenWasEverDefaultNotChanged() {
-        whenever(mockDefaultBrowserDetector.isDefaultBrowser()).thenReturn(true)
-        whenever(mockAppInstallStore.defaultBrowser).thenReturn(true)
-
-        testee.onResume(mockOwner)
-
-        verify(mockAppInstallStore, never()).wasEverDefaultBrowser = any()
-    }
-
     @Test
     fun whenDDGIsNotDefaultBrowserIfItWasNotBeforeThenDoNotFireSetPixel() {
         whenever(mockDefaultBrowserDetector.isDefaultBrowser()).thenReturn(false)

app/src/test/java/com/duckduckgo/app/global/install/AppInstallSharedPreferencesTest.kt

@@ -87,4 +87,35 @@ class AppInstallSharedPreferencesTest {
 
         assertEquals(existingTimestamp, testee.installTimestamp)
     }
+
+    @Test
+    fun whenInitializedThenDefaultBrowserAndWasEverDefaultBrowserAreFalse() = runTest {
+        assertFalse(testee.defaultBrowser)
+        assertFalse(testee.wasEverDefaultBrowser)
+    }
+
+    @Test
+    fun whenDefaultBrowserSetToTrueThenWasEverDefaultBrowserIsTrue() = runTest {
+        testee.defaultBrowser = true
+
+        assertTrue(testee.defaultBrowser)
+        assertTrue(testee.wasEverDefaultBrowser)
+    }
+
+    @Test
+    fun whenDefaultBrowserSetToFalseInitiallyThenWasEverDefaultBrowserRemainsFalse() = runTest {
+        testee.defaultBrowser = false
+
+        assertFalse(testee.defaultBrowser)
+        assertFalse(testee.wasEverDefaultBrowser)
+    }
+
+    @Test
+    fun whenDefaultBrowserSetToFalseAfterBeingTrueThenWasEverDefaultBrowserRemainsTrue() = runTest {
+        testee.defaultBrowser = true
+        testee.defaultBrowser = false
+
+        assertFalse(testee.defaultBrowser)
+        assertTrue(testee.wasEverDefaultBrowser)
+    }
 }

app/src/test/java/com/duckduckgo/app/tabs/ui/TabSwitcherViewModelTest.kt

@@ -2018,6 +2018,10 @@ class TabSwitcherViewModelTest {
             TODO("Not yet implemented")
         }
 
+        override suspend fun wasEverDefaultBrowser(): Boolean {
+            TODO("Not yet implemented")
+        }
+
         override fun emailEnabled(): Boolean {
             TODO("Not yet implemented")
         }

browser-api/src/main/java/com/duckduckgo/browser/api/UserBrowserProperties.kt

@@ -31,6 +31,13 @@ interface UserBrowserProperties {
     fun daysSinceInstalled(): Long
     suspend fun daysUsedSince(since: Date): Long
     fun defaultBrowser(): Boolean
+
+    /**
+     * Returns true if this app has ever been set as the user's default browser.
+     * Once true, this value is permanent — it does not revert if the user later
+     * changes their default browser to something else.
+     */
+    suspend fun wasEverDefaultBrowser(): Boolean
     fun emailEnabled(): Boolean
     fun searchCount(): Long
     fun widgetAdded(): Boolean

dax-prompts/dax-prompts-impl/build.gradle

@@ -25,6 +25,7 @@ apply from: "$rootProject.projectDir/gradle/android-library.gradle"
 
 dependencies {
     implementation project(':dax-prompts-api')
+    implementation project(':modal-coordinator-api')
     implementation project(':browser-api')
     implementation project(':common-utils')
     implementation project(':design-system')

dax-prompts/dax-prompts-impl/src/main/java/com/duckduckgo/daxprompts/impl/WinBackPromptEvaluator.kt

@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2026 DuckDuckGo
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.duckduckgo.daxprompts.impl
+
+import android.content.Context
+import android.content.Intent
+import com.duckduckgo.app.browser.defaultbrowsing.DefaultBrowserDetector
+import com.duckduckgo.app.di.AppCoroutineScope
+import com.duckduckgo.app.onboarding.OnboardingFlowChecker
+import com.duckduckgo.browser.api.UserBrowserProperties
+import com.duckduckgo.common.utils.DispatcherProvider
+import com.duckduckgo.daxprompts.api.DaxPromptBrowserComparisonNoParams
+import com.duckduckgo.daxprompts.impl.repository.DaxPromptsRepository
+import com.duckduckgo.di.scopes.AppScope
+import com.duckduckgo.modalcoordinator.api.ModalEvaluator
+import com.duckduckgo.navigation.api.GlobalActivityStarter
+import com.squareup.anvil.annotations.ContributesBinding
+import com.squareup.anvil.annotations.ContributesMultibinding
+import dagger.SingleInstanceIn
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import javax.inject.Inject
+
+interface WinBackPromptEvaluator
+
+@ContributesMultibinding(
+    scope = AppScope::class,
+    boundType = ModalEvaluator::class,
+)
+@ContributesBinding(
+    scope = AppScope::class,
+    boundType = WinBackPromptEvaluator::class,
+)
+@SingleInstanceIn(scope = AppScope::class)
+class WinBackPromptEvaluatorImpl @Inject constructor(
+    @AppCoroutineScope private val appCoroutineScope: CoroutineScope,
+    private val applicationContext: Context,
+    private val userBrowserProperties: UserBrowserProperties,
+    private val defaultBrowserDetector: DefaultBrowserDetector,
+    private val daxPromptsRepository: DaxPromptsRepository,
+    private val globalActivityStarter: GlobalActivityStarter,
+    private val dispatchers: DispatcherProvider,
+    private val reactivateUsersToggles: ReactivateUsersToggles,
+    private val onboardingFlowChecker: OnboardingFlowChecker,
+) : ModalEvaluator, WinBackPromptEvaluator {
+
+    override val priority: Int = 1
+
+    override val evaluatorId: String = "win_back_prompt"
+
+    override suspend fun evaluate(): ModalEvaluator.EvaluationResult = withContext(dispatchers.io()) {
+        if (isEnabled() && isEligible()) {
+            val intent = globalActivityStarter
+                .startIntent(applicationContext, DaxPromptBrowserComparisonNoParams) ?: return@withContext ModalEvaluator.EvaluationResult.Skipped
+
+            delay(MODAL_DISPLAY_DELAY)
+            appCoroutineScope.launch(dispatchers.main()) {
+                intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_SINGLE_TOP
+                applicationContext.startActivity(intent)
+            }
+
+            return@withContext ModalEvaluator.EvaluationResult.ModalShown
+        } else {
+            return@withContext ModalEvaluator.EvaluationResult.Skipped
+        }
+    }
+
+    private fun isEnabled() = reactivateUsersToggles.self().isEnabled() && reactivateUsersToggles.defaultBrowserWinBackPrompt().isEnabled()
+
+    private suspend fun isEligible() = onboardingFlowChecker.isOnboardingComplete() &&
+        userBrowserProperties.wasEverDefaultBrowser() &&
+        !daxPromptsRepository.getDaxPromptsBrowserComparisonShown() &&
+        !defaultBrowserDetector.isDefaultBrowser()
+
+    companion object {
+        private const val MODAL_DISPLAY_DELAY = 1500L
+    }
+}