Updated on 2026-08-14

app/build.gradle.kts

@@ -35,6 +35,8 @@ dependencies {
     implementation(projects.domain.txhistory)
     implementation(projects.domain.appCurrency)
     implementation(projects.domain.appCurrency.models)
+    implementation(projects.domain.appTheme)
+    implementation(projects.domain.appTheme.models)
 
     implementation(project(":common"))
     implementation(project(":core:analytics"))
@@ -55,6 +57,7 @@ dependencies {
     implementation(projects.data.tokens)
     implementation(projects.data.txhistory)
     implementation(projects.data.appCurrency)
+    implementation(projects.data.appTheme)
 
     /** Features */
     implementation(project(":features:onboarding"))
@@ -86,6 +89,7 @@ dependencies {
     implementation(deps.lifecycle.runtime.ktx)
     implementation(deps.lifecycle.common.java8)
     implementation(deps.lifecycle.viewModel.ktx)
+    implementation(deps.lifecycle.compose)
 
     /** Compose libraries */
     implementation(deps.compose.constraintLayout)

app/src/main/java/com/tangem/tap/di/domain/AppThemeDomainModule.kt

@@ -0,0 +1,24 @@
+package com.tangem.tap.di.domain
+
+import com.tangem.domain.apptheme.ChangeAppThemeModeUseCase
+import com.tangem.domain.apptheme.GetAppThemeModeUseCase
+import com.tangem.domain.apptheme.repository.AppThemeModeRepository
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.android.components.ViewModelComponent
+
+@Module
+@InstallIn(ViewModelComponent::class)
+internal object AppThemeDomainModule {
+
+    @Provides
+    fun provideGetAppThemeModeUpdatesUseCase(appThemeModeRepository: AppThemeModeRepository): GetAppThemeModeUseCase {
+        return GetAppThemeModeUseCase(appThemeModeRepository)
+    }
+
+    @Provides
+    fun provideChangeAppThemeModeUseCase(appThemeModeRepository: AppThemeModeRepository): ChangeAppThemeModeUseCase {
+        return ChangeAppThemeModeUseCase(appThemeModeRepository)
+    }
+}

data/app-theme/.gitignore

@@ -0,0 +1 @@
+/build

data/app-theme/build.gradle.kts

@@ -0,0 +1,34 @@
+plugins {
+    alias(deps.plugins.android.library)
+    alias(deps.plugins.kotlin.android)
+    alias(deps.plugins.kotlin.kapt)
+    id("configuration")
+}
+
+android {
+    namespace = "com.tangem.data.apptheme"
+}
+
+dependencies {
+
+    /** Project - Domain */
+    implementation(projects.domain.core)
+    implementation(projects.domain.appTheme)
+    implementation(projects.domain.appTheme.models)
+
+    /** Project - Data */
+    implementation(projects.core.datasource)
+    implementation(projects.data.common)
+
+    /** Project - Utils */
+    implementation(projects.core.utils)
+
+    /** DI */
+    implementation(deps.hilt.core)
+    kapt(deps.hilt.kapt)
+
+    /** Other */
+    implementation(deps.kotlin.coroutines)
+    implementation(deps.timber)
+    implementation(deps.jodatime)
+}

data/app-theme/src/main/kotlin/com/tangem/data/apptheme/MockAppThemeModeRepository.kt

@@ -0,0 +1,19 @@
+package com.tangem.data.apptheme
+
+import com.tangem.domain.apptheme.model.AppThemeMode
+import com.tangem.domain.apptheme.repository.AppThemeModeRepository
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.MutableStateFlow
+
+internal class MockAppThemeModeRepository : AppThemeModeRepository {
+
+    private val appThemeModeFlow = MutableStateFlow(AppThemeMode.DEFAULT)
+
+    override fun getAppThemeMode(): Flow<AppThemeMode> {
+        return appThemeModeFlow
+    }
+
+    override suspend fun changeAppThemeMode(mode: AppThemeMode) {
+        appThemeModeFlow.value = mode
+    }
+}

data/app-theme/src/main/kotlin/com/tangem/data/apptheme/di/AppThemeModeDataModule.kt

@@ -0,0 +1,20 @@
+package com.tangem.data.apptheme.di
+
+import com.tangem.data.apptheme.MockAppThemeModeRepository
+import com.tangem.domain.apptheme.repository.AppThemeModeRepository
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.components.SingletonComponent
+import javax.inject.Singleton
+
+@Module
+@InstallIn(SingletonComponent::class)
+internal object AppThemeModeDataModule {
+
+    @Provides
+    @Singleton
+    fun provideAppThemeModeRepository(): AppThemeModeRepository {
+        return MockAppThemeModeRepository()
+    }
+}

domain/app-theme/.gitignore

@@ -0,0 +1 @@
+/build

domain/app-theme/build.gradle.kts

@@ -0,0 +1,12 @@
+plugins {
+    alias(deps.plugins.kotlin.jvm)
+    id("configuration")
+}
+
+dependencies {
+
+    /** Project - Domain */
+    implementation(projects.core.utils)
+    implementation(projects.domain.core)
+    implementation(projects.domain.appTheme.models)
+}

domain/app-theme/models/.gitignore

@@ -0,0 +1 @@
+/build

domain/app-theme/models/build.gradle.kts

@@ -0,0 +1,4 @@
+plugins {
+    alias(deps.plugins.kotlin.jvm)
+    id("configuration")
+}

domain/app-theme/models/src/main/kotlin/com/tangem/domain/apptheme/model/AppThemeMode.kt

@@ -0,0 +1,30 @@
+package com.tangem.domain.apptheme.model
+
+/**
+ * Enumerates the possible modes for the application's theme.
+ */
+enum class AppThemeMode {
+    /**
+     * Forces the dark theme mode regardless of system settings.
+     */
+    FORCE_DARK,
+
+    /**
+     * Forces the light theme mode regardless of system settings.
+     */
+    FORCE_LIGHT,
+
+    /**
+     * Follows the system-wide theme mode.
+     */
+    FOLLOW_SYSTEM,
+
+    ;
+
+    companion object {
+        /**
+         * The default [AppThemeMode].
+         */
+        val DEFAULT: AppThemeMode = FORCE_LIGHT
+    }
+}

domain/app-theme/src/main/kotlin/com/tangem/domain/apptheme/ChangeAppThemeModeUseCase.kt

@@ -0,0 +1,31 @@
+package com.tangem.domain.apptheme
+
+import arrow.core.Either
+import arrow.core.raise.catch
+import arrow.core.raise.either
+import com.tangem.domain.apptheme.error.AppThemeModeError
+import com.tangem.domain.apptheme.model.AppThemeMode
+import com.tangem.domain.apptheme.repository.AppThemeModeRepository
+
+/**
+ * Use case responsible for changing the application theme mode.
+ *
+ * @property appThemeModeRepository The repository providing access to theme mode settings.
+ */
+class ChangeAppThemeModeUseCase(
+    private val appThemeModeRepository: AppThemeModeRepository,
+) {
+
+    /**
+     * Changes the application theme mode.
+     *
+     * @param mode The new [AppThemeMode] to set.
+     * @return An [Either] instance. The right side contains a [Unit] value indicating success,
+     * and the left side contains any [AppThemeModeError] that occurred during the process.
+     */
+    suspend operator fun invoke(mode: AppThemeMode): Either<AppThemeModeError, Unit> = either {
+        catch({ appThemeModeRepository.changeAppThemeMode(mode) }) {
+            raise(AppThemeModeError.DataError(it))
+        }
+    }
+}

domain/app-theme/src/main/kotlin/com/tangem/domain/apptheme/GetAppThemeModeUseCase.kt

@@ -0,0 +1,33 @@
+package com.tangem.domain.apptheme
+
+import arrow.core.Either
+import arrow.core.left
+import arrow.core.right
+import com.tangem.domain.apptheme.error.AppThemeModeError
+import com.tangem.domain.apptheme.model.AppThemeMode
+import com.tangem.domain.apptheme.repository.AppThemeModeRepository
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.catch
+import kotlinx.coroutines.flow.map
+
+/**
+ * Use case responsible for retrieving the current application theme mode.
+ *
+ * @property appThemeModeRepository The repository providing access to theme mode settings.
+ */
+class GetAppThemeModeUseCase(
+    private val appThemeModeRepository: AppThemeModeRepository,
+) {
+
+    /**
+     * Invokes the use case to retrieve the current application theme mode.
+     *
+     * @return A [Flow] emitting an [Either] instance. The right side contains the retrieved
+     * [AppThemeMode], and the left side contains any [AppThemeModeError] that occurred during the process.
+     */
+    operator fun invoke(): Flow<Either<AppThemeModeError, AppThemeMode>> {
+        return appThemeModeRepository.getAppThemeMode()
+            .map<AppThemeMode, Either<AppThemeModeError, AppThemeMode>> { it.right() }
+            .catch { emit(AppThemeModeError.DataError(it).left()) }
+    }
+}

domain/app-theme/src/main/kotlin/com/tangem/domain/apptheme/error/AppThemeModeError.kt

@@ -0,0 +1,6 @@
+package com.tangem.domain.apptheme.error
+
+sealed class AppThemeModeError {
+
+    data class DataError(val cause: Throwable) : AppThemeModeError()
+}

domain/app-theme/src/main/kotlin/com/tangem/domain/apptheme/repository/AppThemeModeRepository.kt

@@ -0,0 +1,24 @@
+package com.tangem.domain.apptheme.repository
+
+import com.tangem.domain.apptheme.model.AppThemeMode
+import kotlinx.coroutines.flow.Flow
+
+/**
+ * Represents a repository for managing the application's theme mode settings.
+ */
+interface AppThemeModeRepository {
+
+    /**
+     * Retrieves the current application theme mode as a flow.
+     *
+     * @return A [Flow] emitting the current [AppThemeMode].
+     */
+    fun getAppThemeMode(): Flow<AppThemeMode>
+
+    /**
+     * Changes the application's theme mode to the specified [mode].
+     *
+     * @param mode The new [AppThemeMode] to be set.
+     */
+    suspend fun changeAppThemeMode(mode: AppThemeMode)
+}

settings.gradle.kts

@@ -110,6 +110,8 @@ include(":domain:txhistory")
 include(":domain:txhistory:models")
 include(":domain:app-currency")
 include(":domain:app-currency:models")
+include(":domain:app-theme")
+include(":domain:app-theme:models")
 // endregion Domain modules
 
 // region Data modules
@@ -120,4 +122,5 @@ include(":data:source:preferences")
 include(":data:settings")
 include(":data:txhistory")
 include(":data:app-currency")
+include(":data:app-theme")
 // endregion Data modules