Built Tanga subscription feature (#95)

* Built the subscription feature - users can now subscribe to one the two paid plans for Tanga

* Fixing detekt issues

* Fixing unit tests

* Started adding unit tests

* Minor improvements

.gitignore

@@ -116,3 +116,9 @@ GoogleService-Info.plist
 
 # Sentry Auth Token
 sentry.properties
+# Keystore properties file
+keystore.properties
+# Keystore file
+tangakeystore.jks
+# Secret Keys
+secrets.properties

app/build.gradle.kts

@@ -1,3 +1,5 @@
+import java.util.Properties
+
 plugins {
     id("com.android.application")
     id("org.jetbrains.kotlin.android")
@@ -12,6 +14,16 @@ plugins {
 
 apply(from = "${project.rootDir}/buildscripts/jacoco.gradle.kts")
 
+val keystorePropertiesFile = rootProject.file("keystore.properties")
+val keystoreProperties = Properties().apply {
+    load(keystorePropertiesFile.inputStream())
+}
+
+val secretPropertiesFile = rootProject.file("secrets.properties")
+val secretProperties = Properties().apply {
+    load(secretPropertiesFile.inputStream())
+}
+
 android {
     namespace = "app.books.tanga"
     compileSdk = 34
@@ -20,7 +32,7 @@ android {
         applicationId = "app.books.tanga"
         minSdk = 24
         targetSdk = 34
-        versionCode = 1
+        versionCode = 5
         versionName = "0.5.0"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
@@ -29,22 +41,34 @@ android {
         }
     }
 
+    signingConfigs {
+        create("release") {
+            storeFile = rootProject.file(keystoreProperties["storeFile"].toString())
+            storePassword = keystoreProperties["storePassword"].toString()
+            keyAlias = keystoreProperties["keyAlias"].toString()
+            keyPassword = keystoreProperties["keyPassword"].toString()
+        }
+    }
+
     testOptions {
         unitTests.isReturnDefaultValues = true
     }
 
     buildTypes {
         debug {
+            buildConfigField("String", "REVENUECAT_API_KEY", "\"${secretProperties["revenueCatApiKey"]}\"")
             enableUnitTestCoverage = true
             enableAndroidTestCoverage = true
         }
         release {
-            isMinifyEnabled = false
+            buildConfigField("String", "REVENUECAT_API_KEY", "\"${secretProperties["revenueCatApiKey"]}\"")
+            isMinifyEnabled = false // Will change later
+            isDebuggable = false
             proguardFiles(
                 getDefaultProguardFile("proguard-android-optimize.txt"),
                 "proguard-rules.pro"
             )
-            signingConfig = signingConfigs.getByName("debug")
+            signingConfig = signingConfigs.getByName("release")
         }
     }
 
@@ -119,8 +143,12 @@ dependencies {
     // Google Play Services
     implementation(libs.android.gms.play.services.auth)
 
-    // Media and Logging
+    implementation(libs.revenuecat.purchases)
+
+    // Media
     implementation(libs.media3.exoplayer)
+
+    // Logging
     implementation(libs.timber)
 
     // Kotlin Immutable Collections

app/src/androidTest/java/app/books/tanga/fixtures/Fixtures.kt

@@ -69,7 +69,6 @@ object Fixtures {
         fullName = "John Doe",
         email = "john.doe@example.com",
         photoUrl = "https://example.com/johndoe.jpg",
-        isPro = true,
         createdAt = Date()
     )
 
@@ -78,7 +77,6 @@ object Fixtures {
         fullName = "Mansa Musa",
         email = "some@mail.com",
         photoUrl = "https://someurl.com",
-        isPro = false,
         createdAt = Timestamp(1697806449, 0).toDate()
     )
 

app/src/main/java/app/books/tanga/TangaApp.kt

@@ -4,6 +4,7 @@ import android.app.Application
 import app.books.tanga.di.TimberTrees
 import app.books.tanga.di.plantAll
 import app.books.tanga.errors.TangaErrorTracker
+import app.books.tanga.revenuecat.RevenueCatInitializer
 import dagger.hilt.android.HiltAndroidApp
 import javax.inject.Inject
 
@@ -15,12 +16,17 @@ class TangaApp : Application() {
     @Inject
     lateinit var errorTracker: TangaErrorTracker
 
+    @Inject
+    lateinit var revenueCatInitializer: RevenueCatInitializer
+
     override fun onCreate() {
         super.onCreate()
         // Plant all the Timber trees added to Timber
         timberTrees.plantAll()
 
         // Initialize the error tracker
         errorTracker.init()
+
+        revenueCatInitializer.initialize(this)
     }
 }

app/src/main/java/app/books/tanga/data/user/UserMapper.kt

@@ -15,7 +15,6 @@ fun FirebaseUser.toAnonymousUser(): User =
         fullName = "Anonymous",
         email = "",
         photoUrl = null,
-        isPro = false,
         isAnonymous = true,
         createdAt = metadata?.creationTimestamp?.let { Date(it) } ?: Date()
     )
@@ -25,8 +24,7 @@ fun FirebaseUser.toUser(): User = User(
     fullName = requireNotNull(displayName) { "User must have a display name" },
     email = requireNotNull(email) { "User must have an email" },
     photoUrl = photoUrl?.toString(),
-    isPro = false,
-    createdAt = metadata?.creationTimestamp?.let { Date(it) } ?: Date()
+    createdAt = metadata?.creationTimestamp?.let { Date(it) } ?: Date(),
 )
 
 fun User.toFireStoreUserData() =
@@ -36,7 +34,8 @@ fun User.toFireStoreUserData() =
         FirestoreDatabase.Users.Fields.EMAIL to email,
         FirestoreDatabase.Users.Fields.PHOTO_URL to photoUrl,
         // We use the server timestamp to avoid issues with the device time
-        FirestoreDatabase.Users.Fields.CREATED_AT to FieldValue.serverTimestamp()
+        FirestoreDatabase.Users.Fields.CREATED_AT to FieldValue.serverTimestamp(),
+        FirestoreDatabase.Users.Fields.SUBSCRIBED_AT to subscribedAt?.let { Timestamp(it) }
     )
 
 fun FirestoreData.toUser(uid: String) =
@@ -45,6 +44,6 @@ fun FirestoreData.toUser(uid: String) =
         fullName = this[FirestoreDatabase.Users.Fields.FULL_NAME].toString(),
         email = this[FirestoreDatabase.Users.Fields.EMAIL].toString(),
         photoUrl = this[FirestoreDatabase.Users.Fields.PHOTO_URL].toString(),
-        isPro = false,
-        createdAt = (this[FirestoreDatabase.Users.Fields.CREATED_AT] as Timestamp).toDate()
+        createdAt = (this[FirestoreDatabase.Users.Fields.CREATED_AT] as? Timestamp)?.toDate(),
+        subscribedAt = (this[FirestoreDatabase.Users.Fields.SUBSCRIBED_AT] as? Timestamp)?.toDate()
     )

app/src/main/java/app/books/tanga/data/user/UserRepository.kt

@@ -8,18 +8,27 @@ import app.books.tanga.firestore.FirestoreOperationHandler
 import com.google.firebase.auth.FirebaseAuth
 import com.google.firebase.firestore.CollectionReference
 import com.google.firebase.firestore.FirebaseFirestore
+import com.google.firebase.firestore.ktx.snapshots
 import javax.inject.Inject
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.emitAll
 import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.tasks.await
 
 interface UserRepository {
     suspend fun getUser(): Result<User?>
 
+    suspend fun getUserStream(): Flow<User?>
+
     suspend fun getUserId(): UserId?
 
     suspend fun createUser(user: User): Result<Unit>
 
     suspend fun deleteUser(user: User): Result<Unit>
+
+    suspend fun updateUser(user: User): Result<Unit>
 }
 
 val FirebaseFirestore.userCollection: CollectionReference
@@ -31,6 +40,7 @@ class UserRepositoryImpl @Inject constructor(
     private val operationHandler: FirestoreOperationHandler,
     private val firebaseAuth: FirebaseAuth
 ) : UserRepository, FirestoreOperationHandler by operationHandler {
+
     override suspend fun getUser(): Result<User?> {
         val sessionId = prefDataStoreRepo.getSessionId().first()
         val currentUser = firebaseAuth.currentUser
@@ -57,6 +67,28 @@ class UserRepositoryImpl @Inject constructor(
         return result
     }
 
+    override suspend fun getUserStream(): Flow<User?> = flow {
+        val sessionId = prefDataStoreRepo.getSessionId().first()
+        val currentUser = firebaseAuth.currentUser
+
+        if (sessionId != null) {
+            if (currentUser?.isAnonymous == true) {
+                emit(currentUser.toAnonymousUser())
+            } else {
+                val uid = sessionId.value
+                val stream = firestore.userCollection
+                    .document(uid)
+                    .snapshots().map { documentSnapshot ->
+                        val userDataMap = documentSnapshot.data
+                        userDataMap?.toUser(uid)
+                    }
+                emitAll(stream)
+            }
+        } else {
+            emit(null)
+        }
+    }
+
     override suspend fun getUserId(): UserId? {
         val sessionId = prefDataStoreRepo.getSessionId().first()
         return sessionId?.value?.let { UserId(it) }
@@ -73,6 +105,17 @@ class UserRepositoryImpl @Inject constructor(
         }
     }
 
+    override suspend fun updateUser(user: User): Result<Unit> {
+        val userMap = user.toFireStoreUserData()
+        return executeOperation {
+            firestore
+                .userCollection
+                .document(user.id.value)
+                .update(userMap)
+                .await()
+        }
+    }
+
     override suspend fun deleteUser(user: User): Result<Unit> =
         executeOperation {
             firestore

app/src/main/java/app/books/tanga/entity/Subscription.kt

@@ -0,0 +1,40 @@
+package app.books.tanga.entity
+
+import java.util.Date
+
+/**
+ * Represents a subscription plan that a user can purchase.
+ * @property identifier A unique identifier for the subscription plan.
+ * @property productId The Store product ID of the subscription plan.
+ * @property type The type of the subscription plan (monthly or yearly).
+ * @property price The price of the subscription plan.
+ */
+data class SubscriptionPlan(
+    val identifier: String,
+    val productId: String,
+    val type: SubscriptionType,
+    val price: Price,
+)
+
+/**
+ * Represents the type of a subscription plan.
+ */
+enum class SubscriptionType {
+    MONTHLY,
+    YEARLY
+}
+
+/**
+ * Represents the price of a subscription plan.
+ * @property formattedValue The formatted value of the price.
+ * @property currency The currency in which the price is displayed.
+ */
+data class Price(
+    val formattedValue: String,
+    val currency: String,
+)
+
+data class SubscriberInfo(
+    val hasActiveSubscription: Boolean,
+    val expirationDate: Date?,
+)

app/src/main/java/app/books/tanga/entity/User.kt

@@ -10,9 +10,9 @@ data class User(
     val fullName: String,
     val email: String,
     val photoUrl: String?,
-    val isPro: Boolean,
     val isAnonymous: Boolean = false,
-    val createdAt: Date
+    val createdAt: Date?,
+    val subscribedAt: Date? = null
 ) {
     val firsName: String
         get() = fullName.split(" ").firstOrNull() ?: fullName

app/src/main/java/app/books/tanga/feature/auth/AnonymousAuthService.kt

@@ -69,7 +69,6 @@ class AnonymousAuthServiceImpl @Inject constructor(
             fullName = requireNotNull(displayName) { "User must have a display name" },
             email = requireNotNull(email) { "User must have an email" },
             photoUrl = photoUrl,
-            isPro = false,
             isAnonymous = false,
             createdAt = creationDate
         )

app/src/main/java/app/books/tanga/feature/auth/AuthViewModel.kt

@@ -8,6 +8,7 @@ import app.books.tanga.errors.TangaErrorTracker
 import app.books.tanga.errors.toUiError
 import com.google.android.gms.auth.api.identity.SignInClient
 import dagger.hilt.android.lifecycle.HiltViewModel
+import java.util.Date
 import javax.inject.Inject
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.Flow
@@ -54,7 +55,8 @@ class AuthViewModel @Inject constructor(
                     postEvent(AuthUiEvent.NavigateTo.ToHomeScreen)
                     errorTracker.setUserDetails(
                         userId = user.id,
-                        userCreationDate = user.createdAt
+                        // TODO remove nullability
+                        userCreationDate = user.createdAt ?: Date()
                     )
                 }.onFailure { error ->
                     _state.update { it.copy(skipProgressState = ProgressState.Hide) }
@@ -74,7 +76,8 @@ class AuthViewModel @Inject constructor(
                     _state.update { it.copy(googleSignInButtonProgressState = ProgressState.Hide) }
                     errorTracker.setUserDetails(
                         userId = user.id,
-                        userCreationDate = user.createdAt
+                        // TODO remove nullability
+                        userCreationDate = user.createdAt ?: Date()
                     )
                 }.onFailure { error ->
                     Timber.e("Complete Google sign In failure", error)

app/src/main/java/app/books/tanga/feature/auth/AuthenticationInteractor.kt

@@ -3,9 +3,10 @@ package app.books.tanga.feature.auth
 import app.books.tanga.data.user.UserRepository
 import app.books.tanga.entity.User
 import app.books.tanga.errors.DomainError
-import app.books.tanga.session.SessionId
+import app.books.tanga.revenuecat.RevenueCatAuthenticator
 import app.books.tanga.session.SessionManager
 import app.books.tanga.session.SessionState
+import app.books.tanga.session.toSessionId
 import app.books.tanga.utils.resultOf
 import com.google.android.gms.auth.api.identity.BeginSignInResult
 import com.google.android.gms.auth.api.identity.SignInCredential
@@ -24,7 +25,8 @@ class AuthenticationInteractor @Inject constructor(
     private val userRepository: UserRepository,
     private val sessionManager: SessionManager,
     private val googleAuthService: GoogleAuthService,
-    private val anonymousAuthService: AnonymousAuthService
+    private val anonymousAuthService: AnonymousAuthService,
+    private val revenueCatAuthenticator: RevenueCatAuthenticator
 ) {
 
     fun isUserAnonymous(): Boolean = anonymousAuthService.isUserAnonymous()
@@ -61,17 +63,20 @@ class AuthenticationInteractor @Inject constructor(
 
         val user = authResult.user
         userRepository.createUser(user)
-        val sessionId = SessionId(user.id.value)
+        revenueCatAuthenticator.logIn(user.id)
+        val sessionId = user.id.toSessionId()
         sessionManager.openSession(sessionId)
         user
     }.onFailure {
+        Timber.e(it, "Google sign in failed")
         return Result.failure(DomainError.UnableToSignInWithGoogleError(it))
     }
 
     suspend fun signOut(): Result<SessionState> =
         resultOf {
             googleAuthService.signOut()
             sessionManager.closeSession()
+            revenueCatAuthenticator.logOut()
             SessionState.SignedOut
         }