refactor: migrate proto-datastore to kotlinx serialization JSON-datastore

Author: thunderbiscuit

app/build.gradle.kts

@@ -6,7 +6,6 @@ plugins {
     id("com.android.application") version "9.2.0"
     id("org.jetbrains.kotlin.plugin.compose") version "2.3.21"
     id("org.jetbrains.kotlin.plugin.serialization") version "2.3.21"
-    id("com.google.protobuf") version "0.10.0"
     id("org.jlleitschuh.gradle.ktlint") version "14.2.0"
 }
 
@@ -55,11 +54,12 @@ tasks.withType<KotlinCompile> {
 dependencies {
     // Basic android dependencies
     implementation("androidx.core:core-ktx:1.17.0")
-    implementation("androidx.datastore:datastore:1.2.0")
-    implementation("com.google.protobuf:protobuf-javalite:4.33.5")
     implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.10.0")
     implementation("androidx.core:core-splashscreen:1.2.0")
 
+    // DataStore
+    implementation("androidx.datastore:datastore:1.2.1")
+
     // Jetpack Compose
     // Adding the Bill of Materials synchronizes dependencies in the androidx.compose namespace
     // You can remove the library version in your dependency declarations
@@ -88,22 +88,6 @@ dependencies {
     androidTestImplementation("androidx.test.espresso:espresso-core:3.7.0")
 }
 
-protobuf {
-    protoc {
-        artifact = "com.google.protobuf:protoc:3.25.0"
-    }
-
-    generateProtoTasks {
-        all().forEach { task ->
-            task.builtins {
-                create("java") {
-                    option("lite")
-                }
-            }
-        }
-    }
-}
-
 ktlint {
     version = "1.8.0"
     ignoreFailures = false

app/src/main/java/org/bitcoindevkit/devkitwallet/data/UserPreferencesSerializer.kt

@@ -7,6 +7,7 @@ package org.bitcoindevkit.devkitwallet.data
 
 import org.bitcoindevkit.Descriptor
 import org.bitcoindevkit.Network
+import org.bitcoindevkit.devkitwallet.data.datastore.ActiveWalletScriptType
 
 data class NewWalletConfig(
     val name: String,

app/src/main/java/org/bitcoindevkit/devkitwallet/data/WalletConfigs.kt

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2021-2026 thunderbiscuit and contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the ./LICENSE file.
+ */
+
+package org.bitcoindevkit.devkitwallet.data.datastore
+
+import androidx.datastore.core.CorruptionException
+import androidx.datastore.core.Serializer
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.SerializationException
+import kotlinx.serialization.json.Json
+import java.io.InputStream
+import java.io.OutputStream
+
+@Serializable
+data class AppSettings(
+    val darkTheme: Boolean = true,
+    val introDone: Boolean = false,
+)
+
+object AppSettingsSerializer : Serializer<AppSettings> {
+    override val defaultValue = AppSettings()
+
+    override suspend fun readFrom(input: InputStream): AppSettings {
+        try {
+            return Json.decodeFromString(input.readBytes().decodeToString())
+        } catch (e: SerializationException) {
+            throw CorruptionException("Cannot read AppSettings.", e)
+        }
+    }
+
+    override suspend fun writeTo(t: AppSettings, output: OutputStream) {
+        output.write(Json.encodeToString(t).encodeToByteArray())
+    }
+}

app/src/main/java/org/bitcoindevkit/devkitwallet/data/datastore/AppSettings.kt

@@ -0,0 +1,57 @@
+package org.bitcoindevkit.devkitwallet.data.datastore
+
+import androidx.datastore.core.CorruptionException
+import androidx.datastore.core.Serializer
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.SerializationException
+import kotlinx.serialization.json.Json
+import java.io.InputStream
+import java.io.OutputStream
+
+@Serializable
+enum class ActiveWalletNetwork {
+    TESTNET,
+    SIGNET,
+    REGTEST,
+}
+
+@Serializable
+enum class ActiveWalletScriptType {
+    P2WPKH,
+    P2TR,
+    UNKNOWN,
+}
+
+@Serializable
+data class StoredWallet(
+    val id: String,
+    val name: String,
+    val network: ActiveWalletNetwork,
+    val scriptType: ActiveWalletScriptType,
+    val descriptor: String,
+    val changeDescriptor: String,
+    val recoveryPhrase: String = "",
+    val fullScanCompleted: Boolean = false,
+)
+
+@Serializable
+data class WalletData(
+    val wallets: List<StoredWallet> = emptyList(),
+    // network config fields go here alongside wallets
+)
+
+object WalletDataSerializer : Serializer<WalletData> {
+    override val defaultValue = WalletData()
+
+    override suspend fun readFrom(input: InputStream): WalletData {
+        try {
+            return Json.decodeFromString(input.readBytes().decodeToString())
+        } catch (e: SerializationException) {
+            throw CorruptionException("Cannot read AppSettings.", e)
+        }
+    }
+
+    override suspend fun writeTo(t: WalletData, output: OutputStream) {
+        output.write(Json.encodeToString(t).encodeToByteArray())
+    }
+}

app/src/main/java/org/bitcoindevkit/devkitwallet/data/datastore/WalletData.kt

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2021-2026 thunderbiscuit and contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the ./LICENSE file.
+ */
+
+package org.bitcoindevkit.devkitwallet.domain
+
+import androidx.datastore.core.DataStore
+import kotlinx.coroutines.flow.first
+import org.bitcoindevkit.devkitwallet.data.datastore.AppSettings
+
+class AppSettingsRepository(private val store: DataStore<AppSettings>) {
+    suspend fun fetchDarkTheme() = store.data.first().darkTheme
+
+    suspend fun setDarkTheme(isDark: Boolean) = store.updateData { it.copy(darkTheme = isDark) }
+
+    suspend fun fetchIntroDone() = store.data.first().introDone
+
+    suspend fun setIntroDone() = store.updateData { it.copy(introDone = true) }
+}