Switch from ZIP 32 account indices to UUID account identifiers

backend-lib/src/main/java/cash/z/ecc/android/sdk/internal/jni/JniConstants.kt

@@ -11,4 +11,4 @@ const val JNI_ACCOUNT_UUID_BYTES_SIZE = 16
 /**
  * The number of bytes in the seed fingerprint parameter. It's used e.g. in [JniAccount.seedFingerprint]
  */
-const val JNI_ACCOUNT_SEED_FP_BYTES_SIZE = 16
+const val JNI_ACCOUNT_SEED_FP_BYTES_SIZE = 32

backend-lib/src/main/java/cash/z/ecc/android/sdk/internal/model/JniAccount.kt

@@ -1,8 +1,8 @@
 package cash.z.ecc.android.sdk.internal.model
 
 import androidx.annotation.Keep
-import cash.z.ecc.android.sdk.internal.jni.JNI_ACCOUNT_UUID_BYTES_SIZE
 import cash.z.ecc.android.sdk.internal.jni.JNI_ACCOUNT_SEED_FP_BYTES_SIZE
+import cash.z.ecc.android.sdk.internal.jni.JNI_ACCOUNT_UUID_BYTES_SIZE
 
 /**
  * Serves as cross layer (Kotlin, Rust) communication class.
@@ -12,18 +12,19 @@ import cash.z.ecc.android.sdk.internal.jni.JNI_ACCOUNT_SEED_FP_BYTES_SIZE
  * @param accountName A human-readable name for the account
  * @param keySource A string identifier or other metadata describing the source of the seed
  * @param seedFingerprint The seed fingerprint
- * @param hdAccountIndex
+ * @param hdAccountIndex ZIP 32 account index
  *
  * @throws IllegalArgumentException if the values are inconsistent.
  */
 @Keep
 class JniAccount(
-    val accountUuid: ByteArray,
-    val ufvk: String?,
     val accountName: String?,
+    val accountUuid: ByteArray,
+    // We use -1L to represent NULL across JNI
+    val hdAccountIndex: Long,
     val keySource: String?,
     val seedFingerprint: ByteArray?,
-    val hdAccountIndex: Long?,
+    val ufvk: String?,
 ) {
     init {
         require(accountUuid.size == JNI_ACCOUNT_UUID_BYTES_SIZE) {

backend-lib/src/main/java/cash/z/ecc/android/sdk/internal/model/JniAccountBalance.kt

@@ -1,11 +1,12 @@
 package cash.z.ecc.android.sdk.internal.model
 
 import androidx.annotation.Keep
+import cash.z.ecc.android.sdk.internal.jni.JNI_ACCOUNT_UUID_BYTES_SIZE
 
 /**
  * Serves as cross layer (Kotlin, Rust) communication class.
  *
- * @param account the account ID
+ * @param accountUuid the account UUID in ByteArray
  * @param saplingVerifiedBalance The verified account balance in the Sapling pool.
  * @param saplingChangePending The value in the account of Sapling change notes that do
  *        not yet have sufficient confirmations to be spendable.
@@ -25,7 +26,7 @@ import androidx.annotation.Keep
 @Keep
 @Suppress("LongParameterList")
 class JniAccountBalance(
-    val account: ByteArray,
+    val accountUuid: ByteArray,
     val saplingVerifiedBalance: Long,
     val saplingChangePending: Long,
     val saplingValuePending: Long,
@@ -35,6 +36,9 @@ class JniAccountBalance(
     val unshieldedBalance: Long,
 ) {
     init {
+        require(accountUuid.size == JNI_ACCOUNT_UUID_BYTES_SIZE) {
+            "Account UUID must be 16 bytes"
+        }
         require(saplingVerifiedBalance >= MIN_INCLUSIVE) {
             "Sapling verified balance $saplingVerifiedBalance must by equal or above $MIN_INCLUSIVE"
         }

backend-lib/src/main/rust/lib.rs

@@ -288,22 +288,22 @@ fn encode_account<'a, P: Parameters>(
         None => JObject::null(),
     };
 
-    let null = JObject::null();
     let hd_account_index = match account.source().key_derivation() {
         Some(d) => JValue::Long(i64::from(u32::from(d.account_index()))),
-        None => (&null).into(),
+        // Use -1 to return null across the FFI.
+        None => JValue::Long(-1),
     };
 
     env.new_object(
         JNI_ACCOUNT,
-        "([BLjava/lang/String;Ljava/lang/String;Ljava/lang/String;[BI)V",
+        "(Ljava/lang/String;[BJLjava/lang/String;[BLjava/lang/String;)V",
         &[
-            (&env.byte_array_from_slice(account.id().expose_uuid().as_bytes())?).into(),
-            (&ufvk).into(),
             (&account_name).into(),
+            (&env.byte_array_from_slice(account.id().expose_uuid().as_bytes())?).into(),
+            hd_account_index,
             (&key_source).into(),
             (&seed_fingerprint).into(),
-            hd_account_index
+            (&ufvk).into()
         ],
     )
 }

backend-lib/src/test/java/cash/z/ecc/android/sdk/internal/fixture/JniAccountBalanceFixture.kt

@@ -27,7 +27,7 @@ object JniAccountBalanceFixture {
         orchardValuePending: Long = ORCHARD_VALUE_PENDING,
         unshieldedBalance: Long = UNSHIELDED_BALANCE,
     ) = JniAccountBalance(
-        account = account,
+        accountUuid = account,
         saplingVerifiedBalance = saplingVerifiedBalance,
         saplingChangePending = saplingChangePending,
         saplingValuePending = saplingValuePending,

demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/Constants.kt

@@ -10,6 +10,8 @@ val ANDROID_STATE_FLOW_TIMEOUT = 5.seconds
  */
 const val MINIMAL_WEIGHT = 0.0001f
 
-// TODO [#1644]: Refactor Account ZIP32 index across SDK
-// TODO [#1644]: https://github.com/Electric-Coin-Company/zcash-android-wallet-sdk/issues/1644
+/**
+ * Until we support full multi-account feature in Demo app we use this constant as a single source of truth for
+ * account selection
+ */
 const val CURRENT_ZIP_32_ACCOUNT_INDEX = 0

demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/SharedViewModel.kt

@@ -11,6 +11,7 @@ import cash.z.ecc.android.sdk.demoapp.ext.defaultForNetwork
 import cash.z.ecc.android.sdk.demoapp.util.fromResources
 import cash.z.ecc.android.sdk.ext.onFirst
 import cash.z.ecc.android.sdk.internal.Twig
+import cash.z.ecc.android.sdk.model.AccountCreateSetup
 import cash.z.ecc.android.sdk.model.BlockHeight
 import cash.z.ecc.android.sdk.model.ZcashNetwork
 import co.electriccoin.lightwallet.client.ext.BenchmarkingExt
@@ -76,19 +77,19 @@ class SharedViewModel(application: Application) : AndroidViewModel(application)
                     val network = ZcashNetwork.fromResources(application)
                     val synchronizer =
                         Synchronizer.new(
-                            application,
-                            network,
-                            lightWalletEndpoint = LightWalletEndpoint.defaultForNetwork(network),
-                            seed = seedBytes,
+                            alias = OLD_UI_SYNCHRONIZER_ALIAS,
                             birthday =
-                                if (BenchmarkingExt.isBenchmarking()) {
-                                    BlockHeight.new(BenchmarkingBlockRangeFixture.new().start)
-                                } else {
-                                    birthdayHeight.value
-                                },
+                            if (BenchmarkingExt.isBenchmarking()) {
+                                BlockHeight.new(BenchmarkingBlockRangeFixture.new().start)
+                            } else {
+                                birthdayHeight.value
+                            },
+                            context = application,
+                            lightWalletEndpoint = LightWalletEndpoint.defaultForNetwork(network),
+                            setup = AccountCreateSetup("ZCASH", "Zcash Account 1", seedBytes),
                             // We use restore mode as this is always initialization with an older seed
                             walletInitMode = WalletInitMode.RestoreWallet,
-                            alias = OLD_UI_SYNCHRONIZER_ALIAS
+                            zcashNetwork = network,
                         )
 
                     send(InternalSynchronizerStatus.Available(synchronizer))

demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/demos/getbalance/GetBalanceFragment.kt

@@ -19,7 +19,6 @@ import cash.z.ecc.android.sdk.ext.convertZatoshiToZec
 import cash.z.ecc.android.sdk.ext.convertZatoshiToZecString
 import cash.z.ecc.android.sdk.ext.toUsdString
 import cash.z.ecc.android.sdk.internal.Twig
-import cash.z.ecc.android.sdk.model.Account
 import cash.z.ecc.android.sdk.model.PercentDecimal
 import cash.z.ecc.android.sdk.model.WalletBalance
 import cash.z.ecc.android.sdk.model.Zatoshi
@@ -79,7 +78,7 @@ class GetBalanceFragment : BaseDemoFragment<FragmentGetBalanceBinding>() {
                         DerivationTool.getInstance().deriveUnifiedSpendingKey(
                             seed,
                             network,
-                            Account(CURRENT_ZIP_32_ACCOUNT_INDEX)
+                            CURRENT_ZIP_32_ACCOUNT_INDEX
                         )
                     sharedViewModel.synchronizerFlow.value?.let { synchronizer ->
                         synchronizer.proposeShielding(usk.account, Zatoshi(100000))?.let { it1 ->

demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/demos/getprivatekey/GetPrivateKeyFragment.kt

@@ -13,7 +13,6 @@ import cash.z.ecc.android.sdk.demoapp.BaseDemoFragment
 import cash.z.ecc.android.sdk.demoapp.databinding.FragmentGetPrivateKeyBinding
 import cash.z.ecc.android.sdk.demoapp.ext.requireApplicationContext
 import cash.z.ecc.android.sdk.demoapp.util.fromResources
-import cash.z.ecc.android.sdk.model.Account
 import cash.z.ecc.android.sdk.model.ZcashNetwork
 import cash.z.ecc.android.sdk.tool.DerivationTool
 import kotlinx.coroutines.launch
@@ -50,7 +49,7 @@ class GetPrivateKeyFragment : BaseDemoFragment<FragmentGetPrivateKeyBinding>() {
                     DerivationTool.getInstance().deriveUnifiedSpendingKey(
                         seed,
                         ZcashNetwork.fromResources(requireApplicationContext()),
-                        Account(5)
+                        5
                     )
 
                 // derive the key that allows you to view but not spend transactions

demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/ui/screen/home/viewmodel/WalletViewModel.kt

@@ -20,6 +20,7 @@ import cash.z.ecc.android.sdk.demoapp.ui.common.throttle
 import cash.z.ecc.android.sdk.demoapp.util.fromResources
 import cash.z.ecc.android.sdk.internal.Twig
 import cash.z.ecc.android.sdk.model.Account
+import cash.z.ecc.android.sdk.model.AccountBalance
 import cash.z.ecc.android.sdk.model.BlockHeight
 import cash.z.ecc.android.sdk.model.ObserveFiatCurrencyResult
 import cash.z.ecc.android.sdk.model.PercentDecimal
@@ -104,11 +105,13 @@ class WalletViewModel(application: Application) : AndroidViewModel(application)
                     withContext(Dispatchers.IO) {
                         Mnemonics.MnemonicCode(it.seedPhrase.joinToString()).toSeed()
                     }
+                val accountIndex = getCurrentAccount().hdAccountIndex?.toInt()
+                    ?: error("The account must be set at this point")
+
                 DerivationTool.getInstance().deriveUnifiedSpendingKey(
                     seed = bip39Seed,
                     network = it.network,
-                    // TODO: Get accountIndex from account returned by getCurrentAccount()
-                    accountIndex = 0
+                    accountIndex = accountIndex
                 )
             }.stateIn(
                 viewModelScope,

sdk-incubator-lib/src/main/java/cash/z/ecc/android/sdk/WalletCoordinator.kt

@@ -3,6 +3,7 @@ package cash.z.ecc.android.sdk
 import android.content.Context
 import cash.z.ecc.android.sdk.ext.onFirst
 import cash.z.ecc.android.sdk.internal.Twig
+import cash.z.ecc.android.sdk.model.AccountCreateSetup
 import cash.z.ecc.android.sdk.model.PersistableWallet
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.DelicateCoroutinesApi
@@ -79,7 +80,11 @@ class WalletCoordinator(
                                 zcashNetwork = persistableWallet.network,
                                 lightWalletEndpoint = persistableWallet.endpoint,
                                 birthday = persistableWallet.birthday,
-                                seed = persistableWallet.seedPhrase.toByteArray(),
+                                setup = AccountCreateSetup(
+                                    accountName = "Zcash Account 1",
+                                    keySource = "ZCASH",
+                                    seed = persistableWallet.seedPhrase.toByteArray()
+                                ),
                                 walletInitMode = persistableWallet.walletInitMode,
                             )
 

sdk-incubator-lib/src/main/java/cash/z/ecc/android/sdk/fixture/WalletFixture.kt

@@ -3,6 +3,7 @@ package cash.z.ecc.android.sdk.fixture
 import cash.z.ecc.android.sdk.model.Account
 import cash.z.ecc.android.sdk.model.BlockHeight
 import cash.z.ecc.android.sdk.model.ZcashNetwork
+import java.util.UUID
 
 /**
  * Provides two default wallets, making it easy to test sending funds back and forth between them.
@@ -19,7 +20,7 @@ sealed class WalletFixture {
     @Suppress("MaxLineLength")
     data object Ben : WalletFixture() {
         override val accounts: List<Account>
-            get() = listOf(AccountFixture.new(0))
+            get() = listOf(AccountFixture.new(UUID.fromString("52175368-821a-4664-8a7c-6a75d850f71c")))
 
         override val seedPhrase: String
             get() =
@@ -56,7 +57,7 @@ sealed class WalletFixture {
     @Suppress("MaxLineLength")
     data object Alice : WalletFixture() {
         override val accounts: List<Account>
-            get() = listOf(AccountFixture.new(1))
+            get() = listOf(AccountFixture.new(UUID.fromString("8a204240-73a5-4e7a-93c2-a6e05711a000")))
 
         override val seedPhrase: String
             get() =

sdk-lib/src/androidTest/java/cash/z/ecc/android/sdk/model/UnifiedSpendingKeyTest.kt

@@ -13,9 +13,9 @@ class UnifiedSpendingKeyTest {
     fun factory_copies_bytes() =
         runTest {
             val spendingKey = WalletFixture.getUnifiedSpendingKey()
-            val expected = spendingKey.copyBytes().copyOf()
+            val expected = spendingKey.copyOf()
 
-            val bytes = spendingKey.copyBytes()
+            val bytes = spendingKey
             val newSpendingKey = UnifiedSpendingKey.new(spendingKey.account, bytes)
             bytes.clear()
 

sdk-lib/src/main/java/cash/z/ecc/android/sdk/fixture/AccountFixture.kt

@@ -11,13 +11,23 @@ import java.util.UUID
  * Note that these values are used in the automated tests only and are not passed across the JNI.
  */
 object AccountFixture {
-    @Suppress("UnusedPrivateMember")
+    const val ZIP_32_ACCOUNT_INDEX = 0L
+
     val ACCOUNT_UUID = UUID.fromString("01234567-89ab-cdef-0123-456789abcdef")
-    const val ZIP_32_ACCOUNT_INDEX = 0
+    val ACCOUNT_NAME = "Test Account"
+    val UFVK = "ufvk1d68jqrx0q98rl0w8f5085y898x0p9z5k0sksqre87949w9494949"
+    val KEY_SOURCE = "ZASHI"
+    val SEED_FINGER_PRINT = "8ac5439f"
+    val HD_ACCOUNT_INDEX = ZIP_32_ACCOUNT_INDEX
 
     fun new(accountId: UUID = ACCOUNT_UUID) =
         Account(
-            accountUuid = accountId.toByteArray()
+            accountName = ACCOUNT_NAME,
+            accountUuid = accountId.toByteArray(),
+            hdAccountIndex = HD_ACCOUNT_INDEX,
+            keySource = KEY_SOURCE,
+            seedFingerprint = SEED_FINGER_PRINT.toByteArray(),
+            ufvk = UFVK,
         )
 }
 

sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/DerivationToolExt.kt

@@ -20,7 +20,14 @@ fun Derivation.deriveUnifiedSpendingKey(
     seed: ByteArray,
     network: ZcashNetwork,
     accountIndex: Int
-): UnifiedSpendingKey = UnifiedSpendingKey(deriveUnifiedSpendingKey(seed, network.id, accountIndex))
+): UnifiedSpendingKey =
+    UnifiedSpendingKey(
+        JniUnifiedSpendingKey(
+            // fixme
+            accountUuid = byteArrayOf(),
+            bytes = deriveUnifiedSpendingKey(seed, network.id, accountIndex)
+        )
+    )
 
 fun Derivation.deriveUnifiedFullViewingKey(
     usk: UnifiedSpendingKey,

sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/TypesafeBackendImpl.kt

@@ -29,7 +29,7 @@ internal class TypesafeBackendImpl(private val backend: Backend) : TypesafeBacke
     override val network: ZcashNetwork
         get() = ZcashNetwork.from(backend.networkId)
 
-    override suspend fun getAccounts(): List<Account> = backend.getAccounts().map { Account(it.accountUuid) }
+    override suspend fun getAccounts(): List<Account> = backend.getAccounts().map { Account.new(it) }
 
     override suspend fun createAccountAndGetSpendingKey(
         accountName: String,
@@ -55,15 +55,16 @@ internal class TypesafeBackendImpl(private val backend: Backend) : TypesafeBacke
         setup: AccountImportSetup,
         treeState: ByteArray,
     ): Account {
-        return Account(
-            backend.importAccountUfvk(
-                accountName = setup.accountName,
-                keySource = setup.keySource,
-                purpose = purpose.value,
-                recoverUntil = recoverUntil,
-                treeState = treeState,
-                ufvk = setup.ufvk.encoding,
-            ).accountUuid
+        return Account.new(
+            jniAccount =
+                backend.importAccountUfvk(
+                    accountName = setup.accountName,
+                    keySource = setup.keySource,
+                    purpose = purpose.value,
+                    recoverUntil = recoverUntil,
+                    treeState = treeState,
+                    ufvk = setup.ufvk.encoding
+                )
         )
     }
 

sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/model/WalletSummary.kt

@@ -16,9 +16,10 @@ internal data class WalletSummary(
         fun new(jni: JniWalletSummary): WalletSummary {
             return WalletSummary(
                 accountBalances =
-                    jni.accountBalances.associateBy({ Account(it.account) }, {
-                        AccountBalance.new(it)
-                    }),
+                    jni.accountBalances.associateBy(
+                        { Account.new(it.accountUuid) },
+                        { AccountBalance.new(it) }
+                    ),
                 chainTipHeight = BlockHeight(jni.chainTipHeight),
                 fullyScannedHeight = BlockHeight(jni.fullyScannedHeight),
                 scanProgress = ScanProgress.new(jni),