[#753] Add API for querying recipients

CHANGELOG.md

@@ -10,6 +10,7 @@ Change Log
   - `Synchronizer.getLegacyTransparentAddress`
   - `Synchronizer.isValidUnifiedAddr`
   - `Synchronizer.getMemos(TransactionOverview)`
+  - `Synchronizer.getReceipients(TransactionOverview)`
 - `cash.z.ecc.android.sdk.model`:
   - `Account`
   - `FirstClassByteArray`

MIGRATIONS.md

@@ -16,6 +16,8 @@ For SDK clients that store the key separately from the mnemonic, the migration m
    provided that they can be rederived from the mnemonic.
  * Re-generate the key from the mnemonic using `DerivationTool.deriveUnifiedFullViewingKeys`
 
+Due to internal changes in the SDK, the way transactions are queried and represented works differently.  The previous ConfirmedTransaction object has been replaced with `TransactionOverview` which contains less information.  Missing fields, such as memos and recipients, can be queried with `Synchronizer.getMemos(TransactionOverview)` and `Synchronizer.getReceipients(TransactionOverview)`.
+
 Migration to Version 1.9
 --------------------------------------
 `ZcashNetwork` is no longer an enum. The prior enum values are now declared as object properties `ZcashNetwork.Mainnet` and `ZcashNetwork.Testnet`.  For the most part, this change should have minimal impact.  ZcashNetwork was also moved from the package `cash.z.ecc.android.sdk.type` to `cash.z.ecc.android.sdk.model`, which will require a change to your import statements.  The server fields have been removed from `ZcashNetwork`, allowing server and network configuration to be done independently.

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

@@ -339,6 +339,12 @@ class SdkSynchronizer internal constructor(
         }
     }
 
+    override fun getRecipients(transactionOverview: TransactionOverview): Flow<TransactionRecipient> {
+        require(transactionOverview.isSentTransaction) { "Recipients can only be queried for sent transactions" }
+
+        return storage.getRecipients(transactionOverview.id)
+    }
+
     //
     // Storage APIs
     //

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

@@ -11,6 +11,7 @@ import cash.z.ecc.android.sdk.model.LightWalletEndpoint
 import cash.z.ecc.android.sdk.model.PendingTransaction
 import cash.z.ecc.android.sdk.model.Transaction
 import cash.z.ecc.android.sdk.model.TransactionOverview
+import cash.z.ecc.android.sdk.model.TransactionRecipient
 import cash.z.ecc.android.sdk.model.UnifiedSpendingKey
 import cash.z.ecc.android.sdk.model.WalletBalance
 import cash.z.ecc.android.sdk.model.Zatoshi
@@ -364,6 +365,11 @@ interface Synchronizer {
      */
     fun getMemos(transactionOverview: TransactionOverview): Flow<String>
 
+    /**
+     * Returns a list of recipients for a transaction.
+     */
+    fun getRecipients(transactionOverview: TransactionOverview): Flow<TransactionRecipient>
+
     //
     // Error Handling
     //

sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/db/derived/DbDerivedDataRepository.kt

@@ -5,6 +5,7 @@ import cash.z.ecc.android.sdk.internal.repository.DerivedDataRepository
 import cash.z.ecc.android.sdk.model.BlockHeight
 import cash.z.ecc.android.sdk.model.Transaction
 import cash.z.ecc.android.sdk.model.TransactionOverview
+import cash.z.ecc.android.sdk.model.TransactionRecipient
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.map
@@ -64,6 +65,9 @@ internal class DbDerivedDataRepository(
         get() = invalidatingFlow.map { derivedDataDb.allTransactionView.getAllTransactions().toList() }
 
     override fun getSentNoteIds(transactionId: Long) = derivedDataDb.sentNotesTable.getSentNoteIds(transactionId)
+    override fun getRecipients(transactionId: Long): Flow<TransactionRecipient> {
+        return derivedDataDb.sentNotesTable.getRecipients(transactionId)
+    }
 
     override fun getReceivedNoteIds(transactionId: Long) =
         derivedDataDb.receivedNotesTable.getReceivedNoteIds(transactionId)

sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/db/derived/SentNoteTable.kt

@@ -2,6 +2,8 @@ package cash.z.ecc.android.sdk.internal.db.derived
 
 import androidx.sqlite.db.SupportSQLiteDatabase
 import cash.z.ecc.android.sdk.internal.db.queryAndMap
+import cash.z.ecc.android.sdk.model.Account
+import cash.z.ecc.android.sdk.model.TransactionRecipient
 import cash.z.ecc.android.sdk.model.ZcashNetwork
 import java.util.Locale
 
@@ -20,6 +22,11 @@ internal class SentNoteTable(
 
         private val PROJECTION_ID = arrayOf(SentNoteTableDefinition.COLUMN_INTEGER_ID)
 
+        private val PROJECTION_RECIPIENT = arrayOf(
+            SentNoteTableDefinition.COLUMN_STRING_TO_ADDRESS,
+            SentNoteTableDefinition.COLUMN_INTEGER_TO_ACCOUNT
+        )
+
         private val SELECT_BY_TRANSACTION_ID = String.format(
             Locale.ROOT,
             "%s = ?", // $NON-NLS
@@ -40,6 +47,25 @@ internal class SentNoteTable(
                 it.getLong(idColumnIndex)
             }
         )
+
+    fun getRecipients(transactionId: Long) =
+        sqliteDatabase.queryAndMap(
+            table = SentNoteTableDefinition.TABLE_NAME,
+            columns = PROJECTION_RECIPIENT,
+            selection = SELECT_BY_TRANSACTION_ID,
+            selectionArgs = arrayOf(transactionId),
+            orderBy = ORDER_BY,
+            cursorParser = {
+                val toAccountIndex = it.getColumnIndex(SentNoteTableDefinition.COLUMN_INTEGER_TO_ACCOUNT)
+                val toAddressIndex = it.getColumnIndex(SentNoteTableDefinition.COLUMN_STRING_TO_ADDRESS)
+
+                if (!it.isNull(toAccountIndex)) {
+                    TransactionRecipient.Account(Account(it.getInt(toAccountIndex)))
+                } else {
+                    TransactionRecipient.Address(it.getString(toAddressIndex))
+                }
+            }
+        )
 }
 
 // https://github.com/zcash/librustzcash/blob/277d07c79c7a08907b05a6b29730b74cdb238b97/zcash_client_sqlite/src/wallet/init.rs#L393

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

@@ -4,6 +4,7 @@ import cash.z.ecc.android.sdk.internal.model.EncodedTransaction
 import cash.z.ecc.android.sdk.model.BlockHeight
 import cash.z.ecc.android.sdk.model.Transaction
 import cash.z.ecc.android.sdk.model.TransactionOverview
+import cash.z.ecc.android.sdk.model.TransactionRecipient
 import kotlinx.coroutines.flow.Flow
 
 /**
@@ -106,6 +107,8 @@ internal interface DerivedDataRepository {
 
     fun getSentNoteIds(transactionId: Long): Flow<Long>
 
+    fun getRecipients(transactionId: Long): Flow<TransactionRecipient>
+
     fun getReceivedNoteIds(transactionId: Long): Flow<Long>
 
     suspend fun close()