Add means to retrieve more birthday height values

src/Nerdbank.Zcash/LightWalletClient.cs

@@ -122,6 +122,7 @@ public LightWalletClient(Uri serverUrl, ZcashNetwork network, string walletPath,
 	/// The birthday height is the length of the blockchain when the account was created.
 	/// It serves to reduce initial sync times when this account is imported into another wallet.
 	/// </remarks>
+	/// <seealso cref="GetBirthdayHeights"/>
 	public ulong BirthdayHeight => this.Interop(LightWalletMethods.LightwalletGetBirthdayHeight);
 
 	/// <summary>
@@ -143,6 +144,15 @@ public static ValueTask<ulong> GetLatestBlockHeightAsync(Uri lightWalletServerUr
 			cancellationToken));
 	}
 
+	/// <summary>
+	/// Gets the various forms of birthday heights relevant to this account.
+	/// </summary>
+	/// <returns>The birthday heights.</returns>
+	/// <remarks>
+	/// The resulting struct contains fields which may be influenced by the completeness of the sync to the blockchain.
+	/// </remarks>
+	public BirthdayHeights GetBirthdayHeights() => this.Interop(LightWalletMethods.LightwalletGetBirthdayHeights);
+
 	/// <inheritdoc cref="GetLatestBlockHeightAsync(Uri, CancellationToken)"/>
 	public ValueTask<ulong> GetLatestBlockHeightAsync(CancellationToken cancellationToken) => GetLatestBlockHeightAsync(this.serverUrl, cancellationToken);
 

src/Nerdbank.Zcash/PublicAPI.Unshipped.txt

@@ -36,6 +36,7 @@ Nerdbank.Zcash.LightWalletClient.BirthdayHeight.get -> ulong
 Nerdbank.Zcash.LightWalletClient.Dispose() -> void
 Nerdbank.Zcash.LightWalletClient.DownloadTransactionsAsync(System.IProgress<Nerdbank.Zcash.LightWalletClient.SyncProgress!>? progress, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<Nerdbank.Zcash.LightWalletClient.SyncResult!>!
 Nerdbank.Zcash.LightWalletClient.DownloadTransactionsAsync(System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<Nerdbank.Zcash.LightWalletClient.SyncResult!>!
+Nerdbank.Zcash.LightWalletClient.GetBirthdayHeights() -> uniffi.LightWallet.BirthdayHeights!
 Nerdbank.Zcash.LightWalletClient.GetDownloadedTransactions(uint startingBlock = 0) -> System.Collections.Generic.List<Nerdbank.Zcash.Transaction!>!
 Nerdbank.Zcash.LightWalletClient.GetLatestBlockHeightAsync(System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.ValueTask<ulong>
 Nerdbank.Zcash.LightWalletClient.GetPoolBalances() -> Nerdbank.Zcash.LightWalletClient.PoolBalances

src/Nerdbank.Zcash/RustBindings/LightWallet.cs

@@ -432,6 +432,10 @@
     public static extern ulong uniffi_nerdbank_zcash_rust_fn_func_lightwallet_get_birthday_height(ulong @handle,ref RustCallStatus _uniffi_out_err
     );
 
+    [DllImport("nerdbank_zcash_rust")]
+    public static extern RustBuffer uniffi_nerdbank_zcash_rust_fn_func_lightwallet_get_birthday_heights(ulong @handle,ref RustCallStatus _uniffi_out_err
+    );
+
     [DllImport("nerdbank_zcash_rust")]
     public static extern ulong uniffi_nerdbank_zcash_rust_fn_func_lightwallet_get_block_height(RustBuffer @serverUri,ref RustCallStatus _uniffi_out_err
     );
@@ -716,6 +720,10 @@
     public static extern ushort uniffi_nerdbank_zcash_rust_checksum_func_lightwallet_get_birthday_height(
     );
 
+    [DllImport("nerdbank_zcash_rust")]
+    public static extern ushort uniffi_nerdbank_zcash_rust_checksum_func_lightwallet_get_birthday_heights(
+    );
+
     [DllImport("nerdbank_zcash_rust")]
     public static extern ushort uniffi_nerdbank_zcash_rust_checksum_func_lightwallet_get_block_height(
     );
@@ -794,6 +802,12 @@
                 throw new UniffiContractChecksumException($"uniffi.LightWallet: uniffi bindings expected function `uniffi_nerdbank_zcash_rust_checksum_func_lightwallet_get_birthday_height` checksum `29297`, library returned `{checksum}`");
             }
         }
+        {
+            var checksum = _UniFFILib.uniffi_nerdbank_zcash_rust_checksum_func_lightwallet_get_birthday_heights();
+            if (checksum != 36095) {
+                throw new UniffiContractChecksumException($"uniffi.LightWallet: uniffi bindings expected function `uniffi_nerdbank_zcash_rust_checksum_func_lightwallet_get_birthday_heights` checksum `36095`, library returned `{checksum}`");
+            }
+        }
         {
             var checksum = _UniFFILib.uniffi_nerdbank_zcash_rust_checksum_func_lightwallet_get_block_height();
             if (checksum != 43659) {
@@ -1036,6 +1050,40 @@
 
 
 
+public record BirthdayHeights (
+    ulong @originalBirthdayHeight, 
+    ulong @birthdayHeight, 
+    ulong? @rebirthHeight
+) {
+}
+
+class FfiConverterTypeBirthdayHeights: FfiConverterRustBuffer<BirthdayHeights> {
+    public static FfiConverterTypeBirthdayHeights INSTANCE = new FfiConverterTypeBirthdayHeights();
+
+    public override BirthdayHeights Read(BigEndianStream stream) {
+        return new BirthdayHeights(
+            FfiConverterUInt64.INSTANCE.Read(stream),
+            FfiConverterUInt64.INSTANCE.Read(stream),
+            FfiConverterOptionalUInt64.INSTANCE.Read(stream)
+        );
+    }
+
+    public override int AllocationSize(BirthdayHeights value) {
+        return
+            FfiConverterUInt64.INSTANCE.AllocationSize(value.@originalBirthdayHeight) +
+            FfiConverterUInt64.INSTANCE.AllocationSize(value.@birthdayHeight) +
+            FfiConverterOptionalUInt64.INSTANCE.AllocationSize(value.@rebirthHeight);
+    }
+
+    public override void Write(BirthdayHeights value, BigEndianStream stream) {
+            FfiConverterUInt64.INSTANCE.Write(value.@originalBirthdayHeight, stream);
+            FfiConverterUInt64.INSTANCE.Write(value.@birthdayHeight, stream);
+            FfiConverterOptionalUInt64.INSTANCE.Write(value.@rebirthHeight, stream);
+    }
+}
+
+
+
 public record Config (
     String @serverUri, 
     ChainType @chainType, 
@@ -1956,6 +2004,14 @@
 ));
     }
 
+    /// <exception cref="LightWalletException"></exception>
+    public static BirthdayHeights LightwalletGetBirthdayHeights(ulong @handle) {
+        return FfiConverterTypeBirthdayHeights.INSTANCE.Lift(
+    _UniffiHelpers.RustCallWithError(FfiConverterTypeLightWalletException.INSTANCE, (ref RustCallStatus _status) =>
+    _UniFFILib.uniffi_nerdbank_zcash_rust_fn_func_lightwallet_get_birthday_heights(FfiConverterUInt64.INSTANCE.Lower(@handle), ref _status)
+));
+    }
+
     /// <exception cref="LightWalletException"></exception>
     public static ulong LightwalletGetBlockHeight(String @serverUri) {
         return FfiConverterUInt64.INSTANCE.Lift(

src/nerdbank-zcash-rust/src/ffi.udl

@@ -109,13 +109,19 @@ dictionary PoolBalances {
 };
 
 dictionary UserBalances {
-    u64 spendable;
-    u64 immature_change;
-    u64 minimum_fees;
-    u64 immature_income;
-    u64 dust;
-    u64 incoming;
-    u64 incoming_dust;
+	u64 spendable;
+	u64 immature_change;
+	u64 minimum_fees;
+	u64 immature_income;
+	u64 dust;
+	u64 incoming;
+	u64 incoming_dust;
+};
+
+dictionary BirthdayHeights{
+	u64 original_birthday_height;
+	u64 birthday_height;
+	u64? rebirth_height;
 };
 
 namespace LightWallet {
@@ -159,4 +165,7 @@ namespace LightWallet {
 
 	[Throws=LightWalletError]
 	UserBalances lightwallet_get_user_balances(u64 handle);
+
+	[Throws=LightWalletError]
+	BirthdayHeights lightwallet_get_birthday_heights(u64 handle);
 };

src/nerdbank-zcash-rust/src/lib.rs

@@ -9,11 +9,12 @@ mod sapling;
 
 use lightwallet::{
     last_synced_height, lightwallet_deinitialize, lightwallet_get_balances,
-    lightwallet_get_birthday_height, lightwallet_get_block_height, lightwallet_get_transactions,
-    lightwallet_get_user_balances, lightwallet_initialize, lightwallet_initialize_from_disk,
-    lightwallet_send_check_status, lightwallet_send_to_address, lightwallet_sync,
-    lightwallet_sync_interrupt, lightwallet_sync_status, ChainType, Config, LightWalletError,
-    OrchardNote, SaplingNote, SendUpdate, SyncStatus, Transaction, TransactionSendDetail,
-    UserBalances, WalletInfo,
+    lightwallet_get_birthday_height, lightwallet_get_birthday_heights,
+    lightwallet_get_block_height, lightwallet_get_transactions, lightwallet_get_user_balances,
+    lightwallet_initialize, lightwallet_initialize_from_disk, lightwallet_send_check_status,
+    lightwallet_send_to_address, lightwallet_sync, lightwallet_sync_interrupt,
+    lightwallet_sync_status, BirthdayHeights, ChainType, Config, LightWalletError, OrchardNote,
+    SaplingNote, SendUpdate, SyncStatus, Transaction, TransactionSendDetail, UserBalances,
+    WalletInfo,
 };
 use zingolib::lightclient::{PoolBalances, SyncResult};

src/nerdbank-zcash-rust/src/lightwallet.rs

@@ -610,3 +610,49 @@ pub fn lightwallet_get_user_balances(handle: u64) -> Result<UserBalances, LightW
         Ok(balances)
     })
 }
+
+pub struct BirthdayHeights {
+    /// The original birthday height given at account creation if non-zero,
+    /// otherwise the block number of the first transaction if any,
+    /// otherwise the sapling activation height.
+    pub original_birthday_height: u64,
+    /// The block number of the first transaction if any,
+    /// otherwise the sapling activation height.
+    pub birthday_height: u64,
+    /// The block number of the oldest unspent note or UTXO, if any.
+    pub rebirth_height: Option<u64>,
+}
+
+pub fn lightwallet_get_birthday_heights(handle: u64) -> Result<BirthdayHeights, LightWalletError> {
+    let lightclient = get_lightclient(handle)?;
+    Ok(RT.block_on(async move {
+        let mut block_number_with_oldest_unspent_note_or_utxo = None;
+        lightclient
+            .wallet
+            .transactions()
+            .read()
+            .await
+            .current
+            .iter()
+            .for_each(|(_, tx)| {
+                if tx.orchard_notes.iter().any(|n| n.spent().is_none())
+                    || tx.sapling_notes.iter().any(|n| n.spent().is_none())
+                    || tx.received_utxos.iter().any(|n| n.spent.is_none())
+                {
+                    if block_number_with_oldest_unspent_note_or_utxo.is_none() {
+                        block_number_with_oldest_unspent_note_or_utxo = Some(tx.block_height);
+                    } else if tx.block_height
+                        < block_number_with_oldest_unspent_note_or_utxo.unwrap()
+                    {
+                        block_number_with_oldest_unspent_note_or_utxo = Some(tx.block_height);
+                    }
+                }
+            });
+
+        BirthdayHeights {
+            original_birthday_height: lightclient.wallet.get_birthday().await,
+            birthday_height: lightclient.wallet.get_first_transaction_block().await,
+            rebirth_height: block_number_with_oldest_unspent_note_or_utxo.map(u64::from),
+        }
+    }))
+}