WIP id and recover coin setup from the dart side

lib/flutter_libsparkmobile.dart

@@ -4,6 +4,7 @@ import 'dart:io';
 import 'dart:typed_data';
 
 import 'package:ffi/ffi.dart';
+import 'package:flutter_libsparkmobile/src/models/spark_coin.dart';
 
 import 'src/extensions.dart';
 import 'src/flutter_libsparkmobile_bindings_generated.dart';
@@ -76,4 +77,36 @@ abstract final class LibSpark {
 
     return addressString;
   }
+
+  ///
+  /// Check whether the spark coin is ours and if so recover required data
+  /// and encapsulate into a single object ([SparkCoin]).
+  ///
+  /// Returns a [SparkCoin] if the coin belongs to us, or null otherwise.
+  ///
+  static SparkCoin? identifyAndRecoverCoin(
+    String serializedCoin, {
+    required String privateKeyHex,
+    required int index,
+  }) {
+    final result = _bindings.identifyCoin(
+      serializedCoin.toNativeUtf8().cast<Char>(),
+      serializedCoin.length,
+      privateKeyHex.toNativeUtf8().cast<Char>(),
+      index,
+    );
+
+    throw UnimplementedError(
+      "Have ffi return all the data we need for SparkCoin."
+      " This may or may not encompass all fields currently in SparkCoin.",
+    );
+  }
+}
+
+extension on Uint8List {
+  Pointer<UnsignedChar> unsignedCharPointer() {
+    final pointer = malloc.allocate<Uint8>(sizeOf<Uint8>() * lengthInBytes);
+    pointer.asTypedList(lengthInBytes).setAll(0, this);
+    return pointer.cast<UnsignedChar>();
+  }
 }

lib/src/models/spark_coin.dart

@@ -0,0 +1,89 @@
+import 'dart:typed_data';
+
+enum SparkCoinType {
+  mint(0),
+  spend(1);
+
+  const SparkCoinType(this.value);
+  final int value;
+}
+
+class SparkCoin {
+  final SparkCoinType type;
+
+  final Uint8List? k; // TODO: proper name (not single char!!) is this nonce???
+
+  final String? address;
+
+  final BigInt? value;
+
+  final String? memo;
+  final Uint8List? serialContext;
+
+  final BigInt? diversifier;
+  final Uint8List? encryptedDiversifier;
+
+  final Uint8List? serial;
+  final Uint8List? tag;
+
+  final Uint8List? lTagHash;
+
+  SparkCoin({
+    required this.type,
+    this.k,
+    this.address,
+    this.value,
+    this.memo,
+    this.serialContext,
+    this.diversifier,
+    this.encryptedDiversifier,
+    this.serial,
+    this.tag,
+    this.lTagHash,
+  });
+
+  SparkCoin copyWith({
+    SparkCoinType? type,
+    Uint8List? k,
+    String? address,
+    BigInt? value,
+    String? memo,
+    Uint8List? serialContext,
+    BigInt? diversifier,
+    Uint8List? encryptedDiversifier,
+    Uint8List? serial,
+    Uint8List? tag,
+    Uint8List? lTagHash,
+  }) {
+    return SparkCoin(
+      type: type ?? this.type,
+      k: k ?? this.k,
+      address: address ?? this.address,
+      value: value ?? this.value,
+      memo: memo ?? this.memo,
+      serialContext: serialContext ?? this.serialContext,
+      diversifier: diversifier ?? this.diversifier,
+      encryptedDiversifier: encryptedDiversifier ?? this.encryptedDiversifier,
+      serial: serial ?? this.serial,
+      tag: tag ?? this.tag,
+      lTagHash: lTagHash ?? this.lTagHash,
+    );
+  }
+
+  @override
+  String toString() {
+    return 'SparkCoin('
+        ', type: $type'
+        ', k: $k'
+        ', address: $address'
+        ', value: $value'
+        ', memo: $memo'
+        ', serialContext: $serialContext'
+        ', diversifier: $diversifier'
+        ', encryptedDiversifier: $encryptedDiversifier'
+        ', serial: $serial'
+        ', tag: $tag'
+        ', lTagHash: $lTagHash'
+        ')';
+  }
+}