loss of precision fixes

lib/flutter_libsparkmobile.dart

@@ -761,9 +761,8 @@ abstract final class LibSpark {
         serializedCoins,
     required int privateRecipientsCount,
   }) {
-
     final privateKeyPtr =
-    privateKeyHex.to32BytesFromHex().unsignedCharPointer();
+        privateKeyHex.to32BytesFromHex().unsignedCharPointer();
 
     final serializedCoinsPtr = malloc.allocate<DartSpendCoinData>(
         sizeOf<DartSpendCoinData>() * serializedCoins.length);
@@ -812,13 +811,11 @@ abstract final class LibSpark {
       malloc.free(result.ref.error);
       malloc.free(result);
       throw ex;
+    } else {
+      final fee = result.ref.fee;
+      malloc.free(result);
+      return fee;
     }
-
-    final fee = result.ref.fee;
-
-    malloc.free(result);
-
-    return fee;
   }
 }
 

lib/src/flutter_libsparkmobile_bindings_generated.dart

@@ -320,7 +320,7 @@ class FlutterLibsparkmobileBindings {
           ffi.Pointer<SparkFeeResult> Function(
               ffi.Pointer<ffi.UnsignedChar>,
               ffi.Int,
-              ffi.Int,
+              ffi.Int64,
               ffi.Int,
               ffi.Pointer<DartSpendCoinData>,
               ffi.Int,
@@ -632,7 +632,7 @@ final class SparkSpendTransactionResult extends ffi.Struct {
   @ffi.Int()
   external int outputScriptsLength;
 
-  @ffi.Int()
+  @ffi.Int64()
   external int fee;
 
   @ffi.Int()
@@ -685,6 +685,6 @@ final class DartSpendCoinData extends ffi.Struct {
 final class SparkFeeResult extends ffi.Struct {
   external ffi.Pointer<ffi.Char> error;
 
-  @ffi.Int()
+  @ffi.Int64()
   external int fee;
 }

src/flutter_libsparkmobile.cpp

@@ -547,7 +547,7 @@ FFI_PLUGIN_EXPORT
 SparkFeeResult* estimateSparkFee(
         unsigned char* keyData,
         int index,
-        int sendAmount,
+        int64_t sendAmount,
         int subtractFeeFromAmount,
         struct DartSpendCoinData* coins,
         int coinsLength,
@@ -573,7 +573,7 @@ SparkFeeResult* estimateSparkFee(
 
         std::pair<CAmount, std::vector<CSparkMintMeta>> estimated = SelectSparkCoins(
                 sendAmount,
-                subtractFeeFromAmount,
+                subtractFeeFromAmount > 0,
                 cppCoins,
                 privateRecipientsLength
         );

src/flutter_libsparkmobile.h

@@ -18,14 +18,6 @@
 FFI_PLUGIN_EXPORT
 const char* getAddress(unsigned char* keyData, int index, int diversifier, int isTestNet);
 
-/*
-FFI_PLUGIN_EXPORT
-const char *createFullViewKey(const char* keyData, int index);
-
-FFI_PLUGIN_EXPORT
-const char* createIncomingViewKey(const char* keyData, int index);
-*/
-
 /*
  * FFI-friendly wrapper for spark::identifyCoin.
  *
@@ -115,7 +107,7 @@ FFI_PLUGIN_EXPORT
 struct SparkFeeResult* estimateSparkFee(
         unsigned char* keyData,
         int index,
-        int sendAmount,
+        int64_t sendAmount,
         int subtractFeeFromAmount,
         struct DartSpendCoinData* coins,
         int coinsLength,

src/structs.h

@@ -215,7 +215,7 @@ struct SparkSpendTransactionResult {
     struct OutputScript* outputScripts;
     int outputScriptsLength;
 
-    int fee;
+    int64_t fee;
 
     int isError;
 };
@@ -251,7 +251,7 @@ struct DartSpendCoinData {
 
 struct SparkFeeResult {
     char *error;
-    int fee;
+    int64_t fee;
 };
 
 //#ifdef __cplusplus