migrate to ffi plugin

.gitignore

@@ -28,10 +28,6 @@ doc/api/
 
 .idea/
 
-lib/git_versions.dart
-
 # Ignore build artifacts.
-scripts/*/cache/
+src/build
-scripts/*/sparkmobile
+src/deps/sparkmobile
-scripts/*/CMakeLists/sparkmobile/CMakeLists.txt
-scripts/*/CMakeLists/secp256k1/CMakeLists.txt

.gitmodules

@@ -1,3 +0,0 @@
-[submodule "sparkmobile"]
-	path = sparkmobile
-	url = https://github.com/firoorg/sparkmobile

android/build.gradle

@@ -1,20 +1,21 @@
+// The Android Gradle Plugin builds the native code with the Android NDK.
+
 group 'com.cypherstack.flutter_libsparkmobile'
-version '1.0-SNAPSHOT'
+version '1.0'
 
 buildscript {
-    ext.kotlin_version = '1.7.10'
     repositories {
         google()
         mavenCentral()
     }
 
     dependencies {
+        // The Android Gradle Plugin knows how to build native code with the NDK.
         classpath 'com.android.tools.build:gradle:7.3.0'
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }
 
-allprojects {
+rootProject.allprojects {
     repositories {
         google()
         mavenCentral()
@@ -22,43 +23,37 @@ allprojects {
 }
 
 apply plugin: 'com.android.library'
-apply plugin: 'kotlin-android'
 
 android {
+    // Bumping the plugin compileSdkVersion requires all clients of this plugin
+    // to bump the version in their app.
     compileSdkVersion 31
 
+    // Bumping the plugin ndkVersion requires all clients of this plugin to bump
+    // the version in their app and to download a newer version of the NDK.
+    ndkVersion "23.1.7779620"
+
+    // Invoke the shared CMake build with the Android Gradle Plugin.
+    externalNativeBuild {
+        cmake {
+            path "../src/CMakeLists.txt"
+
+            // The default CMake version for the Android Gradle Plugin is 3.10.2.
+            // https://developer.android.com/studio/projects/install-ndk#vanilla_cmake
+            //
+            // The Flutter tooling requires that developers have CMake 3.10 or later
+            // installed. You should not increase this version, as doing so will cause
+            // the plugin to fail to compile for some customers of the plugin.
+            // version "3.10.2"
+        }
+    }
+
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8
         targetCompatibility JavaVersion.VERSION_1_8
     }
 
-    kotlinOptions {
-        jvmTarget = '1.8'
-    }
-
-    sourceSets {
-        main.java.srcDirs += 'src/main/kotlin'
-        test.java.srcDirs += 'src/test/kotlin'
-    }
-
     defaultConfig {
         minSdkVersion 16
     }
-
-    dependencies {
-        testImplementation 'org.jetbrains.kotlin:kotlin-test'
-        testImplementation 'org.mockito:mockito-core:5.0.0'
-    }
-
-    testOptions {
-        unitTests.all {
-            useJUnitPlatform()
-
-            testLogging {
-               events "passed", "skipped", "failed", "standardOut", "standardError"
-               outputs.upToDateWhen {false}
-               showStandardStreams = true
-            }
-        }
-    }
 }

android/src/main/kotlin/com/cypherstack/flutter_libsparkmobile/FlutterLibsparkmobilePlugin.kt

@@ -1,35 +0,0 @@
-package com.cypherstack.flutter_libsparkmobile
-
-import androidx.annotation.NonNull
-
-import io.flutter.embedding.engine.plugins.FlutterPlugin
-import io.flutter.plugin.common.MethodCall
-import io.flutter.plugin.common.MethodChannel
-import io.flutter.plugin.common.MethodChannel.MethodCallHandler
-import io.flutter.plugin.common.MethodChannel.Result
-
-/** FlutterLibsparkmobilePlugin */
-class FlutterLibsparkmobilePlugin: FlutterPlugin, MethodCallHandler {
-  /// The MethodChannel that will the communication between Flutter and native Android
-  ///
-  /// This local reference serves to register the plugin with the Flutter Engine and unregister it
-  /// when the Flutter Engine is detached from the Activity
-  private lateinit var channel : MethodChannel
-
-  override fun onAttachedToEngine(@NonNull flutterPluginBinding: FlutterPlugin.FlutterPluginBinding) {
-    channel = MethodChannel(flutterPluginBinding.binaryMessenger, "flutter_libsparkmobile")
-    channel.setMethodCallHandler(this)
-  }
-
-  override fun onMethodCall(@NonNull call: MethodCall, @NonNull result: Result) {
-    if (call.method == "getPlatformVersion") {
-      result.success("Android ${android.os.Build.VERSION.RELEASE}")
-    } else {
-      result.notImplemented()
-    }
-  }
-
-  override fun onDetachedFromEngine(@NonNull binding: FlutterPlugin.FlutterPluginBinding) {
-    channel.setMethodCallHandler(null)
-  }
-}

android/src/test/kotlin/com/cypherstack/flutter_libsparkmobile/FlutterLibsparkmobilePluginTest.kt

@@ -1,27 +0,0 @@
-package com.cypherstack.flutter_libsparkmobile
-
-import io.flutter.plugin.common.MethodCall
-import io.flutter.plugin.common.MethodChannel
-import kotlin.test.Test
-import org.mockito.Mockito
-
-/*
- * This demonstrates a simple unit test of the Kotlin portion of this plugin's implementation.
- *
- * Once you have built the plugin's example app, you can run these tests from the command
- * line by running `./gradlew testDebugUnitTest` in the `example/android/` directory, or
- * you can run them directly from IDEs that support JUnit such as Android Studio.
- */
-
-internal class FlutterLibsparkmobilePluginTest {
-  @Test
-  fun onMethodCall_getPlatformVersion_returnsExpectedValue() {
-    val plugin = FlutterLibsparkmobilePlugin()
-
-    val call = MethodCall("getPlatformVersion", null)
-    val mockResult: MethodChannel.Result = Mockito.mock(MethodChannel.Result::class.java)
-    plugin.onMethodCall(call, mockResult)
-
-    Mockito.verify(mockResult).success("Android " + android.os.Build.VERSION.RELEASE)
-  }
-}

example/ios/RunnerTests/RunnerTests.swift

@@ -2,25 +2,11 @@ import Flutter
 import UIKit
 import XCTest
 
-@testable import flutter_libsparkmobile
-
-// This demonstrates a simple unit test of the Swift portion of this plugin's implementation.
-//
-// See https://developer.apple.com/documentation/xctest for more information about using XCTest.
-
 class RunnerTests: XCTestCase {
 
-  func testGetPlatformVersion() {
+  func testExample() {
-    let plugin = FlutterLibsparkmobilePlugin()
+    // If you add code to the Runner application, consider adding tests here.
-
+    // See https://developer.apple.com/documentation/xctest for more information about using XCTest.
-    let call = FlutterMethodCall(methodName: "getPlatformVersion", arguments: [])
-
-    let resultExpectation = expectation(description: "result block must be called.")
-    plugin.handle(call) { result in
-      XCTAssertEqual(result as! String, "iOS " + UIDevice.current.systemVersion)
-      resultExpectation.fulfill()
-    }
-    waitForExpectations(timeout: 1)
   }
 
 }

example/linux/CMakeLists.txt

@@ -86,8 +86,6 @@ set_target_properties(${BINARY_NAME}
   RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/intermediates_do_not_run"
 )
 
-# Enable the test target.
-set(include_flutter_libsparkmobile_tests TRUE)
 
 # Generated plugin build rules, which manage building the plugins and adding
 # them to the application.
@@ -119,10 +117,6 @@ install(FILES "${FLUTTER_ICU_DATA_FILE}" DESTINATION "${INSTALL_BUNDLE_DATA_DIR}
 install(FILES "${FLUTTER_LIBRARY}" DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"
   COMPONENT Runtime)
 
-install(FILES "${CMAKE_CURRENT_SOURCE_DIR}/../../scripts/linux/build/libsparkmobile.so" DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"
-  COMPONENT Runtime)
-# Must have ran build script(s) in order for this library to exist.
-
 foreach(bundled_library ${PLUGIN_BUNDLED_LIBRARIES})
   install(FILES "${bundled_library}"
     DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"

example/linux/flutter/generated_plugin_registrant.cc

@@ -6,10 +6,6 @@
 
 #include "generated_plugin_registrant.h"
 
-#include <flutter_libsparkmobile/flutter_libsparkmobile_plugin.h>
 
 void fl_register_plugins(FlPluginRegistry* registry) {
-  g_autoptr(FlPluginRegistrar) flutter_libsparkmobile_registrar =
-      fl_plugin_registry_get_registrar_for_plugin(registry, "FlutterLibsparkmobilePlugin");
-  flutter_libsparkmobile_plugin_register_with_registrar(flutter_libsparkmobile_registrar);
 }

example/linux/flutter/generated_plugins.cmake

@@ -3,11 +3,11 @@
 #
 
 list(APPEND FLUTTER_PLUGIN_LIST
-  flutter_libsparkmobile
 )
 
 list(APPEND FLUTTER_FFI_PLUGIN_LIST
   coinlib_flutter
+  flutter_libsparkmobile
 )
 
 set(PLUGIN_BUNDLED_LIBRARIES)

example/macos/Flutter/GeneratedPluginRegistrant.swift

@@ -5,8 +5,6 @@
 import FlutterMacOS
 import Foundation
 
-import flutter_libsparkmobile
 
 func RegisterGeneratedPlugins(registry: FlutterPluginRegistry) {
-  FlutterLibsparkmobilePlugin.register(with: registry.registrar(forPlugin: "FlutterLibsparkmobilePlugin"))
 }

example/macos/RunnerTests/RunnerTests.swift

@@ -2,26 +2,11 @@ import FlutterMacOS
 import Cocoa
 import XCTest
 
-@testable import flutter_libsparkmobile
-
-// This demonstrates a simple unit test of the Swift portion of this plugin's implementation.
-//
-// See https://developer.apple.com/documentation/xctest for more information about using XCTest.
-
 class RunnerTests: XCTestCase {
 
-  func testGetPlatformVersion() {
+  func testExample() {
-    let plugin = FlutterLibsparkmobilePlugin()
+    // If you add code to the Runner application, consider adding tests here.
-
+    // See https://developer.apple.com/documentation/xctest for more information about using XCTest.
-    let call = FlutterMethodCall(methodName: "getPlatformVersion", arguments: [])
-
-    let resultExpectation = expectation(description: "result block must be called.")
-    plugin.handle(call) { result in
-      XCTAssertEqual(result as! String,
-                     "macOS " + ProcessInfo.processInfo.operatingSystemVersionString)
-      resultExpectation.fulfill()
-    }
-    waitForExpectations(timeout: 1)
   }
 
 }

example/pubspec.yaml

@@ -4,6 +4,20 @@ description: Demonstrates how to use the flutter_libsparkmobile plugin.
 # pub.dev using `flutter pub publish`. This is preferred for private packages.
 publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 
+# The following defines the version and build number for your application.
+# A version number is three numbers separated by dots, like 1.2.43
+# followed by an optional build number separated by a +.
+# Both the version and the builder number may be overridden in flutter
+# build by specifying --build-name and --build-number, respectively.
+# In Android, build-name is used as versionName while build-number used as versionCode.
+# Read more about Android versioning at https://developer.android.com/studio/publish/versioning
+# In iOS, build-name is used as CFBundleShortVersionString while build-number is used as CFBundleVersion.
+# Read more about iOS versioning at
+# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
+# In Windows, build-name is used as the major, minor, and patch parts
+# of the product and file versions while build-number is used as the build suffix.
+version: 1.0.0+1
+
 environment:
   sdk: '>=3.0.6 <4.0.0'
 

example/windows/CMakeLists.txt

@@ -52,8 +52,6 @@ add_subdirectory(${FLUTTER_MANAGED_DIR})
 # Application build; see runner/CMakeLists.txt.
 add_subdirectory("runner")
 
-# Enable the test target.
-set(include_flutter_libsparkmobile_tests TRUE)
 
 # Generated plugin build rules, which manage building the plugins and adding
 # them to the application.

example/windows/flutter/generated_plugin_registrant.cc

@@ -6,9 +6,6 @@
 
 #include "generated_plugin_registrant.h"
 
-#include <flutter_libsparkmobile/flutter_libsparkmobile_plugin_c_api.h>
 
 void RegisterPlugins(flutter::PluginRegistry* registry) {
-  FlutterLibsparkmobilePluginCApiRegisterWithRegistrar(
-      registry->GetRegistrarForPlugin("FlutterLibsparkmobilePluginCApi"));
 }

example/windows/flutter/generated_plugins.cmake

@@ -3,10 +3,10 @@
 #
 
 list(APPEND FLUTTER_PLUGIN_LIST
-  flutter_libsparkmobile
 )
 
 list(APPEND FLUTTER_FFI_PLUGIN_LIST
+  flutter_libsparkmobile
 )
 
 set(PLUGIN_BUNDLED_LIBRARIES)

ffigen.yaml

@@ -0,0 +1,19 @@
+# Run with `flutter pub run ffigen --config ffigen.yaml`.
+name: FlutterLibsparkmobileBindings
+description: |
+  Bindings for `src/flutter_libsparkmobile.h`.
+
+  Regenerate bindings with `flutter pub run ffigen --config ffigen.yaml`.
+output: 'lib/flutter_libsparkmobile_bindings_generated.dart'
+headers:
+  entry-points:
+    - 'src/flutter_libsparkmobile.h'
+  include-directives:
+    - 'src/flutter_libsparkmobile.h'
+preamble: |
+  // ignore_for_file: always_specify_types
+  // ignore_for_file: camel_case_types
+  // ignore_for_file: non_constant_identifier_names
+comments:
+  style: any
+  length: full

flutter_libsparkmobile.iml

@@ -3,7 +3,7 @@
   <component name="NewModuleRootManager" inherit-compiler-output="true">
     <exclude-output />
     <content url="file://$MODULE_DIR$">
-      <sourceFolder url="file://$MODULE_DIR$/lib" isTestSource="false" />
+      <excludeFolder url="file://$MODULE_DIR$/example/.idea" />
       <excludeFolder url="file://$MODULE_DIR$/.idea" />
       <excludeFolder url="file://$MODULE_DIR$/example/.dart_tool" />
       <excludeFolder url="file://$MODULE_DIR$/example/.pub" />

ios/.gitignore

@@ -1,38 +0,0 @@
-.idea/
-.vagrant/
-.sconsign.dblite
-.svn/
-
-.DS_Store
-*.swp
-profile
-
-DerivedData/
-build/
-GeneratedPluginRegistrant.h
-GeneratedPluginRegistrant.m
-
-.generated/
-
-*.pbxuser
-*.mode1v3
-*.mode2v3
-*.perspectivev3
-
-!default.pbxuser
-!default.mode1v3
-!default.mode2v3
-!default.perspectivev3
-
-xcuserdata
-
-*.moved-aside
-
-*.pyc
-*sync/
-Icon?
-.tags*
-
-/Flutter/Generated.xcconfig
-/Flutter/ephemeral/
-/Flutter/flutter_export_environment.sh

ios/Classes/FlutterLibsparkmobilePlugin.swift

@@ -1,19 +0,0 @@
-import Flutter
-import UIKit
-
-public class FlutterLibsparkmobilePlugin: NSObject, FlutterPlugin {
-  public static func register(with registrar: FlutterPluginRegistrar) {
-    let channel = FlutterMethodChannel(name: "flutter_libsparkmobile", binaryMessenger: registrar.messenger())
-    let instance = FlutterLibsparkmobilePlugin()
-    registrar.addMethodCallDelegate(instance, channel: channel)
-  }
-
-  public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
-    switch call.method {
-    case "getPlatformVersion":
-      result("iOS " + UIDevice.current.systemVersion)
-    default:
-      result(FlutterMethodNotImplemented)
-    }
-  }
-}

ios/Classes/flutter_libsparkmobile.c

@@ -0,0 +1,3 @@
+// Relative import to be able to reuse the C sources.
+// See the comment in ../{projectName}}.podspec for more information.
+#include flutter_libsparkmobile.cpp

ios/flutter_libsparkmobile.podspec

@@ -5,13 +5,18 @@
 Pod::Spec.new do |s|
   s.name             = 'flutter_libsparkmobile'
   s.version          = '0.0.1'
-  s.summary          = 'A new Flutter plugin project.'
+  s.summary          = 'A new Flutter project.'
   s.description      = <<-DESC
-A new Flutter plugin project.
+A new Flutter project.
                        DESC
   s.homepage         = 'http://example.com'
   s.license          = { :file => '../LICENSE' }
   s.author           = { 'Your Company' => 'email@example.com' }
+
+  # This will ensure the source files in Classes/ are included in the native
+  # builds of apps using this FFI plugin. Podspec does not support relative
+  # paths, so Classes contains a forwarder C file that relatively imports
+  # `../src/*` so that the C sources can be shared among all target platforms.
   s.source           = { :path => '.' }
   s.source_files = 'Classes/**/*'
   s.dependency 'Flutter'

lib/flutter_libsparkmobile.dart

@@ -1,3 +1,4 @@
+import 'dart:async';
 import 'dart:ffi';
 import 'dart:io';
 import 'dart:typed_data';
@@ -5,46 +6,67 @@ import 'dart:typed_data';
 import 'package:ffi/ffi.dart';
 import 'package:flutter_libsparkmobile/extensions.dart';
 
-import 'flutter_libsparkmobile_bindings.dart';
+import 'flutter_libsparkmobile_bindings_generated.dart';
 
 const kSparkChain = 6;
 const kSparkBaseDerivationPath = "m/44'/136'/0'/$kSparkChain/";
 
+const String _kLibName = 'flutter_libsparkmobile';
+
+/// The dynamic library in which the symbols for [FlutterLibsparkmobileBindings] can be found.
+final DynamicLibrary _dylib = () {
+  if (Platform.isMacOS || Platform.isIOS) {
+    return DynamicLibrary.open('$_kLibName.framework/$_kLibName');
+  }
+  if (Platform.isAndroid || Platform.isLinux) {
+    return DynamicLibrary.open('lib$_kLibName.so');
+  }
+  if (Platform.isWindows) {
+    return DynamicLibrary.open('$_kLibName.dll');
+  }
+  throw UnsupportedError('Unknown platform: ${Platform.operatingSystem}');
+}();
+
+/// The bindings to the native functions in [_dylib].
+final FlutterLibsparkmobileBindings _bindings =
+    FlutterLibsparkmobileBindings(_dylib);
+
 abstract final class LibSpark {
-  static SparkMobileBindings? _bindings;
+  static final FlutterLibsparkmobileBindings _bindings =
-
+      FlutterLibsparkmobileBindings(_dylib);
-  static void _checkLoaded() {
+  //
-    _bindings ??= SparkMobileBindings(_loadLibrary());
+  // static void _checkLoaded() {
-  }
+  //   _bindings ??= SparkMobileBindings(_loadLibrary());
-
+  // }
-  static DynamicLibrary _loadLibrary() {
+  //
-    // hack in prefix for test env
+  // static DynamicLibrary _loadLibrary() {
-    String testPrefix = "";
+  //   // hack in prefix for test env
-    if (Platform.environment.containsKey('FLUTTER_TEST')) {
+  //   String testPrefix = "";
-      if (Platform.isLinux) {
+  //   if (Platform.environment.containsKey('FLUTTER_TEST')) {
-        testPrefix = 'scripts/linux/build/';
+  //     if (Platform.isLinux) {
-      } else if (Platform.isMacOS) {
+  //       testPrefix = 'scripts/linux/build/';
-        testPrefix = 'scripts/macos/build/';
+  //     } else if (Platform.isMacOS) {
-      } else if (Platform.isWindows) {
+  //       testPrefix = 'scripts/macos/build/';
-        testPrefix = 'scripts/windows/build/';
+  //     } else if (Platform.isWindows) {
-      } else {
+  //       testPrefix = 'scripts/windows/build/';
-        throw UnsupportedError('This platform is not supported');
+  //     } else {
-      }
+  //       throw UnsupportedError('This platform is not supported');
-    }
+  //     }
-
+  //   }
-    if (Platform.isLinux) {
+  //
-      return DynamicLibrary.open('${testPrefix}libsparkmobile.so');
+  //   if (Platform.isLinux) {
-    } else if (Platform.isAndroid) {
+  //     return DynamicLibrary.open('${testPrefix}libsparkmobile.so');
-      // return DynamicLibrary.open('${testPrefix}libsparkmobile.so');
+  //   } else if (Platform.isAndroid) {
-    } else if (Platform.isIOS) {
+  //     // return DynamicLibrary.open('${testPrefix}libsparkmobile.so');
-      // return DynamicLibrary.open('${testPrefix}libsparkmobile.dylib');
+  //   } else if (Platform.isIOS) {
-    } else if (Platform.isMacOS) {
+  //     // return DynamicLibrary.open('${testPrefix}libsparkmobile.dylib');
-      // return DynamicLibrary.open('${testPrefix}libsparkmobile.dylib');
+  //   } else if (Platform.isMacOS) {
-    } else if (Platform.isWindows) {
+  //     // return DynamicLibrary.open('${testPrefix}libsparkmobile.dylib');
-      // return DynamicLibrary.open('${testPrefix}sparkmobile.dll');
+  //   } else if (Platform.isWindows) {
-    }
+  //     // return DynamicLibrary.open('${testPrefix}sparkmobile.dll');
-    throw UnsupportedError('This platform is not supported');
+  //   }
-  }
+  //   throw UnsupportedError('This platform is not supported');
+  // }
 
   // SparkMobileBindings methods:
 
@@ -55,7 +77,7 @@ abstract final class LibSpark {
     required int diversifier,
     bool isTestNet = false,
   }) async {
-    _checkLoaded();
+    // _checkLoaded();
 
     if (index < 0) {
       throw Exception("Index must not be negative.");
@@ -75,7 +97,7 @@ abstract final class LibSpark {
     final keyDataPointer = privateKey.toHexString().toNativeUtf8().cast<Char>();
 
     // Call the native method with the pointer.
-    final addressPointer = _bindings!.getAddress(
+    final addressPointer = _bindings.getAddress(
       keyDataPointer,
       index,
       diversifier,
@@ -92,3 +114,128 @@ abstract final class LibSpark {
     return addressString;
   }
 }
+
+//
+// /// A very short-lived native function.
+// ///
+// /// For very short-lived functions, it is fine to call them on the main isolate.
+// /// They will block the Dart execution while running the native function, so
+// /// only do this for native functions which are guaranteed to be short-lived.
+// int sum(int a, int b) => _bindings.sum(a, b);
+//
+// /// A longer lived native function, which occupies the thread calling it.
+// ///
+// /// Do not call these kind of native functions in the main isolate. They will
+// /// block Dart execution. This will cause dropped frames in Flutter applications.
+// /// Instead, call these native functions on a separate isolate.
+// ///
+// /// Modify this to suit your own use case. Example use cases:
+// ///
+// /// 1. Reuse a single isolate for various different kinds of requests.
+// /// 2. Use multiple helper isolates for parallel execution.
+// Future<int> sumAsync(int a, int b) async {
+//   final SendPort helperIsolateSendPort = await _helperIsolateSendPort;
+//   final int requestId = _nextSumRequestId++;
+//   final _SumRequest request = _SumRequest(requestId, a, b);
+//   final Completer<int> completer = Completer<int>();
+//   _sumRequests[requestId] = completer;
+//   helperIsolateSendPort.send(request);
+//   return completer.future;
+// }
+//
+// const String _libName = 'flutter_libsparkmobile';
+//
+// /// The dynamic library in which the symbols for [FlutterLibsparkmobileBindings] can be found.
+// final DynamicLibrary _dylib = () {
+//   if (Platform.isMacOS || Platform.isIOS) {
+//     return DynamicLibrary.open('$_libName.framework/$_libName');
+//   }
+//   if (Platform.isAndroid || Platform.isLinux) {
+//     return DynamicLibrary.open('lib$_libName.so');
+//   }
+//   if (Platform.isWindows) {
+//     return DynamicLibrary.open('$_libName.dll');
+//   }
+//   throw UnsupportedError('Unknown platform: ${Platform.operatingSystem}');
+// }();
+//
+// /// The bindings to the native functions in [_dylib].
+// final FlutterLibsparkmobileBindings _bindings = FlutterLibsparkmobileBindings(_dylib);
+
+//
+// /// A request to compute `sum`.
+// ///
+// /// Typically sent from one isolate to another.
+// class _SumRequest {
+//   final int id;
+//   final int a;
+//   final int b;
+//
+//   const _SumRequest(this.id, this.a, this.b);
+// }
+//
+// /// A response with the result of `sum`.
+// ///
+// /// Typically sent from one isolate to another.
+// class _SumResponse {
+//   final int id;
+//   final int result;
+//
+//   const _SumResponse(this.id, this.result);
+// }
+//
+// /// Counter to identify [_SumRequest]s and [_SumResponse]s.
+// int _nextSumRequestId = 0;
+//
+// /// Mapping from [_SumRequest] `id`s to the completers corresponding to the correct future of the pending request.
+// final Map<int, Completer<int>> _sumRequests = <int, Completer<int>>{};
+//
+// /// The SendPort belonging to the helper isolate.
+// Future<SendPort> _helperIsolateSendPort = () async {
+//   // The helper isolate is going to send us back a SendPort, which we want to
+//   // wait for.
+//   final Completer<SendPort> completer = Completer<SendPort>();
+//
+//   // Receive port on the main isolate to receive messages from the helper.
+//   // We receive two types of messages:
+//   // 1. A port to send messages on.
+//   // 2. Responses to requests we sent.
+//   final ReceivePort receivePort = ReceivePort()
+//     ..listen((dynamic data) {
+//       if (data is SendPort) {
+//         // The helper isolate sent us the port on which we can sent it requests.
+//         completer.complete(data);
+//         return;
+//       }
+//       if (data is _SumResponse) {
+//         // The helper isolate sent us a response to a request we sent.
+//         final Completer<int> completer = _sumRequests[data.id]!;
+//         _sumRequests.remove(data.id);
+//         completer.complete(data.result);
+//         return;
+//       }
+//       throw UnsupportedError('Unsupported message type: ${data.runtimeType}');
+//     });
+//
+//   // Start the helper isolate.
+//   await Isolate.spawn((SendPort sendPort) async {
+//     final ReceivePort helperReceivePort = ReceivePort()
+//       ..listen((dynamic data) {
+//         // On the helper isolate listen to requests and respond to them.
+//         if (data is _SumRequest) {
+//           final int result = _bindings.sum_long_running(data.a, data.b);
+//           final _SumResponse response = _SumResponse(data.id, result);
+//           sendPort.send(response);
+//           return;
+//         }
+//         throw UnsupportedError('Unsupported message type: ${data.runtimeType}');
+//       });
+//
+//     // Send the port to the main isolate on which we can receive requests.
+//     sendPort.send(helperReceivePort.sendPort);
+//   }, receivePort.sendPort);
+//
+//   // Wait until the helper isolate has sent us back the SendPort on which we
+//   // can start sending requests.
+//   return completer.future;
+// }();

lib/flutter_libsparkmobile_bindings.dart

@@ -1,439 +0,0 @@
-// ignore_for_file: camel_case_types, non_constant_identifier_names, unused_element, unused_field, return_of_invalid_type, void_checks, annotate_overrides, no_leading_underscores_for_local_identifiers, library_private_types_in_public_api
-
-// AUTO GENERATED FILE, DO NOT EDIT.
-//
-// Generated by `package:ffigen`.
-// ignore_for_file: type=lint
-import 'dart:ffi' as ffi;
-
-/// Bindings for sparkmobile.
-class SparkMobileBindings {
-  /// Holds the symbol lookup function.
-  final ffi.Pointer<T> Function<T extends ffi.NativeType>(String symbolName)
-      _lookup;
-
-  /// The symbols are looked up in [dynamicLibrary].
-  SparkMobileBindings(ffi.DynamicLibrary dynamicLibrary)
-      : _lookup = dynamicLibrary.lookup;
-
-  /// The symbols are looked up with [lookup].
-  SparkMobileBindings.fromLookup(
-      ffi.Pointer<T> Function<T extends ffi.NativeType>(String symbolName)
-          lookup)
-      : _lookup = lookup;
-
-  ffi.Pointer<ffi.Char> getAddress(
-    ffi.Pointer<ffi.Char> keyDataHex,
-    int index,
-    int diversifier,
-    int isTestNet,
-  ) {
-    return _getAddress(
-      keyDataHex,
-      index,
-      diversifier,
-      isTestNet,
-    );
-  }
-
-  late final _getAddressPtr = _lookup<
-      ffi.NativeFunction<
-          ffi.Pointer<ffi.Char> Function(
-              ffi.Pointer<ffi.Char>, ffi.Int, ffi.Int, ffi.Int)>>('getAddress');
-  late final _getAddress = _getAddressPtr.asFunction<
-      ffi.Pointer<ffi.Char> Function(ffi.Pointer<ffi.Char>, int, int, int)>();
-
-  CIdentifiedCoinData identifyCoin(
-    CCoin c_struct,
-    ffi.Pointer<ffi.Char> keyDataHex,
-    int index,
-  ) {
-    return _identifyCoin(
-      c_struct,
-      keyDataHex,
-      index,
-    );
-  }
-
-  late final _identifyCoinPtr = _lookup<
-      ffi.NativeFunction<
-          CIdentifiedCoinData Function(
-              CCoin, ffi.Pointer<ffi.Char>, ffi.Int)>>('identifyCoin');
-  late final _identifyCoin = _identifyCoinPtr.asFunction<
-      CIdentifiedCoinData Function(CCoin, ffi.Pointer<ffi.Char>, int)>();
-
-  ffi.Pointer<CCRecipient> createSparkMintRecipients(
-    int numRecipients,
-    ffi.Pointer<PubKeyScript> pubKeyScripts,
-    ffi.Pointer<ffi.Uint64> amounts,
-    ffi.Pointer<ffi.Char> memo,
-    int subtractFee,
-  ) {
-    return _createSparkMintRecipients(
-      numRecipients,
-      pubKeyScripts,
-      amounts,
-      memo,
-      subtractFee,
-    );
-  }
-
-  late final _createSparkMintRecipientsPtr = _lookup<
-      ffi.NativeFunction<
-          ffi.Pointer<CCRecipient> Function(
-              ffi.Int,
-              ffi.Pointer<PubKeyScript>,
-              ffi.Pointer<ffi.Uint64>,
-              ffi.Pointer<ffi.Char>,
-              ffi.Int)>>('createSparkMintRecipients');
-  late final _createSparkMintRecipients =
-      _createSparkMintRecipientsPtr.asFunction<
-          ffi.Pointer<CCRecipient> Function(int, ffi.Pointer<PubKeyScript>,
-              ffi.Pointer<ffi.Uint64>, ffi.Pointer<ffi.Char>, int)>();
-}
-
-final class __fsid_t extends ffi.Struct {
-  @ffi.Array.multi([2])
-  external ffi.Array<ffi.Int> __val;
-}
-
-final class CCoin extends ffi.Struct {
-  @ffi.Char()
-  external int type;
-
-  external ffi.Pointer<ffi.UnsignedChar> k;
-
-  @ffi.Int()
-  external int kLength;
-
-  external ffi.Pointer<ffi.Char> address;
-
-  @ffi.Uint64()
-  external int v;
-
-  external ffi.Pointer<ffi.UnsignedChar> memo;
-
-  @ffi.Int()
-  external int memoLength;
-
-  external ffi.Pointer<ffi.UnsignedChar> serial_context;
-
-  @ffi.Int()
-  external int serial_contextLength;
-}
-
-final class CIdentifiedCoinData extends ffi.Struct {
-  @ffi.Uint64()
-  external int i;
-
-  external ffi.Pointer<ffi.UnsignedChar> d;
-
-  @ffi.Int()
-  external int dLength;
-
-  @ffi.Uint64()
-  external int v;
-
-  external ffi.Pointer<ffi.UnsignedChar> k;
-
-  @ffi.Int()
-  external int kLength;
-
-  external ffi.Pointer<ffi.Char> memo;
-
-  @ffi.Int()
-  external int memoLength;
-}
-
-final class CCRecipient extends ffi.Struct {
-  external ffi.Pointer<ffi.UnsignedChar> pubKey;
-
-  @ffi.Int()
-  external int pubKeyLength;
-
-  @ffi.Uint64()
-  external int cAmount;
-
-  @ffi.Int()
-  external int subtractFee;
-}
-
-final class CMintedCoinData extends ffi.Struct {
-  external ffi.Pointer<ffi.Char> address;
-
-  @ffi.Uint64()
-  external int value;
-
-  external ffi.Pointer<ffi.Char> memo;
-}
-
-final class PubKeyScript extends ffi.Struct {
-  external ffi.Pointer<ffi.UnsignedChar> bytes;
-
-  @ffi.Int()
-  external int length;
-}
-
-final class COutputCoinData extends ffi.Struct {
-  external ffi.Pointer<ffi.Char> address;
-
-  @ffi.Uint64()
-  external int value;
-
-  external ffi.Pointer<ffi.Char> memo;
-}
-
-final class CCSparkMintMeta extends ffi.Struct {
-  @ffi.Uint64()
-  external int height;
-
-  external ffi.Pointer<ffi.Char> id;
-
-  @ffi.Int()
-  external int isUsed;
-
-  external ffi.Pointer<ffi.Char> txid;
-
-  @ffi.Uint64()
-  external int i;
-
-  external ffi.Pointer<ffi.UnsignedChar> d;
-
-  @ffi.Int()
-  external int dLength;
-
-  @ffi.Uint64()
-  external int v;
-
-  external ffi.Pointer<ffi.UnsignedChar> k;
-
-  @ffi.Int()
-  external int kLength;
-
-  external ffi.Pointer<ffi.Char> memo;
-
-  @ffi.Int()
-  external int memoLength;
-
-  external ffi.Pointer<ffi.UnsignedChar> serial_context;
-
-  @ffi.Int()
-  external int serial_contextLength;
-
-  @ffi.Char()
-  external int type;
-
-  external CCoin coin;
-}
-
-const int _STDINT_H = 1;
-
-const int _FEATURES_H = 1;
-
-const int _DEFAULT_SOURCE = 1;
-
-const int __GLIBC_USE_ISOC2X = 1;
-
-const int __USE_ISOC11 = 1;
-
-const int __USE_ISOC99 = 1;
-
-const int __USE_ISOC95 = 1;
-
-const int _POSIX_SOURCE = 1;
-
-const int _POSIX_C_SOURCE = 200809;
-
-const int __USE_POSIX = 1;
-
-const int __USE_POSIX2 = 1;
-
-const int __USE_POSIX199309 = 1;
-
-const int __USE_POSIX199506 = 1;
-
-const int __USE_XOPEN2K = 1;
-
-const int __USE_XOPEN2K8 = 1;
-
-const int _ATFILE_SOURCE = 1;
-
-const int __USE_MISC = 1;
-
-const int __USE_ATFILE = 1;
-
-const int __USE_FORTIFY_LEVEL = 0;
-
-const int __GLIBC_USE_DEPRECATED_GETS = 0;
-
-const int __GLIBC_USE_DEPRECATED_SCANF = 0;
-
-const int _STDC_PREDEF_H = 1;
-
-const int __STDC_IEC_559__ = 1;
-
-const int __STDC_IEC_559_COMPLEX__ = 1;
-
-const int __STDC_ISO_10646__ = 201706;
-
-const int __GNU_LIBRARY__ = 6;
-
-const int __GLIBC__ = 2;
-
-const int __GLIBC_MINOR__ = 31;
-
-const int _SYS_CDEFS_H = 1;
-
-const int __glibc_c99_flexarr_available = 1;
-
-const int __WORDSIZE = 64;
-
-const int __WORDSIZE_TIME64_COMPAT32 = 1;
-
-const int __SYSCALL_WORDSIZE = 64;
-
-const int __LONG_DOUBLE_USES_FLOAT128 = 0;
-
-const int __HAVE_GENERIC_SELECTION = 0;
-
-const int __GLIBC_USE_LIB_EXT2 = 1;
-
-const int __GLIBC_USE_IEC_60559_BFP_EXT = 1;
-
-const int __GLIBC_USE_IEC_60559_BFP_EXT_C2X = 1;
-
-const int __GLIBC_USE_IEC_60559_FUNCS_EXT = 1;
-
-const int __GLIBC_USE_IEC_60559_FUNCS_EXT_C2X = 1;
-
-const int __GLIBC_USE_IEC_60559_TYPES_EXT = 1;
-
-const int _BITS_TYPES_H = 1;
-
-const int __TIMESIZE = 64;
-
-const int _BITS_TYPESIZES_H = 1;
-
-const int __OFF_T_MATCHES_OFF64_T = 1;
-
-const int __INO_T_MATCHES_INO64_T = 1;
-
-const int __RLIM_T_MATCHES_RLIM64_T = 1;
-
-const int __STATFS_MATCHES_STATFS64 = 1;
-
-const int __FD_SETSIZE = 1024;
-
-const int _BITS_TIME64_H = 1;
-
-const int _BITS_WCHAR_H = 1;
-
-const int __WCHAR_MAX = 2147483647;
-
-const int __WCHAR_MIN = -2147483648;
-
-const int _BITS_STDINT_INTN_H = 1;
-
-const int _BITS_STDINT_UINTN_H = 1;
-
-const int INT8_MIN = -128;
-
-const int INT16_MIN = -32768;
-
-const int INT32_MIN = -2147483648;
-
-const int INT64_MIN = -9223372036854775808;
-
-const int INT8_MAX = 127;
-
-const int INT16_MAX = 32767;
-
-const int INT32_MAX = 2147483647;
-
-const int INT64_MAX = 9223372036854775807;
-
-const int UINT8_MAX = 255;
-
-const int UINT16_MAX = 65535;
-
-const int UINT32_MAX = 4294967295;
-
-const int UINT64_MAX = -1;
-
-const int INT_LEAST8_MIN = -128;
-
-const int INT_LEAST16_MIN = -32768;
-
-const int INT_LEAST32_MIN = -2147483648;
-
-const int INT_LEAST64_MIN = -9223372036854775808;
-
-const int INT_LEAST8_MAX = 127;
-
-const int INT_LEAST16_MAX = 32767;
-
-const int INT_LEAST32_MAX = 2147483647;
-
-const int INT_LEAST64_MAX = 9223372036854775807;
-
-const int UINT_LEAST8_MAX = 255;
-
-const int UINT_LEAST16_MAX = 65535;
-
-const int UINT_LEAST32_MAX = 4294967295;
-
-const int UINT_LEAST64_MAX = -1;
-
-const int INT_FAST8_MIN = -128;
-
-const int INT_FAST16_MIN = -9223372036854775808;
-
-const int INT_FAST32_MIN = -9223372036854775808;
-
-const int INT_FAST64_MIN = -9223372036854775808;
-
-const int INT_FAST8_MAX = 127;
-
-const int INT_FAST16_MAX = 9223372036854775807;
-
-const int INT_FAST32_MAX = 9223372036854775807;
-
-const int INT_FAST64_MAX = 9223372036854775807;
-
-const int UINT_FAST8_MAX = 255;
-
-const int UINT_FAST16_MAX = -1;
-
-const int UINT_FAST32_MAX = -1;
-
-const int UINT_FAST64_MAX = -1;
-
-const int INTPTR_MIN = -9223372036854775808;
-
-const int INTPTR_MAX = 9223372036854775807;
-
-const int UINTPTR_MAX = -1;
-
-const int INTMAX_MIN = -9223372036854775808;
-
-const int INTMAX_MAX = 9223372036854775807;
-
-const int UINTMAX_MAX = -1;
-
-const int PTRDIFF_MIN = -9223372036854775808;
-
-const int PTRDIFF_MAX = 9223372036854775807;
-
-const int SIG_ATOMIC_MIN = -2147483648;
-
-const int SIG_ATOMIC_MAX = 2147483647;
-
-const int SIZE_MAX = -1;
-
-const int WCHAR_MIN = -2147483648;
-
-const int WCHAR_MAX = 2147483647;
-
-const int WINT_MIN = 0;
-
-const int WINT_MAX = 4294967295;

lib/flutter_libsparkmobile_bindings_generated.dart

@@ -0,0 +1,198 @@
+// ignore_for_file: always_specify_types
+// ignore_for_file: camel_case_types
+// ignore_for_file: non_constant_identifier_names
+
+// AUTO GENERATED FILE, DO NOT EDIT.
+//
+// Generated by `package:ffigen`.
+import 'dart:ffi' as ffi;
+
+/// Bindings for `src/flutter_libsparkmobile.h`.
+///
+/// Regenerate bindings with `flutter pub run ffigen --config ffigen.yaml`.
+///
+class FlutterLibsparkmobileBindings {
+  /// Holds the symbol lookup function.
+  final ffi.Pointer<T> Function<T extends ffi.NativeType>(String symbolName)
+      _lookup;
+
+  /// The symbols are looked up in [dynamicLibrary].
+  FlutterLibsparkmobileBindings(ffi.DynamicLibrary dynamicLibrary)
+      : _lookup = dynamicLibrary.lookup;
+
+  /// The symbols are looked up with [lookup].
+  FlutterLibsparkmobileBindings.fromLookup(
+      ffi.Pointer<T> Function<T extends ffi.NativeType>(String symbolName)
+          lookup)
+      : _lookup = lookup;
+
+  /// FFI-friendly wrapper for spark::getAddress.
+  ffi.Pointer<ffi.Char> getAddress(
+    ffi.Pointer<ffi.Char> keyDataHex,
+    int index,
+    int diversifier,
+    int isTestNet,
+  ) {
+    return _getAddress(
+      keyDataHex,
+      index,
+      diversifier,
+      isTestNet,
+    );
+  }
+
+  late final _getAddressPtr = _lookup<
+      ffi.NativeFunction<
+          ffi.Pointer<ffi.Char> Function(
+              ffi.Pointer<ffi.Char>, ffi.Int, ffi.Int, ffi.Int)>>('getAddress');
+  late final _getAddress = _getAddressPtr.asFunction<
+      ffi.Pointer<ffi.Char> Function(ffi.Pointer<ffi.Char>, int, int, int)>();
+
+  /// FFI-friendly wrapper for spark::identifyCoin.
+  CIdentifiedCoinData identifyCoin(
+    CCoin c_struct,
+    ffi.Pointer<ffi.Char> keyDataHex,
+    int index,
+  ) {
+    return _identifyCoin(
+      c_struct,
+      keyDataHex,
+      index,
+    );
+  }
+
+  late final _identifyCoinPtr = _lookup<
+      ffi.NativeFunction<
+          CIdentifiedCoinData Function(
+              CCoin, ffi.Pointer<ffi.Char>, ffi.Int)>>('identifyCoin');
+  late final _identifyCoin = _identifyCoinPtr.asFunction<
+      CIdentifiedCoinData Function(CCoin, ffi.Pointer<ffi.Char>, int)>();
+
+  /// FFI-friendly wrapper for spark::createSparkMintRecipients.
+  ffi.Pointer<CCRecipient> createSparkMintRecipients(
+    int numRecipients,
+    ffi.Pointer<PubKeyScript> pubKeyScripts,
+    ffi.Pointer<ffi.Uint64> amounts,
+    ffi.Pointer<ffi.Char> memo,
+    int subtractFee,
+  ) {
+    return _createSparkMintRecipients(
+      numRecipients,
+      pubKeyScripts,
+      amounts,
+      memo,
+      subtractFee,
+    );
+  }
+
+  late final _createSparkMintRecipientsPtr = _lookup<
+      ffi.NativeFunction<
+          ffi.Pointer<CCRecipient> Function(
+              ffi.Int,
+              ffi.Pointer<PubKeyScript>,
+              ffi.Pointer<ffi.Uint64>,
+              ffi.Pointer<ffi.Char>,
+              ffi.Int)>>('createSparkMintRecipients');
+  late final _createSparkMintRecipients =
+      _createSparkMintRecipientsPtr.asFunction<
+          ffi.Pointer<CCRecipient> Function(int, ffi.Pointer<PubKeyScript>,
+              ffi.Pointer<ffi.Uint64>, ffi.Pointer<ffi.Char>, int)>();
+}
+
+/// FFI-friendly wrapper for a spark::Coin.
+///
+/// A Coin is a type, a key, an index, a value, a memo, and a serial context.  We accept these params
+/// as a C struct, deriving the key from the keyData and index.
+final class CCoin extends ffi.Struct {
+  @ffi.Char()
+  external int type;
+
+  external ffi.Pointer<ffi.UnsignedChar> k;
+
+  @ffi.Int()
+  external int kLength;
+
+  external ffi.Pointer<ffi.Char> keyData;
+
+  @ffi.Int()
+  external int index;
+
+  @ffi.Uint64()
+  external int v;
+
+  external ffi.Pointer<ffi.UnsignedChar> memo;
+
+  @ffi.Int()
+  external int memoLength;
+
+  external ffi.Pointer<ffi.UnsignedChar> serial_context;
+
+  @ffi.Int()
+  external int serial_contextLength;
+}
+
+/// FFI-friendly wrapper for a spark::IdentifiedCoinData.
+///
+/// An IdentifiedCoinData is a diversifier, encrypted diversifier, value, nonce, and memo.  We accept
+/// these params as a C struct.
+final class CIdentifiedCoinData extends ffi.Struct {
+  @ffi.Uint64()
+  external int i;
+
+  external ffi.Pointer<ffi.UnsignedChar> d;
+
+  @ffi.Int()
+  external int dLength;
+
+  @ffi.Uint64()
+  external int v;
+
+  external ffi.Pointer<ffi.UnsignedChar> k;
+
+  @ffi.Int()
+  external int kLength;
+
+  external ffi.Pointer<ffi.Char> memo;
+
+  @ffi.Int()
+  external int memoLength;
+}
+
+/// FFI-friendly wrapper for a spark::CRecipient.
+///
+/// A CRecipient is a CScript, CAmount, and a bool.  We accept a C-style, FFI-friendly CCRecipient
+/// struct in order to construct a C++ CRecipient.  A CScript is constructed from a hex string, a
+/// CAmount is just a uint64_t, and the bool will be an int.
+final class CCRecipient extends ffi.Struct {
+  external ffi.Pointer<ffi.UnsignedChar> pubKey;
+
+  @ffi.Int()
+  external int pubKeyLength;
+
+  @ffi.Uint64()
+  external int cAmount;
+
+  @ffi.Int()
+  external int subtractFee;
+}
+
+/// FFI-friendly wrapper for a spark::MintedCoinData.
+///
+/// A MintedCoinData is a struct that contains an Address, a uint64_t value, and a string memo.  We
+/// accept these as a CMintedCoinData from the Dart interface, and convert them to a MintedCoinData
+/// struct.
+final class CMintedCoinData extends ffi.Struct {
+  external ffi.Pointer<ffi.Char> address;
+
+  @ffi.Uint64()
+  external int value;
+
+  external ffi.Pointer<ffi.Char> memo;
+}
+
+final class PubKeyScript extends ffi.Struct {
+  external ffi.Pointer<ffi.UnsignedChar> bytes;
+
+  @ffi.Int()
+  external int length;
+}

lib/flutter_libsparkmobile_method_channel.dart

@@ -1,17 +0,0 @@
-import 'package:flutter/foundation.dart';
-import 'package:flutter/services.dart';
-
-import 'flutter_libsparkmobile_platform_interface.dart';
-
-/// An implementation of [FlutterLibsparkmobilePlatform] that uses method channels.
-class MethodChannelFlutterLibsparkmobile extends FlutterLibsparkmobilePlatform {
-  /// The method channel used to interact with the native platform.
-  @visibleForTesting
-  final methodChannel = const MethodChannel('flutter_libsparkmobile');
-
-  @override
-  Future<String?> getPlatformVersion() async {
-    final version = await methodChannel.invokeMethod<String>('getPlatformVersion');
-    return version;
-  }
-}

lib/flutter_libsparkmobile_platform_interface.dart

@@ -1,29 +0,0 @@
-import 'package:plugin_platform_interface/plugin_platform_interface.dart';
-
-import 'flutter_libsparkmobile_method_channel.dart';
-
-abstract class FlutterLibsparkmobilePlatform extends PlatformInterface {
-  /// Constructs a FlutterLibsparkmobilePlatform.
-  FlutterLibsparkmobilePlatform() : super(token: _token);
-
-  static final Object _token = Object();
-
-  static FlutterLibsparkmobilePlatform _instance = MethodChannelFlutterLibsparkmobile();
-
-  /// The default instance of [FlutterLibsparkmobilePlatform] to use.
-  ///
-  /// Defaults to [MethodChannelFlutterLibsparkmobile].
-  static FlutterLibsparkmobilePlatform get instance => _instance;
-
-  /// Platform-specific implementations should set this with their own
-  /// platform-specific class that extends [FlutterLibsparkmobilePlatform] when
-  /// they register themselves.
-  static set instance(FlutterLibsparkmobilePlatform instance) {
-    PlatformInterface.verifyToken(instance, _token);
-    _instance = instance;
-  }
-
-  Future<String?> getPlatformVersion() {
-    throw UnimplementedError('platformVersion() has not been implemented.');
-  }
-}

lib/git_versions_example.dart

@@ -1,23 +0,0 @@
-import 'dart:io';
-
-/*ANDROID_VERSION*/ const ANDROID_VERSION = "";
-/*IOS_VERSION*/ const IOS_VERSION = "";
-/*MACOS_VERSION*/ const MACOS_VERSION = "";
-/*LINUX_VERSION*/ const LINUX_VERSION = "";
-/*WINDOWS_VERSION*/ const WINDOWS_VERSION = "";
-
-String getPluginVersion() {
-  if (Platform.isAndroid) {
-    return ANDROID_VERSION;
-  } else if (Platform.isIOS) {
-    return IOS_VERSION;
-  } else if (Platform.isMacOS) {
-    return MACOS_VERSION;
-  } else if (Platform.isLinux) {
-    return LINUX_VERSION;
-  } else if (Platform.isWindows) {
-    return WINDOWS_VERSION;
-  } else {
-    return "Unknown version";
-  }
-}

linux/CMakeLists.txt

@@ -5,90 +5,20 @@ cmake_minimum_required(VERSION 3.10)
 
 # Project-level configuration.
 set(PROJECT_NAME "flutter_libsparkmobile")
+set(PROJECT_SYSTEM_NAME "linux")
+
 project(${PROJECT_NAME} LANGUAGES CXX)
 
-# This value is used when generating builds using this plugin, so it must
+# Invoke the build for native code shared with the other target platforms.
-# not be changed.
+# This can be changed to accommodate different builds.
-set(PLUGIN_NAME "flutter_libsparkmobile_plugin")
+add_subdirectory("${CMAKE_CURRENT_SOURCE_DIR}/../src" "${CMAKE_CURRENT_BINARY_DIR}/shared")
-
-# Any new source files that you add to the plugin should be added here.
-list(APPEND PLUGIN_SOURCES
-  "flutter_libsparkmobile_plugin.cc"
-)
-
-# Define the plugin library target. Its name must not be changed (see comment
-# on PLUGIN_NAME above).
-add_library(${PLUGIN_NAME} SHARED
-  ${PLUGIN_SOURCES}
-)
-
-# Apply a standard set of build settings that are configured in the
-# application-level CMakeLists.txt. This can be removed for plugins that want
-# full control over build settings.
-apply_standard_settings(${PLUGIN_NAME})
-
-# Symbols are hidden by default to reduce the chance of accidental conflicts
-# between plugins. This should not be removed; any symbols that should be
-# exported should be explicitly exported with the FLUTTER_PLUGIN_EXPORT macro.
-set_target_properties(${PLUGIN_NAME} PROPERTIES
-  CXX_VISIBILITY_PRESET hidden)
-target_compile_definitions(${PLUGIN_NAME} PRIVATE FLUTTER_PLUGIN_IMPL)
-
-# Source include directories and library dependencies. Add any plugin-specific
-# dependencies here.
-target_include_directories(${PLUGIN_NAME} INTERFACE
-  "${CMAKE_CURRENT_SOURCE_DIR}/include")
-target_link_libraries(${PLUGIN_NAME} PRIVATE flutter)
-target_link_libraries(${PLUGIN_NAME} PRIVATE PkgConfig::GTK)
 
 # List of absolute paths to libraries that should be bundled with the plugin.
 # This list could contain prebuilt libraries, or libraries created by an
 # external build triggered from this build file.
 set(flutter_libsparkmobile_bundled_libraries
-  ""
+  # Defined in ../src/CMakeLists.txt.
+  # This can be changed to accommodate different builds.
+  $<TARGET_FILE:flutter_libsparkmobile>
   PARENT_SCOPE
 )
-
-# === Tests ===
-# These unit tests can be run from a terminal after building the example.
-
-# Only enable test builds when building the example (which sets this variable)
-# so that plugin clients aren't building the tests.
-if (${include_${PROJECT_NAME}_tests})
-if(${CMAKE_VERSION} VERSION_LESS "3.11.0")
-message("Unit tests require CMake 3.11.0 or later")
-else()
-set(TEST_RUNNER "${PROJECT_NAME}_test")
-enable_testing()
-
-# Add the Google Test dependency.
-include(FetchContent)
-FetchContent_Declare(
-  googletest
-  URL https://github.com/google/googletest/archive/release-1.11.0.zip
-)
-# Prevent overriding the parent project's compiler/linker settings
-set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
-# Disable install commands for gtest so it doesn't end up in the bundle.
-set(INSTALL_GTEST OFF CACHE BOOL "Disable installation of googletest" FORCE)
-
-FetchContent_MakeAvailable(googletest)
-
-# The plugin's exported API is not very useful for unit testing, so build the
-# sources directly into the test binary rather than using the shared library.
-add_executable(${TEST_RUNNER}
-  test/flutter_libsparkmobile_plugin_test.cc
-  ${PLUGIN_SOURCES}
-)
-apply_standard_settings(${TEST_RUNNER})
-target_include_directories(${TEST_RUNNER} PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}")
-target_link_libraries(${TEST_RUNNER} PRIVATE flutter)
-target_link_libraries(${TEST_RUNNER} PRIVATE PkgConfig::GTK)
-target_link_libraries(${TEST_RUNNER} PRIVATE gtest_main gmock)
-
-# Enable automatic test discovery.
-include(GoogleTest)
-gtest_discover_tests(${TEST_RUNNER})
-
-endif()  # CMake version check
-endif()  # include_${PROJECT_NAME}_tests

linux/flutter_libsparkmobile_plugin.cc

@@ -1,76 +0,0 @@
-#include "include/flutter_libsparkmobile/flutter_libsparkmobile_plugin.h"
-
-#include <flutter_linux/flutter_linux.h>
-#include <gtk/gtk.h>
-#include <sys/utsname.h>
-
-#include <cstring>
-
-#include "flutter_libsparkmobile_plugin_private.h"
-
-#define FLUTTER_LIBSPARKMOBILE_PLUGIN(obj) \
-  (G_TYPE_CHECK_INSTANCE_CAST((obj), flutter_libsparkmobile_plugin_get_type(), \
-                              FlutterLibsparkmobilePlugin))
-
-struct _FlutterLibsparkmobilePlugin {
-  GObject parent_instance;
-};
-
-G_DEFINE_TYPE(FlutterLibsparkmobilePlugin, flutter_libsparkmobile_plugin, g_object_get_type())
-
-// Called when a method call is received from Flutter.
-static void flutter_libsparkmobile_plugin_handle_method_call(
-    FlutterLibsparkmobilePlugin* self,
-    FlMethodCall* method_call) {
-  g_autoptr(FlMethodResponse) response = nullptr;
-
-  const gchar* method = fl_method_call_get_name(method_call);
-
-  if (strcmp(method, "getPlatformVersion") == 0) {
-    response = get_platform_version();
-  } else {
-    response = FL_METHOD_RESPONSE(fl_method_not_implemented_response_new());
-  }
-
-  fl_method_call_respond(method_call, response, nullptr);
-}
-
-FlMethodResponse* get_platform_version() {
-  struct utsname uname_data = {};
-  uname(&uname_data);
-  g_autofree gchar *version = g_strdup_printf("Linux %s", uname_data.version);
-  g_autoptr(FlValue) result = fl_value_new_string(version);
-  return FL_METHOD_RESPONSE(fl_method_success_response_new(result));
-}
-
-static void flutter_libsparkmobile_plugin_dispose(GObject* object) {
-  G_OBJECT_CLASS(flutter_libsparkmobile_plugin_parent_class)->dispose(object);
-}
-
-static void flutter_libsparkmobile_plugin_class_init(FlutterLibsparkmobilePluginClass* klass) {
-  G_OBJECT_CLASS(klass)->dispose = flutter_libsparkmobile_plugin_dispose;
-}
-
-static void flutter_libsparkmobile_plugin_init(FlutterLibsparkmobilePlugin* self) {}
-
-static void method_call_cb(FlMethodChannel* channel, FlMethodCall* method_call,
-                           gpointer user_data) {
-  FlutterLibsparkmobilePlugin* plugin = FLUTTER_LIBSPARKMOBILE_PLUGIN(user_data);
-  flutter_libsparkmobile_plugin_handle_method_call(plugin, method_call);
-}
-
-void flutter_libsparkmobile_plugin_register_with_registrar(FlPluginRegistrar* registrar) {
-  FlutterLibsparkmobilePlugin* plugin = FLUTTER_LIBSPARKMOBILE_PLUGIN(
-      g_object_new(flutter_libsparkmobile_plugin_get_type(), nullptr));
-
-  g_autoptr(FlStandardMethodCodec) codec = fl_standard_method_codec_new();
-  g_autoptr(FlMethodChannel) channel =
-      fl_method_channel_new(fl_plugin_registrar_get_messenger(registrar),
-                            "flutter_libsparkmobile",
-                            FL_METHOD_CODEC(codec));
-  fl_method_channel_set_method_call_handler(channel, method_call_cb,
-                                            g_object_ref(plugin),
-                                            g_object_unref);
-
-  g_object_unref(plugin);
-}

linux/flutter_libsparkmobile_plugin_private.h

@@ -1,10 +0,0 @@
-#include <flutter_linux/flutter_linux.h>
-
-#include "include/flutter_libsparkmobile/flutter_libsparkmobile_plugin.h"
-
-// This file exposes some plugin internals for unit testing. See
-// https://github.com/flutter/flutter/issues/88724 for current limitations
-// in the unit-testable API.
-
-// Handles the getPlatformVersion method call.
-FlMethodResponse *get_platform_version();

linux/include/flutter_libsparkmobile/flutter_libsparkmobile_plugin.h

@@ -1,26 +0,0 @@
-#ifndef FLUTTER_PLUGIN_FLUTTER_LIBSPARKMOBILE_PLUGIN_H_
-#define FLUTTER_PLUGIN_FLUTTER_LIBSPARKMOBILE_PLUGIN_H_
-
-#include <flutter_linux/flutter_linux.h>
-
-G_BEGIN_DECLS
-
-#ifdef FLUTTER_PLUGIN_IMPL
-#define FLUTTER_PLUGIN_EXPORT __attribute__((visibility("default")))
-#else
-#define FLUTTER_PLUGIN_EXPORT
-#endif
-
-typedef struct _FlutterLibsparkmobilePlugin FlutterLibsparkmobilePlugin;
-typedef struct {
-  GObjectClass parent_class;
-} FlutterLibsparkmobilePluginClass;
-
-FLUTTER_PLUGIN_EXPORT GType flutter_libsparkmobile_plugin_get_type();
-
-FLUTTER_PLUGIN_EXPORT void flutter_libsparkmobile_plugin_register_with_registrar(
-    FlPluginRegistrar* registrar);
-
-G_END_DECLS
-
-#endif  // FLUTTER_PLUGIN_FLUTTER_LIBSPARKMOBILE_PLUGIN_H_

linux/test/flutter_libsparkmobile_plugin_test.cc

@@ -1,31 +0,0 @@
-#include <flutter_linux/flutter_linux.h>
-#include <gmock/gmock.h>
-#include <gtest/gtest.h>
-
-#include "include/flutter_libsparkmobile/flutter_libsparkmobile_plugin.h"
-#include "flutter_libsparkmobile_plugin_private.h"
-
-// This demonstrates a simple unit test of the C portion of this plugin's
-// implementation.
-//
-// Once you have built the plugin's example app, you can run these tests
-// from the command line. For instance, for a plugin called my_plugin
-// built for x64 debug, run:
-// $ build/linux/x64/debug/plugins/my_plugin/my_plugin_test
-
-namespace flutter_libsparkmobile {
-namespace test {
-
-TEST(FlutterLibsparkmobilePlugin, GetPlatformVersion) {
-  g_autoptr(FlMethodResponse) response = get_platform_version();
-  ASSERT_NE(response, nullptr);
-  ASSERT_TRUE(FL_IS_METHOD_SUCCESS_RESPONSE(response));
-  FlValue* result = fl_method_success_response_get_result(
-      FL_METHOD_SUCCESS_RESPONSE(response));
-  ASSERT_EQ(fl_value_get_type(result), FL_VALUE_TYPE_STRING);
-  // The full string varies, so just validate that it has the right format.
-  EXPECT_THAT(fl_value_get_string(result), testing::StartsWith("Linux "));
-}
-
-}  // namespace test
-}  // namespace flutter_libsparkmobile

macos/Classes/FlutterLibsparkmobilePlugin.swift

@@ -1,19 +0,0 @@
-import Cocoa
-import FlutterMacOS
-
-public class FlutterLibsparkmobilePlugin: NSObject, FlutterPlugin {
-  public static func register(with registrar: FlutterPluginRegistrar) {
-    let channel = FlutterMethodChannel(name: "flutter_libsparkmobile", binaryMessenger: registrar.messenger)
-    let instance = FlutterLibsparkmobilePlugin()
-    registrar.addMethodCallDelegate(instance, channel: channel)
-  }
-
-  public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
-    switch call.method {
-    case "getPlatformVersion":
-      result("macOS " + ProcessInfo.processInfo.operatingSystemVersionString)
-    default:
-      result(FlutterMethodNotImplemented)
-    }
-  }
-}

macos/Classes/flutter_libsparkmobile.c

@@ -0,0 +1,3 @@
+// Relative import to be able to reuse the C sources.
+// See the comment in ../{projectName}}.podspec for more information.
+#include flutter_libsparkmobile.cpp

macos/flutter_libsparkmobile.podspec

@@ -5,14 +5,18 @@
 Pod::Spec.new do |s|
   s.name             = 'flutter_libsparkmobile'
   s.version          = '0.0.1'
-  s.summary          = 'A new Flutter plugin project.'
+  s.summary          = 'A new Flutter project.'
   s.description      = <<-DESC
-A new Flutter plugin project.
+A new Flutter project.
                        DESC
   s.homepage         = 'http://example.com'
   s.license          = { :file => '../LICENSE' }
   s.author           = { 'Your Company' => 'email@example.com' }
 
+  # This will ensure the source files in Classes/ are included in the native
+  # builds of apps using this FFI plugin. Podspec does not support relative
+  # paths, so Classes contains a forwarder C file that relatively imports
+  # `../src/*` so that the C sources can be shared among all target platforms.
   s.source           = { :path => '.' }
   s.source_files     = 'Classes/**/*'
   s.dependency 'FlutterMacOS'

pubspec.yaml

@@ -1,5 +1,5 @@
 name: flutter_libsparkmobile
-description: A new Flutter plugin project.
+description: Flutter Sparkmobile ffi wrapper
 version: 0.0.1
 homepage:
 
@@ -12,14 +12,12 @@ dependencies:
   flutter:
     sdk: flutter
   plugin_platform_interface: ^2.0.2
-  test: ^1.24.1
-  typed_data: ^1.3.2
 
 dev_dependencies:
+  ffigen: ^6.1.2
   flutter_test:
     sdk: flutter
   flutter_lints: ^2.0.0
-  ffigen: ^9.0.1
 
 # For information on the generic Dart part of this file, see the
 # following page: https://dart.dev/tools/pub/pubspec
@@ -36,19 +34,20 @@ flutter:
   # This is required for using `dart:ffi`.
   # All these are used by the tooling to maintain consistency when
   # adding or updating assets for this project.
+  #
+  # Please refer to README.md for a detailed explanation.
   plugin:
     platforms:
       android:
-        package: com.cypherstack.flutter_libsparkmobile
+        ffiPlugin: true
-        pluginClass: FlutterLibsparkmobilePlugin
       ios:
-        pluginClass: FlutterLibsparkmobilePlugin
+        ffiPlugin: true
       linux:
-        pluginClass: FlutterLibsparkmobilePlugin
+        ffiPlugin: true
       macos:
-        pluginClass: FlutterLibsparkmobilePlugin
+        ffiPlugin: true
       windows:
-        pluginClass: FlutterLibsparkmobilePluginCApi
+        ffiPlugin: true
 
   # To add assets to your plugin package, add an assets section, like this:
   # assets:
@@ -80,15 +79,3 @@ flutter:
   #
   # For details regarding fonts in packages, see
   # https://flutter.dev/custom-fonts/#from-packages
-
-ffigen:
-  name: SparkMobileBindings
-  description: Bindings for sparkmobile.
-  language: c
-  output: 'lib/flutter_libsparkmobile_bindings.dart'
-  headers:
-    entry-points:
-      - 'sparkmobile/src/dart_interface.h'
-      # copyCMakeLists.sh creates this header, see build_all.sh.
-  preamble: |
-    // ignore_for_file: camel_case_types, non_constant_identifier_names, unused_element, unused_field, return_of_invalid_type, void_checks, annotate_overrides, no_leading_underscores_for_local_identifiers, library_private_types_in_public_api

scripts/linux/build_all.sh

@@ -1,5 +1,7 @@
 #!/bin/bash
 
-mkdir -p build
+set -e
+
 ./build_openssl.sh
-./build_sharedfile.sh
+
+

scripts/linux/build_openssl.sh

@@ -2,67 +2,66 @@
 
 set -e
 
+export WORKDIR="$(pwd)/../../src/build/linux"
+export ORIGINAL_PATH=$PATH
+export THREADS=16
+export TYPES_OF_BUILD="x86_64"
+
 if [ -z "$IS_ARM" ]; then
-  TYPES_OF_BUILD="x86_64"
+  export TYPES_OF_BUILD="x86_64"
 else
-  TYPES_OF_BUILD="aarch64"
+  export TYPES_OF_BUILD="aarch64"
 fi
-THREADS=16
 
-WORKDIR="$(pwd)/"build
+if [ ! -d "$WORKDIR" ] ; then
-CACHEDIR="$(pwd)/"cache
+  mkdir -p "$WORKDIR"
-mkdir -p $CACHEDIR
+fi
 
-OPENSSL_FILENAME=openssl-1.1.1k.tar.gz
+
-OPENSSL_FILE_PATH=$CACHEDIR/$OPENSSL_FILENAME
+OPENSSL_FILENAME="openssl-1.1.1k.tar.gz"
-OPENSSL_SRC_DIR=$WORKDIR/openssl-1.1.1k
+OPENSSL_FILE_PATH="$WORKDIR/$OPENSSL_FILENAME"
+OPENSSL_SRC_DIR="$WORKDIR/openssl-1.1.1k"
 OPENSSL_SHA256="892a0875b9872acd04a9fde79b1f943075d5ea162415de3047c327df33fbaee5"
-
+ZLIB_DIR="$WORKDIR/zlib"
-ZLIB_DIR=$WORKDIR/zlib
+ZLIB_TAG="v1.2.11"
-ZLIB_TAG=v1.2.11
 ZLIB_COMMIT_HASH="cacf7f1d4e3d44d871b605da3b647f07d718623f"
 
-# If a zlib dir exists, we assume that it's already been built.
+
-# TODO make a better zlib-validity check.
 if [ ! -d "$ZLIB_DIR" ] ; then
   git clone -b $ZLIB_TAG --depth 1 https://github.com/madler/zlib $ZLIB_DIR
-  cd $ZLIB_DIR
-  git reset --hard $ZLIB_COMMIT_HASH
-  ./configure --static
-  make
 fi
+cd $ZLIB_DIR
+git reset --hard $ZLIB_COMMIT_HASH
+./configure --static
+make
 
-# Download openssl if it doesn't exist.
 curl https://www.openssl.org/source/$OPENSSL_FILENAME -o $OPENSSL_FILE_PATH
-
-# Validate checksum.
 echo $OPENSSL_SHA256 $OPENSSL_FILE_PATH | sha256sum -c - || exit 1
 
-# Build openssl for each arch.
 for arch in $TYPES_OF_BUILD
 do
-	echo "Building $TYPES_OF_BUILD"
+echo "Building $TYPES_OF_BUILD"
-	PREFIX=$WORKDIR/prefix_${arch}
+PREFIX=$WORKDIR/prefix_${arch}
 
-	case $arch in
+case $arch in
-		"x86_64")  X_ARCH="linux-x86_64";;
+	"x86_64")  X_ARCH="linux-x86_64";;
-		"aarch64")  X_ARCH="linux-aarch64";;
+	"aarch64")  X_ARCH="linux-aarch64";;
-		*)	   X_ARCH="linux-x86_64";;
+	*)	   X_ARCH="linux-x86_64";;
-	esac
+esac
 
-	cd $WORKDIR
+cd $WORKDIR
-	# Don't delete the openssl source dir.  We don't need clean builds every time.
+rm -rf $OPENSSL_SRC_DIR
-  #	rm -rf $OPENSSL_SRC_DIR
+tar -xzf $OPENSSL_FILE_PATH -C $WORKDIR
-	tar -xzf $OPENSSL_FILE_PATH -C $WORKDIR
+cd $OPENSSL_SRC_DIR
-	cd $OPENSSL_SRC_DIR
+
+./Configure ${X_ARCH} \
+	no-asm no-shared \
+	--with-zlib-include=${PREFIX}/include \
+	--with-zlib-lib=${PREFIX}/lib \
+	--prefix=${PREFIX} \
+	--openssldir=${PREFIX}
+make -j$THREADS
+make -j$THREADS install_sw
 
-	#sed -i -e "s/mandroid/target\ ${TARGET}\-linux\-android/" Configure
-		./Configure ${X_ARCH} \
-		no-asm no-shared \
-		--with-zlib-include=${PREFIX}/include \
-		--with-zlib-lib=${PREFIX}/lib \
-		--prefix=${PREFIX} \
-		--openssldir=${PREFIX}
-	make -j$THREADS
-	make -j$THREADS install_sw
 done
+

scripts/linux/build_sharedfile.sh

@@ -1,39 +0,0 @@
-#!/bin/bash
-
-# Copy the sparkmobile submodule to the build directory for interfacing to Dart.
-#
-# We copy the fresh and unmodified sparkmobile submodule to the build directory in order to graft
-# an additional Dart interface onto the sparkmobile library.
-cp -r ../../sparkmobile .
-
-WORKDIR="$(pwd)/build"
-SEDWORKDIR=$(echo $WORKDIR | sed 's/\//\\\//g')
-
-# Create new CMakelists.txt files for the sparkmobile and secp256k1 directories.
-#
-# Copy the template CMakelists.txt files to the working sparkmobile directory and replace the
-# distribution_DIR variable with the working directory.
-sed "s/SET(distribution_DIR \/opt\/android)/SET(distribution_DIR $SEDWORKDIR)/g" ./CMakeLists/sparkmobile/template_CMakeLists.txt > ./CMakeLists/sparkmobile/CMakeLists.txt
-sed "s/SET(distribution_DIR \/opt\/android)/SET(distribution_DIR $SEDWORKDIR)/g" ./CMakeLists/secp256k1/template_CMakeLists.txt > ./CMakeLists/secp256k1/CMakeLists.txt
-
-# Copy the sparkmobile and secp256k1 CMakeLists.txts.
-cp CMakeLists/sparkmobile/CMakeLists.txt     sparkmobile/
-cp CMakeLists/secp256k1/CMakeLists.txt       sparkmobile/secp256k1/
-
-# Git versioning.
-echo ''$(git log -1 --pretty=format:"%H")' '$(date) >> build/git_commit_version.txt
-VERSIONS_FILE=../../lib/git_versions.dart
-EXAMPLE_VERSIONS_FILE=../../lib/git_versions_example.dart
-if [ ! -f "$VERSIONS_FILE" ]; then
-    cp $EXAMPLE_VERSIONS_FILE $VERSIONS_FILE
-fi
-COMMIT=$(git log -1 --pretty=format:"%H")
-OS="LINUX"
-
-# Write the commit hash to the versions file.
-sed -i "/\/\*${OS}_VERSION/c\\/\*${OS}_VERSION\*\/ const ${OS}_VERSION = \"$COMMIT\";" $VERSIONS_FILE
-
-# Build the shared library.
-cd build
-cmake ../sparkmobile
-make -j$(nproc)

scripts/prebuild.sh

@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+
+set -e
+
+cd ../src/deps
+
+if [ -d sparkmobile ]; then
+  rm -rf sparkmobile
+fi
+
+git clone https://github.com/firoorg/sparkmobile.git
+cd sparkmobile
+git checkout ef2e39aae18ecc49e0ddc63a3183e9764b96012e
+
+cd ..
+cp CMakeLists/sparkmobile/CMakeLists.txt     sparkmobile/
+cp CMakeLists/secp256k1/CMakeLists.txt       sparkmobile/secp256k1/

src/CMakeLists.txt

@@ -0,0 +1,26 @@
+# The Flutter tooling requires that developers have CMake 3.10 or later
+# installed. You should not increase this version, as doing so will cause
+# the plugin to fail to compile for some customers of the plugin.
+cmake_minimum_required(VERSION 3.10)
+
+project(flutter_libsparkmobile_library VERSION 0.0.1)
+
+SET(CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake;${CMAKE_MODULE_PATH}")
+
+
+
+add_library(flutter_libsparkmobile SHARED
+  "flutter_libsparkmobile.cpp"
+        "utils.cpp"
+)
+
+add_subdirectory("deps/sparkmobile")
+
+set_target_properties(flutter_libsparkmobile PROPERTIES
+  PUBLIC_HEADER flutter_libsparkmobile.h
+  OUTPUT_NAME "flutter_libsparkmobile"
+)
+
+target_link_libraries(flutter_libsparkmobile sparkmobile)
+
+target_compile_definitions(flutter_libsparkmobile PUBLIC DART_SHARED_LIB)

src/cmake/FindGMP.cmake

@@ -0,0 +1,7 @@
+find_path(GMP_INCLUDE_DIRS NAMES gmp.h)
+find_library(GMP_LIBRARY NAMES gmp libgmp)
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(GMP DEFAULT_MSG
+        GMP_INCLUDE_DIRS
+        GMP_LIBRARY)
+mark_as_advanced(GMP_INCLUDE_DIRS GMP_LIBRARY)

src/deps/CMakeLists/secp256k1/CMakeLists.txt

@@ -1,9 +1,9 @@
 # Copyright (c) 2017 The Bitcoin developers
 
 cmake_minimum_required(VERSION 3.1)
-project(secp256k1)
+project(secp256k1_spark)
 
-SET(distribution_DIR /opt/android)
+SET(distribution_DIR "../../../build/${BUILD_FOR_SYSTEM_NAME}")
 SET(OPENSSL_ROOT_DIR ${distribution_DIR}/prefix_${ANDROID_ABI})
 
 SET(OPENSSL_LIBRARIES_DIR "${OPENSSL_ROOT_DIR}/lib")
@@ -22,14 +22,14 @@ LINK_DIRECTORIES(${OPENSSL_LIBRARIES_DIR})
 # TODO: change this to include when possible
 include_directories(. include src/modules/ecdh src)
 
-add_library(secp256k1 src/secp256k1.c src/cpp/GroupElement.cpp src/cpp/MultiExponent.cpp src/cpp/Scalar.cpp src/modules/ecdh/main_impl.h include/secp256k1_ecdh.h src/scratch_impl.h src/scratch.h)
+add_library(secp256k1_spark src/secp256k1.c src/cpp/GroupElement.cpp src/cpp/MultiExponent.cpp src/cpp/Scalar.cpp src/modules/ecdh/main_impl.h include/secp256k1_ecdh.h src/scratch_impl.h src/scratch.h)
 
 # We need to link in GMP
 find_package(GMP)
 if(GMP_INCLUDE_DIR AND GMP_LIBRARIES)
 	target_include_directories(secp256k1 PUBLIC ${GMP_INCLUDE_DIR})
-	target_link_libraries(secp256k1 ${GMP_LIBRARIES})
+	target_link_libraries(secp256k1_spark ${GMP_LIBRARIES})
-	target_compile_definitions(secp256k1
+	target_compile_definitions(secp256k1_spark
 		PUBLIC
 			HAVE_LIBGMP
 			USE_NUM_GMP
@@ -37,7 +37,7 @@ if(GMP_INCLUDE_DIR AND GMP_LIBRARIES)
 			USE_SCALAR_INV_BUILTIN
 	)
 else()
-	target_compile_definitions(secp256k1
+	target_compile_definitions(secp256k1_spark
 		PUBLIC
 			USE_NUM_NONE
 			USE_FIELD_INV_BUILTIN
@@ -49,7 +49,7 @@ endif()
 include(CheckTypeSize)
 check_type_size(__int128 SIZEOF___INT128)
 if(SIZEOF___INT128 EQUAL 16)
-	target_compile_definitions(secp256k1 PUBLIC HAVE___INT128)
+	target_compile_definitions(secp256k1_spark PUBLIC HAVE___INT128)
 else()
 	# If we do not support __int128, we should be falling back
 	# on 32bits implementations for field and scalar.
@@ -64,17 +64,17 @@ if(CMAKE_SIZEOF_VOID_P EQUAL 8)
 		message(SEND_ERROR "Compiler does not support __int128")
 	endif()
 
-	target_compile_definitions(secp256k1 PUBLIC USE_SCALAR_4X64)
+	target_compile_definitions(secp256k1_spark PUBLIC USE_SCALAR_4X64)
-	target_compile_definitions(secp256k1 PUBLIC USE_FIELD_5X52)
+	target_compile_definitions(secp256k1_spark PUBLIC USE_FIELD_5X52)
 else()
-	target_compile_definitions(secp256k1 PUBLIC USE_SCALAR_8X32)
+	target_compile_definitions(secp256k1_spark PUBLIC USE_SCALAR_8X32)
-	target_compile_definitions(secp256k1 PUBLIC USE_FIELD_10X26)
+	target_compile_definitions(secp256k1_spark PUBLIC USE_FIELD_10X26)
 endif()
 
 
 # TODO: emult static precomputation
 # TODO: ecdh module
 # TODO: RECOVERY module
-TARGET_INCLUDE_DIRECTORIES(secp256k1 PUBLIC ${OPENSSL_INCLUDE_DIR})
+TARGET_INCLUDE_DIRECTORIES(secp256k1_spark PUBLIC ${OPENSSL_INCLUDE_DIR})
-TARGET_LINK_LIBRARIES(secp256k1 ${OPENSSL_LIBRARIES})
+TARGET_LINK_LIBRARIES(secp256k1_spark ${OPENSSL_LIBRARIES})
-#target_link_libraries(secp256k1 ${OPENSSL_LIBRARIES})
+#target_link_libraries(secp256k1_spark ${OPENSSL_LIBRARIES})

src/deps/CMakeLists/sparkmobile/CMakeLists.txt

@@ -4,7 +4,7 @@ project(sparkmobile)
 
 set(OPENSSL_USE_STATIC_LIBS OFF CACHE BOOL "" FORCE)
 
-SET(distribution_DIR /opt/android)
+SET(distribution_DIR "../../build/${BUILD_FOR_SYSTEM_NAME}")
 SET(OPENSSL_ROOT_DIR ${distribution_DIR}/prefix_${ANDROID_ABI})
 
 SET(OPENSSL_LIBRARIES_DIR "${OPENSSL_ROOT_DIR}/lib")
@@ -42,9 +42,7 @@ set_property(SOURCE src/spark.cpp
     src/schnorr.cpp
     src/spend_transaction.cpp
     src/transcript.cpp
-    src/util.cpp
+        src/util.cpp
-    src/utils.cpp
-    src/dart_interface.cpp
     PROPERTY COMPILE_FLAGS "-std=c++17" )
 
 add_library(sparkmobile SHARED
@@ -75,12 +73,10 @@ add_library(sparkmobile SHARED
     src/schnorr.cpp
     src/spend_transaction.cpp
     src/transcript.cpp
-    src/util.cpp
+        src/util.cpp)
-    src/utils.cpp
-    src/dart_interface.cpp)
 
-target_link_libraries(sparkmobile ${OPENSSL_LIBRARIES} secp256k1)
+target_link_libraries(sparkmobile ${OPENSSL_LIBRARIES} secp256k1_spark)
 
-add_dependencies(sparkmobile secp256k1)
+add_dependencies(sparkmobile secp256k1_spark)
 
-target_include_directories(sparkmobile PUBLIC secp256k1 ${OPENSSL_INCLUDE_DIR})
+target_include_directories(sparkmobile PUBLIC secp256k1_spark ${OPENSSL_INCLUDE_DIR})

src/flutter_libsparkmobile.cpp

@@ -0,0 +1,111 @@
+#include "flutter_libsparkmobile.h"
+#include "utils.h"
+#include "deps/sparkmobile/include/spark.h"
+
+#include <cstring>
+#include <iostream> // Just for printing.
+
+using namespace spark;
+
+
+/*
+ * FFI-friendly wrapper for spark::getAddress.
+ */
+FFI_PLUGIN_EXPORT
+const char* getAddress(const char* keyDataHex, int index, int diversifier, int isTestNet) {
+  try {
+    // Use the hex string directly to create the SpendKey.
+    spark::SpendKey spendKey = createSpendKeyFromData(keyDataHex, index);
+
+    spark::FullViewKey fullViewKey(spendKey);
+    spark::IncomingViewKey incomingViewKey(fullViewKey);
+    spark::Address address(incomingViewKey, static_cast<uint64_t>(diversifier));
+
+    // Encode the Address object into a string using the appropriate network.
+    std::string encodedAddress = address.encode(isTestNet ? spark::ADDRESS_NETWORK_TESTNET : spark::ADDRESS_NETWORK_MAINNET);
+
+    // Allocate memory for the C-style string.
+    char* cstr = new char[encodedAddress.length() + 1];
+    std::strcpy(cstr, encodedAddress.c_str());
+
+    return cstr;
+  } catch (const std::exception& e) {
+    std::cerr << "Exception: " << e.what() << std::endl;
+    return nullptr;
+  }
+}
+
+/*
+ * FFI-friendly wrapper for spark:identifyCoin.
+ *
+ * Uses the utility functions spark::Coin fromFFI(const CCoin& c_struct) to pass parameters to the
+ * C++ function spark::identifyCoin(const Coin& coin), then uses the utility function
+ * CIdentifiedCoinData toFFI(const spark::IdentifiedCoinData& cpp_struct) to convert the result back
+ * to a C struct.
+ *
+ * We also need the incoming view key or we need to derive it, so accept keyDataHex and index.
+ */
+FFI_PLUGIN_EXPORT
+struct CIdentifiedCoinData identifyCoin(struct CCoin c_struct, const char* keyDataHex, int index) {
+  try {
+    spark::Coin coin = fromFFI(c_struct);
+
+    // Derive the incoming view key from the key data and index.
+    spark::SpendKey spendKey = createSpendKeyFromData(keyDataHex, index);
+    spark::FullViewKey fullViewKey(spendKey);
+    spark::IncomingViewKey incomingViewKey(fullViewKey);
+
+    spark::IdentifiedCoinData identifiedCoinData = coin.identify(incomingViewKey);
+    return toFFI(identifiedCoinData);
+  } catch (const std::exception& e) {
+    std::cerr << "Exception: " << e.what() << std::endl;
+    return CIdentifiedCoinData();
+  }
+}
+
+/*
+ * FFI-friendly wrapper for spark::createSparkMintRecipients.
+ */
+FFI_PLUGIN_EXPORT
+struct CCRecipient* createSparkMintRecipients(
+        int numRecipients,
+        struct PubKeyScript* pubKeyScripts,
+        uint64_t* amounts,
+        const char* memo,
+        int subtractFee)
+{
+  try {
+    std::vector<CRecipient> recipients;
+
+    for (int i = 0; i < numRecipients; i++) {
+      CScript scriptPubKey = createCScriptFromBytes(
+              pubKeyScripts[i].bytes,
+              pubKeyScripts[i].length
+      );
+
+      CRecipient recipient;
+      recipient.pubKey = scriptPubKey;
+
+      recipient.amount = amounts[i];
+
+      recipient.subtractFeeFromAmount = (bool)subtractFee;
+
+      recipients.push_back(recipient);
+    }
+
+    std::vector<CCRecipient> ccRecipients;
+
+    for (const CRecipient& recipient : recipients) {
+      CCRecipient ccRecipient = toFFI(recipient);
+      ccRecipients.push_back(ccRecipient);
+    }
+
+    CCRecipient* result = new CCRecipient[numRecipients];
+    std::copy(ccRecipients.begin(), ccRecipients.end(), result);
+
+    return result;
+  } catch (const std::exception& e) {
+    std::cerr << "Exception: " << e.what() << std::endl;
+    return nullptr;
+  }
+}

src/flutter_libsparkmobile.h

@@ -0,0 +1,118 @@
+
+#ifndef ORG_FIRO_SPARK_DART_INTERFACE_H
+#define ORG_FIRO_SPARK_DART_INTERFACE_H
+
+#include <stdint.h>
+
+#ifndef FFI_PLUGIN_EXPORT
+#ifdef __cplusplus
+#define FFI_PLUGIN_EXPORT extern "C" __attribute__((visibility("default"))) __attribute__((used))
+#else
+#define FFI_PLUGIN_EXPORT __attribute__((visibility("default"))) __attribute__((used))
+#endif
+#ifdef _WIN32
+#define FFI_PLUGIN_EXPORT __declspec(dllexport)
+#endif
+#endif
+
+
+/*
+ * FFI-friendly wrapper for spark::getAddress.
+ */
+FFI_PLUGIN_EXPORT
+const char* getAddress(const char* keyDataHex, 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 a spark::Coin.
+ *
+ * A Coin is a type, a key, an index, a value, a memo, and a serial context.  We accept these params
+ * as a C struct, deriving the key from the keyData and index.
+ */
+struct CCoin {
+    char type;
+    const unsigned char* k;
+    int kLength;
+    const char* keyData;
+    int index;
+    uint64_t v;
+    const unsigned char* memo;
+    int memoLength;
+    const unsigned char* serial_context;
+    int serial_contextLength;
+};
+
+/*
+ * FFI-friendly wrapper for a spark::IdentifiedCoinData.
+ *
+ * An IdentifiedCoinData is a diversifier, encrypted diversifier, value, nonce, and memo.  We accept
+ * these params as a C struct.
+ */
+struct CIdentifiedCoinData {
+    uint64_t i;
+    const unsigned char* d;
+    int dLength;
+    uint64_t v;
+    const unsigned char* k;
+    int kLength;
+    const char* memo;
+    int memoLength;
+};
+
+/*
+ * FFI-friendly wrapper for spark::identifyCoin.
+ */
+FFI_PLUGIN_EXPORT
+struct CIdentifiedCoinData identifyCoin(struct CCoin c_struct, const char* keyDataHex, int index);
+
+/*
+ * FFI-friendly wrapper for a spark::CRecipient.
+ *
+ * A CRecipient is a CScript, CAmount, and a bool.  We accept a C-style, FFI-friendly CCRecipient
+ * struct in order to construct a C++ CRecipient.  A CScript is constructed from a hex string, a
+ * CAmount is just a uint64_t, and the bool will be an int.
+ */
+struct CCRecipient {
+    const unsigned char* pubKey;
+    int pubKeyLength;
+    uint64_t cAmount;
+    int subtractFee;
+};
+
+/*
+ * FFI-friendly wrapper for a spark::MintedCoinData.
+ *
+ * A MintedCoinData is a struct that contains an Address, a uint64_t value, and a string memo.  We
+ * accept these as a CMintedCoinData from the Dart interface, and convert them to a MintedCoinData
+ * struct.
+ */
+struct CMintedCoinData {
+    const char* address;
+    uint64_t value;
+    const char* memo;
+};
+
+struct PubKeyScript {
+    unsigned char* bytes;
+    int length;
+};
+
+/*
+ * FFI-friendly wrapper for spark::createSparkMintRecipients.
+ */
+FFI_PLUGIN_EXPORT
+struct CCRecipient* createSparkMintRecipients(
+        int numRecipients,
+        struct PubKeyScript* pubKeyScripts,
+        uint64_t* amounts,
+        const char* memo,
+        int subtractFee);
+
+#endif //ORG_FIRO_SPARK_DART_INTERFACE_H

src/utils.cpp

@@ -0,0 +1,318 @@
+#include "utils.h"
+#include <iomanip>
+#include <iostream>
+#include <sstream>
+#include <utility>
+#include <vector>
+#include <string>
+
+
+#include "flutter_libsparkmobile.h"
+#include "deps/sparkmobile/src/coin.h"
+#include "deps/sparkmobile/src/keys.h"
+#include "deps/sparkmobile//bitcoin/script.h"  // For CScript.
+
+/*
+ * Utility function to generate an address from keyData, index, and a diversifier.
+ */
+const char* getAddressFromData(const char* keyData, int index, const uint64_t diversifier) {
+	try {
+		spark::SpendKey spendKey = createSpendKeyFromData(keyData, index);
+		spark::FullViewKey fullViewKey(spendKey);
+		spark::IncomingViewKey incomingViewKey(fullViewKey);
+		spark::Address address(incomingViewKey, diversifier);
+
+		// Encode the Address object into a string.
+		std::string encodedAddress = address.encode(spark::ADDRESS_NETWORK_TESTNET);
+
+		// Allocate memory for the C-style string and return it.
+		char* result = new char[encodedAddress.size() + 1];
+		std::copy(encodedAddress.begin(), encodedAddress.end(), result);
+		result[encodedAddress.size()] = '\0'; // Null-terminate the C string.
+
+		return result;
+	} catch (const std::exception& e) {
+		return nullptr;
+	}
+}
+
+/*
+ * Utility function to generate SpendKey from keyData and index.
+ */
+spark::SpendKey createSpendKeyFromData(const char *keyData, int index) {
+	try {
+		// Convert the keyData from hex string to binary
+		unsigned char* key_data_bin = hexToBytes(keyData);
+
+		const SpendKeyData *data = new SpendKeyData(key_data_bin, index);
+
+		return createSpendKey(*data);
+	} catch (const std::exception& e) {
+		// We can't return here, so just throw the exception again.
+		throw e;
+	}
+}
+
+/*
+ * CCoin factory.
+ *
+ * TODO manage the memory allocated by this function.
+ */
+struct CCoin createCCoin(char type, const unsigned char* k, int kLength, const char* keyData, int index, uint64_t v, const unsigned char* memo, int memoLength, const unsigned char* serial_context, int serial_contextLength) {
+	CCoin coin;
+	coin.type = type;
+	coin.k = copyBytes(k, kLength);
+	coin.kLength = kLength;
+	coin.keyData = strdup(keyData);
+	coin.index = index;
+	coin.v = v;
+	coin.memo = copyBytes(memo, memoLength);
+	coin.memoLength = memoLength;
+	coin.serial_context = copyBytes(serial_context, serial_contextLength);
+	coin.serial_contextLength = serial_contextLength;
+	return coin;
+}
+
+/*
+ * Utility function to convert an FFI-friendly C CCoin struct to a C++ Coin struct.
+ */
+spark::Coin fromFFI(const CCoin& c_struct) {
+	spark::Coin cpp_struct(
+			// The test params are only used for unit tests.
+			spark::Params::get_default(),
+			c_struct.type,
+			spark::Scalar(c_struct.k),
+			spark::Address(spark::IncomingViewKey(spark::FullViewKey(createSpendKeyFromData(c_struct.keyData, c_struct.index))), c_struct.index),
+			c_struct.v,
+			std::string(reinterpret_cast<const char*>(c_struct.memo), c_struct.memoLength),
+			std::vector<unsigned char>(c_struct.serial_context, c_struct.serial_context + c_struct.serial_contextLength)
+	);
+
+	return cpp_struct;
+}
+
+/*
+ * Utility function to convert a C++ IdentifiedCoinData struct to an FFI-friendly struct.
+ */
+CIdentifiedCoinData toFFI(const spark::IdentifiedCoinData& cpp_struct) {
+	CIdentifiedCoinData c_struct;
+
+	c_struct.i = cpp_struct.i;
+	c_struct.d = copyBytes(cpp_struct.d.data(), cpp_struct.d.size());
+	c_struct.dLength = cpp_struct.d.size();
+	c_struct.v = cpp_struct.v;
+
+	// Serialize and copy the Scalar k.
+	std::vector<unsigned char> scalarBytes(32);
+	cpp_struct.k.serialize(scalarBytes.data());
+	c_struct.k = copyBytes(scalarBytes.data(), scalarBytes.size());
+	c_struct.kLength = scalarBytes.size();
+
+	// Copy the memo.
+	c_struct.memo = strdup(cpp_struct.memo.c_str());
+	c_struct.memoLength = cpp_struct.memo.size();
+
+	return c_struct;
+}
+
+/*
+ * Factory function to create a CScript from a byte array.
+ */
+CScript createCScriptFromBytes(const unsigned char* bytes, int length) {
+	// Construct a CScript object
+	CScript script;
+
+	// Check if bytes is not nullptr and length is positive
+	if (bytes != nullptr && length > 0) {
+		// Append each byte to the script
+		for (int i = 0; i < length; ++i) {
+			script << bytes[i];
+		}
+	}
+
+	return script;
+}
+
+/*
+ * Utility function to convert a C++ CScript to a byte array.
+ */
+std::vector<unsigned char> serializeCScript(const CScript& script) {
+	return std::vector<unsigned char>(script.begin(), script.end());
+}
+
+/*
+ * Utility function to convert an FFI-friendly C CCRecipient struct to a C++ CRecipient struct.
+ */
+CRecipient fromFFI(const CCRecipient& c_struct) {
+	// Use the factory function to create a CScript object.
+	CScript script = createCScriptFromBytes(c_struct.pubKey, c_struct.pubKeyLength);
+
+	CRecipient cpp_struct = createCRecipient(
+			script,
+			c_struct.cAmount,
+			static_cast<bool>(c_struct.subtractFee)
+	);
+
+	return cpp_struct;
+}
+
+/*
+ * CCRecipient factory.
+ *
+ * TODO manage the memory allocated by this function.
+ */
+struct CCRecipient createCCRecipient(const unsigned char* pubKey, uint64_t amount, int subtractFee) {
+	CCRecipient recipient;
+	recipient.pubKey = copyBytes(pubKey, 32);
+	recipient.cAmount = amount;
+	recipient.subtractFee = subtractFee;
+	return recipient;
+}
+
+/*
+ * Utility function to convert a C++ CRecipient struct to an FFI-friendly struct.
+ */
+CCRecipient toFFI(const CRecipient& cpp_struct) {
+	CCRecipient c_struct;
+
+	// Serialize CScript and copy.
+	std::vector<unsigned char> scriptBytes = serializeCScript(cpp_struct.pubKey);
+	if (!scriptBytes.empty()) {
+		c_struct.pubKey = copyBytes(scriptBytes.data(), scriptBytes.size());
+		c_struct.pubKeyLength = static_cast<int>(scriptBytes.size());
+	} else {
+		c_struct.pubKey = nullptr;
+		c_struct.pubKeyLength = 0;
+	}
+
+	c_struct.cAmount = cpp_struct.amount;
+	c_struct.subtractFee = static_cast<int>(cpp_struct.subtractFeeFromAmount);
+
+	return c_struct;
+}
+
+/*
+ * CRecipient factory.
+ *
+ * TODO manage the memory allocated by this function.
+ */
+CRecipient createCRecipient(const CScript& script, CAmount amount, bool subtractFee) {
+	CRecipient recipient;
+	recipient.pubKey = script;
+	recipient.amount = amount;
+	recipient.subtractFeeFromAmount = subtractFee;
+	return recipient;
+}
+
+/*
+ * Utility function to decode an Address from a string.
+ */
+spark::Address decodeAddress(const std::string& str) {
+	spark::Address address;
+	address.decode(str);
+
+	return address;
+}
+
+/*
+ * MintedCoinData factory.
+ */
+spark::MintedCoinData createMintedCoinData(const char* address, uint64_t v, const char* memo) {
+	return {
+			decodeAddress(address),
+			v,
+			memo
+	};
+}
+
+/*
+ * Utility function to convert an FFI-friendly C CMintedCoinData struct to a C++ MintedCoinData.
+ */
+spark::MintedCoinData fromFFI(const CMintedCoinData& c_struct) {
+	return createMintedCoinData(
+			c_struct.address,
+			c_struct.value,
+			c_struct.memo
+	);
+}
+
+/*
+ * CMintedCoinData factory.
+ */
+CMintedCoinData createCMintedCoinData(const char* address, uint64_t value, const char* memo) {
+	CMintedCoinData c_struct;
+	c_struct.address = strdup(address);
+	c_struct.value = value;
+	c_struct.memo = strdup(memo);
+	return c_struct;
+}
+
+/*
+ * Utility function to convert a C++ MintedCoinData struct to an FFI-friendly CMintedCoinData.
+ */
+CMintedCoinData toFFI(const spark::MintedCoinData& cpp_struct) {
+	return createCMintedCoinData(
+			cpp_struct.address.encode(true).c_str(),
+			cpp_struct.v,
+			cpp_struct.memo.c_str()
+	);
+}
+
+/*
+ * Utility function for deep copying byte arrays.
+ *
+ * Used by createCCoin.
+ */
+unsigned char* copyBytes(const unsigned char* source, int length) {
+	if (source == nullptr || length <= 0) return nullptr;
+
+	unsigned char* dest = new unsigned char[length];
+	std::memcpy(dest, source, length);
+	return dest;
+}
+
+unsigned char *hexToBytes(const char *hexstr) {
+	size_t length = strlen(hexstr) / 2;
+	auto *chrs = (unsigned char *) malloc((length + 1) * sizeof(unsigned char));
+	for (size_t i = 0, j = 0; j < length; i += 2, j++) {
+		chrs[j] = (hexstr[i] % 32 + 9) % 25 * 16 + (hexstr[i + 1] % 32 + 9) % 25;
+	}
+	chrs[length] = '\0';
+	return chrs;
+}
+
+const char *bytesToHex(const unsigned char *bytes, int size) {
+	std::string str;
+	for (int i = 0; i < size; ++i) {
+		const unsigned char ch = bytes[i];
+		str.append(&hexArray[(ch & 0xF0) >> 4], 1);
+		str.append(&hexArray[ch & 0xF], 1);
+	}
+	char *new_str = new char[std::strlen(str.c_str()) + 1];
+	std::strcpy(new_str, str.c_str());
+	return new_str;
+}
+
+const char *bytesToHex(const char *bytes, int size) {
+	std::string str;
+	for (int i = 0; i < size; ++i) {
+		const unsigned char ch = (const unsigned char) bytes[i];
+		str.append(&hexArray[(ch & 0xF0) >> 4], 1);
+		str.append(&hexArray[ch & 0xF], 1);
+	}
+	char *new_str = new char[std::strlen(str.c_str()) + 1];
+	std::strcpy(new_str, str.c_str());
+	return new_str;
+}
+
+const char *bytesToHex(std::vector<unsigned char> bytes, int size) {
+	std::string str;
+	for (int i = 0; i < size; ++i) {
+		const unsigned char ch = bytes[i];
+		str.append(&hexArray[(ch & 0xF0) >> 4], 1);
+		str.append(&hexArray[ch & 0xF], 1);
+	}
+	char *new_str = new char[std::strlen(str.c_str()) + 1];
+	std::strcpy(new_str, str.c_str());
+	return new_str;
+}

src/utils.h

@@ -0,0 +1,62 @@
+#ifndef ORG_FIRO_SPARK_UTILS_H
+#define ORG_FIRO_SPARK_UTILS_H
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "flutter_libsparkmobile.h"
+#include "deps/sparkmobile/include/spark.h"
+
+const char* getAddressFromData(const char* keyData, int index, const uint64_t diversifier);
+
+spark::SpendKey createSpendKeyFromData(const char *keyData, int index);
+
+spark::Coin fromFFI(const CCoin& c_struct);
+
+CCoin toFFI(const spark::Coin& cpp_struct);
+
+struct CCoin createCCoin(char type, const unsigned char* k, int kLength, const char* keyData, int index, uint64_t v, const unsigned char* memo, int memoLength, const unsigned char* serial_context, int serial_contextLength);
+
+spark::IdentifiedCoinData fromFFI(const CIdentifiedCoinData& c_struct);
+
+CIdentifiedCoinData toFFI(const spark::IdentifiedCoinData& cpp_struct);
+
+CScript createCScriptFromBytes(const unsigned char* bytes, int length);
+
+std::vector<unsigned char> serializeCScript(const CScript& script);
+
+CRecipient createCRecipient(const CScript& script, CAmount amount, bool subtractFee);
+
+CRecipient fromFFI(const CCRecipient& c_struct);
+
+struct CCRecipient createCCRecipient(const unsigned char* pubKey, uint64_t amount, int subtractFee);
+
+CCRecipient toFFI(const CRecipient& cpp_struct);
+
+spark::Address decodeAddress(const std::string& str);
+
+spark::MintedCoinData createMintedCoinData(const char* address, uint64_t v, const char* memo);
+
+spark::MintedCoinData fromFFI(const CMintedCoinData& c_struct);
+
+CMintedCoinData createCMintedCoinData(const char* address, uint64_t value, const char* memo);
+
+CMintedCoinData toFFI(const spark::MintedCoinData& cpp_struct);
+
+char const hexArray[16] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd',
+						   'e', 'f'};
+
+unsigned char* copyBytes(const unsigned char* source, int length);
+
+unsigned char *hexToBytes(const char *str);
+
+const char *bytesToHex(const unsigned char *bytes, int size);
+
+const char *bytesToHex(const char *bytes, int size);
+
+const char *bytesToHex(std::vector<unsigned char> bytes, int size);
+
+
+#endif //ORG_FIRO_SPARK_UTILS_H

test/flutter_libsparkmobile_method_channel_test.dart

@@ -1,27 +0,0 @@
-import 'package:flutter/services.dart';
-import 'package:flutter_test/flutter_test.dart';
-import 'package:flutter_libsparkmobile/flutter_libsparkmobile_method_channel.dart';
-
-void main() {
-  TestWidgetsFlutterBinding.ensureInitialized();
-
-  MethodChannelFlutterLibsparkmobile platform = MethodChannelFlutterLibsparkmobile();
-  const MethodChannel channel = MethodChannel('flutter_libsparkmobile');
-
-  setUp(() {
-    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger.setMockMethodCallHandler(
-      channel,
-      (MethodCall methodCall) async {
-        return '42';
-      },
-    );
-  });
-
-  tearDown(() {
-    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger.setMockMethodCallHandler(channel, null);
-  });
-
-  test('getPlatformVersion', () async {
-    expect(await platform.getPlatformVersion(), '42');
-  });
-}

windows/CMakeLists.txt

@@ -8,89 +8,16 @@ cmake_minimum_required(VERSION 3.14)
 set(PROJECT_NAME "flutter_libsparkmobile")
 project(${PROJECT_NAME} LANGUAGES CXX)
 
-# This value is used when generating builds using this plugin, so it must
+# Invoke the build for native code shared with the other target platforms.
-# not be changed
+# This can be changed to accommodate different builds.
-set(PLUGIN_NAME "flutter_libsparkmobile_plugin")
+add_subdirectory("${CMAKE_CURRENT_SOURCE_DIR}/../src" "${CMAKE_CURRENT_BINARY_DIR}/shared")
-
-# Any new source files that you add to the plugin should be added here.
-list(APPEND PLUGIN_SOURCES
-  "flutter_libsparkmobile_plugin.cpp"
-  "flutter_libsparkmobile_plugin.h"
-)
-
-# Define the plugin library target. Its name must not be changed (see comment
-# on PLUGIN_NAME above).
-add_library(${PLUGIN_NAME} SHARED
-  "include/flutter_libsparkmobile/flutter_libsparkmobile_plugin_c_api.h"
-  "flutter_libsparkmobile_plugin_c_api.cpp"
-  ${PLUGIN_SOURCES}
-)
-
-# Apply a standard set of build settings that are configured in the
-# application-level CMakeLists.txt. This can be removed for plugins that want
-# full control over build settings.
-apply_standard_settings(${PLUGIN_NAME})
-
-# Symbols are hidden by default to reduce the chance of accidental conflicts
-# between plugins. This should not be removed; any symbols that should be
-# exported should be explicitly exported with the FLUTTER_PLUGIN_EXPORT macro.
-set_target_properties(${PLUGIN_NAME} PROPERTIES
-  CXX_VISIBILITY_PRESET hidden)
-target_compile_definitions(${PLUGIN_NAME} PRIVATE FLUTTER_PLUGIN_IMPL)
-
-# Source include directories and library dependencies. Add any plugin-specific
-# dependencies here.
-target_include_directories(${PLUGIN_NAME} INTERFACE
-  "${CMAKE_CURRENT_SOURCE_DIR}/include")
-target_link_libraries(${PLUGIN_NAME} PRIVATE flutter flutter_wrapper_plugin)
 
 # List of absolute paths to libraries that should be bundled with the plugin.
 # This list could contain prebuilt libraries, or libraries created by an
 # external build triggered from this build file.
 set(flutter_libsparkmobile_bundled_libraries
-  ""
+  # Defined in ../src/CMakeLists.txt.
+  # This can be changed to accommodate different builds.
+  $<TARGET_FILE:flutter_libsparkmobile>
   PARENT_SCOPE
 )
-
-# === Tests ===
-# These unit tests can be run from a terminal after building the example, or
-# from Visual Studio after opening the generated solution file.
-
-# Only enable test builds when building the example (which sets this variable)
-# so that plugin clients aren't building the tests.
-if (${include_${PROJECT_NAME}_tests})
-set(TEST_RUNNER "${PROJECT_NAME}_test")
-enable_testing()
-
-# Add the Google Test dependency.
-include(FetchContent)
-FetchContent_Declare(
-  googletest
-  URL https://github.com/google/googletest/archive/release-1.11.0.zip
-)
-# Prevent overriding the parent project's compiler/linker settings
-set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
-# Disable install commands for gtest so it doesn't end up in the bundle.
-set(INSTALL_GTEST OFF CACHE BOOL "Disable installation of googletest" FORCE)
-FetchContent_MakeAvailable(googletest)
-
-# The plugin's C API is not very useful for unit testing, so build the sources
-# directly into the test binary rather than using the DLL.
-add_executable(${TEST_RUNNER}
-  test/flutter_libsparkmobile_plugin_test.cpp
-  ${PLUGIN_SOURCES}
-)
-apply_standard_settings(${TEST_RUNNER})
-target_include_directories(${TEST_RUNNER} PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}")
-target_link_libraries(${TEST_RUNNER} PRIVATE flutter_wrapper_plugin)
-target_link_libraries(${TEST_RUNNER} PRIVATE gtest_main gmock)
-# flutter_wrapper_plugin has link dependencies on the Flutter DLL.
-add_custom_command(TARGET ${TEST_RUNNER} POST_BUILD
-  COMMAND ${CMAKE_COMMAND} -E copy_if_different
-  "${FLUTTER_LIBRARY}" $<TARGET_FILE_DIR:${TEST_RUNNER}>
-)
-
-# Enable automatic test discovery.
-include(GoogleTest)
-gtest_discover_tests(${TEST_RUNNER})
-endif()

windows/flutter_libsparkmobile_plugin.cpp

@@ -1,59 +0,0 @@
-#include "flutter_libsparkmobile_plugin.h"
-
-// This must be included before many other Windows headers.
-#include <windows.h>
-
-// For getPlatformVersion; remove unless needed for your plugin implementation.
-#include <VersionHelpers.h>
-
-#include <flutter/method_channel.h>
-#include <flutter/plugin_registrar_windows.h>
-#include <flutter/standard_method_codec.h>
-
-#include <memory>
-#include <sstream>
-
-namespace flutter_libsparkmobile {
-
-// static
-void FlutterLibsparkmobilePlugin::RegisterWithRegistrar(
-    flutter::PluginRegistrarWindows *registrar) {
-  auto channel =
-      std::make_unique<flutter::MethodChannel<flutter::EncodableValue>>(
-          registrar->messenger(), "flutter_libsparkmobile",
-          &flutter::StandardMethodCodec::GetInstance());
-
-  auto plugin = std::make_unique<FlutterLibsparkmobilePlugin>();
-
-  channel->SetMethodCallHandler(
-      [plugin_pointer = plugin.get()](const auto &call, auto result) {
-        plugin_pointer->HandleMethodCall(call, std::move(result));
-      });
-
-  registrar->AddPlugin(std::move(plugin));
-}
-
-FlutterLibsparkmobilePlugin::FlutterLibsparkmobilePlugin() {}
-
-FlutterLibsparkmobilePlugin::~FlutterLibsparkmobilePlugin() {}
-
-void FlutterLibsparkmobilePlugin::HandleMethodCall(
-    const flutter::MethodCall<flutter::EncodableValue> &method_call,
-    std::unique_ptr<flutter::MethodResult<flutter::EncodableValue>> result) {
-  if (method_call.method_name().compare("getPlatformVersion") == 0) {
-    std::ostringstream version_stream;
-    version_stream << "Windows ";
-    if (IsWindows10OrGreater()) {
-      version_stream << "10+";
-    } else if (IsWindows8OrGreater()) {
-      version_stream << "8";
-    } else if (IsWindows7OrGreater()) {
-      version_stream << "7";
-    }
-    result->Success(flutter::EncodableValue(version_stream.str()));
-  } else {
-    result->NotImplemented();
-  }
-}
-
-}  // namespace flutter_libsparkmobile

windows/flutter_libsparkmobile_plugin.h

@@ -1,31 +0,0 @@
-#ifndef FLUTTER_PLUGIN_FLUTTER_LIBSPARKMOBILE_PLUGIN_H_
-#define FLUTTER_PLUGIN_FLUTTER_LIBSPARKMOBILE_PLUGIN_H_
-
-#include <flutter/method_channel.h>
-#include <flutter/plugin_registrar_windows.h>
-
-#include <memory>
-
-namespace flutter_libsparkmobile {
-
-class FlutterLibsparkmobilePlugin : public flutter::Plugin {
- public:
-  static void RegisterWithRegistrar(flutter::PluginRegistrarWindows *registrar);
-
-  FlutterLibsparkmobilePlugin();
-
-  virtual ~FlutterLibsparkmobilePlugin();
-
-  // Disallow copy and assign.
-  FlutterLibsparkmobilePlugin(const FlutterLibsparkmobilePlugin&) = delete;
-  FlutterLibsparkmobilePlugin& operator=(const FlutterLibsparkmobilePlugin&) = delete;
-
-  // Called when a method is called on this plugin's channel from Dart.
-  void HandleMethodCall(
-      const flutter::MethodCall<flutter::EncodableValue> &method_call,
-      std::unique_ptr<flutter::MethodResult<flutter::EncodableValue>> result);
-};
-
-}  // namespace flutter_libsparkmobile
-
-#endif  // FLUTTER_PLUGIN_FLUTTER_LIBSPARKMOBILE_PLUGIN_H_

windows/flutter_libsparkmobile_plugin_c_api.cpp

@@ -1,12 +0,0 @@
-#include "include/flutter_libsparkmobile/flutter_libsparkmobile_plugin_c_api.h"
-
-#include <flutter/plugin_registrar_windows.h>
-
-#include "flutter_libsparkmobile_plugin.h"
-
-void FlutterLibsparkmobilePluginCApiRegisterWithRegistrar(
-    FlutterDesktopPluginRegistrarRef registrar) {
-  flutter_libsparkmobile::FlutterLibsparkmobilePlugin::RegisterWithRegistrar(
-      flutter::PluginRegistrarManager::GetInstance()
-          ->GetRegistrar<flutter::PluginRegistrarWindows>(registrar));
-}

windows/include/flutter_libsparkmobile/flutter_libsparkmobile_plugin_c_api.h

@@ -1,23 +0,0 @@
-#ifndef FLUTTER_PLUGIN_FLUTTER_LIBSPARKMOBILE_PLUGIN_C_API_H_
-#define FLUTTER_PLUGIN_FLUTTER_LIBSPARKMOBILE_PLUGIN_C_API_H_
-
-#include <flutter_plugin_registrar.h>
-
-#ifdef FLUTTER_PLUGIN_IMPL
-#define FLUTTER_PLUGIN_EXPORT __declspec(dllexport)
-#else
-#define FLUTTER_PLUGIN_EXPORT __declspec(dllimport)
-#endif
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-FLUTTER_PLUGIN_EXPORT void FlutterLibsparkmobilePluginCApiRegisterWithRegistrar(
-    FlutterDesktopPluginRegistrarRef registrar);
-
-#if defined(__cplusplus)
-}  // extern "C"
-#endif
-
-#endif  // FLUTTER_PLUGIN_FLUTTER_LIBSPARKMOBILE_PLUGIN_C_API_H_

windows/test/flutter_libsparkmobile_plugin_test.cpp

@@ -1,43 +0,0 @@
-#include <flutter/method_call.h>
-#include <flutter/method_result_functions.h>
-#include <flutter/standard_method_codec.h>
-#include <gtest/gtest.h>
-#include <windows.h>
-
-#include <memory>
-#include <string>
-#include <variant>
-
-#include "flutter_libsparkmobile_plugin.h"
-
-namespace flutter_libsparkmobile {
-namespace test {
-
-namespace {
-
-using flutter::EncodableMap;
-using flutter::EncodableValue;
-using flutter::MethodCall;
-using flutter::MethodResultFunctions;
-
-}  // namespace
-
-TEST(FlutterLibsparkmobilePlugin, GetPlatformVersion) {
-  FlutterLibsparkmobilePlugin plugin;
-  // Save the reply value from the success callback.
-  std::string result_string;
-  plugin.HandleMethodCall(
-      MethodCall("getPlatformVersion", std::make_unique<EncodableValue>()),
-      std::make_unique<MethodResultFunctions<>>(
-          [&result_string](const EncodableValue* result) {
-            result_string = std::get<std::string>(*result);
-          },
-          nullptr, nullptr));
-
-  // Since the exact string varies by host, just ensure that it's a string
-  // with the expected format.
-  EXPECT_TRUE(result_string.rfind("Windows ", 0) == 0);
-}
-
-}  // namespace test
-}  // namespace flutter_libsparkmobile