chore: Make use of optional params for nicer API

Author: irgendeinich

example/lib/main.dart

@@ -98,7 +98,7 @@ class _MyAppState extends State<MyApp> {
                 child: const Text('Track User Action')),
             ElevatedButton(
                 onPressed: () async => {
-                      _contextSdkPlugin.calibrate("my_flow", null, {
+                      _contextSdkPlugin.calibrate("my_flow", customSignals: {
                         'string': 'string',
                         'int': 14,
                         'bool': true,
@@ -117,31 +117,61 @@ class _MyAppState extends State<MyApp> {
                 child: const Text('Calibrate')),
             ElevatedButton(
                 onPressed: () async => {
-                      _contextSdkPlugin.optimize("my_flow", null, {
-                        'string': 'string',
-                        'int': 14,
-                        'bool': true,
-                        'float': 1.124
-                      }, (value) async {
-                        print("Optimized context: ${await value.validate()}");
-                        value.appendOutcomeMetadata({
+                      _contextSdkPlugin.optimize("my_flow", (context) async {
+                        print("Optimized context: ${await context.validate()}");
+                        context.appendOutcomeMetadata({
                           'string': 'string',
                           'int': 14,
                           'bool': true,
                           'float': 1.124
                         });
-                        value.log(Outcome.positive);
+                        await context.log(Outcome.positive);
                       })
                     },
                 child: const Text('Optimize')),
             ElevatedButton(
                 onPressed: () async => {
-                      _contextSdkPlugin.fetchContext("my_flow", 3, {
+                      _contextSdkPlugin.optimize("my_flow", customSignals: {
                         'string': 'string',
                         'int': 14,
                         'bool': true,
                         'float': 1.124
-                      }).then((value) async {
+                      }, (context) async {
+                        print("Optimized context: ${await context.validate()}");
+                        context.appendOutcomeMetadata({
+                          'string': 'string',
+                          'int': 14,
+                          'bool': true,
+                          'float': 1.124
+                        });
+                        await context.log(Outcome.positive);
+                      })
+                    },
+                child: const Text('Optimize (Custom Signals)')),
+            ElevatedButton(
+                onPressed: () async => {
+                      _contextSdkPlugin.optimize("my_flow", maxDelay: 0,
+                          (context) async {
+                        print("Optimized context: ${await context.validate()}");
+                        context.appendOutcomeMetadata({
+                          'string': 'string',
+                          'int': 14,
+                          'bool': true,
+                          'float': 1.124
+                        });
+                        await context.log(Outcome.positive);
+                      })
+                    },
+                child: const Text('Optimize (Instant)')),
+            ElevatedButton(
+                onPressed: () async => {
+                      _contextSdkPlugin.fetchContext("my_flow", 3,
+                          customSignals: {
+                            'string': 'string',
+                            'int': 14,
+                            'bool': true,
+                            'float': 1.124
+                          }).then((value) async {
                         print("Fetch context: ${await value.validate()}");
                         value.appendOutcomeMetadata({
                           'string': 'string',
@@ -155,8 +185,8 @@ class _MyAppState extends State<MyApp> {
                 child: const Text('Fetch Context')),
             ElevatedButton(
                 onPressed: () async {
-                  final context = await _contextSdkPlugin.instantContext(
-                      "my_flow", 3, null);
+                  final context =
+                      await _contextSdkPlugin.instantContext("my_flow", 3);
                   print("Instant context: ${await context.validate()}");
                   if (await context.shouldUpsell()) {
                     await context.appendOutcomeMetadata({

lib/context_sdk.dart

@@ -50,10 +50,11 @@ class ContextSdk {
   }
 
   void calibrate(
-      String flowName,
-      int? maxDelay,
-      Map<String, dynamic>? customSignals,
-      ValueSetter<RealWorldContext> onContextReady) async {
+    String flowName,
+    ValueSetter<RealWorldContext> onContextReady, {
+    int? maxDelay,
+    Map<String, dynamic>? customSignals,
+  }) async {
     ContextSdkPlatform.instance.calibrate(flowName, maxDelay, customSignals,
         (contextId) {
       onContextReady(RealWorldContext(ContextIdHolder(contextId)));
@@ -66,10 +67,11 @@ class ContextSdk {
   ///
   /// [onGoodMoment] Will only be called if ContextSDK deems it a good moment, meaning it might never be called.
   void optimize(
-      String flowName,
-      int? maxDelay,
-      Map<String, dynamic>? customSignals,
-      ValueSetter<RealWorldContext> onGoodMoment) {
+    String flowName,
+    ValueSetter<RealWorldContext> onGoodMoment, {
+    int? maxDelay,
+    Map<String, dynamic>? customSignals,
+  }) {
     ContextSdkPlatform.instance.optimize(flowName, maxDelay, customSignals,
         (contextId) {
       onGoodMoment(RealWorldContext(ContextIdHolder(contextId)));
@@ -82,7 +84,7 @@ class ContextSdk {
   /// - [customSignals] A map of custom signals you want to add to the context
   /// Returns: A Future that resolves to a [RealWorldContext] object. If ContextSDK wasn't running this might take upto [duration] seconds to resolve, otherwise this will resolve instantly.
   Future<RealWorldContext> fetchContext(String flowName, int duration,
-      Map<String, dynamic>? customSignals) async {
+      {Map<String, dynamic>? customSignals}) async {
     final contextId = await ContextSdkPlatform.instance
         .fetchContext(flowName, duration, customSignals);
     return RealWorldContext(ContextIdHolder(contextId));
@@ -95,7 +97,7 @@ class ContextSdk {
   /// - [customSignals] A map of custom signals you want to add to the context
   /// Returns: A [RealWorldContext] object. This will always resolve instantly, but might lead to an incomplete context object if the duration wasn't reached.
   Future<RealWorldContext> instantContext(String flowName, int duration,
-      Map<String, dynamic>? customSignals) async {
+      {Map<String, dynamic>? customSignals}) async {
     final contextId = await ContextSdkPlatform.instance
         .instantContext(flowName, duration, customSignals);
     return RealWorldContext(ContextIdHolder(contextId));