feat: implement post-response script handling and update environment variables

lib/services/flutter_js_service.dart

@@ -6,6 +6,7 @@ import 'dart:developer';
 import 'package:apidash/consts.dart';
 import 'package:apidash/models/request_model.dart';
 import 'package:apidash_core/models/http_request_model.dart';
+import 'package:apidash_core/models/http_response_model.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_js/flutter_js.dart';
 
@@ -133,7 +134,6 @@ Future<
   })(); // Immediately invoke the function
   """;
 
-
   // TODO: Do something better to avoid null check here.
   HttpRequestModel resultingRequest = httpRequest!;
   Map<String, dynamic> resultingEnvironment = Map.from(activeEnvironment);
@@ -177,6 +177,101 @@ Future<
   );
 }
 
+Future<
+    ({
+      HttpResponseModel updatedResponse,
+      Map<String, dynamic> updatedEnvironment
+    })> executePostResponseScript({
+  required RequestModel currentRequestModel,
+  required Map<String, dynamic> activeEnvironment,
+}) async {
+  if (currentRequestModel.postRequestScript.trim().isEmpty) {
+    // No script, return original data
+    // return (
+    //   updatedRequest: currentRequestModel.httpRequestModel,
+    //   updatedEnvironment: activeEnvironment
+    // );
+  }
+
+  final httpRequest = currentRequestModel.httpRequestModel;
+  final httpResponse = currentRequestModel.httpResponseModel;
+  final userScript = currentRequestModel.postRequestScript;
+
+  // Prepare Data
+  final requestJson = jsonEncode(httpRequest?.toJson());
+  final responseJson = jsonEncode(httpResponse?.toJson());
+  final environmentJson = jsonEncode(activeEnvironment);
+
+  // Inject data as JS variables
+  // Escape strings properly if embedding directly
+  final dataInjection = """
+  var injectedRequestJson = ${jsEscapeString(requestJson)};
+  var injectedEnvironmentJson = ${jsEscapeString(environmentJson)};
+  var injectedResponseJson = ${jsEscapeString(responseJson)};
+  """;
+
+  // Concatenate & Add Return
+  final fullScript = """
+  (function() {
+    // --- Data Injection (now constants within the IIFE scope) ---
+    $dataInjection
+
+    // --- Setup Script (will declare variables within the IIFE scope) ---
+    $setupScript
+
+    // --- User Script (will execute within the IIFE scope)---
+    $userScript
+
+    // --- Return Result (accesses variables from the IIFE scope) ---
+    return JSON.stringify({ response: response, environment: environment });
+  })(); // Immediately invoke the function
+  """;
+
+  // TODO: Do something better to avoid null check here.
+  // HttpRequestModel resultingRequest = httpRequest!;
+  HttpResponseModel resultingResponse = httpResponse!;
+  Map<String, dynamic> resultingEnvironment = Map.from(activeEnvironment);
+
+  try {
+    // Execute
+    final JsEvalResult result = jsRuntime.evaluate(fullScript);
+
+    // Process Results
+    if (result.isError) {
+      print("Post-Response script execution error: ${result.stringResult}");
+      // TODO: Handle error - maybe show in UI, keep original request/env
+    } else if (result.stringResult.isNotEmpty) {
+      final resultMap = jsonDecode(result.stringResult);
+      log(resultMap['response'].toString());
+      if (resultMap is Map<String, dynamic>) {
+        // Deserialize Request
+        if (resultMap.containsKey('response') && resultMap['response'] is Map) {
+          try {
+            resultingResponse = HttpResponseModel.fromJson(
+                Map<String, Object?>.from(resultMap['response']));
+          } catch (e) {
+            print("Error deserializing modified response from script: $e");
+            //TODO: Handle error - maybe keep original response?
+          }
+        }
+        // Get Environment Modifications
+        if (resultMap.containsKey('environment') &&
+            resultMap['environment'] is Map) {
+          resultingEnvironment =
+              Map<String, dynamic>.from(resultMap['environment']);
+        }
+      }
+    }
+  } catch (e) {
+    print("Dart-level error during post-response script execution: $e");
+  }
+
+  return (
+    updatedResponse: resultingResponse,
+    updatedEnvironment: resultingEnvironment
+  );
+}
+
 // Helper to properly escape strings for JS embedding
 String jsEscapeString(String s) {
   return jsonEncode(