fix: resolve errors in MultiStreamBuilder and income display

finance_app/lib/screens/expenses_screen.dart

@@ -3,6 +3,8 @@ import 'package:flutter/material.dart';
 import 'package:fl_chart/fl_chart.dart'; // Used indirectly by SpendingPieChart
 import 'package:intl/intl.dart'; // For date formatting
 import 'dart:async';
+import 'package:async/async.dart'; // Import StreamZip
+
 // Removed import 'dart:math'; // No longer needed for random data
 
 import '../database/database.dart' as db; // Import database with prefix 'db'
@@ -226,10 +228,12 @@ class _ExpensesScreenState extends State<ExpensesScreen> with TickerProviderStat
         ],
         builder: (context, snapshots) {
           // Handle loading states for all streams
+          // FIX: Call .any on the list `snapshots`
           if (snapshots.any((s) => s.connectionState == ConnectionState.waiting && !s.hasData)) {
             return const Center(child: CircularProgressIndicator());
           }
           // Handle error states for all streams
+          // FIX: Call .any on the list `snapshots`
           if (snapshots.any((s) => s.hasError)) {
             // Combine error messages or show a generic one
             String errors = snapshots.where((s) => s.hasError).map((s) => s.error.toString()).join('\n');
@@ -495,9 +499,10 @@ class _ExpensesScreenState extends State<ExpensesScreen> with TickerProviderStat
                                       // Get the db.Transaction object from the stream
                                       final dbTransaction = transactions[index];
                                       // Get the corresponding category details (icon, color) - use defaults for income
-                                      final categoryDetails = dbTransaction.type == 'expense'
+                                      // FIX: Define icon/color directly for income, no CategoryDetails class
+                                      final ({IconData iconCode, Color colorCode}) categoryDetails = dbTransaction.type == 'expense'
                                           ? CategoryUtils.getCategoryDetails(dbTransaction.categoryName)
-                                          : CategoryDetails( // Default/Placeholder for Income type
+                                          : ( // Default/Placeholder for Income type
                                               iconCode: Icons.attach_money, // Or a more specific income icon
                                               colorCode: Colors.green,
                                             );
@@ -580,6 +585,7 @@ class _ExpensesScreenState extends State<ExpensesScreen> with TickerProviderStat
 // Helper widget to manage multiple streams for the main body
 class MultiStreamBuilder extends StatelessWidget {
   final List<Stream<dynamic>> streams;
+  // FIX: Use AsyncWidgetBuilder<List<AsyncSnapshot<dynamic>>> for clarity
   final AsyncWidgetBuilder<List<AsyncSnapshot<dynamic>>> builder;
 
   const MultiStreamBuilder({
@@ -595,19 +601,35 @@ class MultiStreamBuilder extends StatelessWidget {
       stream: StreamZip(streams), // Use StreamZip to combine latest values
       builder: (context, snapshot) {
         // Create a list of AsyncSnapshot objects from the combined snapshot data
-        final List<AsyncSnapshot<dynamic>> snapshots = streams.map((stream) {
-          // Find the corresponding data in the combined snapshot
-          // This assumes StreamZip maintains order, which it does.
-          int index = streams.indexOf(stream);
-          dynamic data = snapshot.hasData ? snapshot.data![index] : null;
-          // Reconstruct individual AsyncSnapshot states
-          return AsyncSnapshot<dynamic>(
-            connectionState: snapshot.connectionState,
-            data: data,
-            error: snapshot.error, // Note: StreamZip might only report the first error
-            stackTrace: snapshot.stackTrace,
-          );
-        }).toList();
+        final List<AsyncSnapshot<dynamic>> snapshots = List.generate(
+          streams.length,
+          (index) {
+            // Reconstruct individual AsyncSnapshot states based on the combined snapshot
+            if (snapshot.connectionState == ConnectionState.waiting && !snapshot.hasData) {
+              // If waiting and no data yet, return waiting snapshot
+              return AsyncSnapshot<dynamic>.waiting();
+            }
+            if (snapshot.hasError) {
+              // If combined stream has error, propagate error
+              // Note: StreamZip might only report the first error
+              return AsyncSnapshot<dynamic>.withError(
+                snapshot.connectionState,
+                snapshot.error!,
+                snapshot.stackTrace ?? StackTrace.empty,
+              );
+            }
+            if (snapshot.hasData) {
+              // If data exists, extract the data for this specific stream index
+              return AsyncSnapshot<dynamic>.withData(
+                snapshot.connectionState,
+                snapshot.data![index], // Assumes StreamZip maintains order
+              );
+            }
+            // Default/fallback case (e.g., ConnectionState.none)
+            return AsyncSnapshot<dynamic>.nothing();
+          },
+          growable: false, // Fixed-size list
+        );
 
         return builder(context, snapshots);
       },