Moved long running task to an isolate

lib/providers/tasks_provider.dart

@@ -139,69 +139,107 @@ final tasksProvider = StreamProvider<List<Task>>((ref) {
 
   // NOTE: Supabase stream builder does not support `.range(...)` —
   // apply pagination and remaining filters client-side after mapping.
-  final baseStream = client
+  final baseStream = client.from('tasks').stream(primaryKey: ['id']);
-      .from('tasks')
+
-      .stream(primaryKey: ['id'])
+  return baseStream.asyncMap((rows) async {
-      .map((rows) => rows.map(Task.fromMap).toList());
+    final rowsList = (rows as List<dynamic>).cast<Map<String, dynamic>>();
 
-  return baseStream.map((allTasks) {
-    debugPrint('[tasksProvider] stream event: ${allTasks.length} rows');
-    // RBAC (server-side filtering isn't possible via `.range` on stream builder,
-    // so enforce allowed IDs here).
-    var list = allTasks;
-    if (!isGlobal) {
     final allowedTicketIds =
         ticketsAsync.valueOrNull?.map((ticket) => ticket.id).toList() ??
         <String>[];
-      final officeIds =
+    final allowedOfficeIds =
         assignmentsAsync.valueOrNull
             ?.where((assignment) => assignment.userId == profile.id)
             .map((assignment) => assignment.officeId)
-              .toSet()
             .toList() ??
         <String>[];
-      if (allowedTicketIds.isEmpty && officeIds.isEmpty) return <Task>[];
+
-      final allowedTickets = allowedTicketIds.toSet();
+    final payload = <String, dynamic>{
-      final allowedOffices = officeIds.toSet();
+      'rows': rowsList,
+      'isGlobal': isGlobal,
+      'allowedTicketIds': allowedTicketIds,
+      'allowedOfficeIds': allowedOfficeIds,
+      'officeId': query.officeId,
+      'status': query.status,
+      'searchQuery': query.searchQuery,
+      'taskNumber': query.taskNumber,
+      'dateStart': query.dateRange?.start.millisecondsSinceEpoch,
+      'dateEnd': query.dateRange?.end.millisecondsSinceEpoch,
+    };
+
+    final processed = await compute(_processTasksInIsolate, payload);
+
+    final tasks = (processed as List<dynamic>)
+        .cast<Map<String, dynamic>>()
+        .map(Task.fromMap)
+        .toList();
+
+    debugPrint('[tasksProvider] processed ${tasks.length} tasks');
+    return tasks;
+  });
+});
+
+// Runs inside a background isolate to filter/sort tasks represented as
+// plain maps. Returns a List<Map<String,dynamic>> suitable for
+// reconstruction with `Task.fromMap` on the main isolate.
+List<Map<String, dynamic>> _processTasksInIsolate(
+  Map<String, dynamic> payload,
+) {
+  var list = List<Map<String, dynamic>>.from(
+    (payload['rows'] as List).cast<Map<String, dynamic>>(),
+  );
+
+  final isGlobal = payload['isGlobal'] as bool? ?? false;
+  final allowedTicketIds =
+      (payload['allowedTicketIds'] as List?)?.cast<String>().toSet() ??
+      <String>{};
+  final allowedOfficeIds =
+      (payload['allowedOfficeIds'] as List?)?.cast<String>().toSet() ??
+      <String>{};
+
+  if (!isGlobal) {
+    if (allowedTicketIds.isEmpty && allowedOfficeIds.isEmpty)
+      return <Map<String, dynamic>>[];
+    list = list.where((t) {
+      final tid = t['ticket_id'] as String?;
+      final oid = t['office_id'] as String?;
+      return (tid != null && allowedTicketIds.contains(tid)) ||
+          (oid != null && allowedOfficeIds.contains(oid));
+    }).toList();
+  }
+
+  final officeId = payload['officeId'] as String?;
+  if (officeId != null) {
+    list = list.where((t) => t['office_id'] == officeId).toList();
+  }
+  final status = payload['status'] as String?;
+  if (status != null) {
+    list = list.where((t) => t['status'] == status).toList();
+  }
+
+  final searchQuery = (payload['searchQuery'] as String?) ?? '';
+  if (searchQuery.isNotEmpty) {
+    final q = searchQuery.toLowerCase();
+    list = list.where((t) {
+      final title = (t['title'] as String?)?.toLowerCase() ?? '';
+      final desc = (t['description'] as String?)?.toLowerCase() ?? '';
+      final tn = (t['task_number'] as String?)?.toLowerCase() ?? '';
+      return title.contains(q) || desc.contains(q) || tn.contains(q);
+    }).toList();
+  }
+
+  final taskNumberFilter = (payload['taskNumber'] as String?)?.trim();
+  if (taskNumberFilter != null && taskNumberFilter.isNotEmpty) {
+    final tnLow = taskNumberFilter.toLowerCase();
     list = list
         .where(
-            (t) =>
+          (t) => ((t['task_number'] as String?) ?? '').toLowerCase().contains(
-                (t.ticketId != null && allowedTickets.contains(t.ticketId)) ||
+            tnLow,
-                (t.officeId != null && allowedOffices.contains(t.officeId)),
+          ),
         )
         .toList();
   }
 
-    // Query filters (apply client-side)
-    if (query.officeId != null) {
-      list = list.where((t) => t.officeId == query.officeId).toList();
-    }
-    if (query.status != null) {
-      list = list.where((t) => t.status == query.status).toList();
-    }
-    if (query.searchQuery.isNotEmpty) {
-      final q = query.searchQuery.toLowerCase();
-      list = list
-          .where(
-            (t) =>
-                t.title.toLowerCase().contains(q) ||
-                t.description.toLowerCase().contains(q) ||
-                (t.taskNumber?.toLowerCase().contains(q) ?? false),
-          )
-          .toList();
-    }
-    if (query.taskNumber != null && query.taskNumber!.trim().isNotEmpty) {
-      final tn = query.taskNumber!.toLowerCase();
-      list = list
-          .where((t) => (t.taskNumber ?? '').toLowerCase().contains(tn))
-          .toList();
-    }
-
-    // Sort by status groups then within-group ordering:
-    // 1. queued – order by priority (desc), then queue_order (asc), then created_at
-    // 2. in_progress – preserve recent order (created_at asc)
-    // 3. completed – order by numeric task_number when available (asc)
-    // 4. other statuses – fallback to queue_order then created_at
   int statusRank(String s) {
     switch (s) {
       case 'queued':
@@ -217,65 +255,69 @@ final tasksProvider = StreamProvider<List<Task>>((ref) {
     }
   }
 
-    int? parseTaskNumber(Task t) {
+  int? parseTaskNumberFromString(String? tn) {
-      final tn = t.taskNumber;
     if (tn == null) return null;
     final m = RegExp(r'\d+').firstMatch(tn);
     if (m == null) return null;
     return int.tryParse(m.group(0)!);
   }
 
+  int _parseCreatedAt(Map<String, dynamic> m) {
+    final v = m['created_at'];
+    if (v == null) return 0;
+    if (v is int) return v;
+    if (v is double) return v.toInt();
+    if (v is String) {
+      try {
+        return DateTime.parse(v).millisecondsSinceEpoch;
+      } catch (_) {
+        return 0;
+      }
+    }
+    return 0;
+  }
+
   list.sort((a, b) {
-      final ra = statusRank(a.status);
+    final ra = statusRank((a['status'] as String?) ?? '');
-      final rb = statusRank(b.status);
+    final rb = statusRank((b['status'] as String?) ?? '');
     final rcmp = ra.compareTo(rb);
     if (rcmp != 0) return rcmp;
 
-      // Same status: apply within-group ordering
     if (ra == 0) {
       // queued: higher priority first, then queue_order asc, then created_at
-        final pcmp = b.priority.compareTo(a.priority);
+      final pa = (a['priority'] as num?)?.toInt() ?? 1;
+      final pb = (b['priority'] as num?)?.toInt() ?? 1;
+      final pcmp = pb.compareTo(pa);
       if (pcmp != 0) return pcmp;
-        final aOrder = a.queueOrder ?? 0x7fffffff;
+      final aOrder = (a['queue_order'] as int?) ?? 0x7fffffff;
-        final bOrder = b.queueOrder ?? 0x7fffffff;
+      final bOrder = (b['queue_order'] as int?) ?? 0x7fffffff;
       final qcmp = aOrder.compareTo(bOrder);
       if (qcmp != 0) return qcmp;
-        return a.createdAt.compareTo(b.createdAt);
+      return _parseCreatedAt(a).compareTo(_parseCreatedAt(b));
     }
 
     if (ra == 1) {
-        // in_progress: keep older first
+      return _parseCreatedAt(a).compareTo(_parseCreatedAt(b));
-        return a.createdAt.compareTo(b.createdAt);
     }
 
     if (ra == 2) {
-        // completed: prefer numeric task_number DESC when present
+      final an = parseTaskNumberFromString(a['task_number'] as String?);
-        final an = parseTaskNumber(a);
+      final bn = parseTaskNumberFromString(b['task_number'] as String?);
-        final bn = parseTaskNumber(b);
       if (an != null && bn != null) return bn.compareTo(an);
       if (an != null) return -1;
       if (bn != null) return 1;
-        return b.createdAt.compareTo(a.createdAt);
+      return _parseCreatedAt(b).compareTo(_parseCreatedAt(a));
     }
 
-      // fallback: queue_order then created_at
+    final aOrder = (a['queue_order'] as int?) ?? 0x7fffffff;
-      final aOrder = a.queueOrder ?? 0x7fffffff;
+    final bOrder = (b['queue_order'] as int?) ?? 0x7fffffff;
-      final bOrder = b.queueOrder ?? 0x7fffffff;
     final cmp = aOrder.compareTo(bOrder);
     if (cmp != 0) return cmp;
-      return a.createdAt.compareTo(b.createdAt);
+    return _parseCreatedAt(a).compareTo(_parseCreatedAt(b));
   });
 
-    // Return the full filtered & sorted list to allow the UI layer to
-    // perform pagination (desktop PaginatedDataTable expects the full
-    // row count so it can render pagination controls reliably). The
-    // Supabase stream currently delivers all rows and the provider
-    // applies filtering/sorting; leaving pagination to the UI avoids
-    // off-by-one issues where a full page of results would hide the
-    // presence of a next page.
   return list;
-  });
+}
-});
 
 /// Provider for task query parameters.
 final tasksQueryProvider = StateProvider<TaskQuery>((ref) => const TaskQuery());

lib/providers/tickets_provider.dart

@@ -3,6 +3,7 @@ import 'dart:async';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:supabase_flutter/supabase_flutter.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter/foundation.dart';
 
 import '../models/office.dart';
 import '../models/ticket.dart';
@@ -127,57 +128,113 @@ final ticketsProvider = StreamProvider<List<Ticket>>((ref) {
       profile.role == 'dispatcher' ||
       profile.role == 'it_staff';
 
-  // Use stream for realtime updates, then apply pagination & search filters
+  // Use stream for realtime updates. Offload expensive client-side
-  // client-side because `.range(...)` is not supported on the stream builder.
+  // filtering/sorting/pagination to a background isolate via `compute`
-  final baseStream = client
+  // so UI navigation and builds remain smooth.
-      .from('tickets')
+  final baseStream = client.from('tickets').stream(primaryKey: ['id']);
-      .stream(primaryKey: ['id'])
-      .map((rows) => rows.map(Ticket.fromMap).toList());
 
-  return baseStream.map((allTickets) {
+  return baseStream.asyncMap((rows) async {
-    debugPrint('[ticketsProvider] stream event: ${allTickets.length} rows');
+    // rows is List<dynamic> of maps coming from Supabase
-    var list = allTickets;
+    final rowsList = (rows as List<dynamic>).cast<Map<String, dynamic>>();
 
-    if (!isGlobal) {
+    // Prepare lightweight serializable args for background processing
-      final officeIds =
+    final allowedOfficeIds =
         assignmentsAsync.valueOrNull
             ?.where((assignment) => assignment.userId == profile.id)
             .map((assignment) => assignment.officeId)
-              .toSet()
             .toList() ??
         <String>[];
-      if (officeIds.isEmpty) return <Ticket>[];
-      final allowedOffices = officeIds.toSet();
-      list = list.where((t) => allowedOffices.contains(t.officeId)).toList();
-    }
 
-    if (query.officeId != null) {
+    final payload = <String, dynamic>{
-      list = list.where((t) => t.officeId == query.officeId).toList();
+      'rows': rowsList,
-    }
+      'isGlobal': isGlobal,
-    if (query.status != null) {
+      'allowedOfficeIds': allowedOfficeIds,
-      list = list.where((t) => t.status == query.status).toList();
+      'offset': query.offset,
-    }
+      'limit': query.limit,
-    if (query.searchQuery.isNotEmpty) {
+      'searchQuery': query.searchQuery,
-      final q = query.searchQuery.toLowerCase();
+      'officeId': query.officeId,
+      'status': query.status,
+      'dateStart': query.dateRange?.start.millisecondsSinceEpoch,
+      'dateEnd': query.dateRange?.end.millisecondsSinceEpoch,
+    };
+
+    final processed = await compute(_processTicketsInIsolate, payload);
+
+    // `processed` is List<Map<String,dynamic>> — convert to Ticket objects
+    final tickets = (processed as List<dynamic>)
+        .cast<Map<String, dynamic>>()
+        .map(Ticket.fromMap)
+        .toList();
+
+    debugPrint('[ticketsProvider] processed ${tickets.length} tickets');
+    return tickets;
+  });
+});
+
+// Runs inside a background isolate. Accepts a serializable payload and
+// returns a list of ticket maps after filtering/sorting/pagination.
+List<Map<String, dynamic>> _processTicketsInIsolate(
+  Map<String, dynamic> payload,
+) {
+  final rows = (payload['rows'] as List).cast<Map<String, dynamic>>();
+  var list = List<Map<String, dynamic>>.from(rows);
+
+  final isGlobal = payload['isGlobal'] as bool? ?? false;
+  final allowedOfficeIds =
+      (payload['allowedOfficeIds'] as List?)?.cast<String>().toSet() ??
+      <String>{};
+
+  if (!isGlobal) {
+    if (allowedOfficeIds.isEmpty) return <Map<String, dynamic>>[];
     list = list
-          .where(
+        .where((t) => allowedOfficeIds.contains(t['office_id']))
-            (t) =>
-                t.subject.toLowerCase().contains(q) ||
-                t.description.toLowerCase().contains(q),
-          )
         .toList();
   }
 
-    // Sort: newest first
+  final officeId = payload['officeId'] as String?;
-    list.sort((a, b) => b.createdAt.compareTo(a.createdAt));
+  if (officeId != null) {
+    list = list.where((t) => t['office_id'] == officeId).toList();
+  }
+  final status = payload['status'] as String?;
+  if (status != null) {
+    list = list.where((t) => t['status'] == status).toList();
+  }
 
-    // Pagination
+  final searchQuery = (payload['searchQuery'] as String?) ?? '';
-    final start = query.offset;
+  if (searchQuery.isNotEmpty) {
-    final end = (start + query.limit).clamp(0, list.length);
+    final q = searchQuery.toLowerCase();
-    if (start >= list.length) return <Ticket>[];
+    list = list.where((t) {
+      final subj = (t['subject'] as String?)?.toLowerCase() ?? '';
+      final desc = (t['description'] as String?)?.toLowerCase() ?? '';
+      return subj.contains(q) || desc.contains(q);
+    }).toList();
+  }
+
+  // Sort newest first. `created_at` may be ISO strings or timestamps;
+  // handle strings and numeric values.
+  int _parseCreatedAt(Map<String, dynamic> m) {
+    final v = m['created_at'];
+    if (v == null) return 0;
+    if (v is int) return v;
+    if (v is double) return v.toInt();
+    if (v is String) {
+      try {
+        return DateTime.parse(v).millisecondsSinceEpoch;
+      } catch (_) {
+        return 0;
+      }
+    }
+    return 0;
+  }
+
+  list.sort((a, b) => _parseCreatedAt(b).compareTo(_parseCreatedAt(a)));
+
+  final start = (payload['offset'] as int?) ?? 0;
+  final limit = (payload['limit'] as int?) ?? 50;
+  final end = (start + limit).clamp(0, list.length);
+  if (start >= list.length) return <Map<String, dynamic>>[];
   return list.sublist(start, end);
-  });
+}
-});
 
 /// Provider for ticket query parameters.
 final ticketsQueryProvider = StateProvider<TicketQuery>(