feat: implement real cross-platform voice recording utilizing record package with mic permission configuration

whatsapp_app/lib/controllers/chat_controller.dart

@@ -1,7 +1,11 @@
 import 'dart:async';
+import 'dart:convert';
+import 'dart:io';
 import 'package:flutter/material.dart';
 import 'package:get/get.dart';
 import 'package:intl/intl.dart';
+import 'package:record/record.dart';
+import 'package:path_provider/path_provider.dart';
 import '../services/whatsapp_service.dart';
 import '../models/conversation_model.dart';
 import '../models/message_model.dart';
@@ -17,6 +21,13 @@ class ChatController extends GetxController {
 
   final inputCtrl = TextEditingController();
   final scrollCtrl = ScrollController();
+  final hasText = false.obs;
+
+  // Recording State
+  final audioRecord = AudioRecorder();
+  final isRecording = false.obs;
+  final recordDuration = 0.obs;
+  Timer? _recordTimer;
 
   StreamSubscription? _eventSub;
 
@@ -32,6 +43,10 @@ class ChatController extends GetxController {
       Get.find<ConversationsController>().clearUnreadCount(conversation.id);
     } catch (_) {}
 
+    inputCtrl.addListener(() {
+      hasText.value = inputCtrl.text.trim().isNotEmpty;
+    });
+
     loadMessages();
     markAsRead();
 
@@ -45,6 +60,8 @@ class ChatController extends GetxController {
       _svc.activeChatId.value = null;
     }
     _eventSub?.cancel();
+    _recordTimer?.cancel();
+    audioRecord.dispose();
     inputCtrl.dispose();
     scrollCtrl.dispose();
     super.onClose();
@@ -228,4 +245,72 @@ class ChatController extends GetxController {
       return DateFormat('MMMM d, yyyy').format(dt);
     }
   }
+
+  // ── Audio Recording Engine ───────────────────────────────────────────────
+  Future<void> startRecording() async {
+    try {
+      if (await audioRecord.hasPermission()) {
+        final tempDir = await getTemporaryDirectory();
+        final path = '${tempDir.path}/rec_${DateTime.now().millisecondsSinceEpoch}.m4a';
+        
+        await audioRecord.start(
+          const RecordConfig(encoder: AudioEncoder.aacLc),
+          path: path,
+        );
+        
+        recordDuration.value = 0;
+        isRecording.value = true;
+        
+        _recordTimer?.cancel();
+        _recordTimer = Timer.periodic(const Duration(seconds: 1), (timer) {
+          recordDuration.value++;
+        });
+      } else {
+        Get.snackbar(
+          'Permission Denied',
+          'Microphone permission is required to record voice notes.',
+          snackPosition: SnackPosition.BOTTOM,
+          backgroundColor: Colors.redAccent.withOpacity(0.8),
+          colorText: Colors.white,
+        );
+      }
+    } catch (e) {
+      print('[START RECORDING ERROR] $e');
+    }
+  }
+
+  Future<void> stopAndSendRecording() async {
+    try {
+      _recordTimer?.cancel();
+      final path = await audioRecord.stop();
+      isRecording.value = false;
+      
+      if (path != null && recordDuration.value > 0) {
+        final file = File(path);
+        if (await file.exists()) {
+          final bytes = await file.readAsBytes();
+          final base64String = base64Encode(bytes);
+          
+          await sendMediaMessage(
+            base64String,
+            'audio/mp4', // Recorded as M4A (AAC), perfect for all platforms natively!
+            'voice_note.m4a',
+          );
+        }
+      }
+    } catch (e) {
+      print('[STOP RECORDING ERROR] $e');
+    }
+  }
+
+  Future<void> cancelRecording() async {
+    try {
+      _recordTimer?.cancel();
+      await audioRecord.stop();
+      isRecording.value = false;
+      recordDuration.value = 0;
+    } catch (e) {
+      print('[CANCEL RECORDING ERROR] $e');
+    }
+  }
 }