feat: add full-screen image viewer and reactive ack icons

whatsapp_app/lib/widgets/message_bubble.dart

@@ -9,6 +9,41 @@ import '../models/message_model.dart';
 import '../theme/app_theme.dart';
 import '../services/whatsapp_service.dart';
 
+// ─── Full-Screen Image Viewer ─────────────────────────────────────────────
+class FullScreenImageViewer extends StatelessWidget {
+  final Uint8List bytes;
+  final String heroTag;
+
+  const FullScreenImageViewer({
+    super.key,
+    required this.bytes,
+    required this.heroTag,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      backgroundColor: Colors.black,
+      appBar: AppBar(
+        backgroundColor: Colors.black,
+        iconTheme: const IconThemeData(color: Colors.white),
+        elevation: 0,
+      ),
+      body: Center(
+        child: Hero(
+          tag: heroTag,
+          child: InteractiveViewer(
+            minScale: 0.5,
+            maxScale: 5.0,
+            child: Image.memory(bytes, fit: BoxFit.contain),
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+// ─── Message Bubble ───────────────────────────────────────────────────────
 class MessageBubble extends StatelessWidget {
   final MessageModel message;
 
@@ -51,7 +86,7 @@ class MessageBubble extends StatelessWidget {
               crossAxisAlignment: CrossAxisAlignment.start,
               mainAxisSize: MainAxisSize.min,
               children: [
-                // Show sender name in group chats if not from me
+                // Sender name in group chats
                 if (!isMe && message.author != null) ...[
                   Text(
                     message.author!,
@@ -64,13 +99,13 @@ class MessageBubble extends StatelessWidget {
                   const SizedBox(height: 4),
                 ],
 
-                // Interactive Media widget if message has media
+                // Media widget
                 if (message.hasMedia) ...[
                   InteractiveMediaWidget(message: message),
                   const SizedBox(height: 6),
                 ],
 
-                // Message text & time row
+                // Text + time + ACK row
                 Row(
                   mainAxisSize: MainAxisSize.min,
                   crossAxisAlignment: CrossAxisAlignment.end,
@@ -116,13 +151,15 @@ class MessageBubble extends StatelessWidget {
 
   Widget _buildAckIcon(int ack) {
     switch (ack) {
-      case 1: // Pending
+      case 1: // Pending/Queued
         return const Icon(Icons.access_time, size: 13, color: AppTheme.textSecondary);
-      case 2: // Sent
+      case 2: // Sent (single grey tick)
         return const Icon(Icons.done, size: 15, color: AppTheme.textSecondary);
-      case 3: // Delivered
+      case 3: // Delivered (double grey tick)
         return const Icon(Icons.done_all, size: 15, color: AppTheme.textSecondary);
-      case 4: // Read
+      case 4: // Read (double blue tick)
+        return const Icon(Icons.done_all, size: 15, color: Colors.blue);
+      case 5: // Played audio/video (double blue with wave icon)
         return const Icon(Icons.done_all, size: 15, color: Colors.blue);
       default:
         return const SizedBox.shrink();
@@ -136,6 +173,7 @@ class MessageBubble extends StatelessWidget {
   }
 }
 
+// ─── Interactive Media Widget ─────────────────────────────────────────────
 class InteractiveMediaWidget extends StatefulWidget {
   final MessageModel message;
 
@@ -144,6 +182,7 @@ class InteractiveMediaWidget extends StatefulWidget {
   @override
   State<InteractiveMediaWidget> createState() => _InteractiveMediaWidgetState();
 }
+
 class _InteractiveMediaWidgetState extends State<InteractiveMediaWidget> {
   final WhatsAppService _svc = Get.find<WhatsAppService>();
   bool _isLoading = false;
@@ -211,7 +250,6 @@ class _InteractiveMediaWidgetState extends State<InteractiveMediaWidget> {
         await _player.pause();
       } else {
         final bytes = base64Decode(base64Data);
-        // Clean special characters from ID to construct a safe filename
         final safeId = widget.message.id.replaceAll(RegExp(r'[^a-zA-Z0-9]'), '');
         final tempDir = Directory.systemTemp;
         final tempFile = File('${tempDir.path}/voice_$safeId.mp3');
@@ -240,7 +278,7 @@ class _InteractiveMediaWidgetState extends State<InteractiveMediaWidget> {
       final cachedMedia = _svc.mediaCache[widget.message.id];
 
       if (cachedMedia != null) {
-        return _buildDownloadedMedia(cachedMedia);
+        return _buildDownloadedMedia(context, cachedMedia);
       }
 
       if (_isLoading) {
@@ -260,7 +298,7 @@ class _InteractiveMediaWidgetState extends State<InteractiveMediaWidget> {
         );
       }
 
-      // Tap to download media placeholder
+      // Tap to download placeholder
       return GestureDetector(
         onTap: _downloadMedia,
         child: Container(
@@ -304,11 +342,30 @@ class _InteractiveMediaWidgetState extends State<InteractiveMediaWidget> {
     }
   }
 
-  Widget _buildDownloadedMedia(String base64Data) {
+  Widget _buildDownloadedMedia(BuildContext context, String base64Data) {
     final bytes = base64Decode(base64Data);
 
+    // ── Image / Sticker: full-screen viewer on tap ─────────────────────────
     if (widget.message.type == "image" || widget.message.type == "sticker") {
-      return ClipRRect(
+      final heroTag = 'img_${widget.message.id}';
+      return GestureDetector(
+        onTap: () {
+          Navigator.of(context).push(
+            PageRouteBuilder(
+              opaque: false,
+              barrierColor: Colors.black,
+              pageBuilder: (_, __, ___) => FullScreenImageViewer(
+                bytes: bytes,
+                heroTag: heroTag,
+              ),
+              transitionsBuilder: (_, anim, __, child) =>
+                  FadeTransition(opacity: anim, child: child),
+            ),
+          );
+        },
+        child: Hero(
+          tag: heroTag,
+          child: ClipRRect(
             borderRadius: BorderRadius.circular(8),
             child: ConstrainedBox(
               constraints: const BoxConstraints(maxHeight: 250),
@@ -318,10 +375,17 @@ class _InteractiveMediaWidgetState extends State<InteractiveMediaWidget> {
                 width: double.infinity,
               ),
             ),
+          ),
+        ),
       );
     }
 
+    // ── Audio / Voice Note ─────────────────────────────────────────────────
     if (widget.message.type == "audio") {
+      final durationStr = _audioDurationSeconds > 1
+          ? '${(_audioDurationSeconds ~/ 60).toString().padLeft(1, '0')}:${(_audioDurationSeconds % 60).toString().padLeft(2, '0')}'
+          : '0:${_audioCurrentSeconds.toString().padLeft(2, '0')}';
+
       return Container(
         padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 6),
         decoration: BoxDecoration(
@@ -333,28 +397,49 @@ class _InteractiveMediaWidgetState extends State<InteractiveMediaWidget> {
           children: [
             IconButton(
               icon: Icon(
-                _isPlaying ? Icons.pause : Icons.play_arrow,
+                _isPlaying ? Icons.pause_circle_filled : Icons.play_circle_filled,
                 color: AppTheme.primary,
-                size: 24,
+                size: 36,
               ),
               onPressed: () => _toggleAudioPlayback(base64Data),
+              padding: EdgeInsets.zero,
+              constraints: const BoxConstraints(),
             ),
+            const SizedBox(width: 8),
             Expanded(
-              child: Padding(
-                padding: const EdgeInsets.symmetric(horizontal: 8),
-                child: LinearProgressIndicator(
-                  value: _audioProgress,
-                  backgroundColor: AppTheme.surfaceLight,
-                  color: AppTheme.primary,
+              child: Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                children: [
+                  SliderTheme(
+                    data: SliderTheme.of(context).copyWith(
+                      trackHeight: 2.5,
+                      thumbShape: const RoundSliderThumbShape(enabledThumbRadius: 5),
+                      overlayShape: const RoundSliderOverlayShape(overlayRadius: 10),
+                      activeTrackColor: AppTheme.primary,
+                      inactiveTrackColor: AppTheme.surfaceLight,
+                      thumbColor: AppTheme.primary,
+                      overlayColor: AppTheme.primary.withOpacity(0.2),
+                    ),
+                    child: Slider(
+                      value: _audioProgress.clamp(0.0, 1.0),
+                      onChanged: (v) async {
+                        final targetMs = (v * _audioDurationSeconds * 1000).toInt();
+                        await _player.seek(Duration(milliseconds: targetMs));
+                      },
                     ),
                   ),
-            ),
-            Text(
-              '0:${_audioCurrentSeconds.toString().padLeft(2, '0')}',
+                  Padding(
+                    padding: const EdgeInsets.only(left: 4),
+                    child: Text(
+                      durationStr,
                       style: const TextStyle(
-                color: AppTheme.textPrimary,
+                        color: AppTheme.textSecondary,
                         fontFamily: 'monospace',
-                fontSize: 11,
+                        fontSize: 10,
+                      ),
+                    ),
+                  ),
+                ],
               ),
             ),
           ],
@@ -362,7 +447,7 @@ class _InteractiveMediaWidgetState extends State<InteractiveMediaWidget> {
       );
     }
 
-    // Default download complete file placeholder
+    // ── Default: Document / File ───────────────────────────────────────────
     return Container(
       padding: const EdgeInsets.all(12),
       decoration: BoxDecoration(