feat: New account data wallpaper feature

lib/pages/settings_style/settings_style.dart

@@ -1,7 +1,12 @@
 import 'package:flutter/material.dart';
 
+import 'package:file_picker/file_picker.dart';
+import 'package:future_loading_dialog/future_loading_dialog.dart';
+
 import 'package:fluffychat/config/app_config.dart';
 import 'package:fluffychat/config/setting_keys.dart';
+import 'package:fluffychat/utils/account_config.dart';
+import 'package:fluffychat/widgets/app_lock.dart';
 import 'package:fluffychat/widgets/theme_builder.dart';
 import '../../widgets/matrix.dart';
 import 'settings_style_view.dart';
@@ -19,6 +24,51 @@ class SettingsStyleController extends State<SettingsStyle> {
     ThemeController.of(context).setPrimaryColor(color);
   }
 
+  void setWallpaper() async {
+    final client = Matrix.of(context).client;
+    final picked = await AppLock.of(context).pauseWhile(
+      FilePicker.platform.pickFiles(
+        type: FileType.image,
+        withData: true,
+      ),
+    );
+    final pickedFile = picked?.files.firstOrNull;
+    if (pickedFile == null) return;
+
+    await showFutureLoadingDialog(
+      context: context,
+      future: () async {
+        final url = await client.uploadContent(
+          pickedFile.bytes!,
+          filename: pickedFile.name,
+        );
+        await client.updateApplicationAccountConfig(
+          ApplicationAccountConfig(wallpaperUrl: url),
+        );
+      },
+    );
+  }
+
+  void setChatWallpaperOpacity(double opacity) {
+    final client = Matrix.of(context).client;
+    showFutureLoadingDialog(
+      context: context,
+      future: () => client.updateApplicationAccountConfig(
+        ApplicationAccountConfig(wallpaperOpacity: opacity),
+      ),
+    );
+  }
+
+  void deleteChatWallpaper() => showFutureLoadingDialog(
+        context: context,
+        future: () => Matrix.of(context).client.setApplicationAccountConfig(
+              const ApplicationAccountConfig(
+                wallpaperUrl: null,
+                wallpaperOpacity: null,
+              ),
+            ),
+      );
+
   ThemeMode get currentTheme => ThemeController.of(context).themeMode;
   Color? get currentColor => ThemeController.of(context).primaryColor;