render the avatar upload status

src/PostIt/PostIt/Services/YavscApiClient.cs

@@ -357,7 +357,7 @@ public class YavscApiClient : IYavscApiClient, IAsyncDisposable
     /// single multipart file named <c>file</c> and validates the image
     /// content type before persisting it.
     /// </summary>
-    public async Task SetAvatarAsync(
+    public async Task<string> SetAvatarAsync(
         Stream imageStream,
         string fileName,
         string? contentType = null,
@@ -400,6 +400,27 @@ public class YavscApiClient : IYavscApiClient, IAsyncDisposable
         }
 
         await EnsureSuccessOrThrowAsync(response, ct).ConfigureAwait(false);
+
+        var payload = await response.Content.ReadAsStringAsync(ct).ConfigureAwait(false);
+        if (string.IsNullOrWhiteSpace(payload))
+            return "Avatar mis à jour.";
+
+        try
+        {
+            using var json = JsonDocument.Parse(payload);
+            if (json.RootElement.TryGetProperty("message", out var msgEl))
+            {
+                var message = msgEl.GetString();
+                if (!string.IsNullOrWhiteSpace(message))
+                    return message;
+            }
+        }
+        catch (JsonException)
+        {
+            // Keep a user-friendly fallback when the API payload is not JSON.
+        }
+
+        return "Avatar mis à jour.";
     }
 
     public async Task LogoutAsync()

src/PostIt/PostIt/Views/SettingsPage.axaml

@@ -46,8 +46,18 @@
         <TextBlock Grid.Row="10" Text="Dark mode"/>
         <CheckBox Grid.Row="11" x:Name="DarkModeCheckBox" IsChecked="{Binding DarkMode, Mode=TwoWay}"/>
 
-        <StackPanel Grid.Row="12" Orientation="Horizontal" HorizontalAlignment="Right">
-            <Button Content="Choisir l'avatar"
+        <StackPanel Grid.Row="12" Spacing="8">
+            <TextBlock Text="Avatar: PNG, JPG/JPEG, WEBP, GIF. Taille max 2 MB."
+                   Opacity="0.8"
+                   TextWrapping="Wrap" />
+
+            <TextBlock x:Name="AvatarUploadStatusText"
+                       Text=""
+                       TextWrapping="Wrap" />
+
+            <StackPanel Orientation="Horizontal" HorizontalAlignment="Right">
+            <Button x:Name="ChooseAvatarButton"
+                Content="Choisir l'avatar"
                     Click="ChooseAvatar_Click"
                     Margin="0,0,8,0"/>
 
@@ -62,6 +72,7 @@
             <Button Content="Sauver"
                     Command="{Binding Save}"
                     IsEnabled="{Binding IsDirty}"/>
+                </StackPanel>
         </StackPanel>
 
     </Grid>

src/PostIt/PostIt/Views/SettingsPage.axaml.cs

@@ -3,7 +3,10 @@
 using System;
 using System.IO;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using Avalonia.Controls;
+using Avalonia.Media;
 using Avalonia.Platform.Storage;
 using Microsoft.Extensions.DependencyInjection;
 using PostIt.Services;
@@ -11,6 +14,11 @@ using PostIt.Services;
 namespace PostIt.Views;
 public partial class SettingsPage: ContentPage
 {
+    private const int MaxAvatarSizeMegabytes = 2;
+    private const string AcceptedAvatarFormats = "PNG, JPG/JPEG, WEBP, GIF";
+
+    private int _avatarStatusVersion;
+
     public SettingsPage()
     {
         InitializeComponent();
@@ -18,9 +26,15 @@ public partial class SettingsPage: ContentPage
 
     private async void ChooseAvatar_Click(object? sender, Avalonia.Interactivity.RoutedEventArgs e)
     {
+        var statusVersion = Interlocked.Increment(ref _avatarStatusVersion);
+        ChooseAvatarButton.IsEnabled = false;
+        SetAvatarStatus("Sélection d'un fichier avatar...", Brushes.Gray);
+
         var topLevel = TopLevel.GetTopLevel(this);
         if (topLevel is null)
         {
+            SetAvatarStatus("Impossible d'accéder à la fenêtre active.", Brushes.IndianRed);
+            ChooseAvatarButton.IsEnabled = true;
             return;
         }
 
@@ -40,19 +54,51 @@ public partial class SettingsPage: ContentPage
         var file = files.FirstOrDefault();
         if (file is null)
         {
+            SetAvatarStatus("Upload annulé.", Brushes.Gray);
+            ChooseAvatarButton.IsEnabled = true;
             return;
         }
 
         try
         {
+            SetAvatarStatus("Upload avatar en cours...", Brushes.Gray);
+
             await using var stream = await file.OpenReadAsync();
             var api = ((App)App.Current!).ServiceProvider!.GetRequiredService<YavscApiClient>();
-            await api.SetAvatarAsync(stream, file.Name, GetMimeType(file.Name));
+            var message = await api.SetAvatarAsync(stream, file.Name, GetMimeType(file.Name));
+            SetAvatarStatus(string.IsNullOrWhiteSpace(message)
+                ? "Avatar mis à jour."
+                : message, Brushes.ForestGreen);
+
+            _ = ClearSuccessStatusLaterAsync(statusVersion);
         }
         catch (Exception ex)
         {
+            SetAvatarStatus($"Échec upload avatar: {ex.Message}", Brushes.IndianRed);
             Console.Error.WriteLine($"🩎 Avatar upload failed: {ex.Message}");
         }
+        finally
+        {
+            ChooseAvatarButton.IsEnabled = true;
+        }
+    }
+
+    private async Task ClearSuccessStatusLaterAsync(int statusVersion)
+    {
+        await Task.Delay(TimeSpan.FromSeconds(5)).ConfigureAwait(true);
+        if (statusVersion != _avatarStatusVersion)
+            return;
+
+        if (AvatarUploadStatusText.Foreground == Brushes.ForestGreen)
+        {
+            SetAvatarStatus($"Avatar prêt. Formats supportés: {AcceptedAvatarFormats}. Taille max: {MaxAvatarSizeMegabytes} MB.", Brushes.Gray);
+        }
+    }
+
+    private void SetAvatarStatus(string message, IBrush color)
+    {
+        AvatarUploadStatusText.Foreground = color;
+        AvatarUploadStatusText.Text = message;
     }
 
     private static string GetMimeType(string fileName)