feat(server): lossy avatar thumbnails, gzip upload and separate avatar endpoints

server/src/WebDrop.Api/ApiJson.cs

@@ -165,6 +165,10 @@ public sealed class AccountProfileRequest
 {
     [JsonPropertyName("displayName")] public required string DisplayName { get; init; }
     [JsonPropertyName("avatar")] public string? Avatar { get; init; }
+    /// <summary>头像的有损小图(data URL)。列表、聊天默认只分发它,原图在预览时才下载</summary>
+    [JsonPropertyName("avatarThumb")] public string? AvatarThumb { get; init; }
+    /// <summary>只改名字、不动头像:保留服务端现有的头像(不带 avatar 的请求默认表示移除头像)</summary>
+    [JsonPropertyName("keepAvatar")] public bool KeepAvatar { get; init; }
 }
 public sealed class WorkspaceNameRequest { [JsonPropertyName("name")] public required string Name { get; init; } }
 public sealed class WorkspaceChannelRequest

server/src/WebDrop.Api/Endpoints.Accounts.cs

@@ -11,17 +11,25 @@ public static partial class Endpoints
         api.MapGet("/accounts/profile", (HttpContext ctx) =>
         {
             if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
-            return Json(accounts.Profile(username), ApiJson.Default.AccountProfile);
+            return Json(accounts.Profile(username).WithoutAvatar(), ApiJson.Default.AccountProfile);
+        });
+        // 头像单独取:默认给有损的缩略图(列表、聊天用),size=full 才是原图(预览时)。带 ETag,没变化时只回 304。需要登录账号
+        api.MapGet("/accounts/users/{username}/avatar", (string username, HttpContext ctx) =>
+        {
+            if (!TryAccount(ctx, accounts, out _)) throw new WebDropException(ErrorCode.AccountRequired);
+            var profile = accounts.Profile(NormalizeUsername(username));
+            var full = ctx.Request.Query["size"] == "full";
+            return AvatarResult(ctx, full ? profile.Avatar : profile.AvatarThumb ?? profile.Avatar, $"{profile.ModifiedAt}-{(full ? "f" : "t")}");
         });
         api.MapPatch("/accounts/profile", async (HttpContext ctx, ChannelService svc, CancellationToken ct) =>
         {
             if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
             // 动图头像比其他请求大得多,单独放宽(全局上限 2 MB)
             if (ctx.Features.Get<IHttpMaxRequestBodySizeFeature>() is { IsReadOnly: false } size) size.MaxRequestBodySize = 8 * 1024 * 1024;
-            var req = await ReadJson(ctx.Request, ApiJson.Default.AccountProfileRequest, ct);
-            var profile = accounts.UpdateProfile(username, req.DisplayName, req.Avatar);
+            var req = await ReadJsonCompressed(ctx.Request, ApiJson.Default.AccountProfileRequest, 12 * 1024 * 1024, ct);
+            var profile = accounts.UpdateProfile(username, req.DisplayName, req.Avatar, req.AvatarThumb, req.KeepAvatar);
             svc.AccountProfileChanged(username);
-            return Json(profile, ApiJson.Default.AccountProfile);
+            return Json(profile.WithoutAvatar(), ApiJson.Default.AccountProfile);
         });
         api.MapPost("/accounts", async (HttpContext ctx, CancellationToken ct) =>
         {

server/src/WebDrop.Api/Endpoints.Workspace.cs

@@ -13,7 +13,7 @@ public static partial class Endpoints
             Structure = state,
             People = state.Locations.Select(l => l.AuthorAccount).Where(u => u is not null).Select(u => u!)
                 .Concat(service.MemberAccounts(space)).Distinct(StringComparer.OrdinalIgnoreCase)
-                .Select(u => accounts.Profile(u)).ToList(),
+                .Select(u => accounts.Profile(u).WithoutAvatar()).ToList(),
         };
         api.MapGet("/spaces/{id}/structure", (string id, HttpContext ctx, ChannelService svc) =>
             Json(View(svc, ParseId(id), svc.GetWorkspace(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false))), ApiJson.Default.WorkspaceBody));

server/src/WebDrop.Api/Endpoints.cs

@@ -1,5 +1,6 @@
 using System.Buffers;
 using System.Diagnostics;
+using System.IO.Compression;
 using System.Net.WebSockets;
 using System.Security.Cryptography;
 using System.Text.Json;
@@ -75,11 +76,18 @@ public static partial class Endpoints
         {
             // 空间头像(动图)比其他设置大得多,单独放宽请求体上限
             if (ctx.Features.Get<Microsoft.AspNetCore.Http.Features.IHttpMaxRequestBodySizeFeature>() is { IsReadOnly: false } size) size.MaxRequestBodySize = 4 * 1024 * 1024;
-            var patch = await ReadJson(ctx.Request, ApiJson.Default.ChannelSettingsPatch, ct);
+            var patch = await ReadJsonCompressed(ctx.Request, ApiJson.Default.ChannelSettingsPatch, 6 * 1024 * 1024, ct);
             var info = svc.UpdateSettings(ParseId(id), RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false), patch);
             return Json(info, ApiJson.Default.ChannelInfo);
         });
 
+        // 空间头像原图(信息里只带缩略图):预览时才下载。带 ETag(内容哈希),没变时回 304
+        api.MapGet("/channels/{id}/avatar", (string id, HttpContext ctx, ChannelService svc) =>
+        {
+            var data = svc.GetChannelAvatarFull(ParseId(id), RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false));
+            return AvatarResult(ctx, data, Convert.ToHexString(SHA256.HashData(System.Text.Encoding.UTF8.GetBytes(data ?? ""))));
+        });
+
         api.MapDelete("/channels/{id}", (string id, HttpContext ctx, ChannelService svc) =>
         {
             svc.DeleteChannel(ParseId(id), RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false));
@@ -454,6 +462,41 @@ public static partial class Endpoints
         return long.TryParse(header, out long n) && n >= 0 ? n : throw new WebDropException(ErrorCode.BadRequest);
     }
 
+    /// <summary>
+    /// 读 JSON 请求体,支持 Content-Encoding: gzip(头像这类带 base64 的大请求,压缩后能省下 base64 多出来的约四分之一)。
+    /// 解压后的大小另外限制,防止小体积的压缩炸弹。
+    /// </summary>
+    private static async Task<T> ReadJsonCompressed<T>(HttpRequest req, JsonTypeInfo<T> info, int maxBytes, CancellationToken ct) where T : class
+    {
+        try
+        {
+            Stream body = req.Body;
+            if (string.Equals(req.Headers.ContentEncoding.ToString(), "gzip", StringComparison.OrdinalIgnoreCase)) body = new GZipStream(req.Body, CompressionMode.Decompress);
+            using var plain = new MemoryStream();
+            var buffer = new byte[81920]; int read;
+            while ((read = await body.ReadAsync(buffer, ct)) > 0)
+            {
+                if (plain.Length + read > maxBytes) throw new WebDropException(ErrorCode.BadRequest);
+                plain.Write(buffer, 0, read);
+            }
+            plain.Position = 0;
+            return await JsonSerializer.DeserializeAsync(plain, info, ct) ?? throw new WebDropException(ErrorCode.BadRequest);
+        }
+        catch (Exception error) when (error is JsonException or InvalidDataException) { throw new WebDropException(ErrorCode.BadRequest); }
+    }
+
+    /// <summary>data URL 头像 → 图片字节(带 ETag,没变时 304)</summary>
+    private static IResult AvatarResult(HttpContext ctx, string? data, string version)
+    {
+        if (data is null) return Results.NotFound();
+        var etag = $"\"{version}\"";
+        ctx.Response.Headers.ETag = etag;
+        ctx.Response.Headers.CacheControl = "private, no-cache";
+        if (ctx.Request.Headers.IfNoneMatch == etag) return Results.StatusCode(StatusCodes.Status304NotModified);
+        var mime = data[5..data.IndexOf(';')];
+        return Results.Bytes(Convert.FromBase64String(data[(data.IndexOf(',') + 1)..]), mime);
+    }
+
     private static async Task<T> ReadJson<T>(HttpRequest req, JsonTypeInfo<T> info, CancellationToken ct) where T : class
     {
         try