[backend/razor] Move public preview to Blazor SSR (razor components)

Iceshrimp.Backend/Components/Helpers/AsyncComponentBase.cs

@@ -0,0 +1,34 @@
+using Microsoft.AspNetCore.Components;
+
+namespace Iceshrimp.Backend.Components.Helpers;
+
+/// <summary>
+/// Overrides to allow for asynchronous actions to be performed in fully SSR pages before the page gets rendered
+/// </summary>
+public class AsyncComponentBase : ComponentBase
+{
+	private bool _initialized;
+
+	public override Task SetParametersAsync(ParameterView parameters)
+	{
+		parameters.SetParameterProperties(this);
+		if (_initialized) return CallOnParametersSetAsync();
+		_initialized = true;
+
+		return RunInitAndSetParametersAsync();
+	}
+
+	private async Task RunInitAndSetParametersAsync()
+	{
+		OnInitialized();
+		await OnInitializedAsync();
+		await CallOnParametersSetAsync();
+	}
+
+	private async Task CallOnParametersSetAsync()
+	{
+		OnParametersSet();
+		await OnParametersSetAsync();
+		StateHasChanged();
+	}
+}

Iceshrimp.Backend/Components/PublicPreview/Attributes/PublicPreviewRouteFilter.cs

@@ -0,0 +1,42 @@
+using AngleSharp.Io;
+using Microsoft.AspNetCore.Routing.Matching;
+
+namespace Iceshrimp.Backend.Components.PublicPreview.Attributes;
+
+public class PublicPreviewRouteMatcher : MatcherPolicy, IEndpointSelectorPolicy
+{
+	public override int Order => 99999; // That's ActionConstraintMatcherPolicy - 1
+
+	public bool AppliesToEndpoints(IReadOnlyList<Endpoint> endpoints)
+	{
+		return endpoints.Any(p => p.Metadata.GetMetadata<PublicPreviewRouteFilterAttribute>() != null);
+	}
+
+	public Task ApplyAsync(HttpContext ctx, CandidateSet candidates)
+	{
+		var applies = Enumerate(candidates)
+			.Any(p => p.Score >= 0 && p.Endpoint.Metadata.GetMetadata<PublicPreviewRouteFilterAttribute>() != null);
+		if (!applies) return Task.CompletedTask;
+
+		// Add Vary: Accept to the response headers to prevent caches serving the wrong response
+		ctx.Response.Headers.Append(HeaderNames.Vary, HeaderNames.Cookie);
+
+		var hasCookie = ctx.Request.Cookies.ContainsKey("sessions");
+		for (var i = 0; i < candidates.Count; i++)
+		{
+			var candidate = candidates[i];
+			var hasAttr   = candidate.Endpoint.Metadata.GetMetadata<PublicPreviewRouteFilterAttribute>() != null;
+			candidates.SetValidity(i, !hasCookie || !hasAttr);
+		}
+
+		return Task.CompletedTask;
+	}
+
+	private static IEnumerable<CandidateState> Enumerate(CandidateSet candidates)
+	{
+		for (var i = 0; i < candidates.Count; i++) yield return candidates[i];
+	}
+}
+
+[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method)]
+public class PublicPreviewRouteFilterAttribute : Attribute;

Iceshrimp.Backend/Components/PublicPreview/NoteComponent.razor

@@ -0,0 +1,34 @@
+@using Iceshrimp.Backend.Components.PublicPreview.Schemas
+
+
+<UserComponent User="Note.User" Link="true"/>
+
+<!-- TODO: figure out a better place to put this
+<small>Published at: @Note.CreatedAt</small>
+@if (Note.UpdatedAt != null)
+{
+    <br/>
+    <small>Edited at: @Note.UpdatedAt</small>
+}
+-->
+
+<div class="content">
+    @if (Note.Text != null)
+    {
+        if (Note.Cw != null)
+        {
+            <details>
+                <summary>@Note.Cw</summary>
+                @Note.Text
+            </details>
+        }
+        else
+        {
+            @Note.Text
+        }
+    }
+</div>
+
+@code {
+    [Parameter, EditorRequired] public required PreviewNote Note { get; set; }
+}

Iceshrimp.Backend/Components/PublicPreview/NoteComponent.razor.css

@@ -0,0 +1,11 @@
+.content {
+    display: flex;
+    flex-direction: column;
+    align-items: flex-start;
+    background-color: #f7f7f7;
+    background-color: var(--background-alt);
+    padding: 10px;
+    margin: 1em 0;
+    border-radius: 6px;
+    overflow: hidden;
+}

Iceshrimp.Backend/Components/PublicPreview/Renderers/MfmRenderer.cs

@@ -0,0 +1,23 @@
+using Iceshrimp.Backend.Core.Configuration;
+using Iceshrimp.Backend.Core.Database.Tables;
+using Iceshrimp.Backend.Core.Helpers.LibMfm.Conversion;
+using Iceshrimp.Parsing;
+using Microsoft.AspNetCore.Components;
+using Microsoft.Extensions.Options;
+
+namespace Iceshrimp.Backend.Components.PublicPreview.Renderers;
+
+public class MfmRenderer(IOptions<Config.InstanceSection> config)
+{
+	private readonly MfmConverter _converter = new(config);
+
+	public async Task<MarkupString?> Render(
+		string? text, string? host, List<Note.MentionedUser> mentions, List<Emoji> emoji, string rootElement
+	)
+	{
+		if (text is null) return null;
+		var parsed     = Mfm.parse(text);
+		var serialized = await _converter.ToHtmlAsync(parsed, mentions, host, emoji: emoji, rootElement: rootElement);
+		return new MarkupString(serialized);
+	}
+}

Iceshrimp.Backend/Components/PublicPreview/Renderers/NoteRenderer.cs

@@ -0,0 +1,118 @@
+using Iceshrimp.Backend.Components.PublicPreview.Schemas;
+using Iceshrimp.Backend.Core.Configuration;
+using Iceshrimp.Backend.Core.Database;
+using Iceshrimp.Backend.Core.Database.Tables;
+using Iceshrimp.Backend.Core.Extensions;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Options;
+
+namespace Iceshrimp.Backend.Components.PublicPreview.Renderers;
+
+public class NoteRenderer(
+	DatabaseContext db,
+	UserRenderer userRenderer,
+	MfmRenderer mfm,
+	IOptions<Config.InstanceSection> instance,
+	IOptionsSnapshot<Config.SecuritySection> security
+)
+{
+	public async Task<PreviewNote?> RenderOne(Note? note)
+	{
+		if (note == null) return null;
+
+		var allNotes = ((Note?[]) [note, note.Reply, note.Renote]).NotNull().ToList();
+
+		var mentions    = await GetMentions(allNotes);
+		var emoji       = await GetEmoji(allNotes);
+		var users       = await GetUsers(allNotes);
+		var attachments = await GetAttachments(allNotes);
+
+		return await Render(note, users, mentions, emoji, attachments);
+	}
+
+	private async Task<PreviewNote> Render(
+		Note note, List<PreviewUser> users, Dictionary<string, List<Note.MentionedUser>> mentions,
+		Dictionary<string, List<Emoji>> emoji, Dictionary<string, List<PreviewAttachment>?> attachments
+	)
+	{
+		var res = new PreviewNote
+		{
+			User              = users.First(p => p.Id == note.User.Id),
+			Text              = await mfm.Render(note.Text, note.User.Host, mentions[note.Id], emoji[note.Id], "span"),
+			Cw                = note.Cw,
+			RawText           = note.Text,
+			QuoteUrl          = note.Renote?.Url ?? note.Renote?.Uri ?? note.Renote?.GetPublicUriOrNull(instance.Value),
+			QuoteInaccessible = note.Renote?.VisibilityIsPublicOrHome == false,
+			Attachments       = attachments[note.Id],
+			CreatedAt         = note.CreatedAt.ToDisplayStringTz(),
+			UpdatedAt         = note.UpdatedAt?.ToDisplayStringTz()
+		};
+
+		return res;
+	}
+
+	private async Task<Dictionary<string, List<Note.MentionedUser>>> GetMentions(List<Note> notes)
+	{
+		var mentions = notes.SelectMany(n => n.Mentions).Distinct().ToList();
+		if (mentions.Count == 0) return notes.ToDictionary<Note, string, List<Note.MentionedUser>>(p => p.Id, _ => []);
+
+		var users = await db.Users.Where(p => mentions.Contains(p.Id))
+		                    .ToDictionaryAsync(p => p.Id,
+		                                       p => new Note.MentionedUser
+		                                       {
+			                                       Host     = p.Host,
+			                                       Uri      = p.Uri ?? p.GetPublicUri(instance.Value),
+			                                       Url      = p.UserProfile?.Url,
+			                                       Username = p.Username
+		                                       });
+		return notes.ToDictionary(p => p.Id,
+		                          p => users.Where(u => p.Mentions.Contains(u.Key)).Select(u => u.Value).ToList());
+	}
+
+	private async Task<Dictionary<string, List<Emoji>>> GetEmoji(List<Note> notes)
+	{
+		var ids = notes.SelectMany(n => n.Emojis).Distinct().ToList();
+		if (ids.Count == 0) return notes.ToDictionary<Note, string, List<Emoji>>(p => p.Id, _ => []);
+
+		var emoji = await db.Emojis.Where(p => ids.Contains(p.Id)).ToListAsync();
+		return notes.ToDictionary(p => p.Id, p => emoji.Where(e => p.Emojis.Contains(e.Id)).ToList());
+	}
+
+	private async Task<List<PreviewUser>> GetUsers(List<Note> notes)
+	{
+		if (notes is []) return [];
+		return await userRenderer.RenderMany(notes.Select(p => p.User).Distinct().ToList());
+	}
+
+	private async Task<Dictionary<string, List<PreviewAttachment>?>> GetAttachments(List<Note> notes)
+	{
+		if (security.Value.PublicPreview is Enums.PublicPreview.RestrictedNoMedia)
+			return notes.ToDictionary<Note, string, List<PreviewAttachment>?>(p => p.Id,
+			                                                                  p => p.FileIds is [] ? null : []);
+
+		var ids   = notes.SelectMany(p => p.FileIds).ToList();
+		var files = await db.DriveFiles.Where(p => ids.Contains(p.Id)).ToListAsync();
+		return notes.ToDictionary<Note, string, List<PreviewAttachment>?>(p => p.Id,
+		                                                                  p => files
+		                                                                       .Where(f => p.FileIds.Contains(f.Id))
+		                                                                       .Select(f => new PreviewAttachment
+		                                                                       {
+			                                                                       MimeType = f.Type,
+			                                                                       Url      = f.AccessUrl,
+			                                                                       Name     = f.Name,
+			                                                                       Alt      = f.Comment
+		                                                                       })
+		                                                                       .ToList());
+	}
+
+	public async Task<List<PreviewNote>> RenderMany(List<Note> notes)
+	{
+		if (notes is []) return [];
+		var allNotes    = notes.SelectMany<Note, Note?>(p => [p, p.Renote, p.Reply]).NotNull().Distinct().ToList();
+		var users       = await GetUsers(allNotes);
+		var mentions    = await GetMentions(allNotes);
+		var emoji       = await GetEmoji(allNotes);
+		var attachments = await GetAttachments(allNotes);
+		return await notes.Select(p => Render(p, users, mentions, emoji, attachments)).AwaitAllAsync().ToListAsync();
+	}
+}

Iceshrimp.Backend/Components/PublicPreview/Renderers/UserRenderer.cs

@@ -0,0 +1,68 @@
+using Iceshrimp.Backend.Components.PublicPreview.Schemas;
+using Iceshrimp.Backend.Core.Configuration;
+using Iceshrimp.Backend.Core.Database;
+using Iceshrimp.Backend.Core.Database.Tables;
+using Iceshrimp.Backend.Core.Extensions;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Options;
+
+namespace Iceshrimp.Backend.Components.PublicPreview.Renderers;
+
+public class UserRenderer(
+	DatabaseContext db,
+	MfmRenderer mfm,
+	IOptions<Config.InstanceSection> instance,
+	IOptionsSnapshot<Config.SecuritySection> security
+)
+{
+	public async Task<PreviewUser?> RenderOne(User? user)
+	{
+		if (user == null) return null;
+		var emoji = await GetEmoji([user]);
+		return await Render(user, emoji);
+	}
+
+	private async Task<PreviewUser> Render(User user, Dictionary<string, List<Emoji>> emoji)
+	{
+		var mentions = user.UserProfile?.Mentions ?? [];
+
+		// @formatter:off
+		var res = new PreviewUser
+		{
+			Id             = user.Id,
+			Username       = user.Username,
+			Host           = user.Host ?? instance.Value.AccountDomain,
+			Url            = user.UserProfile?.Url ?? user.Uri ?? user.PublicUrlPath,
+			AvatarUrl      = user.AvatarUrl ?? user.IdenticonUrlPath,
+			BannerUrl      = user.BannerUrl,
+			RawDisplayName = user.DisplayName,
+			DisplayName    = await mfm.Render(user.DisplayName, user.Host, mentions, emoji[user.Id], "span"),
+			Bio            = await mfm.Render(user.UserProfile?.Description, user.Host, mentions, emoji[user.Id], "span"),
+			MovedToUri     = user.MovedToUri
+		};
+		// @formatter:on
+
+		if (security.Value.PublicPreview is Enums.PublicPreview.RestrictedNoMedia)
+		{
+			res.AvatarUrl = user.IdenticonUrlPath;
+			res.BannerUrl = null;
+		}
+
+		return res;
+	}
+
+	private async Task<Dictionary<string, List<Emoji>>> GetEmoji(List<User> users)
+	{
+		var ids = users.SelectMany(n => n.Emojis).Distinct().ToList();
+		if (ids.Count == 0) return users.ToDictionary<User, string, List<Emoji>>(p => p.Id, _ => []);
+
+		var emoji = await db.Emojis.Where(p => ids.Contains(p.Id)).ToListAsync();
+		return users.ToDictionary(p => p.Id, p => emoji.Where(e => p.Emojis.Contains(e.Id)).ToList());
+	}
+
+	public async Task<List<PreviewUser>> RenderMany(List<User> users)
+	{
+		var emoji = await GetEmoji(users);
+		return await users.Select(p => Render(p, emoji)).AwaitAllAsync().ToListAsync();
+	}
+}

Iceshrimp.Backend/Components/PublicPreview/Schemas/PreviewNote.cs

@@ -0,0 +1,24 @@
+using Microsoft.AspNetCore.Components;
+
+namespace Iceshrimp.Backend.Components.PublicPreview.Schemas;
+
+public class PreviewNote
+{
+	public required PreviewUser              User;
+	public required string?                  RawText;
+	public required MarkupString?            Text;
+	public required string?                  Cw;
+	public required string?                  QuoteUrl;
+	public required bool                     QuoteInaccessible;
+	public required List<PreviewAttachment>? Attachments;
+	public required string                   CreatedAt;
+	public required string?                  UpdatedAt;
+}
+
+public class PreviewAttachment
+{
+	public required string  MimeType;
+	public required string  Url;
+	public required string  Name;
+	public required string? Alt;
+}

Iceshrimp.Backend/Components/PublicPreview/Schemas/PreviewUser.cs

@@ -0,0 +1,17 @@
+using Microsoft.AspNetCore.Components;
+
+namespace Iceshrimp.Backend.Components.PublicPreview.Schemas;
+
+public class PreviewUser
+{
+	public required string        Id;
+	public required string?       RawDisplayName;
+	public required MarkupString? DisplayName;
+	public required MarkupString? Bio;
+	public required string        Username;
+	public required string        Host;
+	public required string        Url;
+	public required string        AvatarUrl;
+	public required string?       BannerUrl;
+	public required string?       MovedToUri;
+}

Iceshrimp.Backend/Components/PublicPreview/UserComponent.razor

@@ -0,0 +1,32 @@
+@using Iceshrimp.Backend.Components.PublicPreview.Schemas
+
+@if (Link)
+{
+    <div class="user">
+        <a href="@User.Url">
+            <img src="@User.AvatarUrl" class="avatar" alt="User avatar"/>
+        </a>
+        <div class="title">
+            <a class="display-name" href="@User.Url">
+                @if (User.DisplayName != null)
+                {
+                    @User.DisplayName
+                }
+                else
+                {
+                    @User.Username
+                }
+            </a>
+        </div>
+        <span class="acct">@@@User.Username<span class="host">@@@User.Host</span></span>
+    </div>
+}
+else
+{
+    <img src="@User.AvatarUrl" class="avatar" alt="User avatar"/>
+}
+
+@code {
+    [Parameter, EditorRequired] public required PreviewUser User   { get; set; }
+    [Parameter]                 public          bool        Link   { get; set; } = true;
+}

Iceshrimp.Backend/Components/PublicPreview/UserComponent.razor.css

@@ -1,15 +1,3 @@
-.content {
-    display: flex;
-    flex-direction: column;
-    align-items: flex-start;
-    background-color: #f7f7f7;
-    background-color: var(--background-alt);
-    padding: 10px;
-    margin: 1em 0;
-    border-radius: 6px;
-    overflow: hidden;
-}
-
 .user {
     display: grid;
     grid-template-columns: repeat(auto-fill, minmax(3em, 3em));
@@ -45,4 +33,8 @@
 
 .display-name {
     color: var(--text-bright);
+}
+
+.host {
+    color: var(--text-dim);
 }

Iceshrimp.Backend/Components/RootComponent.razor

@@ -0,0 +1,38 @@
+@using System.Text.Encodings.Web
+@using Iceshrimp.Backend.Core.Configuration
+@using Iceshrimp.Backend.Core.Middleware
+@using Microsoft.Extensions.Options
+@using Microsoft.AspNetCore.Components.Routing
+@using Microsoft.AspNetCore.Components.Web
+@inject IOptions<Config.InstanceSection> Instance
+@preservewhitespace true
+@attribute [RazorSsr]
+<!DOCTYPE html>
+<html lang="en">
+<!--suppress HtmlRequiredTitleElement, Justification: HeadOutlet -->
+<head>
+    <meta charset="utf-8"/>
+    <link rel="stylesheet" href="/Iceshrimp.Backend.styles.css"/>
+    <link rel="stylesheet" href="/css/default.css"/>
+    <link rel="icon" type="image/png" href="/favicon.png"/>
+    <HeadOutlet/>
+    <PageTitle>Iceshrimp.NET</PageTitle>
+</head>
+<body>
+<Router AppAssembly="@typeof(RootComponent).Assembly">
+    <Found Context="routeData">
+        <RouteView RouteData="@routeData"/>
+    </Found>
+</Router>
+<footer>
+    <strong>Iceshrimp.NET</strong> v@(Instance.Value.Version)
+    <span class="float-right">
+        <a href="/login?rd=@UrlEncoder.Default.Encode(Context.Request.Path)">Login</a>
+    </span>
+</footer>
+</body>
+</html>
+
+@code {
+    [CascadingParameter] public required HttpContext Context { get; set; }
+}

Iceshrimp.Backend/Components/RootComponent.razor.css

@@ -0,0 +1,3 @@
+.float-right {
+    float: right;
+}

Iceshrimp.Backend/Core/Database/Tables/User.cs

@@ -624,9 +624,11 @@ public class User : IEntity
 		: throw new Exception("Cannot access PublicUri for remote user");
 
 	public string GetPublicUrl(string webDomain) => Host == null
-		? $"https://{webDomain}/@{Username}"
+		? $"https://{webDomain}{PublicUrlPath}"
 		: throw new Exception("Cannot access PublicUrl for remote user");
 
+	[Projectable] public string PublicUrlPath => $"/@{Username}";
+
 	public string GetIdenticonUrl(string webDomain) => $"https://{webDomain}{IdenticonUrlPath}";
 }
 

Iceshrimp.Backend/Core/Extensions/MvcBuilderExtensions.cs

@@ -101,11 +101,6 @@ public static class MvcBuilderExtensions
 
 		return builder;
 	}
-
-	public static IMvcBuilder AddRouteOverrides(this IMvcBuilder builder)
-	{
-		return builder.AddRazorPagesOptions(o => { o.Conventions.AddPageRoute("/User", "@{user}@{host}"); });
-	}
 }
 
 /// <summary>

Iceshrimp.Backend/Core/Extensions/ServiceExtensions.cs

@@ -1,6 +1,8 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Threading.RateLimiting;
 using System.Xml.Linq;
+using Iceshrimp.Backend.Components.PublicPreview.Attributes;
+using Iceshrimp.Backend.Components.PublicPreview.Renderers;
 using Iceshrimp.Backend.Controllers.Federation;
 using Iceshrimp.Backend.Controllers.Mastodon.Renderers;
 using Iceshrimp.Backend.Controllers.Web.Renderers;
@@ -83,7 +85,9 @@ public static class ServiceExtensions
 			.AddScoped<CacheService>()
 			.AddScoped<MetaService>()
 			.AddScoped<StorageMaintenanceService>()
-			.AddScoped<RelayService>();
+			.AddScoped<RelayService>()
+			.AddScoped<Components.PublicPreview.Renderers.UserRenderer>()
+			.AddScoped<Components.PublicPreview.Renderers.NoteRenderer>();
 
 		// Singleton = instantiated once across application lifetime
 		services
@@ -101,7 +105,10 @@ public static class ServiceExtensions
 			.AddSingleton<PushService>()
 			.AddSingleton<StreamingService>()
 			.AddSingleton<ImageProcessor>()
-			.AddSingleton<RazorViewRenderService>();
+			.AddSingleton<RazorViewRenderService>()
+			.AddSingleton<StripRazorJsInitMiddleware>()
+			.AddSingleton<MfmRenderer>()
+			.AddSingleton<MatcherPolicy, PublicPreviewRouteMatcher>();
 
 		var config = configuration.GetSection("Storage").Get<Config.StorageSection>() ??
 		             throw new Exception("Failed to read storage config section");

Iceshrimp.Backend/Core/Extensions/StringExtensions.cs

@@ -19,6 +19,12 @@ public static class StringExtensions
 	{
 		return target[..Math.Min(target.Length, maxLength)];
 	}
+	
+	public static string TruncateEllipsis(this string target, int maxLength)
+	{
+		if (target.Length <= maxLength) return target;
+		return target[..(maxLength-3)] + "...";
+	}
 
 	private static string ToPunycode(this string target)
 	{

Iceshrimp.Backend/Core/Extensions/WebApplicationExtensions.cs

@@ -27,7 +27,8 @@ public static class WebApplicationExtensions
 		          .UseMiddleware<AuthorizationMiddleware>()
 		          .UseMiddleware<FederationSemaphoreMiddleware>()
 		          .UseMiddleware<AuthorizedFetchMiddleware>()
-		          .UseMiddleware<InboxValidationMiddleware>();
+		          .UseMiddleware<InboxValidationMiddleware>()
+		          .UseMiddleware<StripRazorJsInitMiddleware>();
 	}
 
 	public static IApplicationBuilder UseSwaggerWithOptions(this WebApplication app)

Iceshrimp.Backend/Core/Helpers/LibMfm/Conversion/MfmConverter.cs

@@ -60,13 +60,13 @@ public class MfmConverter(IOptions<Config.InstanceSection> config)
 
 	public async Task<string> ToHtmlAsync(
 		IEnumerable<MfmNode> nodes, List<Note.MentionedUser> mentions, string? host, string? quoteUri = null,
-		bool quoteInaccessible = false, bool replyInaccessible = false, bool divAsRoot = false,
+		bool quoteInaccessible = false, bool replyInaccessible = false, string rootElement = "p",
 		List<Emoji>? emoji = null
 	)
 	{
 		var context    = BrowsingContext.New();
 		var document   = await context.OpenNewAsync();
-		var element    = document.CreateElement(divAsRoot ? "div" : "p");
+		var element    = document.CreateElement(rootElement);
 		var nodeList   = nodes.ToList();
 		var hasContent = nodeList.Count > 0;
 
@@ -131,13 +131,13 @@ public class MfmConverter(IOptions<Config.InstanceSection> config)
 
 	public async Task<string> ToHtmlAsync(
 		string mfm, List<Note.MentionedUser> mentions, string? host, string? quoteUri = null,
-		bool quoteInaccessible = false, bool replyInaccessible = false, bool divAsRoot = false,
+		bool quoteInaccessible = false, bool replyInaccessible = false, string rootElement = "p",
 		List<Emoji>? emoji = null
 	)
 	{
 		var nodes = MfmParser.Parse(mfm);
 		return await ToHtmlAsync(nodes, mentions, host, quoteUri, quoteInaccessible,
-		                         replyInaccessible, divAsRoot, emoji);
+		                         replyInaccessible, rootElement, emoji);
 	}
 
 	private INode FromMfmNode(

Iceshrimp.Backend/Core/Middleware/ErrorHandlerMiddleware.cs

@@ -131,7 +131,6 @@ public class ErrorHandlerMiddleware(
 				};
 
 				await WriteResponse(error);
-				//TODO: use the overload that takes an exception instead of printing it ourselves
 				logger.LogError("Request encountered an unexpected error: {exception}", e);
 			}
 
@@ -167,7 +166,7 @@ public class ErrorHandlerMiddleware(
 					{
 						var model = new ErrorPageModel(payload);
 						ctx.Response.ContentType = "text/html; charset=utf8";
-						var stream = ctx.Response.BodyWriter.AsStream();
+						var stream = ctx.Response.Body;
 						await razor.RenderToStreamAsync("Shared/ErrorPage.cshtml", model, stream);
 						return;
 					}

Iceshrimp.Backend/Core/Middleware/StripRazorJsInitMiddleware.cs

@@ -0,0 +1,50 @@
+using System.Reflection;
+using Microsoft.AspNetCore.Components.Endpoints;
+
+namespace Iceshrimp.Backend.Core.Middleware;
+
+public class StripRazorJsInitMiddleware : IMiddleware
+{
+	private static readonly byte[] Magic = "<!--Blazor-Web-Initializers"u8.ToArray();
+
+	public async Task InvokeAsync(HttpContext context, RequestDelegate next)
+	{
+		var attribute = context.GetEndpoint()
+		                       ?.Metadata.GetMetadata<RootComponentMetadata>()
+		                       ?.Type.GetCustomAttributes<RazorSsrAttribute>()
+		                       .FirstOrDefault();
+
+		if (attribute == null)
+		{
+			await next(context);
+			return;
+		}
+
+		var body   = context.Response.Body;
+		var stream = new MemoryStream();
+		context.Response.Body = stream;
+
+		try
+		{
+			await next(context);
+
+			stream.Seek(0, SeekOrigin.Begin);
+			if (stream.TryGetBuffer(out var buffer))
+			{
+				var index = buffer.AsSpan().IndexOf(Magic);
+				if (index != -1)
+					stream.SetLength(index);
+			}
+
+			context.Response.Headers.ContentLength = stream.Length;
+			await stream.CopyToAsync(body);
+		}
+		finally
+		{
+			// Revert body stream
+			context.Response.Body = body;
+		}
+	}
+}
+
+public class RazorSsrAttribute : Attribute;

Iceshrimp.Backend/Pages/Index.cshtml.cs

@@ -15,7 +15,7 @@ public class IndexModel(MetaService meta, IOptionsSnapshot<Config.InstanceSectio
 
 	public async Task<IActionResult> OnGet()
 	{
-		if (Request.Cookies.ContainsKey("session") || Request.Cookies.ContainsKey("sessions"))
+		if (Request.Cookies.ContainsKey("sessions"))
 			return Partial("Shared/FrontendSPA");
 
 		if (config.Value.RedirectIndexTo is { } dest)

Iceshrimp.Backend/Pages/Note.cshtml

@@ -1,171 +0,0 @@
-@page "/notes/{id}"
-@using AngleSharp
-@using Iceshrimp.Backend.Core.Database.Tables
-@using Iceshrimp.Backend.Core.Extensions
-@model NoteModel
-
-@section styles
-{
-    <link rel="stylesheet" href="~/css/public-preview.css"/>
-}
-
-@if (Model.Note == null)
-{
-    Response.StatusCode = 404;
-    <div>
-        <h2>Not found</h2>
-        <p>This note either doesn't exist or is only accessible to authenticated users</p>
-    </div>
-}
-else
-{
-    async Task RenderNote(string name, Note note)
-    {
-        Model.TextContent.TryGetValue(note.Id, out var textContent);
-        var acct        = "@" + note.User.Username + (note.User.IsLocalUser ? "" : "@" + note.User.Host);
-        var displayName = await RenderDisplayName(note.User.DisplayName ?? note.User.Username);
-        var url         = note.User.UserProfile?.Url ?? note.User.Uri ?? note.User.GetPublicUrl(Model.WebDomain);
-        var avatarUrl   = note.User.AvatarUrl == null || !Model.ShowMedia ? note.User.IdenticonUrlPath : note.User.AvatarUrl;
-
-        <div class="user">
-            <a href="@url">
-                <img src="@avatarUrl" class="avatar" alt="User avatar"/>
-            </a>
-            <div class="title">@name by <a class="display-name" href="@url">@Html.Raw(displayName)</a></div>
-            <span class="acct">@acct</span>
-        </div>
-        <small>Published at: @note.CreatedAt.ToDisplayString()</small>
-        @if (note.UpdatedAt != null)
-        {
-            <small>Edited at: @note.UpdatedAt.Value.ToDisplayString()</small>
-        }
-
-        if (textContent != null)
-        {
-            <div class="content-wrapper">
-                @if (note.Cw != null)
-                {
-                    <details>
-                        <summary>@note.Cw</summary>
-                        @Html.Raw(textContent)
-                    </details>
-                }
-                else
-                {
-                    <div class="content">@Html.Raw(textContent)</div>
-                }
-            </div>
-        }
-
-        if (!Model.MediaAttachments.TryGetValue(note.Id, out var files)) return;
-
-        if (!Model.ShowMedia)
-        {
-            <p>
-                <i>This post has attachments, but this server's configuration prevents them from being displayed here.</i>
-            </p>
-            return;
-        }
-
-        @foreach (var file in files)
-        {
-            if (file.Type.StartsWith("image/"))
-            {
-                <img src="@file.Url" max-width="200px" alt="@file.Comment"/>
-            }
-            else if (file.Type.StartsWith("video/"))
-            {
-                <video controls max-width="200px">
-                    <source src="@file.Url" type="@file.Type"/>
-                    <p>@(file.Comment ?? "No alt text.")</p>
-                </video>
-            }
-            else
-            {
-                <div>Attachment: <a href="@file.Url">@file.Name</a> (@file.Type)</div>
-            }
-        }
-
-        return;
-
-        async Task<string> RenderDisplayName(string input)
-        {
-            var res    = Html.Encode(input);
-            var emojis = Model.UserEmoji[note.User.Id];
-            if (emojis is []) return res;
-
-            var context  = BrowsingContext.New();
-            var document = await context.OpenNewAsync();
-            foreach (var emoji in emojis)
-            {
-                var el    = document.CreateElement("span");
-                var inner = document.CreateElement("img");
-                inner.SetAttribute("src", emoji.PublicUrl);
-                el.AppendChild(inner);
-                el.ClassList.Add("emoji");
-                res = res.Replace($":{emoji.Name.Trim(':')}:", el.OuterHtml);
-            }
-
-            return res;
-        }
-    }
-
-    async Task RenderQuoteUrl(string url)
-    {
-        var displayUrl = url.StartsWith("https://") ? url[8..] : url[7..];
-        <p>
-            <i>This post is quoting <a href="@url">@displayUrl</a>, but that post either has been deleted or is not publicly visible.</i>
-        </p>
-    }
-
-    ViewData["title"] = $"Note by @{Model.Note.User.Username} - {Model.InstanceName}";
-    @section head
-    {
-        @{
-            Model.MediaAttachments.TryGetValue(Model.Note.Id, out var attachments);
-        }
-        <meta name="twitter:card" content="summary">
-        <meta name="og:title" content="Note by @@@Model.Note.User.Username">
-        @if (Model.Note.Cw != null)
-        {
-            <meta name="og:description" content="Content warning: @Model.Note.Cw)">
-        }
-        else
-        {
-            var text = Model.Note.Text;
-            if (attachments is { Count: > 0 })
-            {
-                var attachmentText = $"({attachments.Count} attachments)";
-                if (string.IsNullOrWhiteSpace(text))
-                    text = attachmentText;
-                else
-                    text += $"\n{attachmentText}";
-            }
-
-            <meta name="og:description" content="@(text + (Model.QuoteUrl != null ? $"\n\nRE: {Model.QuoteUrl}" : ""))">
-        }
-        <meta name="og:site_name" content="@Model.InstanceName">
-        @if (Model.ShowMedia && attachments != null)
-        {
-            if (attachments.Any(p => p.Type.StartsWith("image/")))
-            {
-                <meta name="og:image" content="@attachments.First(p => p.Type.StartsWith("image/")).Url">
-            }
-        }
-    }
-    <div class="note">
-        @{
-            await RenderNote("Note", Model.Note);
-            if (Model.Note.Renote != null)
-                await RenderNote("Quote", Model.Note.Renote);
-            else if (Model.QuoteUrl != null)
-                await RenderQuoteUrl(Model.QuoteUrl);
-        }
-    </div>
-    if (!Model.ShowRemoteReplies)
-    {
-        <p>
-            <i>This server's configuration is preventing remotely originating content from being shown. This view may therefore be incomplete.</i>
-        </p>
-    }
-}

Iceshrimp.Backend/Pages/Note.cshtml.cs

@@ -1,133 +0,0 @@
-using System.Diagnostics.CodeAnalysis;
-using Iceshrimp.Backend.Core.Configuration;
-using Iceshrimp.Backend.Core.Database;
-using Iceshrimp.Backend.Core.Database.Tables;
-using Iceshrimp.Backend.Core.Extensions;
-using Iceshrimp.Backend.Core.Helpers.LibMfm.Conversion;
-using Iceshrimp.Backend.Core.Middleware;
-using Iceshrimp.Backend.Core.Services;
-using Microsoft.AspNetCore.Mvc;
-using Microsoft.AspNetCore.Mvc.RazorPages;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Options;
-
-namespace Iceshrimp.Backend.Pages;
-
-public class NoteModel(
-	DatabaseContext db,
-	IOptions<Config.InstanceSection> config,
-	IOptions<Config.SecuritySection> security,
-	MetaService meta,
-	MfmConverter mfmConverter
-) : PageModel
-{
-	public Dictionary<string, List<DriveFile>> MediaAttachments = new();
-	public Note? Note;
-	public string? QuoteUrl;
-	public bool ShowMedia = security.Value.PublicPreview > Enums.PublicPreview.RestrictedNoMedia;
-	public bool ShowRemoteReplies = security.Value.PublicPreview > Enums.PublicPreview.Restricted;
-	public string InstanceName = "Iceshrimp.NET";
-	public string WebDomain = config.Value.WebDomain;
-
-	public Dictionary<string, string>      TextContent = new();
-	public Dictionary<string, List<Emoji>> UserEmoji   = new();
-
-	[SuppressMessage("ReSharper", "EntityFramework.NPlusOne.IncompleteDataQuery",
-	                 Justification = "IncludeCommonProperties")]
-	[SuppressMessage("ReSharper", "EntityFramework.NPlusOne.IncompleteDataUsage", Justification = "Same as above")]
-	public async Task<IActionResult> OnGet(string id)
-	{
-		if (Request.Cookies.ContainsKey("session") || Request.Cookies.ContainsKey("sessions"))
-			return Partial("Shared/FrontendSPA");
-
-		if (security.Value.PublicPreview == Enums.PublicPreview.Lockdown)
-			throw new PublicPreviewDisabledException();
-
-		InstanceName = await meta.Get(MetaEntity.InstanceName) ?? InstanceName;
-
-		//TODO: thread view (respect public preview settings - don't show remote replies if set to restricted or lower)
-
-		Note = await db.Notes
-		               .IncludeCommonProperties()
-		               .Where(p => p.Id == id && p.VisibilityIsPublicOrHome)
-		               .PrecomputeVisibilities(null)
-		               .FirstOrDefaultAsync();
-
-		QuoteUrl = Note?.Renote?.Url ?? Note?.Renote?.Uri ?? Note?.Renote?.GetPublicUriOrNull(config.Value);
-		Note     = Note?.EnforceRenoteReplyVisibility();
-
-		if (Note != null)
-		{
-			MediaAttachments[Note.Id] = await GetAttachments(Note);
-			UserEmoji[Note.User.Id]   = await GetEmoji(Note.User);
-		}
-
-		if (Note?.Renote != null)
-		{
-			MediaAttachments[Note.Renote.Id] = await GetAttachments(Note.Renote);
-			UserEmoji[Note.Renote.User.Id]   = await GetEmoji(Note.User);
-		}
-
-		if (Note is { IsPureRenote: true })
-			return RedirectPermanent(Note.Renote?.Url ??
-			                         Note.Renote?.Uri ??
-			                         Note.Renote?.GetPublicUriOrNull(config.Value) ??
-			                         throw new Exception("Note is remote but has no uri"));
-
-		if (Note is { UserHost: not null })
-			return RedirectPermanent(Note.Url ?? Note.Uri ?? throw new Exception("Note is remote but has no uri"));
-
-		if (Note is { Text: not null })
-		{
-			TextContent[Note.Id] = await mfmConverter.ToHtmlAsync(Note.Text, await GetMentions(Note), Note.UserHost,
-			                                                      divAsRoot: true, emoji: await GetEmoji(Note));
-		}
-
-		if (Note?.Renote is { Text: not null })
-		{
-			TextContent[Note.Renote.Id] = await mfmConverter.ToHtmlAsync(Note.Renote.Text!,
-			                                                             await GetMentions(Note.Renote),
-			                                                             Note.Renote.UserHost,
-			                                                             divAsRoot: true,
-			                                                             emoji: await GetEmoji(Note));
-		}
-
-		return Page();
-	}
-
-	private async Task<List<DriveFile>> GetAttachments(Note? note)
-	{
-		if (note == null || note.FileIds.Count == 0) return [];
-		return await db.DriveFiles.Where(p => note.FileIds.Contains(p.Id)).ToListAsync();
-	}
-
-	private async Task<List<Note.MentionedUser>> GetMentions(Note note)
-	{
-		return await db.Users.IncludeCommonProperties()
-		               .Where(p => note.Mentions.Contains(p.Id))
-		               .Select(u => new Note.MentionedUser
-		               {
-			               Host     = u.Host ?? config.Value.AccountDomain,
-			               Uri      = u.Uri ?? u.GetPublicUri(config.Value),
-			               Username = u.Username,
-			               Url      = u.UserProfile != null ? u.UserProfile.Url : null
-		               })
-		               .ToListAsync();
-	}
-
-	private async Task<List<Emoji>> GetEmoji(Note note)
-	{
-		var ids = note.Emojis;
-		if (ids.Count == 0) return [];
-
-		return await db.Emojis.Where(p => ids.Contains(p.Id)).ToListAsync();
-	}
-
-	private async Task<List<Emoji>> GetEmoji(User user)
-	{
-		var ids = user.Emojis;
-		if (ids.Count == 0) return [];
-
-		return await db.Emojis.Where(p => ids.Contains(p.Id)).ToListAsync();
-	}
-}

Iceshrimp.Backend/Pages/NotePreview.razor

@@ -0,0 +1,111 @@
+@page "/notes/{id}"
+@using Iceshrimp.Backend.Components.PublicPreview.Attributes
+@using Iceshrimp.Backend.Core.Extensions
+@attribute [PublicPreviewRouteFilter]
+@inherits AsyncComponentBase
+
+@if (_note is null)
+{
+    Context.Response.StatusCode = 404;
+    <div>
+        <h2>Not found</h2>
+        <p>This note either doesn't exist or is only accessible to authenticated users</p>
+    </div>
+}
+else
+{
+    <NoteComponent Note="_note"/>
+    if (_note.QuoteUrl != null)
+    {
+        var displayUrl = _note.QuoteUrl.StartsWith("https://") ? _note.QuoteUrl[8..] : _note.QuoteUrl[7..];
+        <p>
+            @if (_note.QuoteInaccessible)
+            {
+                <i>This note is quoting <a href="@_note.QuoteUrl">@displayUrl</a>, which has either been deleted or is not publicly visible.</i>
+            }
+            else
+            {
+                <i>This note is quoting <a href="@_note.QuoteUrl">@displayUrl</a></i>
+            }
+        </p>
+    }
+
+    if (!ShowMedia && _note.Attachments != null)
+    {
+        <p>
+            <i>This post has attachments, but this server's configuration prevents them from being displayed here.</i>
+        </p>
+    }
+    else if (ShowMedia && _note.Attachments is { Count: > 0 })
+    {
+        foreach (var file in _note.Attachments)
+        {
+            if (file.MimeType.StartsWith("image/"))
+            {
+                <img src="@file.Url" max-width="200px" max-height="200px" alt="@(file.Alt ?? "")"/>
+            }
+            else if (file.MimeType.StartsWith("video/"))
+            {
+                <video controls max-width="200px" max-height="200px">
+                    <source src="@file.Url" type="@file.MimeType"/>
+                    <p>@(file.Alt ?? "No alt text.")</p>
+                </video>
+            }
+            else
+            {
+                <div>Attachment: <a href="@file.Url">@file.Name</a> (@file.MimeType)</div>
+            }
+        }
+    }
+
+    <PageTitle>Note by @@@_note.User.Username - @_instanceName</PageTitle>
+    <HeadContent>
+        @{
+            var previewImageUrl = _note.User.AvatarUrl;
+            if (ShowMedia && _note.Attachments != null)
+            {
+                if (_note.Attachments.FirstOrDefault(p => p.MimeType.StartsWith("image/")) is { } img)
+                {
+                    previewImageUrl = img.Url;
+                }
+            }
+
+            string description;
+            if (_note.Cw is { } cw)
+            {
+                description = $"Content warning: {cw}";
+            }
+            else
+            {
+                var text = _note.RawText?.TruncateEllipsis(280);
+                if (_note.Attachments is { Count: > 0 })
+                {
+                    var attachmentText = $"({_note.Attachments.Count} attachments)";
+                    text = text is null
+                        ? attachmentText
+                        : text + $"\n{attachmentText}";
+                }
+
+                description = text + (_note.QuoteUrl != null ? $"\n\nRE: {_note.QuoteUrl}" : "");
+            }
+
+            var username = _note.User.Username;
+            var title    = _note.User.RawDisplayName is { } name ? $"{name} (@{username})" : $"@{username}";
+        }
+
+        <meta name="twitter:card" content="summary">
+        <meta name="og:site_name" content="@_instanceName">
+        <meta name="og:title" content="@title">
+        <meta name="og:image" content="@previewImageUrl">
+        <meta name="og:description" content="@description">
+
+        <link rel="stylesheet" href="/css/public-preview.css"/>
+    </HeadContent>
+
+    if (!ShowRemoteReplies)
+    {
+        <p>
+            <i>This server's configuration is preventing remotely originating content from being shown. This view may therefore be incomplete.</i>
+        </p>
+    }
+}

Iceshrimp.Backend/Pages/NotePreview.razor.cs

@@ -0,0 +1,69 @@
+using Iceshrimp.Backend.Components.Helpers;
+using Iceshrimp.Backend.Components.PublicPreview.Renderers;
+using Iceshrimp.Backend.Components.PublicPreview.Schemas;
+using Iceshrimp.Backend.Core.Configuration;
+using Iceshrimp.Backend.Core.Database;
+using Iceshrimp.Backend.Core.Extensions;
+using Iceshrimp.Backend.Core.Middleware;
+using Iceshrimp.Backend.Core.Services;
+using Microsoft.AspNetCore.Components;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Options;
+
+namespace Iceshrimp.Backend.Pages;
+
+public partial class NotePreview : AsyncComponentBase
+{
+	[Inject]             public required IOptions<Config.InstanceSection>         Config   { get; set; }
+	[Inject]             public required IOptionsSnapshot<Config.SecuritySection> Security { get; set; }
+	[Inject]             public required MetaService                              Meta     { get; set; }
+	[Inject]             public required DatabaseContext                          Database { get; set; }
+	[Inject]             public required NoteRenderer                             Renderer { get; set; }
+	[Parameter]          public required string                                   Id       { get; set; }
+	[CascadingParameter] public required HttpContext                              Context  { get; set; }
+
+	private PreviewNote? _note;
+	private string       _instanceName = "Iceshrimp.NET";
+
+	private bool ShowMedia         => Security.Value.PublicPreview > Enums.PublicPreview.RestrictedNoMedia;
+	private bool ShowRemoteReplies => Security.Value.PublicPreview > Enums.PublicPreview.Restricted;
+
+	protected override async Task OnInitializedAsync()
+	{
+		if (Security.Value.PublicPreview == Enums.PublicPreview.Lockdown)
+			throw new PublicPreviewDisabledException();
+
+		_instanceName = await Meta.Get(MetaEntity.InstanceName) ?? _instanceName;
+
+		//TODO: show publish & edit timestamps
+		//TODO: show quotes inline (enforce visibility by checking VisibilityIsPublicOrHome)
+		//TODO: show parent post inline (enforce visibility by checking VisibilityIsPublicOrHome)
+		//TODO: show avatar instead of image as fallback? can we do both?
+		//TODO: thread view (respect public preview settings - don't show remote replies if set to restricted or lower)
+
+		var note = await Database.Notes
+		                         .IncludeCommonProperties()
+		                         .EnsureVisibleFor(null)
+		                         .FirstOrDefaultAsync(p => p.Id == Id);
+
+		if (note is { IsPureRenote: true })
+		{
+			var target = note.Renote?.Url ??
+			             note.Renote?.Uri ??
+			             note.Renote?.GetPublicUriOrNull(Config.Value) ??
+			             throw new Exception("Note is remote but has no uri");
+
+			Context.Response.Redirect(target, permanent: true);
+			return;
+		}
+
+		if (note is { User.Host: not null })
+		{
+			var target = note.Url ?? note.Uri ?? throw new Exception("Note is remote but has no uri");
+			Context.Response.Redirect(target, permanent: true);
+			return;
+		}
+
+		_note = await Renderer.RenderOne(note);
+	}
+}

Iceshrimp.Backend/Pages/Tag.cshtml.cs

@@ -9,7 +9,7 @@ public class TagModel : PageModel
 
 	public IActionResult OnGet(string tag)
 	{
-		if (Request.Cookies.ContainsKey("session") || Request.Cookies.ContainsKey("sessions"))
+		if (Request.Cookies.ContainsKey("sessions"))
 			return Partial("Shared/FrontendSPA");
 
 		Tag = tag;

Iceshrimp.Backend/Pages/User.cshtml

@@ -1,52 +0,0 @@
-@page
-@attribute [RazorCompiledItemMetadata("RouteTemplate", "/@{user}")]
-@using Microsoft.AspNetCore.Razor.Hosting
-@model UserModel
-
-@section styles
-{
-    <link rel="stylesheet" href="~/css/public-preview.css"/>
-}
-
-@if (Model.User == null)
-{
-    Response.StatusCode = 404;
-    <div>
-        <h2>Not found</h2>
-        <p>This user doesn't appear to exist on this server</p>
-    </div>
-}
-else
-{
-    ViewData["title"] = $"@{Model.User.Username} - {Model.InstanceName}";
-    @section head
-    {
-        <meta name="twitter:card" content="summary">
-        <meta name="og:site_name" content="@Model.InstanceName">
-        <meta name="og:title" content="@@@Model.User.Username">
-        @if (Model.User.UserProfile?.Description is { } bio)
-        {
-            <meta name="og:description" content="@bio">
-        }
-        <meta name="og:image" content="@(Model.User.AvatarUrl ?? Model.User.IdenticonUrlPath)">
-    }
-
-    <div class="user">
-        <div class="header">
-            <img src="@(Model.User.AvatarUrl)" class="avatar" alt="User avatar"/>
-            <div class="title">
-                <span>@Html.Raw(Model.DisplayName)</span>
-            </div>
-            <span class="acct">@@@Model.User.Username<span class="host">@@@Model.User.Host</span></span>
-        </div>
-        <div class="bio">
-            @Html.Raw(Model.Bio ?? "<i>This user hasn't added a bio yet.</i>")
-        </div>
-        @if (Model.User.MovedToUri is { } target)
-        {
-            <div class="bio">
-                <i>This user has migrated to a <a href="@target">different account</a>.</i>
-            </div>
-        }
-    </div>
-}

Iceshrimp.Backend/Pages/User.cshtml.cs

@@ -1,102 +0,0 @@
-using System.Diagnostics.CodeAnalysis;
-using System.Text.Encodings.Web;
-using AngleSharp;
-using Iceshrimp.Backend.Core.Configuration;
-using Iceshrimp.Backend.Core.Database;
-using Iceshrimp.Backend.Core.Database.Tables;
-using Iceshrimp.Backend.Core.Extensions;
-using Iceshrimp.Backend.Core.Helpers.LibMfm.Conversion;
-using Iceshrimp.Backend.Core.Middleware;
-using Iceshrimp.Backend.Core.Services;
-using Microsoft.AspNetCore.Mvc;
-using Microsoft.AspNetCore.Mvc.RazorPages;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Options;
-
-namespace Iceshrimp.Backend.Pages;
-
-public class UserModel(
-	DatabaseContext db,
-	IOptions<Config.SecuritySection> security,
-	IOptions<Config.InstanceSection> instance,
-	MetaService meta,
-	MfmConverter mfm
-) : PageModel
-{
-	public new User?        User;
-	public     string?      Bio;
-	public     List<Emoji>? Emoji;
-	public     bool         ShowMedia    = security.Value.PublicPreview > Enums.PublicPreview.RestrictedNoMedia;
-	public     string       InstanceName = "Iceshrimp.NET";
-	public     string?      DisplayName;
-
-	[SuppressMessage("ReSharper", "EntityFramework.NPlusOne.IncompleteDataQuery",
-	                 Justification = "IncludeCommonProperties")]
-	[SuppressMessage("ReSharper", "EntityFramework.NPlusOne.IncompleteDataUsage", Justification = "Same as above")]
-	public async Task<IActionResult> OnGet(string user, string? host)
-	{
-		if (Request.Cookies.ContainsKey("session") || Request.Cookies.ContainsKey("sessions"))
-			return Partial("Shared/FrontendSPA");
-
-		if (security.Value.PublicPreview == Enums.PublicPreview.Lockdown)
-			throw new PublicPreviewDisabledException();
-
-		InstanceName = await meta.Get(MetaEntity.InstanceName) ?? InstanceName;
-
-		//TODO: user note view (respect public preview settings - don't show renotes of remote notes if set to restricted or lower)
-
-		user = user.ToLowerInvariant();
-		host = host?.ToLowerInvariant();
-
-		if (host == instance.Value.AccountDomain || host == instance.Value.WebDomain)
-			host = null;
-
-		User = await db.Users.IncludeCommonProperties()
-		               .Where(p => p.UsernameLower == user && p.Host == host)
-		               .FirstOrDefaultAsync();
-
-		if (User is { IsRemoteUser: true })
-			return RedirectPermanent(User.UserProfile?.Url ??
-			                         User.Uri ??
-			                         throw new Exception("User is remote but has no uri"));
-
-		if (User != null)
-		{
-			Emoji       = await GetEmoji(User);
-			DisplayName = HtmlEncoder.Default.Encode(User.DisplayName ?? User.Username);
-			if (Emoji is { Count: > 0 })
-			{
-				var context  = BrowsingContext.New();
-				var document = await context.OpenNewAsync();
-				foreach (var emoji in Emoji)
-				{
-					var el    = document.CreateElement("span");
-					var inner = document.CreateElement("img");
-					inner.SetAttribute("src", emoji.PublicUrl);
-					el.AppendChild(inner);
-					el.ClassList.Add("emoji");
-					DisplayName = DisplayName.Replace($":{emoji.Name.Trim(':')}:", el.OuterHtml);
-				}
-			}
-		}
-
-		if (User?.UserProfile?.Description is { } bio)
-			Bio = await mfm.ToHtmlAsync(bio, User.UserProfile.Mentions, User.Host, divAsRoot: true, emoji: Emoji);
-
-		if (User is { AvatarUrl: null } || (User is not null && !ShowMedia))
-			User.AvatarUrl = User.GetIdenticonUrl(instance.Value);
-
-		if (User is { Host: null })
-			User.Host = instance.Value.AccountDomain;
-
-		return Page();
-	}
-
-	private async Task<List<Emoji>> GetEmoji(User user)
-	{
-		var ids = user.Emojis;
-		if (ids.Count == 0) return [];
-
-		return await db.Emojis.Where(p => ids.Contains(p.Id)).ToListAsync();
-	}
-}

Iceshrimp.Backend/Pages/User.cshtml.css

@@ -1,48 +0,0 @@
-.bio {
-    display: flex;
-    flex-direction: column;
-    align-items: flex-start;
-    padding-top: inherit;
-}
-
-.user {
-    background-color: #f7f7f7;
-    background-color: var(--background-alt);
-    padding: 12px;
-    margin: 1em 0;
-    border-radius: 6px;
-    overflow: hidden;
-}
-
-.header {
-    display: grid;
-    grid-template-columns: repeat(auto-fill, minmax(3em, 3em));
-    grid-template-rows: repeat(2, 1.5em);
-}
-
-.avatar {
-    grid-column: 1;
-    grid-row: 1/3;
-    border-radius: 5px;
-    object-fit: cover;
-    width: 3em;
-    max-height: 3em;
-}
-
-.title {
-    grid-column: 2/-1;
-    grid-row: 1;
-    padding-left: 10px;
-    color: var(--text-bright);
-    font-weight: 600;
-}
-
-.acct {
-    grid-column: 2/-1;
-    grid-row: 2;
-    padding-left: 10px;
-}
-
-.host {
-    color: var(--text-dim);
-}

Iceshrimp.Backend/Pages/UserPreview.razor

@@ -0,0 +1,41 @@
+@page "/User"
+@using Iceshrimp.Backend.Components.PublicPreview.Attributes
+@attribute [Route("/@{Acct}")]
+@attribute [PublicPreviewRouteFilter]
+@inherits AsyncComponentBase
+
+@if (_user is null)
+{
+    Context.Response.StatusCode = 404;
+    <div>
+        <h2>Not found</h2>
+        <p>This user doesn't appear to exist on this server</p>
+    </div>
+}
+else
+{
+    <div class="user">
+        <UserComponent User="_user"/>
+        <div class="bio">
+            @(_user.Bio ?? new MarkupString("<i>This user hasn't added a bio yet.</i>"))
+        </div>
+        @if (_user.MovedToUri != null)
+        {
+            <div class="bio">
+                <i>This user has migrated to a <a href="@_user.MovedToUri">different account</a>.</i>
+            </div>
+        }
+    </div>
+    <PageTitle>@@@_user.Username - @_instanceName</PageTitle>
+    <HeadContent>
+        <meta name="twitter:card" content="summary">
+        <meta name="og:site_name" content="@_instanceName">
+        <meta name="og:title" content="@@@_user.Username">
+        @if (_user.Bio is { } bio)
+        {
+            <meta name="og:description" content="@bio">
+        }
+        <meta name="og:image" content="@_user.AvatarUrl">
+        <link rel="stylesheet" href="/css/public-preview.css"/>
+    </HeadContent>
+}

Iceshrimp.Backend/Pages/UserPreview.razor.cs

@@ -0,0 +1,65 @@
+using System.Diagnostics.CodeAnalysis;
+using Iceshrimp.Backend.Components.Helpers;
+using Iceshrimp.Backend.Components.PublicPreview.Renderers;
+using Iceshrimp.Backend.Components.PublicPreview.Schemas;
+using Iceshrimp.Backend.Core.Configuration;
+using Iceshrimp.Backend.Core.Database;
+using Iceshrimp.Backend.Core.Extensions;
+using Iceshrimp.Backend.Core.Middleware;
+using Iceshrimp.Backend.Core.Services;
+using Microsoft.AspNetCore.Components;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Options;
+
+namespace Iceshrimp.Backend.Pages;
+
+public partial class UserPreview : AsyncComponentBase
+{
+	[Inject]             public required DatabaseContext                          Database { get; set; }
+	[Inject]             public required UserRenderer                             Renderer { get; set; }
+	[Inject]             public required MetaService                              Meta     { get; set; }
+	[Inject]             public required IOptions<Config.InstanceSection>         Instance { get; set; }
+	[Inject]             public required IOptionsSnapshot<Config.SecuritySection> Security { get; set; }
+	[Parameter]          public required string                                   Id       { get; set; }
+	[Parameter]          public required string                                   Acct     { get; set; }
+	[CascadingParameter] public required HttpContext                              Context  { get; set; }
+
+	private PreviewUser? _user;
+	private string       _instanceName = "Iceshrimp.NET";
+
+	[SuppressMessage("ReSharper", "EntityFramework.NPlusOne.IncompleteDataQuery")]
+	[SuppressMessage("ReSharper", "EntityFramework.NPlusOne.IncompleteDataUsage")]
+	protected override async Task OnInitializedAsync()
+	{
+		if (Security.Value.PublicPreview == Enums.PublicPreview.Lockdown)
+			throw new PublicPreviewDisabledException();
+
+		_instanceName = await Meta.Get(MetaEntity.InstanceName) ?? _instanceName;
+
+		//TODO: user banner
+		//TODO: user note view (respect public preview settings - don't show renotes of remote notes if set to restricted or lower)
+
+		var split = Acct.Split("@");
+		if (split.Length > 2) throw GracefulException.BadRequest("Invalid acct");
+		var username = split[0].ToLowerInvariant();
+		var host     = split.Length == 2 ? split[1].ToPunycodeLower() : null;
+
+		if (host == Instance.Value.AccountDomain || host == Instance.Value.WebDomain)
+			host = null;
+
+		var user = await Database.Users
+		                         .IncludeCommonProperties()
+		                         .FirstOrDefaultAsync(p => p.UsernameLower == username &&
+		                                                   p.Host == host &&
+		                                                   !p.IsSystemUser);
+
+		if (user is { IsRemoteUser: true })
+		{
+			var target = user.UserProfile?.Url ?? user.Uri ?? throw new Exception("User is remote but has no uri");
+			Context.Response.Redirect(target, permanent: true);
+			return;
+		}
+
+		_user = await Renderer.RenderOne(user);
+	}
+}

Iceshrimp.Backend/Pages/UserPreview.razor.css

@@ -0,0 +1,15 @@
+.user {
+    background-color: #f7f7f7;
+    background-color: var(--background-alt);
+    padding: 12px;
+    margin: 1em 0;
+    border-radius: 6px;
+    overflow: hidden;
+}
+
+.bio {
+    display: flex;
+    flex-direction: column;
+    align-items: flex-start;
+    padding-top: inherit;
+}

Iceshrimp.Backend/Pages/_Imports.razor

@@ -0,0 +1,4 @@
+@using Iceshrimp.Backend.Components
+@using Iceshrimp.Backend.Components.Helpers
+@using Iceshrimp.Backend.Components.PublicPreview
+@using Microsoft.AspNetCore.Components.Web

Iceshrimp.Backend/Startup.cs

@@ -1,3 +1,4 @@
+using Iceshrimp.Backend.Components;
 using Iceshrimp.Backend.Core.Extensions;
 using Iceshrimp.Backend.Core.Helpers;
 using Iceshrimp.Backend.SignalR;
@@ -30,7 +31,8 @@ builder.Services.AddAuthorizationPolicies();
 builder.Services.AddAuthenticationServices();
 builder.Services.AddSignalR().AddMessagePackProtocol();
 builder.Services.AddResponseCompression();
-builder.Services.AddRazorPages().AddRouteOverrides();
+builder.Services.AddRazorPages(); //.AddRouteOverrides();
+builder.Services.AddRazorComponents();
 
 builder.Services.AddServices(builder.Configuration);
 builder.Services.ConfigureServices(builder.Configuration);
@@ -65,6 +67,7 @@ app.MapControllers();
 app.MapFallbackToController("/api/{**slug}", "FallbackAction", "Fallback").WithOrder(int.MaxValue - 3);
 app.MapHub<StreamingHub>("/hubs/streaming");
 app.MapRazorPages();
+app.MapRazorComponents<RootComponent>().DisableAntiforgery();
 app.MapFrontendRoutes("/Shared/FrontendSPA");
 
 PluginLoader.RunAppHooks(app);