[backend/razor] Add basic user page public preview, handle user id redirects correctly

Iceshrimp.Backend/Controllers/Razor/RedirectController.cs

@@ -0,0 +1,42 @@
+using System.Diagnostics.CodeAnalysis;
+using System.Net;
+using System.Net.Mime;
+using Iceshrimp.Backend.Controllers.Shared.Attributes;
+using Iceshrimp.Backend.Core.Configuration;
+using Iceshrimp.Backend.Core.Database;
+using Iceshrimp.Backend.Core.Extensions;
+using Iceshrimp.Backend.Core.Middleware;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.RateLimiting;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Options;
+
+namespace Iceshrimp.Backend.Controllers.Razor;
+
+[ApiController]
+[Authenticate]
+[EnableRateLimiting("sliding")]
+[Produces(MediaTypeNames.Application.Json)]
+public class RedirectController(IOptionsSnapshot<Config.SecuritySection> config, DatabaseContext db) : ControllerBase
+{
+	// @formatter:off
+	[SuppressMessage("ReSharper", "EntityFramework.NPlusOne.IncompleteDataUsage", Justification = "IncludeCommonProperties")]
+	[SuppressMessage("ReSharper", "EntityFramework.NPlusOne.IncompleteDataQuery", Justification = "IncludeCommonProperties")]
+	// @formatter:on
+	[HttpGet("/users/{id}")]
+	[ProducesResults(HttpStatusCode.OK)]
+	[ProducesErrors(HttpStatusCode.Forbidden, HttpStatusCode.NotFound)]
+	public async Task<IActionResult> GetUser(string id)
+	{
+		var localUser = HttpContext.GetUser();
+		if (config.Value.PublicPreview == Enums.PublicPreview.Lockdown && localUser == null)
+			throw GracefulException.Forbidden("Public preview is disabled on this instance");
+
+		var user = await db.Users.IncludeCommonProperties().FirstOrDefaultAsync(p => p.Id == id) ??
+		           throw GracefulException.NotFound("User not found");
+
+		return user.IsLocalUser
+			? Redirect($"/@{user.Username}")
+			: Redirect(user.UserProfile?.Url ?? user.Uri ?? throw new Exception("Remote user must have an URI"));
+	}
+}

Iceshrimp.Backend/Core/Extensions/MvcBuilderExtensions.cs

@@ -101,6 +101,11 @@ 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/Pages/User.cshtml

@@ -0,0 +1,41 @@
+@page
+@attribute [RazorCompiledItemMetadata("RouteTemplate", "/@{user}")]
+@using Microsoft.AspNetCore.Razor.Hosting
+@model UserModel
+
+@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} - Iceshrimp.NET";
+    @section head
+    {
+        <meta name="twitter:card" content="summary">
+        <meta name="og:site_name" content="Iceshrimp.NET">
+        <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 ?? $"/identicon/{Model.User.Id}")">
+    }
+
+    <div class="user">
+        <div class="header">
+            <img src="@(Model.User.AvatarUrl ?? $"/identicon/{Model.User.Id}")" class="avatar" alt="User avatar"/>
+            <div class="title">
+                <span>@(Model.User.DisplayName ?? Model.User.Username)</span>
+            </div>
+            <span class="acct">@@@Model.User.Acct</span>
+        </div>
+        <div class="bio">
+            @Html.Raw(Model.Bio ?? "<i>This user hasn't added a bio yet.</i>")
+        </div>
+    </div>
+}

Iceshrimp.Backend/Pages/User.cshtml.cs

@@ -0,0 +1,61 @@
+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 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,
+	MfmConverter mfm
+) : PageModel
+{
+	public new User?   User;
+	public     string? Bio;
+
+	[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 GracefulException.Forbidden("Public preview is disabled on this instance.",
+			                                  "The instance administrator has intentionally disabled this feature for privacy reasons.");
+
+		//TODO: login button
+		//TODO: user note view (respect public preview settings - don't show renotes of remote notes if set to restricted or lower)
+		//TODO: emoji
+
+		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?.UserProfile?.Description is { } bio)
+			Bio = await mfm.ToHtmlAsync(bio, User.UserProfile.Mentions, User.Host, divAsRoot: true);
+
+		return Page();
+	}
+}

Iceshrimp.Backend/Pages/User.cshtml.css

@@ -0,0 +1,44 @@
+.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;
+}

Iceshrimp.Backend/Startup.cs

@@ -30,7 +30,7 @@ builder.Services.AddAuthorizationPolicies();
 builder.Services.AddAuthenticationServices();
 builder.Services.AddSignalR().AddMessagePackProtocol();
 builder.Services.AddResponseCompression();
-builder.Services.AddRazorPages();
+builder.Services.AddRazorPages().AddRouteOverrides();
 
 builder.Services.AddServices(builder.Configuration);
 builder.Services.ConfigureServices(builder.Configuration);