From 62aa5f30756aa08b34ffca1ab6790aaff528660c Mon Sep 17 00:00:00 2001
From: pancakes <trypancakes@tutanota.com>
Date: Thu, 24 Oct 2024 19:26:12 +1000
Subject: [PATCH] [backend/api] Add follow list import endpoint

---
 .../Controllers/Web/SettingsController.cs     | 25 +++++++++++++++++-
 .../Core/Services/UserService.cs              | 26 +++++++++++++++++++
 2 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/Iceshrimp.Backend/Controllers/Web/SettingsController.cs b/Iceshrimp.Backend/Controllers/Web/SettingsController.cs
index 867da6a6..b3e413e6 100644
--- a/Iceshrimp.Backend/Controllers/Web/SettingsController.cs
+++ b/Iceshrimp.Backend/Controllers/Web/SettingsController.cs
@@ -1,9 +1,11 @@
 using System.Net;
 using System.Net.Mime;
+using AngleSharp.Text;
 using Iceshrimp.Backend.Controllers.Shared.Attributes;
 using Iceshrimp.Backend.Core.Database;
 using Iceshrimp.Backend.Core.Database.Tables;
 using Iceshrimp.Backend.Core.Middleware;
+using Iceshrimp.Backend.Core.Services;
 using Iceshrimp.Shared.Schemas.Web;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.RateLimiting;
@@ -16,7 +18,7 @@ namespace Iceshrimp.Backend.Controllers.Web;
 [EnableRateLimiting("sliding")]
 [Route("/api/iceshrimp/settings")]
 [Produces(MediaTypeNames.Application.Json)]
-public class SettingsController(DatabaseContext db) : ControllerBase
+public class SettingsController(DatabaseContext db, UserService userSvc) : ControllerBase
 {
 	[HttpGet]
 	[ProducesResults(HttpStatusCode.OK)]
@@ -63,4 +65,25 @@ public class SettingsController(DatabaseContext db) : ControllerBase
 		await db.ReloadEntityAsync(settings);
 		return settings;
 	}
+
+	[HttpPost("import/following")]
+	[ProducesResults(HttpStatusCode.Accepted)]
+	public async Task<AcceptedResult> ImportFollowing(IFormFile file)
+	{
+		var user = HttpContext.GetUserOrFail();
+		
+		var reader   = new StreamReader(file.OpenReadStream());
+		var contents = await reader.ReadToEndAsync();
+
+		var fqns = contents
+		           .Split("\n")
+		           .Where(line => !string.IsNullOrWhiteSpace(line))
+		           .Select(line => line.SplitCommas().First())
+		           .Where(fqn => fqn.Contains('@'))
+		           .ToList();
+
+		await userSvc.ImportFollowingAsync(user, fqns);
+
+		return Accepted();
+	}
 }
\ No newline at end of file
diff --git a/Iceshrimp.Backend/Core/Services/UserService.cs b/Iceshrimp.Backend/Core/Services/UserService.cs
index 3041dbbc..21af6d7d 100644
--- a/Iceshrimp.Backend/Core/Services/UserService.cs
+++ b/Iceshrimp.Backend/Core/Services/UserService.cs
@@ -39,6 +39,7 @@ public class UserService(
 	QueueService queueSvc,
 	EventService eventSvc,
 	WebFingerService webFingerSvc,
+	CacheService cacheSvc,
 	ActivityPub.FederationControlService fedCtrlSvc
 )
 {
@@ -945,6 +946,31 @@ public class UserService(
 		await db.UserListMembers.Where(p => p.UserList.User == user && p.User == followee).ExecuteDeleteAsync();
 	}
 
+	public async Task ImportFollowingAsync(User user, List<string> fqns)
+	{
+		foreach (var fqn in fqns.Select(fqn => fqn.Split("@")))
+		{
+			var followee = await db.Users
+			                       .IncludeCommonProperties()
+			                       .FirstOrDefaultAsync(p => fqn[0].ToLower() == p.UsernameLower &&
+			                                                 fqn[1] == (p.Host ?? instance.Value.AccountDomain));
+
+			if (followee == null) continue;
+
+			try
+			{
+				await FollowUserAsync(user, followee);
+			}
+			catch (Exception e)
+			{
+				logger.LogWarning("Failed to import follow {followee} for user {follower}: {error}",
+				                  followee.Id, user.Id, e);
+			}
+		}
+
+		await QueryableTimelineExtensions.ResetHeuristic(user, cacheSvc);
+	}
+
 	[SuppressMessage("ReSharper", "SuggestBaseTypeForParameter", Justification = "Method only makes sense for users")]
 	private void UpdateUserPinnedNotesInBackground(ASActor actor, User user, bool force = false)
 	{