Add following and followers

lib/nulla/activitypub.ex

@@ -139,4 +139,90 @@ defmodule Nulla.ActivityPub do
       to: activity.to
     )
   end
+
+  @spec following(String.t(), Nulla.Models.User.t(), Integer.t()) :: Jason.OrderedObject.t()
+  def following(domain, user, total) do
+    Jason.OrderedObject.new(
+      "@context": "https://www.w3.org/ns/activitystreams",
+      id: "https://#{domain}/@#{user.username}/following",
+      type: "OrderedCollection",
+      totalItems: total,
+      first: "https://#{domain}/@#{user.username}/following?page=1"
+    )
+  end
+
+  @spec following(String.t(), Nulla.Models.User.t(), Integer.t(), List.t(), Integer.t(), Integer.t()) :: Jason.OrderedObject.t()
+  def following(domain, user, total, following_list, page, offset) when is_integer(page) and page > 0 do
+    data = [
+      "@context": "https://www.w3.org/ns/activitystreams",
+      id: "https://#{domain}/@#{user.username}/following?page=#{page}",
+      type: "OrderedCollectionPage",
+      totalItems: total,
+      next: "https://#{domain}/@#{user.username}/following?page=#{page + 1}",
+      prev: "https://#{domain}/@#{user.username}/following?page=#{page - 1}",
+      partOf: "https://#{domain}/@#{user.username}/following",
+      orderedItems: following_list
+    ]
+
+    data =
+      if page <= 1 do
+        Keyword.delete(data, :prev)
+      else
+        data
+      end
+
+    data =
+      if page * offset > total do
+        data
+        |> Keyword.delete(:next)
+        |> Keyword.delete(:prev)
+      else
+        data
+      end
+
+    Jason.OrderedObject.new(data)
+  end
+
+  @spec followers(String.t(), Nulla.Models.User.t(), Integer.t()) :: Jason.OrderedObject.t()
+  def followers(domain, user, total) do
+    Jason.OrderedObject.new(
+      "@context": "https://www.w3.org/ns/activitystreams",
+      id: "https://#{domain}/@#{user.username}/followers",
+      type: "OrderedCollection",
+      totalItems: total,
+      first: "https://#{domain}/@#{user.username}/followers?page=1"
+    )
+  end
+
+  @spec followers(String.t(), Nulla.Models.User.t(), Integer.t(), List.t(), Integer.t(), Integer.t()) :: Jason.OrderedObject.t()
+  def followers(domain, user, total, followers_list, page, offset) when is_integer(page) and page > 0 do
+    data = [
+      "@context": "https://www.w3.org/ns/activitystreams",
+      id: "https://#{domain}/@#{user.username}/followers?page=#{page}",
+      type: "OrderedCollectionPage",
+      totalItems: total,
+      next: "https://#{domain}/@#{user.username}/followers?page=#{page + 1}",
+      prev: "https://#{domain}/@#{user.username}/followers?page=#{page - 1}",
+      partOf: "https://#{domain}/@#{user.username}/followers",
+      orderedItems: followers_list
+    ]
+
+    data =
+      if page <= 1 do
+        Keyword.delete(data, :prev)
+      else
+        data
+      end
+
+    data =
+      if page * offset > total do
+        data
+        |> Keyword.delete(:next)
+        |> Keyword.delete(:prev)
+      else
+        data
+      end
+
+    Jason.OrderedObject.new(data)
+  end
 end

lib/nulla/models/instance_settings.ex

@@ -11,6 +11,7 @@ defmodule Nulla.Models.InstanceSettings do
     field :registration, :boolean, default: false
     field :max_characters, :integer, default: 5000
     field :max_upload_size, :integer, default: 50
+    field :offset, :integer, default: 100
     field :public_key, :string
     field :private_key, :string
   end
@@ -25,6 +26,7 @@ defmodule Nulla.Models.InstanceSettings do
       :registration,
       :max_characters,
       :max_upload_size,
+      :offset,
       :public_key,
       :private_key
     ])
@@ -35,6 +37,7 @@ defmodule Nulla.Models.InstanceSettings do
       :registration,
       :max_characters,
       :max_upload_size,
+      :offset,
       :public_key,
       :private_key
     ])

lib/nulla/utils.ex

@@ -0,0 +1,87 @@
+defmodule Nulla.Utils do
+  import Ecto.Query
+  alias Nulla.Repo
+  alias Nulla.Models.User
+  alias Nulla.Models.Follow
+  alias Nulla.Models.InstanceSettings
+
+  def count_following_by_username!(username) do
+    case Repo.get_by(User, username: username) do
+      nil ->
+        {:error, :user_not_found}
+
+      %User{id: user_id} ->
+        count =
+          Follow
+          |> where([f], f.user_id == ^user_id)
+          |> select([f], count(f.id))
+          |> Repo.one()
+
+        count
+    end
+  end
+
+  def get_following_users_by_username!(username, page) when is_integer(page) and page > 0 do
+    case Repo.get_by(User, username: username) do
+      nil ->
+        {:error, :user_not_found}
+
+      %User{id: user_id} ->
+        instance_settings = InstanceSettings.get_instance_settings!()
+        per_page = instance_settings.offset
+        offset = (page - 1) * per_page
+
+        query =
+          from [f, u] in
+            from(f in Follow,
+              join: u in User, on: u.id == f.target_id,
+              where: f.user_id == ^user_id,
+              order_by: [asc: u.inserted_at],
+              offset: ^offset,
+              limit: ^per_page,
+              select: u
+            )
+
+        users = Repo.all(query)
+
+        users
+    end
+  end
+
+  def count_followers_by_username!(username) do
+    case Repo.get_by(User, username: username) do
+      nil ->
+        0
+
+      %User{id: user_id} ->
+        from(f in Follow, where: f.target_id == ^user_id)
+        |> select([f], count(f.id))
+        |> Repo.one()
+    end
+  end
+
+  def get_followers_by_username!(username, page) when is_integer(page) and page > 0 do
+    case Repo.get_by(User, username: username) do
+      nil ->
+        {:error, :user_not_found}
+
+      %User{id: user_id} ->
+        instance_settings = InstanceSettings.get_instance_settings!()
+        per_page = instance_settings.offset
+        offset = (page - 1) * per_page
+
+        query =
+          from f in Follow,
+            where: f.target_id == ^user_id,
+            join: u in User, on: u.id == f.user_id,
+            order_by: [asc: u.inserted_at],
+            offset: ^offset,
+            limit: ^per_page,
+            select: u
+
+        users = Repo.all(query)
+
+        users
+    end
+  end
+end

lib/nulla_web/components/templates/user/show.html.heex

@@ -66,9 +66,9 @@
         </dl>
       <% end %>
       <div class="flex mt-5 gap-3">
-        <a href={~p"/@#{@user.username}"}>1.7K Posts</a>
-        <a href={~p"/@#{@user.username}/following"}>33 Following</a>
-        <a href={~p"/@#{@user.username}/followers"}>31 Followers</a>
+        <a href={~p"/@#{@user.username}"}>{length(@notes)} Posts</a>
+        <a href={~p"/@#{@user.username}/following"}>{@following} Following</a>
+        <a href={~p"/@#{@user.username}/followers"}>{@followers} Followers</a>
       </div>
     </div>
     <div class="flex justify-between px-20 py-2 mt-5 border-y border-gray-300">

lib/nulla_web/controllers/follow_controller.ex

@@ -0,0 +1,65 @@
+defmodule NullaWeb.FollowController do
+  use NullaWeb, :controller
+  alias Nulla.Models.User
+  alias Nulla.Models.InstanceSettings
+  alias Nulla.ActivityPub
+  alias Nulla.Utils
+
+  def following(conn, %{"username" => username, "page" => page_param}) do
+    instance_settings = InstanceSettings.get_instance_settings!()
+    domain = instance_settings.domain
+    offset = instance_settings.offset
+    user = User.get_user_by_username!(username)
+    total = Utils.count_following_by_username!(user.username)
+    page =
+    case Integer.parse(page_param) do
+      {int, _} when int > 0 -> int
+      _ -> 1
+    end
+    following_list = Utils.get_following_users_by_username!(user.username, page)
+
+    conn
+      |> put_resp_content_type("application/activity+json")
+      |> json(ActivityPub.following(domain, user, total, following_list, page, offset))
+  end
+
+  def following(conn, %{"username" => username}) do
+    instance_settings = InstanceSettings.get_instance_settings!()
+    domain = instance_settings.domain
+    user = User.get_user_by_username!(username)
+    total = Utils.count_following_by_username!(user.username)
+
+    conn
+      |> put_resp_content_type("application/activity+json")
+      |> json(ActivityPub.following(domain, user, total))
+  end
+
+  def followers(conn, %{"username" => username, "page" => page_param}) do
+    instance_settings = InstanceSettings.get_instance_settings!()
+    domain = instance_settings.domain
+    offset = instance_settings.offset
+    user = User.get_user_by_username!(username)
+    total = Utils.count_followers_by_username!(user.username)
+    page =
+    case Integer.parse(page_param) do
+      {int, _} when int > 0 -> int
+      _ -> 1
+    end
+    followers_list = Utils.get_followers_by_username!(user.username, page)
+
+    conn
+      |> put_resp_content_type("application/activity+json")
+      |> json(ActivityPub.followers(domain, user, total, followers_list, page, offset))
+  end
+
+  def followers(conn, %{"username" => username}) do
+    instance_settings = InstanceSettings.get_instance_settings!()
+    domain = instance_settings.domain
+    user = User.get_user_by_username!(username)
+    total = Utils.count_followers_by_username!(user.username)
+
+    conn
+      |> put_resp_content_type("application/activity+json")
+      |> json(ActivityPub.followers(domain, user, total))
+  end
+end

lib/nulla_web/controllers/user_controller.ex

@@ -4,6 +4,7 @@ defmodule NullaWeb.UserController do
   alias Nulla.Models.Note
   alias Nulla.Models.InstanceSettings
   alias Nulla.ActivityPub
+  alias Nulla.Utils
 
   def show(conn, %{"username" => username}) do
     accept = List.first(get_req_header(conn, "accept"))
@@ -17,7 +18,19 @@ defmodule NullaWeb.UserController do
       |> put_resp_content_type("application/activity+json")
       |> json(ActivityPub.user(domain, user))
     else
-      render(conn, :show, domain: domain, user: user, notes: notes, layout: false)
+      following = Utils.count_following_by_username!(user.username)
+      followers = Utils.count_followers_by_username!(user.username)
+
+      render(
+        conn,
+        :show,
+        domain: domain,
+        user: user,
+        notes: notes,
+        following: following,
+        followers: followers,
+        layout: false
+      )
     end
   end
 end

lib/nulla_web/router.ex

@@ -22,6 +22,8 @@ defmodule NullaWeb.Router do
     pipe_through :browser
 
     get "/@:username", UserController, :show
+    get "/@:username/following", FollowController, :following
+    get "/@:username/followers", FollowController, :followers
     get "/@:username/:note_id", NoteController, :show
   end
 

priv/repo/migrations/20250527054942_create_instance_settings.exs

@@ -9,6 +9,7 @@ defmodule Nulla.Repo.Migrations.CreateInstanceSettings do
       add :registration, :boolean, default: false, null: false
       add :max_characters, :integer, default: 5000, null: false
       add :max_upload_size, :integer, default: 50, null: false
+      add :offset, :integer, default: 100, null: false
       add :public_key, :string
       add :private_key, :string