feat: Handle follows

.vscode/extensions.json

@@ -0,0 +1,13 @@
+{
+	// See https://go.microsoft.com/fwlink/?LinkId=827846 to learn about workspace recommendations.
+	// Extension identifier format: ${publisher}.${name}. Example: vscode.csharp
+
+	// List of extensions which should be recommended for users of this workspace.
+	"recommendations": [
+		
+	],
+	// List of extensions recommended by VS Code that should not be recommended for users of this workspace.
+	"unwantedRecommendations": [
+		
+	]
+}

lib/activity_pub.ex

@@ -0,0 +1,2 @@
+defmodule ActivityPub do
+end

lib/postland.ex

@@ -7,6 +7,8 @@ defmodule Postland do
   if it comes from the database, an external API or others.
   """
 
+  use Phoenix.VerifiedRoutes, endpoint: PostlandWeb.Endpoint, router: PostlandWeb.Router
+
   alias Postland.Accounts
 
   def temporary_password() do
@@ -51,4 +53,8 @@ defmodule Postland do
   def setup?() do
     Accounts.solo_user() != nil
   end
+
+  def my_actor_id do
+    url(~p"/actor")
+  end
 end

lib/postland/activities.ex

@@ -1,10 +1,37 @@
 defmodule Postland.Activities do
+  use Phoenix.VerifiedRoutes, endpoint: PostlandWeb.Endpoint, router: PostlandWeb.Router
+
   alias Postland.Activity
   alias Postland.Repo
 
+  def process_activity(params) do
+    case record_activity(params) do
+      {:ok, activity} ->
+        cause_effects(activity)
+
+        other ->
+          other
+    end
+  end
+
   def record_activity(params) do
     params
     |> Activity.changeset()
     |> Repo.insert()
   end
+
+  def cause_effects(%Activity{actor_id: actor_id, type: "Follow", data: %{"object" => object}} = activity) do
+    if object == Postland.my_actor_id() do
+      case Postland.Follows.record_inbound_request(actor_id) do
+        {:ok, _follow} ->
+          {:ok, activity}
+        other ->
+          other
+      end
+    else
+      {:ok, activity}
+    end
+  end
+
+  def cause_effects(activity), do: activity
 end

lib/postland/follow.ex

@@ -0,0 +1,29 @@
+defmodule Postland.Follow do
+  use Ecto.Schema
+
+  import Ecto.Changeset
+
+  schema "follows" do
+    field :follower, :string, primary_key: true
+    field :followee, :string, primary_key: true
+    field :confirmed_at, :naive_datetime
+  end
+
+  def changeset(follower, followee, confirmed \\ false) do
+    attrs = %{
+      follower: follower,
+      followee: followee,
+      confirmed_at: (if confirmed, do: NaiveDateTime.utc_now())
+    }
+
+    %__MODULE__{}
+    |> cast(attrs, [:follower, :followee, :confirmed_at])
+    |> validate_required(:followee)
+    |> validate_required(:follower)
+  end
+
+  def confirm_changeset(request) do
+    request
+    |> cast(%{confirmed_at: NaiveDateTime.utc_now()}, [:confirmed_at])
+  end
+end

lib/postland/follows.ex

@@ -0,0 +1,31 @@
+defmodule Postland.Follows do
+  import Ecto.Query, warn: false
+
+  alias Postland.Follow
+  alias Postland.Repo
+
+  def pending_inbound_requests() do
+    my_actor_id = Postland.my_actor_id()
+
+    from(f in Follow, where: f.followee == ^my_actor_id, where: is_nil(f.confirmed_at))
+    |> Repo.all()
+  end
+
+  def record_outbound_request(to_actor_id) do
+    Postland.my_actor_id()
+    |> Follow.changeset(to_actor_id)
+    |> Repo.insert(conflict_target: [:followee, :follower], on_conflict: :nothing)
+  end
+
+  def record_inbound_request(from_actor_id) do
+    from_actor_id
+    |> Follow.changeset(Postland.my_actor_id())
+    |> Repo.insert(conflict_target: [:followee, :follower], on_conflict: :nothing)
+  end
+
+  def confirm_request(request) do
+    request
+    |> Follow.confirm_changeset()
+    |> Repo.update()
+  end
+end

lib/postland_web/controllers/inbox_controller.ex

@@ -8,7 +8,7 @@ defmodule PostlandWeb.InboxController do
 
   def post(conn, params) do
     if Headers.verify(conn.method, conn.request_path, conn.req_headers) do
-      case Activities.record_activity(params) do
+      case Activities.process_activity(params) do
         {:ok, _activity} ->
           render(conn, :ok)
         error ->

mix.lock

@@ -18,7 +18,7 @@
   "finch": {:hex, :finch, "0.19.0", "c644641491ea854fc5c1bbaef36bfc764e3f08e7185e1f084e35e0672241b76d", [:mix], [{:mime, "~> 1.0 or ~> 2.0", [hex: :mime, repo: "hexpm", optional: false]}, {:mint, "~> 1.6.2 or ~> 1.7", [hex: :mint, repo: "hexpm", optional: false]}, {:nimble_options, "~> 0.4 or ~> 1.0", [hex: :nimble_options, repo: "hexpm", optional: false]}, {:nimble_pool, "~> 1.1", [hex: :nimble_pool, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "fc5324ce209125d1e2fa0fcd2634601c52a787aff1cd33ee833664a5af4ea2b6"},
   "floki": {:hex, :floki, "0.36.2", "a7da0193538c93f937714a6704369711998a51a6164a222d710ebd54020aa7a3", [:mix], [], "hexpm", "a8766c0bc92f074e5cb36c4f9961982eda84c5d2b8e979ca67f5c268ec8ed580"},
   "gettext": {:hex, :gettext, "0.26.1", "38e14ea5dcf962d1fc9f361b63ea07c0ce715a8ef1f9e82d3dfb8e67e0416715", [:mix], [{:expo, "~> 0.5.1 or ~> 1.0", [hex: :expo, repo: "hexpm", optional: false]}], "hexpm", "01ce56f188b9dc28780a52783d6529ad2bc7124f9744e571e1ee4ea88bf08734"},
-  "heroicons": {:git, "https://github.com/tailwindlabs/heroicons.git", "88ab3a0d790e6a47404cba02800a6b25d2afae50", [tag: "v2.1.1", sparse: "optimized"]},
+  "heroicons": {:git, "https://github.com/tailwindlabs/heroicons.git", "88ab3a0d790e6a47404cba02800a6b25d2afae50", [tag: "v2.1.1", sparse: "optimized", depth: 1]},
   "hpax": {:hex, :hpax, "1.0.0", "28dcf54509fe2152a3d040e4e3df5b265dcb6cb532029ecbacf4ce52caea3fd2", [:mix], [], "hexpm", "7f1314731d711e2ca5fdc7fd361296593fc2542570b3105595bb0bc6d0fad601"},
   "jason": {:hex, :jason, "1.4.4", "b9226785a9aa77b6857ca22832cffa5d5011a667207eb2a0ad56adb5db443b8a", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "c5eb0cab91f094599f94d55bc63409236a8ec69a21a67814529e8d5f6cc90b3b"},
   "mime": {:hex, :mime, "2.0.6", "8f18486773d9b15f95f4f4f1e39b710045fa1de891fada4516559967276e4dc2", [:mix], [], "hexpm", "c9945363a6b26d747389aac3643f8e0e09d30499a138ad64fe8fd1d13d9b153e"},

priv/repo/migrations/20241009214840_add_follows.exs

@@ -0,0 +1,11 @@
+defmodule Postland.Repo.Migrations.AddActors do
+  use Ecto.Migration
+
+  def change do
+    create table("follows", primary_key: false) do
+      add :follower, :string, primary_key: true
+      add :followee, :string, primary_key: true
+      add :confirmed_at, :naive_datetime
+    end
+  end
+end