feat: Add rudimentary follow UI

lib/activity_pub.ex

@@ -1,15 +1,31 @@
 defmodule ActivityPub do
+  def get(url, actor_url, private_key) do
+    headers = ActivityPub.Headers.signing_headers("GET", url, "", actor_url, private_key)
+
+    Req.new(url: url)
+    |> Req.Request.put_header("accept", "application/activity+json")
+    |> Req.Request.put_headers(headers)
+    |> Req.get()
+    |> case do
+      {:ok, response} ->
+        {:ok, response.body}
+
+      other ->
+        other
+    end
+  end
+
   def fetch_actor(actor_id) do
-      request =
-        Req.new(url: actor_id)
-        |> Req.Request.put_header("accept", "application/json")
+    request =
+      Req.new(url: actor_id)
+      |> Req.Request.put_header("accept", "application/json")
 
-      case Req.get(request) do
-        {:ok, result} ->
-          {:ok, result.body}
+    case Req.get(request) do
+      {:ok, result} ->
+        {:ok, result.body}
 
-        error ->
-          error
-      end
+      error ->
+        error
+    end
   end
 end

lib/activity_pub/webfinger.ex

@@ -0,0 +1,22 @@
+defmodule ActivityPub.Webfinger do
+  def lookup_resource(acct_handle) do
+    [_handle, domain] = String.split(acct_handle, "@")
+
+    uri = %URI{
+      scheme: "https",
+      authority: domain,
+      host: domain,
+      port: 443,
+      path: "/.well-known/webfinger",
+      query: "resource=acct:#{acct_handle}"
+    }
+
+    case Req.get(uri) do
+      {:ok, response} ->
+        {:ok, response.body}
+
+      other ->
+        other
+    end
+  end
+end

lib/postland/follows.ex

@@ -43,14 +43,27 @@ defmodule Postland.Follows do
           }
           |> Jason.encode!()
 
-        headers = Headers.signing_headers("POST", inbox, body, Postland.my_actor_id(), Accounts.solo_user().private_key)
+        headers =
+          Headers.signing_headers(
+            "POST",
+            inbox,
+            body,
+            Postland.my_actor_id(),
+            Accounts.solo_user().private_key
+          )
 
         Req.post(inbox, headers: headers, body: body)
     end
   end
 
   def get_follow_activity(follower) do
-    from(a in Activity, where: a.type == "Follow", where: a.actor_id == ^follower, limit: 1, order_by: [desc: :inserted_at]) |> Repo.one()
+    from(a in Activity,
+      where: a.type == "Follow",
+      where: a.actor_id == ^follower,
+      limit: 1,
+      order_by: [desc: :inserted_at]
+    )
+    |> Repo.one()
   end
 
   def record_and_send_follow_request(to_actor_id) do
@@ -60,6 +73,19 @@ defmodule Postland.Follows do
       send_follow_request(to_actor_id)
     end)
     |> Repo.transaction()
+    |> case do
+      {:ok, %{follow_record: follow_record}} = result ->
+        Phoenix.PubSub.broadcast(
+          Postland.PubSub,
+          "follows:#{to_actor_id}",
+          {:update, follow_record}
+        )
+
+        result
+
+      other ->
+        other
+    end
   end
 
   def send_follow_request(to_actor_id) do
@@ -68,22 +94,32 @@ defmodule Postland.Follows do
 
     {:ok, actor} = ActivityPub.fetch_actor(to_actor_id)
     inbox = Map.get(actor, "inbox")
-    follow_request = %{
+
+    follow_request =
+      %{
         "@context" => "https://www.w3.org/ns/activitystreams",
         "id" => url(~p"/follows/#{encoded_followee}/#{encoded_follower}"),
         "type" => "Follow",
         "actor" => Postland.my_actor_id(),
         "object" => to_actor_id
-    }
-    |> Jason.encode!()
+      }
+      |> Jason.encode!()
 
-    headers = Headers.signing_headers("POST", inbox, follow_request, Postland.my_actor_id(), Accounts.solo_user().private_key)
+    headers =
+      Headers.signing_headers(
+        "POST",
+        inbox,
+        follow_request,
+        Postland.my_actor_id(),
+        Accounts.solo_user().private_key
+      )
 
     Req.post(inbox, headers: headers, body: follow_request)
   end
 
   def get(follower, followee) do
-    from(f in Follow, where: f.followee == ^followee, where: f.follower == ^follower) |> Repo.one()
+    from(f in Follow, where: f.followee == ^followee, where: f.follower == ^follower)
+    |> Repo.one()
   end
 
   def pending_inbound_requests() do
@@ -109,5 +145,9 @@ defmodule Postland.Follows do
     request
     |> Follow.confirm_changeset()
     |> Repo.update()
+    |> case do
+      {:ok, follow} ->
+        Phoenix.PubSub.broadcast(Postland.PubSub, "follows:#{follow.followee}", {:update, follow})
+    end
   end
 end

lib/postland_web/controllers/export_controller.ex

@@ -9,7 +9,7 @@ defmodule PostlandWeb.ExportController do
     files = [filename, "#{filename}-shm", "#{filename}-wal"] |> Enum.map(&String.to_charlist/1)
     zip_path = Path.join([File.cwd!(), "priv", "tmp", "db-export.zip"])
 
-    :zip.create(zip_path, files, cwd: dirname)
+    :zip.create(String.to_charlist(zip_path), files, cwd: dirname)
 
     send_download(conn, {:file, zip_path}, filename: "db-export.zip")
   end

lib/postland_web/live/other_profile_live.ex

@@ -0,0 +1,77 @@
+defmodule PostlandWeb.OtherProfileLive do
+  use PostlandWeb, :live_view
+
+  alias Postland.Follows
+
+  def render(assigns) do
+    ~H"""
+    <h1><%= Map.get(@profile, "name") %> (<%= @acct %>)</h1>
+    <%= case @follow do %>
+      <% nil -> %>
+        <.button phx-click="follow">Follow</.button>
+      <% %{confirmed_at: nil} -> %>
+        <.button disabled>Pending</.button>
+      <% _ -> %>
+        <.button phx-click="unfollow">Unfollow</.button>
+    <% end %>
+    <.list>
+      <:item :for={attachment <- Map.get(@profile, "attachment")} title={attachment["name"]}>
+        <%= attachment["value"] %>
+      </:item>
+    </.list>
+    """
+  end
+
+  def mount(params, _session, socket) do
+    {:ok, resource} = ActivityPub.Webfinger.lookup_resource(Map.get(params, "acct"))
+
+    %{"href" => json_profile} =
+      resource
+      |> Map.get("links")
+      |> Enum.find(fn %{"rel" => rel} = link ->
+        rel == "self" && String.contains?(Map.get(link, "type"), "json")
+      end)
+
+    {:ok, profile} =
+      ActivityPub.get(
+        json_profile,
+        Postland.my_actor_id(),
+        Postland.Accounts.solo_user().private_key
+      )
+
+    follow = Follows.get(Postland.my_actor_id(), json_profile)
+
+    if Phoenix.LiveView.connected?(socket) do
+      Phoenix.PubSub.subscribe(Postland.PubSub, "follows:#{json_profile}")
+    end
+
+    {:ok,
+     assign(socket,
+       acct: Map.get(params, "acct"),
+       actor_id: json_profile,
+       follow: follow,
+       profile: profile
+     )}
+  end
+
+  def handle_event("follow", _unsigned_params, socket) do
+    actor_id = socket.assigns.actor_id
+
+    case Follows.record_and_send_follow_request(actor_id) do
+      {:ok, _} ->
+        {:noreply,
+         socket
+         |> put_flash(:success, "Follow request sent.")
+         |> assign(follow: Follows.get(Postland.my_actor_id(), actor_id))}
+
+      _other ->
+        {:noreply,
+         socket
+         |> put_flash(:error, "An unexpected error has occurred.")}
+    end
+  end
+
+  def handle_info({:update, follow}, socket) do
+    {:noreply, assign(socket, follow: follow)}
+  end
+end

lib/postland_web/router.ex

@@ -80,6 +80,7 @@ defmodule PostlandWeb.Router do
     live_session :require_authenticated_user,
       on_mount: [{PostlandWeb.UserAuth, :ensure_authenticated}] do
       live "/users/settings", UserSettingsLive, :edit
+      live "/@:acct", OtherProfileLive, :show
     end
   end