Revert "Revert "Add remote follow pages.""

This reverts commit b259b4e4d1.

lib/pleroma/web/router.ex

@@ -28,6 +28,13 @@ defmodule Pleroma.Web.Router do
     plug Pleroma.Plugs.AuthenticationPlug, %{fetcher: &Router.user_fetcher/1, optional: true}
   end
 
+  pipeline :pleroma_html do
+    plug :accepts, ["html"]
+    plug :fetch_session
+    plug Pleroma.Plugs.OAuthPlug
+    plug Pleroma.Plugs.AuthenticationPlug, %{fetcher: &Router.user_fetcher/1, optional: true}
+  end
+
   pipeline :well_known do
     plug :accepts, ["xml", "xrd+xml"]
   end
@@ -51,6 +58,12 @@ defmodule Pleroma.Web.Router do
     get "/emoji", UtilController, :emoji
   end
 
+  scope "/", Pleroma.Web.TwitterAPI do
+    pipe_through :pleroma_html
+    get "/ostatus_subscribe", UtilController, :remote_follow
+    post "/ostatus_subscribe", UtilController, :do_remote_follow
+  end
+
   scope "/api/pleroma", Pleroma.Web.TwitterAPI do
     pipe_through :authenticated_api
     post "/follow_import", UtilController, :follow_import

lib/pleroma/web/templates/twitter_api/util/follow.html.eex

@@ -0,0 +1,11 @@
+<%= if @error == :error do %>
+    <h2>Error fetching user</h2>
+<% else %>
+    <h2>Remote follow</h2>
+    <img width="128" height="128" src="<%= @avatar %>">
+    <p><%= @name %></p>
+    <%= form_for @conn, util_path(@conn, :do_remote_follow), [as: "user"], fn f -> %>
+    <%= hidden_input f, :id, value: @id %>
+    <%= submit "Authorize" %>
+    <% end %>
+<% end %>

lib/pleroma/web/templates/twitter_api/util/follow_login.html.eex

@@ -0,0 +1,14 @@
+<%= if @error do %>
+    <h2><%= @error %></h2>
+<% end %>
+<h2>Log in to follow</h2>
+<p><%= @name %></p>
+<img height="128" width="128" src="<%= @avatar %>">
+<%= form_for @conn, util_path(@conn, :do_remote_follow), [as: "authorization"], fn f -> %>
+<%= text_input f, :name, placeholder: "Username" %>
+<br>
+<%= password_input f, :password, placeholder: "Password" %>
+<br>
+<%= hidden_input f, :id, value: @id %>
+<%= submit "Authorize" %>
+<% end %>

lib/pleroma/web/templates/twitter_api/util/followed.html.eex

@@ -0,0 +1,6 @@
+<%= if @error do %>
+<p>Error following account</p>
+<% else %>
+<h2>Account followed!</h2>
+<% end %>
+

lib/pleroma/web/twitter_api/controllers/util_controller.ex

@@ -2,6 +2,8 @@ defmodule Pleroma.Web.TwitterAPI.UtilController do
   use Pleroma.Web, :controller
   require Logger
   alias Pleroma.Web
+  alias Pleroma.Web.OStatus
+  alias Comeonin.Pbkdf2
   alias Pleroma.Formatter
   alias Pleroma.Web.ActivityPub.ActivityPub
   alias Pleroma.{Repo, PasswordResetToken, User}
@@ -30,6 +32,52 @@ defmodule Pleroma.Web.TwitterAPI.UtilController do
     json(conn, "ok")
   end
 
+  def remote_follow(%{assigns: %{user: user}} = conn, %{"acct" => acct}) do
+    {err, followee} = OStatus.find_or_make_user(acct)
+    avatar = User.avatar_url(followee)
+    name = followee.nickname
+    id = followee.id
+
+    if !!user do
+      conn
+      |> render("follow.html", %{error: err, acct: acct, avatar: avatar, name: name, id: id})
+    else
+      conn
+      |> render("follow_login.html", %{error: false, acct: acct, avatar: avatar, name: name, id: id})
+    end
+  end
+
+  def do_remote_follow(conn, %{"authorization" => %{"name" => username, "password" => password, "id" => id}}) do
+    followee = Repo.get(User, id)
+    avatar = User.avatar_url(followee)
+    name = followee.nickname
+    with %User{} = user <- User.get_cached_by_nickname(username),
+         true <- Pbkdf2.checkpw(password, user.password_hash),
+           %User{} = followed <- Repo.get(User, id),
+         {:ok, follower} <- User.follow(user, followee),
+         {:ok, _activity} <- ActivityPub.follow(follower, followee) do
+      conn
+      |> render("followed.html", %{error: false})
+    else
+      _e ->
+        conn
+        |> render("follow_login.html", %{error: "Wrong username or password", id: id, name: name, avatar: avatar})
+    end
+  end
+  def do_remote_follow(%{assigns: %{user: user}} = conn, %{"user" => %{"id" => id}}) do
+    with %User{} = followee <- Repo.get(User, id),
+         {:ok, follower} <- User.follow(user, followee),
+         {:ok, _activity} <- ActivityPub.follow(follower, followee) do
+      conn
+      |> render("followed.html", %{error: false})
+    else
+      e ->
+        Logger.debug("Remote follow failed with error #{inspect e}")
+      conn
+      |> render("followed.html", %{error: inspect(e)})
+    end
+  end
+
   @instance Application.get_env(:pleroma, :instance)
   def config(conn, _params) do
     case get_format(conn) do