Merge branch 'feature/unsubscribe-user-task' into 'develop'

mix tasks: add new task to unsubscribe all users from, and then ban a remote user (e.g. followbots)

See merge request pleroma/pleroma!399

lib/mix/tasks/unsubscribe_user.ex

+defmodule Mix.Tasks.UnsubscribeUser do
+  use Mix.Task
+  alias Pleroma.{User, Repo}
+  require Logger
+
+  @shortdoc "Unsubscribe all users from a target and then deactivate them"
+  def run([nickname]) do
+    Mix.Task.run("app.start")
+
+    with %User{} = user <- User.get_by_nickname(nickname) do
+      Logger.info("Deactivating #{user.nickname}")
+      User.deactivate(user)
+
+      {:ok, friends} = User.get_friends(user)
+
+      Enum.each(friends, fn friend ->
+        user = Repo.get(User, user.id)
+
+        Logger.info("Unsubscribing #{friend.nickname} from #{user.nickname}")
+        User.unfollow(user, friend)
+      end)
+
+      :timer.sleep(500)
+
+      user = Repo.get(User, user.id)
+
+      if length(user.following) == 0 do
+        Logger.info("Successfully unsubscribed all followers from #{user.nickname}")
+      end
+    end
+  end
+end