mobilizon/lib/federation/activity_pub/relay.ex
2020-01-26 21:39:49 +01:00

157 lines
5.1 KiB
Elixir

# Portions of this file are derived from Pleroma:
# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social>
# SPDX-License-Identifier: AGPL-3.0-only
# Upstream: https://git.pleroma.social/pleroma/pleroma/blob/develop/lib/pleroma/web/activity_pub/relay.ex
defmodule Mobilizon.Federation.ActivityPub.Relay do
@moduledoc """
Handles following and unfollowing relays and instances.
"""
alias Mobilizon.Actors
alias Mobilizon.Actors.{Actor, Follower}
alias Mobilizon.Federation.ActivityPub
alias Mobilizon.Federation.ActivityPub.{Activity, Transmogrifier}
alias Mobilizon.Federation.WebFinger
alias Mobilizon.GraphQL.API.Follows
require Logger
def init() do
# Wait for everything to settle.
Process.sleep(1000 * 5)
get_actor()
end
@spec get_actor() :: Actor.t() | {:error, Ecto.Changeset.t()}
def get_actor do
with {:ok, %Actor{} = actor} <-
Actors.get_or_create_instance_actor_by_url("#{Mobilizon.Web.Endpoint.url()}/relay") do
actor
end
end
@spec follow(String.t()) :: {:ok, Activity.t(), Follower.t()}
def follow(address) do
with {:ok, target_instance} <- fetch_actor(address),
%Actor{} = local_actor <- get_actor(),
{:ok, %Actor{} = target_actor} <- ActivityPub.get_or_fetch_actor_by_url(target_instance),
{:ok, activity, follow} <- Follows.follow(local_actor, target_actor) do
Logger.info("Relay: followed instance #{target_instance}; id=#{activity.data["id"]}")
{:ok, activity, follow}
else
e ->
Logger.warn("Error while following remote instance: #{inspect(e)}")
{:error, e}
end
end
@spec unfollow(String.t()) :: {:ok, Activity.t(), Follower.t()}
def unfollow(address) do
with {:ok, target_instance} <- fetch_actor(address),
%Actor{} = local_actor <- get_actor(),
{:ok, %Actor{} = target_actor} <- ActivityPub.get_or_fetch_actor_by_url(target_instance),
{:ok, activity, follow} <- Follows.unfollow(local_actor, target_actor) do
Logger.info("Relay: unfollowed instance #{target_instance}: id=#{activity.data["id"]}")
{:ok, activity, follow}
else
e ->
Logger.warn("Error while unfollowing remote instance: #{inspect(e)}")
{:error, e}
end
end
@spec accept(String.t()) :: {:ok, Activity.t(), Follower.t()}
def accept(address) do
Logger.debug("We're trying to accept a relay subscription")
with {:ok, target_instance} <- fetch_actor(address),
%Actor{} = local_actor <- get_actor(),
{:ok, %Actor{} = target_actor} <- ActivityPub.get_or_fetch_actor_by_url(target_instance),
{:ok, activity, follow} <- Follows.accept(target_actor, local_actor) do
{:ok, activity, follow}
end
end
def reject(address) do
Logger.debug("We're trying to reject a relay subscription")
with {:ok, target_instance} <- fetch_actor(address),
%Actor{} = local_actor <- get_actor(),
{:ok, %Actor{} = target_actor} <- ActivityPub.get_or_fetch_actor_by_url(target_instance),
{:ok, activity, follow} <- Follows.reject(target_actor, local_actor) do
{:ok, activity, follow}
end
end
@doc """
Publish an activity to all relays following this instance
"""
def publish(%Activity{data: %{"object" => object}} = _activity) do
with %Actor{id: actor_id} = actor <- get_actor(),
{object, object_id} <- fetch_object(object),
id <- "#{object_id}/announces/#{actor_id}" do
Logger.info("Publishing activity #{id} to all relays")
ActivityPub.announce(actor, object, id, true, false)
else
e ->
Logger.error("Error while getting local instance actor: #{inspect(e)}")
end
end
def publish(err) do
Logger.error("Tried to publish a bad activity")
Logger.debug(inspect(err))
nil
end
defp fetch_object(object) when is_map(object) do
with {:ok, object} <- Transmogrifier.fetch_obj_helper_as_activity_streams(object) do
{object, object["id"]}
end
end
defp fetch_object(object) when is_bitstring(object), do: {object, object}
@spec fetch_actor(String.t()) :: {:ok, String.t()} | {:error, String.t()}
# Dirty hack
defp fetch_actor("https://" <> address), do: fetch_actor(address)
defp fetch_actor("http://" <> address), do: fetch_actor(address)
defp fetch_actor(address) do
%URI{host: host} = URI.parse("http://" <> address)
cond do
String.contains?(address, "@") ->
check_actor(address)
!is_nil(host) ->
check_actor("relay@#{host}")
true ->
{:error, "Bad URL"}
end
end
@spec check_actor(String.t()) :: {:ok, String.t()} | {:error, String.t()}
defp check_actor(username_and_domain) do
case Actors.get_actor_by_name(username_and_domain) do
%Actor{url: url} -> {:ok, url}
nil -> finger_actor(username_and_domain)
end
end
@spec finger_actor(String.t()) :: {:ok, String.t()} | {:error, String.t()}
defp finger_actor(nickname) do
case WebFinger.finger(nickname) do
{:ok, %{"url" => url}} when not is_nil(url) ->
{:ok, url}
_e ->
{:error, "No ActivityPub URL found in WebFinger"}
end
end
end