Revert "Merge branch 'streamer-refactoring' into 'develop'"

This reverts merge request !1653

1 files changed, 318 insertions, 0 deletions

diff --git a/lib/pleroma/web/streamer.ex b/lib/pleroma/web/streamer.ex
new file mode 100644
index 000000000..587c43f40
--- /dev/null
+++ b/lib/pleroma/web/streamer.ex
@@ -0,0 +1,318 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.Streamer do
+  use GenServer
+  require Logger
+  alias Pleroma.Activity
+  alias Pleroma.Config
+  alias Pleroma.Conversation.Participation
+  alias Pleroma.Notification
+  alias Pleroma.Object
+  alias Pleroma.User
+  alias Pleroma.Web.ActivityPub.ActivityPub
+  alias Pleroma.Web.ActivityPub.Visibility
+  alias Pleroma.Web.CommonAPI
+  alias Pleroma.Web.MastodonAPI.NotificationView
+
+  @keepalive_interval :timer.seconds(30)
+
+  def start_link(_) do
+    GenServer.start_link(__MODULE__, %{}, name: __MODULE__)
+  end
+
+  def add_socket(topic, socket) do
+    GenServer.cast(__MODULE__, %{action: :add, socket: socket, topic: topic})
+  end
+
+  def remove_socket(topic, socket) do
+    GenServer.cast(__MODULE__, %{action: :remove, socket: socket, topic: topic})
+  end
+
+  def stream(topic, item) do
+    GenServer.cast(__MODULE__, %{action: :stream, topic: topic, item: item})
+  end
+
+  def init(args) do
+    Process.send_after(self(), %{action: :ping}, @keepalive_interval)
+
+    {:ok, args}
+  end
+
+  def handle_info(%{action: :ping}, topics) do
+    topics
+    |> Map.values()
+    |> List.flatten()
+    |> Enum.each(fn socket ->
+      Logger.debug("Sending keepalive ping")
+      send(socket.transport_pid, {:text, ""})
+    end)
+
+    Process.send_after(self(), %{action: :ping}, @keepalive_interval)
+
+    {:noreply, topics}
+  end
+
+  def handle_cast(%{action: :stream, topic: "direct", item: item}, topics) do
+    recipient_topics =
+      User.get_recipients_from_activity(item)
+      |> Enum.map(fn %{id: id} -> "direct:#{id}" end)
+
+    Enum.each(recipient_topics || [], fn user_topic ->
+      Logger.debug("Trying to push direct message to #{user_topic}\n\n")
+      push_to_socket(topics, user_topic, item)
+    end)
+
+    {:noreply, topics}
+  end
+
+  def handle_cast(%{action: :stream, topic: "participation", item: participation}, topics) do
+    user_topic = "direct:#{participation.user_id}"
+    Logger.debug("Trying to push a conversation participation to #{user_topic}\n\n")
+
+    push_to_socket(topics, user_topic, participation)
+
+    {:noreply, topics}
+  end
+
+  def handle_cast(%{action: :stream, topic: "list", item: item}, topics) do
+    # filter the recipient list if the activity is not public, see #270.
+    recipient_lists =
+      case Visibility.is_public?(item) do
+        true ->
+          Pleroma.List.get_lists_from_activity(item)
+
+        _ ->
+          Pleroma.List.get_lists_from_activity(item)
+          |> Enum.filter(fn list ->
+            owner = User.get_cached_by_id(list.user_id)
+
+            Visibility.visible_for_user?(item, owner)
+          end)
+      end
+
+    recipient_topics =
+      recipient_lists
+      |> Enum.map(fn %{id: id} -> "list:#{id}" end)
+
+    Enum.each(recipient_topics || [], fn list_topic ->
+      Logger.debug("Trying to push message to #{list_topic}\n\n")
+      push_to_socket(topics, list_topic, item)
+    end)
+
+    {:noreply, topics}
+  end
+
+  def handle_cast(
+        %{action: :stream, topic: topic, item: %Notification{} = item},
+        topics
+      )
+      when topic in ["user", "user:notification"] do
+    topics
+    |> Map.get("#{topic}:#{item.user_id}", [])
+    |> Enum.each(fn socket ->
+      with %User{} = user <- User.get_cached_by_ap_id(socket.assigns[:user].ap_id),
+           true <- should_send?(user, item) do
+        send(
+          socket.transport_pid,
+          {:text, represent_notification(socket.assigns[:user], item)}
+        )
+      end
+    end)
+
+    {:noreply, topics}
+  end
+
+  def handle_cast(%{action: :stream, topic: "user", item: item}, topics) do
+    Logger.debug("Trying to push to users")
+
+    recipient_topics =
+      User.get_recipients_from_activity(item)
+      |> Enum.map(fn %{id: id} -> "user:#{id}" end)
+
+    Enum.each(recipient_topics, fn topic ->
+      push_to_socket(topics, topic, item)
+    end)
+
+    {:noreply, topics}
+  end
+
+  def handle_cast(%{action: :stream, topic: topic, item: item}, topics) do
+    Logger.debug("Trying to push to #{topic}")
+    Logger.debug("Pushing item to #{topic}")
+    push_to_socket(topics, topic, item)
+    {:noreply, topics}
+  end
+
+  def handle_cast(%{action: :add, topic: topic, socket: socket}, sockets) do
+    topic = internal_topic(topic, socket)
+    sockets_for_topic = sockets[topic] || []
+    sockets_for_topic = Enum.uniq([socket | sockets_for_topic])
+    sockets = Map.put(sockets, topic, sockets_for_topic)
+    Logger.debug("Got new conn for #{topic}")
+    {:noreply, sockets}
+  end
+
+  def handle_cast(%{action: :remove, topic: topic, socket: socket}, sockets) do
+    topic = internal_topic(topic, socket)
+    sockets_for_topic = sockets[topic] || []
+    sockets_for_topic = List.delete(sockets_for_topic, socket)
+    sockets = Map.put(sockets, topic, sockets_for_topic)
+    Logger.debug("Removed conn for #{topic}")
+    {:noreply, sockets}
+  end
+
+  def handle_cast(m, state) do
+    Logger.info("Unknown: #{inspect(m)}, #{inspect(state)}")
+    {:noreply, state}
+  end
+
+  defp represent_update(%Activity{} = activity, %User{} = user) do
+    %{
+      event: "update",
+      payload:
+        Pleroma.Web.MastodonAPI.StatusView.render(
+          "status.json",
+          activity: activity,
+          for: user
+        )
+        |> Jason.encode!()
+    }
+    |> Jason.encode!()
+  end
+
+  defp represent_update(%Activity{} = activity) do
+    %{
+      event: "update",
+      payload:
+        Pleroma.Web.MastodonAPI.StatusView.render(
+          "status.json",
+          activity: activity
+        )
+        |> Jason.encode!()
+    }
+    |> Jason.encode!()
+  end
+
+  def represent_conversation(%Participation{} = participation) do
+    %{
+      event: "conversation",
+      payload:
+        Pleroma.Web.MastodonAPI.ConversationView.render("participation.json", %{
+          participation: participation,
+          for: participation.user
+        })
+        |> Jason.encode!()
+    }
+    |> Jason.encode!()
+  end
+
+  @spec represent_notification(User.t(), Notification.t()) :: binary()
+  defp represent_notification(%User{} = user, %Notification{} = notify) do
+    %{
+      event: "notification",
+      payload:
+        NotificationView.render(
+          "show.json",
+          %{notification: notify, for: user}
+        )
+        |> Jason.encode!()
+    }
+    |> Jason.encode!()
+  end
+
+  defp should_send?(%User{} = user, %Activity{} = item) do
+    blocks = user.info.blocks || []
+    mutes = user.info.mutes || []
+    reblog_mutes = user.info.muted_reblogs || []
+    domain_blocks = Pleroma.Web.ActivityPub.MRF.subdomains_regex(user.info.domain_blocks)
+
+    with parent when not is_nil(parent) <- Object.normalize(item),
+         true <- Enum.all?([blocks, mutes, reblog_mutes], &(item.actor not in &1)),
+         true <- Enum.all?([blocks, mutes], &(parent.data["actor"] not in &1)),
+         %{host: item_host} <- URI.parse(item.actor),
+         %{host: parent_host} <- URI.parse(parent.data["actor"]),
+         false <- Pleroma.Web.ActivityPub.MRF.subdomain_match?(domain_blocks, item_host),
+         false <- Pleroma.Web.ActivityPub.MRF.subdomain_match?(domain_blocks, parent_host),
+         true <- thread_containment(item, user),
+         false <- CommonAPI.thread_muted?(user, item) do
+      true
+    else
+      _ -> false
+    end
+  end
+
+  defp should_send?(%User{} = user, %Notification{activity: activity}) do
+    should_send?(user, activity)
+  end
+
+  def push_to_socket(topics, topic, %Activity{data: %{"type" => "Announce"}} = item) do
+    Enum.each(topics[topic] || [], fn socket ->
+      # Get the current user so we have up-to-date blocks etc.
+      if socket.assigns[:user] do
+        user = User.get_cached_by_ap_id(socket.assigns[:user].ap_id)
+
+        if should_send?(user, item) do
+          send(socket.transport_pid, {:text, represent_update(item, user)})
+        end
+      else
+        send(socket.transport_pid, {:text, represent_update(item)})
+      end
+    end)
+  end
+
+  def push_to_socket(topics, topic, %Participation{} = participation) do
+    Enum.each(topics[topic] || [], fn socket ->
+      send(socket.transport_pid, {:text, represent_conversation(participation)})
+    end)
+  end
+
+  def push_to_socket(topics, topic, %Activity{
+        data: %{"type" => "Delete", "deleted_activity_id" => deleted_activity_id}
+      }) do
+    Enum.each(topics[topic] || [], fn socket ->
+      send(
+        socket.transport_pid,
+        {:text, %{event: "delete", payload: to_string(deleted_activity_id)} |> Jason.encode!()}
+      )
+    end)
+  end
+
+  def push_to_socket(_topics, _topic, %Activity{data: %{"type" => "Delete"}}), do: :noop
+
+  def push_to_socket(topics, topic, item) do
+    Enum.each(topics[topic] || [], fn socket ->
+      # Get the current user so we have up-to-date blocks etc.
+      if socket.assigns[:user] do
+        user = User.get_cached_by_ap_id(socket.assigns[:user].ap_id)
+        blocks = user.info.blocks || []
+        mutes = user.info.mutes || []
+
+        with true <- Enum.all?([blocks, mutes], &(item.actor not in &1)),
+             true <- thread_containment(item, user) do
+          send(socket.transport_pid, {:text, represent_update(item, user)})
+        end
+      else
+        send(socket.transport_pid, {:text, represent_update(item)})
+      end
+    end)
+  end
+
+  defp internal_topic(topic, socket) when topic in ~w[user user:notification direct] do
+    "#{topic}:#{socket.assigns[:user].id}"
+  end
+
+  defp internal_topic(topic, _), do: topic
+
+  @spec thread_containment(Activity.t(), User.t()) :: boolean()
+  defp thread_containment(_activity, %User{info: %{skip_thread_containment: true}}), do: true
+
+  defp thread_containment(activity, user) do
+    if Config.get([:instance, :skip_thread_containment]) do
+      true
+    else
+      ActivityPub.contain_activity(activity, user)
+    end
+  end
+end