Fix/1019 correct count remote users

lib/pleroma/application.ex

@@ -151,7 +151,11 @@ defmodule Pleroma.Application do
             start: {Pleroma.Web.Endpoint, :start_link, []},
             type: :supervisor
           },
-          %{id: Pleroma.Gopher.Server, start: {Pleroma.Gopher.Server, :start_link, []}}
+          %{id: Pleroma.Gopher.Server, start: {Pleroma.Gopher.Server, :start_link, []}},
+          %{
+            id: Pleroma.User.SynchronizationWorker,
+            start: {Pleroma.User.SynchronizationWorker, :start_link, []}
+          }
         ]
 
     # See http://elixir-lang.org/docs/stable/elixir/Supervisor.html

lib/pleroma/user.ex

@@ -107,15 +107,25 @@ defmodule Pleroma.User do
   def ap_followers(%User{follower_address: fa}) when is_binary(fa), do: fa
   def ap_followers(%User{} = user), do: "#{ap_id(user)}/followers"
 
-  def user_info(%User{} = user) do
+  def user_info(%User{} = user, args \\ %{}) do
+    following_count =
+      if args[:following_count], do: args[:following_count], else: following_count(user)
+
+    follower_count =
+      if args[:follower_count], do: args[:follower_count], else: user.info.follower_count
+
     %{
-      following_count: following_count(user),
       note_count: user.info.note_count,
-      follower_count: user.info.follower_count,
       locked: user.info.locked,
       confirmation_pending: user.info.confirmation_pending,
       default_scope: user.info.default_scope
     }
+    |> Map.put(:following_count, following_count)
+    |> Map.put(:follower_count, follower_count)
+  end
+
+  def set_info_cache(user, args) do
+    Cachex.put(:user_cache, "user_info:#{user.id}", user_info(user, args))
   end
 
   def restrict_deactivated(query) do
@@ -1000,6 +1010,56 @@ defmodule Pleroma.User do
     )
   end
 
+  @spec sync_follow_counter() :: :ok
+  def sync_follow_counter,
+    do: PleromaJobQueue.enqueue(:background, __MODULE__, [:sync_follow_counters])
+
+  @spec perform(:sync_follow_counters) :: :ok
+  def perform(:sync_follow_counters) do
+    {:ok, _pid} = Agent.start_link(fn -> %{} end, name: :domain_errors)
+    config = Pleroma.Config.get([:instance, :external_user_synchronization])
+
+    :ok = sync_follow_counters(config)
+    Agent.stop(:domain_errors)
+  end
+
+  @spec sync_follow_counters(keyword()) :: :ok
+  def sync_follow_counters(opts \\ []) do
+    users = external_users(opts)
+
+    if length(users) > 0 do
+      errors = Agent.get(:domain_errors, fn state -> state end)
+      {last, updated_errors} = User.Synchronization.call(users, errors, opts)
+      Agent.update(:domain_errors, fn _state -> updated_errors end)
+      sync_follow_counters(max_id: last.id, limit: opts[:limit])
+    else
+      :ok
+    end
+  end
+
+  @spec external_users(keyword()) :: [User.t()]
+  def external_users(opts \\ []) do
+    query =
+      User.Query.build(%{
+        external: true,
+        active: true,
+        order_by: :id,
+        select: [:id, :ap_id, :info]
+      })
+
+    query =
+      if opts[:max_id],
+        do: where(query, [u], u.id > ^opts[:max_id]),
+        else: query
+
+    query =
+      if opts[:limit],
+        do: limit(query, ^opts[:limit]),
+        else: query
+
+    Repo.all(query)
+  end
+
   def blocks_import(%User{} = blocker, blocked_identifiers) when is_list(blocked_identifiers),
     do:
       PleromaJobQueue.enqueue(:background, __MODULE__, [

lib/pleroma/user/query.ex

@@ -7,7 +7,7 @@ defmodule Pleroma.User.Query do
   User query builder module. Builds query from new query or another user query.
 
     ## Example:
-        query = Pleroma.User.Query(%{nickname: "nickname"})
+        query = Pleroma.User.Query.build(%{nickname: "nickname"})
         another_query = Pleroma.User.Query.build(query, %{email: "email@example.com"})
         Pleroma.Repo.all(query)
         Pleroma.Repo.all(another_query)
@@ -47,7 +47,10 @@ defmodule Pleroma.User.Query do
             friends: User.t(),
             recipients_from_activity: [String.t()],
             nickname: [String.t()],
-            ap_id: [String.t()]
+            ap_id: [String.t()],
+            order_by: term(),
+            select: term(),
+            limit: pos_integer()
           }
           | %{}
 
@@ -141,6 +144,18 @@ defmodule Pleroma.User.Query do
     where(query, [u], u.ap_id in ^to or fragment("? && ?", u.following, ^to))
   end
 
+  defp compose_query({:order_by, key}, query) do
+    order_by(query, [u], field(u, ^key))
+  end
+
+  defp compose_query({:select, keys}, query) do
+    select(query, [u], ^keys)
+  end
+
+  defp compose_query({:limit, limit}, query) do
+    limit(query, ^limit)
+  end
+
   defp compose_query(_unsupported_param, query), do: query
 
   defp prepare_tag_criteria(tag, query) do

lib/pleroma/user/synchronization.ex

@@ -0,0 +1,60 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2018 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.User.Synchronization do
+  alias Pleroma.HTTP
+  alias Pleroma.User
+
+  @spec call([User.t()], map(), keyword()) :: {User.t(), map()}
+  def call(users, errors, opts \\ []) do
+    do_call(users, errors, opts)
+  end
+
+  defp do_call([user | []], errors, opts) do
+    updated = fetch_counters(user, errors, opts)
+    {user, updated}
+  end
+
+  defp do_call([user | others], errors, opts) do
+    updated = fetch_counters(user, errors, opts)
+    do_call(others, updated, opts)
+  end
+
+  defp fetch_counters(user, errors, opts) do
+    %{host: host} = URI.parse(user.ap_id)
+
+    info = %{}
+    {following, errors} = fetch_counter(user.ap_id <> "/following", host, errors, opts)
+    info = if following, do: Map.put(info, :following_count, following), else: info
+
+    {followers, errors} = fetch_counter(user.ap_id <> "/followers", host, errors, opts)
+    info = if followers, do: Map.put(info, :follower_count, followers), else: info
+
+    User.set_info_cache(user, info)
+    errors
+  end
+
+  defp available_domain?(domain, errors, opts) do
+    max_retries = Keyword.get(opts, :max_retries, 3)
+    not (Map.has_key?(errors, domain) && errors[domain] >= max_retries)
+  end
+
+  defp fetch_counter(url, host, errors, opts) do
+    with true <- available_domain?(host, errors, opts),
+         {:ok, %{body: body, status: code}} when code in 200..299 <-
+           HTTP.get(
+             url,
+             [{:Accept, "application/activity+json"}]
+           ),
+         {:ok, data} <- Jason.decode(body) do
+      {data["totalItems"], errors}
+    else
+      false ->
+        {nil, errors}
+
+      _ ->
+        {nil, Map.update(errors, host, 1, &(&1 + 1))}
+    end
+  end
+end

lib/pleroma/user/synchronization_worker.ex

@@ -0,0 +1,32 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2018 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-onl
+
+defmodule Pleroma.User.SynchronizationWorker do
+  use GenServer
+
+  def start_link do
+    config = Pleroma.Config.get([:instance, :external_user_synchronization])
+
+    if config[:enabled] do
+      GenServer.start_link(__MODULE__, interval: config[:interval])
+    else
+      :ignore
+    end
+  end
+
+  def init(opts) do
+    schedule_next(opts)
+    {:ok, opts}
+  end
+
+  def handle_info(:sync_follow_counters, opts) do
+    Pleroma.User.sync_follow_counter()
+    schedule_next(opts)
+    {:noreply, opts}
+  end
+
+  defp schedule_next(opts) do
+    Process.send_after(self(), :sync_follow_counters, opts[:interval])
+  end
+end