From 8add1194448cfc183dce01b86451422195d44023 Mon Sep 17 00:00:00 2001
From: Roman Chvanikov <chvanikoff@gmail.com>
Date: Fri, 19 Apr 2019 22:17:54 +0700
Subject: [PATCH] Add User.list_inactive_users_query/1

---
 lib/pleroma/user.ex                           |  38 +++++++
 ...d_signin_and_last_digest_dates_to_user.exs |   9 ++
 test/user_test.exs                            | 103 ++++++++++++++++++
 3 files changed, 150 insertions(+)
 create mode 100644 priv/repo/migrations/20190413085040_add_signin_and_last_digest_dates_to_user.exs

diff --git a/lib/pleroma/user.ex b/lib/pleroma/user.ex
index 0982f6ed8..c67a7b7a1 100644
--- a/lib/pleroma/user.ex
+++ b/lib/pleroma/user.ex
@@ -1447,4 +1447,42 @@ defp paginate(query, page, page_size) do
   def showing_reblogs?(%User{} = user, %User{} = target) do
     target.ap_id not in user.info.muted_reblogs
   end
+
+  @doc """
+  The function returns a query to get users with no activity for given interval of days.
+  Inactive users are those who didn't read any notification, or had any activity where
+  the user is the activity's actor, during `inactivity_threshold` days.
+  Deactivated users will not appear in this list.
+
+  ## Examples
+
+      iex> Pleroma.User.list_inactive_users()
+      %Ecto.Query{}
+  """
+  @spec list_inactive_users_query(integer()) :: Ecto.Query.t()
+  def list_inactive_users_query(inactivity_threshold \\ 7) do
+    negative_inactivity_threshold = -inactivity_threshold
+    now = NaiveDateTime.truncate(NaiveDateTime.utc_now(), :second)
+    # Subqueries are not supported in `where` clauses, join gets too complicated.
+    has_read_notifications =
+      from(n in Pleroma.Notification,
+        where: n.seen == true,
+        group_by: n.id,
+        having: max(n.updated_at) > datetime_add(^now, ^negative_inactivity_threshold, "day"),
+        select: n.user_id
+      )
+      |> Pleroma.Repo.all()
+
+    from(u in Pleroma.User,
+      left_join: a in Pleroma.Activity,
+      on: u.ap_id == a.actor,
+      where: not is_nil(u.nickname),
+      where: fragment("not (?->'deactivated' @> 'true')", u.info),
+      where: u.id not in ^has_read_notifications,
+      group_by: u.id,
+      having:
+        max(a.inserted_at) < datetime_add(^now, ^negative_inactivity_threshold, "day") or
+          is_nil(max(a.inserted_at))
+    )
+  end
 end
diff --git a/priv/repo/migrations/20190413085040_add_signin_and_last_digest_dates_to_user.exs b/priv/repo/migrations/20190413085040_add_signin_and_last_digest_dates_to_user.exs
new file mode 100644
index 000000000..4312b171f
--- /dev/null
+++ b/priv/repo/migrations/20190413085040_add_signin_and_last_digest_dates_to_user.exs
@@ -0,0 +1,9 @@
+defmodule Pleroma.Repo.Migrations.AddSigninAndLastDigestDatesToUser do
+  use Ecto.Migration
+
+  def change do
+    alter table(:users) do
+      add(:last_digest_emailed_at, :naive_datetime, default: fragment("now()"))
+    end
+  end
+end
diff --git a/test/user_test.exs b/test/user_test.exs
index d2167a970..ba02997dc 100644
--- a/test/user_test.exs
+++ b/test/user_test.exs
@@ -1167,4 +1167,107 @@ test "follower count is updated when a follower is blocked" do
 
     assert Map.get(user_show, "followers_count") == 2
   end
+
+  describe "list_inactive_users_query/1" do
+    defp days_ago(days) do
+      NaiveDateTime.add(
+        NaiveDateTime.truncate(NaiveDateTime.utc_now(), :second),
+        -days * 60 * 60 * 24,
+        :second
+      )
+    end
+
+    test "Users are inactive by default" do
+      total = 10
+
+      users =
+        Enum.map(1..total, fn _ ->
+          insert(:user, last_digest_emailed_at: days_ago(20), info: %{deactivated: false})
+        end)
+
+      inactive_users_ids =
+        Pleroma.User.list_inactive_users_query()
+        |> Pleroma.Repo.all()
+        |> Enum.map(& &1.id)
+
+      Enum.each(users, fn user ->
+        assert user.id in inactive_users_ids
+      end)
+    end
+
+    test "Only includes users who has no recent activity" do
+      total = 10
+
+      users =
+        Enum.map(1..total, fn _ ->
+          insert(:user, last_digest_emailed_at: days_ago(20), info: %{deactivated: false})
+        end)
+
+      {inactive, active} = Enum.split(users, trunc(total / 2))
+
+      Enum.map(active, fn user ->
+        to = Enum.random(users -- [user])
+
+        {:ok, _} =
+          Pleroma.Web.TwitterAPI.TwitterAPI.create_status(user, %{
+            "status" => "hey @#{to.nickname}"
+          })
+      end)
+
+      inactive_users_ids =
+        Pleroma.User.list_inactive_users_query()
+        |> Pleroma.Repo.all()
+        |> Enum.map(& &1.id)
+
+      Enum.each(active, fn user ->
+        refute user.id in inactive_users_ids
+      end)
+
+      Enum.each(inactive, fn user ->
+        assert user.id in inactive_users_ids
+      end)
+    end
+
+    test "Only includes users with no read notifications" do
+      total = 10
+
+      users =
+        Enum.map(1..total, fn _ ->
+          insert(:user, last_digest_emailed_at: days_ago(20), info: %{deactivated: false})
+        end)
+
+      [sender | recipients] = users
+      {inactive, active} = Enum.split(recipients, trunc(total / 2))
+
+      Enum.each(recipients, fn to ->
+        {:ok, _} =
+          Pleroma.Web.TwitterAPI.TwitterAPI.create_status(sender, %{
+            "status" => "hey @#{to.nickname}"
+          })
+
+        {:ok, _} =
+          Pleroma.Web.TwitterAPI.TwitterAPI.create_status(sender, %{
+            "status" => "hey again @#{to.nickname}"
+          })
+      end)
+
+      Enum.each(active, fn user ->
+        [n1, _n2] = Pleroma.Notification.for_user(user)
+        {:ok, _} = Pleroma.Notification.read_one(user, n1.id)
+      end)
+
+      inactive_users_ids =
+        Pleroma.User.list_inactive_users_query()
+        |> Pleroma.Repo.all()
+        |> Enum.map(& &1.id)
+
+      Enum.each(active, fn user ->
+        refute user.id in inactive_users_ids
+      end)
+
+      Enum.each(inactive, fn user ->
+        assert user.id in inactive_users_ids
+      end)
+    end
+  end
 end