+ |> validate_required([:scheduled_at])
+ |> validate_scheduled_at()
+ end
+
+ def validate_scheduled_at(changeset) do
+ validate_change(changeset, :scheduled_at, fn _, scheduled_at ->
+ cond do
+ not far_enough?(scheduled_at) ->
+ [scheduled_at: "must be at least 5 minutes from now"]
+
+ exceeds_daily_user_limit?(changeset.data.user_id, scheduled_at) ->
+ [scheduled_at: "daily limit exceeded"]
+
+ exceeds_total_user_limit?(changeset.data.user_id) ->
+ [scheduled_at: "total limit exceeded"]
+
+ true ->
+ []
+ end
+ end)
+ end
+
+ def exceeds_daily_user_limit?(user_id, scheduled_at) do
+ ScheduledActivity
+ |> where(user_id: ^user_id)
+ |> where([sa], type(sa.scheduled_at, :date) == type(^scheduled_at, :date))
+ |> select([sa], count(sa.id))
+ |> Repo.one()
+ |> Kernel.>=(Config.get([ScheduledActivity, :daily_user_limit]))
+ end
+
+ def exceeds_total_user_limit?(user_id) do
+ ScheduledActivity
+ |> where(user_id: ^user_id)
+ |> select([sa], count(sa.id))
+ |> Repo.one()
+ |> Kernel.>=(Config.get([ScheduledActivity, :total_user_limit]))
+ end
+
+ def far_enough?(scheduled_at) when is_binary(scheduled_at) do
+ with {:ok, scheduled_at} <- Ecto.Type.cast(:naive_datetime, scheduled_at) do
+ far_enough?(scheduled_at)
+ else
+ _ -> false
+ end
+ end
+
+ def far_enough?(scheduled_at) do
+ now = NaiveDateTime.utc_now()
+ diff = NaiveDateTime.diff(scheduled_at, now, :millisecond)
+ diff > @min_offset