philomena/lib/philomena/user_statistics.ex

defmodule Philomena.UserStatistics do
  @moduledoc """
  The UserStatistics context.
  """

  import Ecto.Query, warn: false
  alias Philomena.Repo

  alias Philomena.UserStatistics.UserStatistic
  alias Philomena.Users.User

  @doc """
  Updates a user_statistic.

  ## Examples

      iex> update_user_statistic(user_statistic, %{field: new_value})
      {:ok, %UserStatistic{}}

      iex> update_user_statistic(user_statistic, %{field: bad_value})
      {:error, %Ecto.Changeset{}}

  """
  def inc_stat(user, action, amount \\ 1)

  def inc_stat(nil, _action, _amount), do: {:ok, nil}
  def inc_stat(%{id: user_id}, action, amount)
    when action in [:uploads, :images_favourited, :comments_posted, :votes_cast, :metadata_updates, :forum_posts]
  do
    now =
      DateTime.utc_now()
      |> DateTime.to_unix(:second)
      |> div(86400)

    user = User |> where(id: ^user_id)
    action_count = :"#{action}_count"

    run = fn ->
      Repo.update_all(user, inc: [{action_count, amount}])
      Repo.insert(
        Map.put(%UserStatistic{day: now, user_id: user_id}, action, amount),
        on_conflict: [inc: [{action, amount}]],
        conflict_target: [:day, :user_id]
      )
    end

    Repo.transaction(run)
  end
end