defmodule Ding do
  @moduledoc """
  `Ding` handles desktop notifications on your local PC.
  Plays nice alongside:

  * Terminal Notifier
  * NotifySend
  * TmuxNotifier
  * TerminalTitle

  Only OS X and Linux are enabled so far;
  seeking help on Windows notifications!

  Source code originally appeared in the `ex_unit_notifier` package;
  this is a copy of only the general-purpose notification logic.
  Some modules and options are renamed.
  """

  @handlers [
    Ding.TerminalNotifier,
    Ding.NotifySend,
    Ding.TmuxNotifier,
    Ding.TerminalTitle
  ]

  @doc """
  ## Send a message

  iex> Ding.send("Hello!", "Here is your message.")

  ## Options and appearance

  Each handler only recognizes a portion of these options;
  some options are recognized by more than one handler.

  iex> Ding.send("Hello!", "Here is your message.", %{
    clear_history: true,
    color: color(status(counter)),
    icon_png: icon_png(status(counter)),
    icon_icns: icon_icns(status(counter)),
  })
  """
  def send(head, message), do: send(head, message, %{ clear_history: false })
  def send(head, message, opts),
    do: handlers() |> Enum.map(& apply(&1, :send, [head, message, opts]))
  defp handlers, do: Application.get_env(:message, :handlers, choose_handlers())
  defp choose_handlers, do: @handlers |> Enum.filter(fn handler -> handler.enabled? end)
end