defmodule Services do
  def start_all do
    start_external_services()
    start_internal_services()
  end

  defp start_external_services do
    {:ok, _} = Application.ensure_all_started(:briefly)
  end

  defp start_internal_services do
    # Start Globals first, since it is the foundation for config.
    Services.Globals.start_link()

    # Start UI.Queue next, since other services may want to log messages
    # during their startup.
    UI.Queue.start_link()

    # Start core services that don't depend on CLI configuration
    Registry.start_link(keys: :unique, name: MCP.ClientRegistry)
    Services.Once.start_link()
    Services.Notes.start_link()
    Services.Conversation.Interrupts.start_link([])

    Services.BackupFile.start_link()
    Services.TempFile.start_link([])
    Services.FileCache.start_link()

    # Start TaskSupervisor commonly used by services to spawn supervised tasks
    # Ensure Task.Supervisor is started only once
    case Process.whereis(Services.TaskSupervisor) do
      nil -> Task.Supervisor.start_link(name: Services.TaskSupervisor)
      _ -> {:ok, Process.whereis(Services.TaskSupervisor)}
    end
  end

  @doc """
  Starts services that depend on CLI configuration.

  These services must be started AFTER set_globals() is called because they need
  to read configuration settings parsed from CLI arguments in set_globals().
  """
  def start_config_dependent_services(_command \\ nil) do
    Services.NamePool.start_link()
    Services.Approvals.start_link()
    Services.Approvals.Gate.start_link([])

    # MCP is started lazily on-demand when a completion needs MCP-backed tools.
    # It is started from AI.Tools.basic_tools, which is always called for any
    # agent that has access to tools, making it a logical place to start MCP
    # on-demand. It is guarded with a pid check to ensure it is only started
    # once.
    :ok
  end
end