defmodule Backplane.McpProtocol.Application do
  # See https://hexdocs.pm/elixir/Application.html
  # for more information on OTP Applications
  @moduledoc false

  use Application

  @impl true
  def start(_type, _args) do
    :logger.add_handlers(:backplane_mcp_protocol)

    children =
      [
        {Finch, name: Backplane.McpProtocol.Finch, pools: %{default: [size: 15]}}
      ] ++ maybe_start_session_store()

    # See https://hexdocs.pm/elixir/Supervisor.html
    # for other strategies and supported options
    opts = [strategy: :one_for_one, name: Backplane.McpProtocol.Supervisor]
    {:ok, pid} = Supervisor.start_link(children, opts)

    if Backplane.McpProtocol.should_compile_cli?() do
      with {:module, cli} <- Code.ensure_loaded(Backplane.McpProtocol.CLI), do: cli.main()
      {:ok, pid}
    else
      {:ok, pid}
    end
  end

  defp maybe_start_session_store do
    config = Application.get_env(:backplane_mcp_protocol, :session_store, [])
    session_store_children(config)
  end

  @doc false
  def session_store_children(config) when is_list(config) do
    enabled? = Keyword.get(config, :enabled, false)
    adapter = Keyword.get(config, :adapter)

    cond do
      not enabled? ->
        []

      is_nil(adapter) ->
        Backplane.McpProtocol.Logging.log(:warning, "Session store enabled but adapter not configured", [])
        []

      Code.ensure_loaded?(adapter) ->
        Backplane.McpProtocol.Logging.log(:info, "Starting session store",
          enabled: true,
          adapter: adapter,
          ttl: Keyword.get(config, :ttl),
          namespace: Keyword.get(config, :namespace)
        )

        [{adapter, config}]

      true ->
        Backplane.McpProtocol.Logging.log(:warning, "Session store enabled but adapter not available", adapter: adapter)
        []
    end
  end
end