defmodule Crawly.API.Router do
  @moduledoc """
  Crawly HTTP API. Allows to schedule/stop/get_stats
  of all running spiders.
  """
  use Plug.Router

  plug(:match)
  plug(:dispatch)

  get "/spiders" do
    msg =
      case Crawly.Engine.running_spiders() do
        %{} ->
          "No spiders are currently running"

        spiders ->
          "Following spiders are running: #{inspect(spiders)}"
      end

    send_resp(conn, 200, msg)
  end

  get "/spiders/:spider_name/schedule" do
    spider_name = String.to_atom("Elixir.#{spider_name}")
    result = Crawly.Engine.start_spider(spider_name)

    msg =
      case result do
        {:error, :spider_already_started} -> "Already started"
        {:error, _} -> "Can't load the spider"
        :ok -> "Started!"
      end

    send_resp(conn, 200, msg)
  end

  get "/spiders/:spider_name/stop" do
    spider_name = String.to_atom("Elixir.#{spider_name}")
    result = Crawly.Engine.stop_spider(spider_name)

    msg =
      case result do
        {:error, :not_found} -> "Not found"
        {:error, :spider_not_running} -> "Spider is not running"
        :ok -> "Stopped!"
      end

    send_resp(conn, 200, msg)
  end

  get "/spiders/:spider_name/scheduled-requests" do
    spider_name = String.to_atom("Elixir.#{spider_name}")
    result = Crawly.RequestsStorage.stats(spider_name)

    msg =
      case result do
        {:error, :storage_worker_not_running} -> "Spider is not running"
        _ -> "#{inspect(result)}"
      end

    send_resp(conn, 200, msg)
  end

  get "/spiders/:spider_name/scraped-items" do
    spider_name = String.to_atom("Elixir.#{spider_name}")
    result = Crawly.DataStorage.stats(spider_name)

    msg =
      case result do
        {:error, _} -> "Spider is not running"
        _ -> "#{inspect(result)}"
      end

    send_resp(conn, 200, msg)
  end

  match _ do
    send_resp(conn, 404, "Oops!")
  end
end