defmodule MicrowavepropWeb.WeatherTileController do
  use MicrowavepropWeb, :controller

  alias Microwaveprop.Weather.MapLayers
  alias Microwaveprop.Weather.TileRenderer

  @spec show(Plug.Conn.t(), map()) :: Plug.Conn.t()
  def show(conn, %{"z" => z, "x" => x, "y" => y, "layer" => layer_id, "time" => time_param}) do
    with true <- MapLayers.valid_id?(layer_id),
         {z, ""} <- Integer.parse(z),
         {x, ""} <- Integer.parse(x),
         {y, ""} <- Integer.parse(y),
         {:ok, valid_time, _offset} <- DateTime.from_iso8601(time_param) do
      body = TileRenderer.render_svg(valid_time, layer_id, z, x, y)

      conn
      |> put_resp_content_type("image/svg+xml")
      |> put_resp_header("cache-control", "public, max-age=60")
      |> send_resp(200, body)
    else
      _ ->
        conn
        |> put_resp_content_type("image/svg+xml")
        |> put_resp_header("cache-control", "public, max-age=5")
        |> send_resp(200, TileRenderer.empty_svg())
    end
  end
end