defmodule GeoIP do
  @moduledoc """
  Elixir library to lookup the geo location for an IP address or hostname using freegeoip.net

      iex> GeoIP.lookup("google.com")
      {:ok,
       %GeoIP.Location{city: "Mountain View", country_code: "US",
        country_name: "United States", ip: "172.217.4.78", latitude: 37.4192,
        longitude: -122.0574, metro_code: 807, region_code: "CA",
        region_name: "California", time_zone: "America/Los_Angeles",
        zip_code: "94043"}}
  """

  use Application
  alias GeoIP.Config

  def start(_type, _args) do
    import Supervisor.Spec, warn: false

    children = [
      worker(Cachex, [:geoip_lookup_cache, [default_ttl: :timer.seconds(Config.cache_ttl_secs)]])
    ]

    opts = [strategy: :one_for_one, name: GeoIP.Supervisor]
    Supervisor.start_link(children, opts)
  end

  @doc """
  Lookup the location for the given IP address/hostname.

  Args:
    * `host` - The IP/hostname or Plug.Conn instance to use for the lookup. The IP can be either a string or a tuple.

  This function returns `{:ok, response}` if the lookup is successful, `{:error, %GeoIP.Error{reason: reason}}` otherwise.

  ## Examples:

  ```ex
  {:ok, location} = GeoIP.lookup({8, 8, 8, 8})
  {:ok, location} = GeoIP.lookup("8.8.8.8")
  {:ok, location} = GeoIP.lookup("google.com")
  {:ok, location} = GeoIP.lookup(conn)         # A `Plug.Conn` instance
  ```
  """
  def lookup(host), do: GeoIP.Lookup.lookup(host)
end