defmodule Mobilizon.Service.Geospatial.Nominatim do @moduledoc """ [Nominatim](https://wiki.openstreetmap.org/wiki/Nominatim) backend. """ alias Mobilizon.Addresses.Address alias Mobilizon.Service.Geospatial.Provider alias Mobilizon.Service.HTTP.GeospatialClient import Mobilizon.Service.Geospatial.Provider, only: [endpoint: 1] require Logger @behaviour Provider @impl Provider @doc """ Nominatim implementation for `c:Mobilizon.Service.Geospatial.Provider.geocode/3`. """ @spec geocode(String.t(), keyword()) :: list(Address.t()) def geocode(lon, lat, options \\ []) do :geocode |> build_url(%{lon: lon, lat: lat}, options) |> fetch_features end @impl Provider @doc """ Nominatim implementation for `c:Mobilizon.Service.Geospatial.Provider.search/2`. """ @spec search(String.t(), keyword()) :: list(Address.t()) def search(q, options \\ []) do :search |> build_url(%{q: q}, options) |> fetch_features end @spec build_url(atom(), map(), list()) :: String.t() defp build_url(method, args, options) do limit = Keyword.get(options, :limit, 10) lang = Keyword.get(options, :lang, "en") endpoint = Keyword.get(options, :endpoint, endpoint(__MODULE__)) url = case method do :search -> "#{endpoint}/search?format=geocodejson&q=#{URI.encode(args.q)}&limit=#{limit}&accept-language=#{lang}&addressdetails=1&namedetails=1" :geocode -> "#{endpoint}/reverse?format=geocodejson&lat=#{args.lat}&lon=#{args.lon}&accept-language=#{lang}&addressdetails=1&namedetails=1" |> add_parameter(options, :zoom) end url |> add_parameter(options, :country_code) |> add_parameter(options, :api_key, api_key()) end @spec fetch_features(String.t()) :: list(Address.t()) defp fetch_features(url) do Logger.debug("Asking Nominatim with #{url}") with {:ok, %{status: 200, body: body}} <- GeospatialClient.get(url), %{"features" => features} <- body do features |> process_data |> Enum.filter(& &1) else _ -> Logger.error("Asking Nominatim with #{url}") [] end end defp process_data(features) do features |> Enum.map(fn %{ "geometry" => %{"coordinates" => coordinates}, "properties" => %{"geocoding" => geocoding} } -> address = process_address(geocoding) coordinates = Provider.coordinates(coordinates) %Address{address | geom: coordinates, timezone: Provider.timezone(coordinates)} end) end defp process_address(geocoding) do %Address{ country: Map.get(geocoding, "country"), locality: Map.get(geocoding, "city") || Map.get(geocoding, "town") || Map.get(geocoding, "county"), region: Map.get(geocoding, "state"), description: description(geocoding), postal_code: Map.get(geocoding, "postcode"), type: Map.get(geocoding, "type"), street: street_address(geocoding), origin_id: "nominatim:" <> to_string(Map.get(geocoding, "osm_id")) } end @spec street_address(map()) :: String.t() defp street_address(body) do road = cond do Map.has_key?(body, "road") -> Map.get(body, "road") Map.has_key?(body, "street") -> Map.get(body, "street") Map.has_key?(body, "pedestrian") -> Map.get(body, "pedestrian") true -> "" end Map.get(body, "housenumber", "") <> " " <> road end @address29_classes ["amenity", "shop", "tourism", "leisure"] @address29_categories ["office"] @spec description(map()) :: String.t() defp description(body) do description = Map.get(body, "name") address = Map.get(body, "address") description = if Map.has_key?(body, "namedetails"), do: body |> Map.get("namedetails") |> Map.get("name", description), else: description description = if is_nil(description), do: street_address(body), else: description if (Map.get(body, "category") in @address29_categories or Map.get(body, "class") in @address29_classes) and Map.has_key?(address, "address29") do Map.get(address, "address29") else description end end @spec add_parameter(String.t(), Keyword.t(), atom()) :: String.t() defp add_parameter(url, options, key, default \\ nil) do value = Keyword.get(options, key, default) if is_nil(value), do: url, else: do_add_parameter(url, key, value) end @spec do_add_parameter(String.t(), :zoom | :country_code | :api_key, any()) :: String.t() defp do_add_parameter(url, :zoom, zoom), do: "#{url}&zoom=#{zoom}" defp do_add_parameter(url, :country_code, country_code), do: "#{url}&countrycodes=#{country_code}" defp do_add_parameter(url, :api_key, api_key), do: "#{url}&key=#{api_key}" defp api_key do Application.get_env(:mobilizon, __MODULE__) |> get_in([:api_key]) end end