mobilizon.chapril.org-mobil.../lib/service/geospatial/google_maps.ex
Thomas Citharel 98b7618338
Add GeoSpatial backends for geocoding
Signed-off-by: Thomas Citharel <tcit@tcit.fr>

Geospatial Backend

Signed-off-by: Thomas Citharel <tcit@tcit.fr>
2019-03-15 16:37:43 +01:00

127 lines
3.9 KiB
Elixir

defmodule Mobilizon.Service.Geospatial.GoogleMaps do
@moduledoc """
Google Maps [Geocoding service](https://developers.google.com/maps/documentation/geocoding/intro)
Note: Endpoint is hardcoded to Google Maps API
"""
alias Mobilizon.Service.Geospatial.Provider
alias Mobilizon.Addresses.Address
require Logger
@behaviour Provider
@api_key Application.get_env(:mobilizon, __MODULE__) |> get_in([:api_key])
@components [
"street_number",
"route",
"locality",
"administrative_area_level_1",
"country",
"postal_code"
]
@api_key_missing_message "API Key required to use Google Maps"
@impl Provider
@doc """
Google Maps implementation for `c:Mobilizon.Service.Geospatial.Provider.geocode/3`.
"""
@spec geocode(String.t(), keyword()) :: list(Address.t())
def geocode(lon, lat, options \\ []) do
url = build_url(:geocode, %{lon: lon, lat: lat}, options)
Logger.debug("Asking Google Maps for reverse geocode with #{url}")
with {:ok, %HTTPoison.Response{status_code: 200, body: body}} <-
HTTPoison.get(url),
{:ok, %{"results" => results, "status" => "OK"}} <- Poison.decode(body) do
Enum.map(results, &process_data/1)
else
{:ok, %{"status" => "REQUEST_DENIED", "error_message" => error_message}} ->
raise ArgumentError, message: to_string(error_message)
end
end
@impl Provider
@doc """
Google Maps implementation for `c:Mobilizon.Service.Geospatial.Provider.search/2`.
"""
@spec search(String.t(), keyword()) :: list(Address.t())
def search(q, options \\ []) do
url = build_url(:search, %{q: q}, options)
Logger.debug("Asking Google Maps for addresses with #{url}")
with {:ok, %HTTPoison.Response{status_code: 200, body: body}} <-
HTTPoison.get(url),
{:ok, %{"results" => results, "status" => "OK"}} <- Poison.decode(body) do
Enum.map(results, fn entry -> process_data(entry) end)
else
{:ok, %{"status" => "REQUEST_DENIED", "error_message" => error_message}} ->
raise ArgumentError, message: to_string(error_message)
end
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")
api_key = Keyword.get(options, :api_key, @api_key)
if is_nil(api_key), do: raise(ArgumentError, message: @api_key_missing_message)
url =
"https://maps.googleapis.com/maps/api/geocode/json?limit=#{limit}&key=#{api_key}&language=#{
lang
}"
case method do
:search ->
url <> "&address=#{URI.encode(args.q)}"
:geocode ->
url <> "&latlng=#{args.lat},#{args.lon}"
end
end
defp process_data(%{
"formatted_address" => description,
"geometry" => %{"location" => %{"lat" => lat, "lng" => lon}},
"address_components" => components
}) do
components =
@components
|> Enum.reduce(%{}, fn component, acc ->
Map.put(acc, component, extract_component(components, component))
end)
%Address{
addressCountry: Map.get(components, "country"),
addressLocality: Map.get(components, "locality"),
addressRegion: Map.get(components, "administrative_area_level_1"),
description: description,
floor: nil,
geom: [lon, lat] |> Provider.coordinates(),
postalCode: Map.get(components, "postal_code"),
streetAddress: street_address(components)
}
end
defp extract_component(components, key) do
case components
|> Enum.filter(fn component -> key in component["types"] end)
|> Enum.map(& &1["long_name"]) do
[] -> nil
component -> hd(component)
end
end
defp street_address(body) do
if Map.has_key?(body, "street_number") && !is_nil(Map.get(body, "street_number")) do
Map.get(body, "street_number") <> " " <> Map.get(body, "route")
else
Map.get(body, "route")
end
end
end