Add CSP Policy for pictures

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/service/pictures/provider.ex

@@ -29,8 +29,12 @@ defmodule Mobilizon.Service.Pictures.Provider do
       iex> search("London")
       %Information{url: "https://some_url_to.a/picture.jpeg", author: %{name: "An author", url: "https://url.to/profile"}, source: %{name: "The source name", url: "The source URL" }}
   """
-  @callback search(location :: String.t(), options :: keyword) ::
-              [Information.t()]
+  @callback search(location :: String.t(), options :: keyword) :: Information.t()
+
+  @doc """
+  The CSP configuration to add for the service to work
+  """
+  @callback csp() :: keyword()
 
   @spec endpoint(atom()) :: String.t()
   def endpoint(provider) do

lib/service/pictures/unsplash.ex

@@ -16,7 +16,7 @@ defmodule Mobilizon.Service.Pictures.Unsplash do
   @doc """
   Unsplash implementation for `c:Mobilizon.Service.Geospatial.Provider.geocode/3`.
   """
-  @spec search(String.t(), keyword()) :: list(Information.t())
+  @spec search(String.t(), keyword()) :: Information.t()
   def search(location, _options \\ []) do
     url = "#{unsplash_endpoint()}#{@unsplash_api}?query=#{location}&orientation=landscape"
 
@@ -42,6 +42,16 @@ defmodule Mobilizon.Service.Pictures.Unsplash do
     end
   end
 
+  @impl Provider
+  @doc """
+  Returns the CSP configuration for this search provider to work
+  """
+  def csp do
+    :mobilizon
+    |> Application.get_env(__MODULE__, [])
+    |> Keyword.get(:csp_policy, [])
+  end
+
   defp unsplash_app_name do
     Application.get_env(:mobilizon, __MODULE__) |> get_in([:app_name])
   end