+
+ def add_link_headers(conn, activities, extra_params \\ %{}) do
+ case List.last(activities) do
+ %{id: max_id} ->
+ params =
+ conn.params
+ |> Map.drop(Map.keys(conn.path_params))
+ |> Map.drop(["since_id", "max_id", "min_id"])
+ |> Map.merge(extra_params)
+
+ limit =
+ params
+ |> Map.get("limit", "20")
+ |> String.to_integer()
+
+ min_id =
+ if length(activities) <= limit do
+ activities
+ |> List.first()
+ |> Map.get(:id)
+ else
+ activities
+ |> Enum.at(limit * -1)
+ |> Map.get(:id)
+ end
+
+ next_url = current_url(conn, Map.merge(params, %{max_id: max_id}))
+ prev_url = current_url(conn, Map.merge(params, %{min_id: min_id}))
+
+ put_resp_header(conn, "link", "<#{next_url}>; rel=\"next\", <#{prev_url}>; rel=\"prev\"")
+
+ _ ->
+ conn
+ end
+ end