defmodule NullaWeb.WebfingerController do
  use NullaWeb, :controller
  alias Nulla.Repo
  alias Nulla.ActivityPub
  alias Nulla.Models.User
  alias Nulla.Models.InstanceSettings

  def index(conn, %{"resource" => resource}) do
    case Regex.run(~r/^acct:([^@]+)@(.+)$/, resource) do
      [_, username, domain] ->
        case User.get_user_by_username(username) do
          nil ->
            conn
            |> put_status(:not_found)
            |> json(%{error: "Not Found"})

          user ->
            instance_settings = InstanceSettings.get_instance_settings!()

            if domain == instance_settings.domain do
              json(conn, ActivityPub.webfinger(domain, username, resource))
            else
              conn
              |> put_status(:not_found)
              |> json(%{error: "Not Found"})
            end
        end

      _ ->
        conn
        |> put_status(:bad_request)
        |> json(%{error: "Bad Request"})
    end
  end
end