postland/lib/postland_web/controllers/inbox_controller.ex

defmodule PostlandWeb.InboxController do
  use PostlandWeb, :controller

  require Logger

  alias ActivityPub.Headers
  alias Postland.Activities

  def post(conn, params) do
    if Headers.verify(conn.method, conn.request_path, conn.req_headers, conn.assigns.raw_body) &&
         Postland.Permissions.permitted?(params) do
      case Activities.process_activity(params) do
        {:ok, _activity} ->
          send_resp(conn, 200, Jason.encode!(params))

        error ->
          Logger.error(error)
          send_resp(conn, 422, "unprocessable_entity")
      end
    else
      Logger.info("Failed to verify type=#{Map.get(params, "type")}")

      send_resp(conn, 403, "forbidden")
    end
  end
end