defmodule HiiveRisk.Model do
  @moduledoc "Model transport contract. Results are validated before they can change a review."
  @callback decision(map()) :: {:ok, map()} | {:error, term()}
  @callback sft(map()) :: {:ok, map()} | {:error, term()}
end

defmodule HiiveRisk.Model.HTTP do
  @behaviour HiiveRisk.Model

  @impl true
  def decision(snapshot), do: request(:decision_url, snapshot)

  @impl true
  def sft(snapshot), do: request(:sft_url, snapshot)

  defp request(endpoint, snapshot) do
    config = Application.get_env(:hiive_risk, __MODULE__, [])

    case Keyword.get(config, endpoint) do
      nil ->
        {:error, :model_endpoint_not_configured}

      url ->
        headers =
          case Keyword.get(config, :token) do
            nil -> []
            token -> [{"authorization", "Bearer " <> token}]
          end

        case Req.post(url,
               json: snapshot,
               headers: headers,
               retry: false,
               redirect: false,
               receive_timeout: Keyword.get(config, :receive_timeout, 30_000)
             ) do
          {:ok, %{status: status, body: body}} when status in 200..299 -> {:ok, body}
          {:ok, %{status: status}} -> {:error, {:model_http_status, status}}
          {:error, _reason} -> {:error, :model_request_failed}
        end
    end
  end
end