defmodule CA.CMC do
  @moduledoc "CA/CMC TLS TCP server."
  require CA

  # Authority PKI X.509 CMC over TCP RFC 5272-5275 6402

  # [1] https://www.rfc-editor.org/rfc/rfc6402
  # [2] https://www.rfc-editor.org/rfc/rfc5272
  # [3] https://www.rfc-editor.org/rfc/rfc5273
  # [4] https://www.rfc-editor.org/rfc/rfc5274
  # [5] https://www.rfc-editor.org/rfc/rfc5275

  def start_link(port: port), do: {:ok, :erlang.spawn_link(fn -> listen(port) end)}

  def child_spec(opt) do
    %{
      id: CMC,
      start: {CA.CMC, :start_link, [opt]},
      type: :supervisor,
      restart: :permanent,
      shutdown: 500
    }
  end

  def listen(port) do
    :logger.info(~c"Running CA.CMC with Authority 5.11.15 at 0.0.0.0:~p (tcp)", [port])

    {:ok, socket} =
      :gen_tcp.listen(
        port,
        [:binary, {:packet, 0}, {:active, false}, {:reuseaddr, true}]
      )

    accept(socket)
  end

  def accept(socket) do
    {:ok, fd} = :gen_tcp.accept(socket)
    :erlang.spawn(fn -> __MODULE__.loop(fd) end)
    accept(socket)
  end

  def message(_socket, cms) do
    :logger.info(~c"Unknown message request ~p", [cms])
  end

  def answer(socket, res) do
    :gen_tcp.send(socket, res)
  end

  def loop(socket) do
    case :gen_tcp.recv(socket, 0) do
      {:ok, data} ->
        {:ok, dec} = :"EnrollmentMessageSyntax-2009".decode(:PKIData, data)
        {:PKIData, _controlSequence, _reqSequence, cmsSequence, _otherMsgSequence} = dec
        :io.format(~c"PKIData:~n~p~n", [dec])
        __MODULE__.message(socket, cmsSequence)
        __MODULE__.loop(socket)

      {:error, _} ->
        :exit
    end
  end

  def oid(:"id-cmc-identification"), do: {1, 3, 6, 1, 5, 5, 7, 7, 2}
  def oid(:"id-cmc-identityProof"), do: {1, 3, 6, 1, 5, 5, 7, 7, 3}
  def oid(:"id-cmc-dataReturn"), do: {1, 3, 6, 1, 5, 5, 7, 7, 4}
  def oid(:"id-cmc-transactionId"), do: {1, 3, 6, 1, 5, 5, 7, 7, 5}
  def oid(:"id-cmc-senderNonce"), do: {1, 3, 6, 1, 5, 5, 7, 7, 6}
  def oid(:"id-cmc-recipientNonce"), do: {1, 3, 6, 1, 5, 5, 7, 7, 7}
  def oid(:"id-cmc-statusInfo"), do: {1, 3, 6, 1, 5, 5, 7, 7, 1}
  def oid(:"id-cmc-addExtensions"), do: {1, 3, 6, 1, 5, 5, 7, 7, 8}
  def oid(:"id-cmc-encryptedPOP"), do: {1, 3, 6, 1, 5, 5, 7, 7, 9}
  def oid(:"id-cmc-decryptedPOP"), do: {1, 3, 6, 1, 5, 5, 7, 7, 10}
  def oid(:"id-cmc-lraPOPWitness"), do: {1, 3, 6, 1, 5, 5, 7, 7, 11}
  def oid(:"id-cmc-getCert"), do: {1, 3, 6, 1, 5, 5, 7, 7, 15}
  def oid(:"id-cmc-getCRL"), do: {1, 3, 6, 1, 5, 5, 7, 7, 16}
  def oid(:"id-cmc-revokeRequest"), do: {1, 3, 6, 1, 5, 5, 7, 7, 17}
  def oid(:"id-cmc-regInfo"), do: {1, 3, 6, 1, 5, 5, 7, 7, 18}
  def oid(:"id-cmc-responseInfo"), do: {1, 3, 6, 1, 5, 5, 7, 7, 19}
  def oid(:"id-cmc-queryPending"), do: {1, 3, 6, 1, 5, 5, 7, 7, 21}
  def oid(:"id-cmc-popLinkRandom"), do: {1, 3, 6, 1, 5, 5, 7, 7, 22}
  def oid(:"id-cmc-popLinkWitness"), do: {1, 3, 6, 1, 5, 5, 7, 7, 23}
  def oid(:"id-cmc-confirmCertAcceptance"), do: {1, 3, 6, 1, 5, 5, 7, 7, 24}
  def oid(:"id-cmc-statusInfoV2"), do: {1, 3, 6, 1, 5, 5, 7, 7, 25}
  def oid(:"id-cmc-trustedAnchors"), do: {1, 3, 6, 1, 5, 5, 7, 7, 26}
  def oid(:"id-cmc-authData"), do: {1, 3, 6, 1, 5, 5, 7, 7, 27}
  def oid(:"id-cmc-batchRequests"), do: {1, 3, 6, 1, 5, 5, 7, 7, 28}
  def oid(:"id-cmc-batchResponses"), do: {1, 3, 6, 1, 5, 5, 7, 7, 29}
  def oid(:"id-cmc-publishCert"), do: {1, 3, 6, 1, 5, 5, 7, 7, 30}
  def oid(:"id-cmc-modCertTemplate"), do: {1, 3, 6, 1, 5, 5, 7, 7, 31}
  def oid(:"id-cmc-controlProcessed"), do: {1, 3, 6, 1, 5, 5, 7, 7, 32}
  def oid(:"id-cmc-identityProofV2"), do: {1, 3, 6, 1, 5, 5, 7, 7, 33}
  def oid(:"id-cmc-popLinkWitnessV2"), do: {1, 3, 6, 1, 5, 5, 7, 7, 34}

  def code(), do: :binary.encode_hex(:crypto.strong_rand_bytes(8))
end