defmodule DaProductApp.Acquirer.YSP.Config do
  @moduledoc """
  Centralized YSP configuration management.

  This module provides a unified interface to access YSP configuration
  from the consolidated upstream_networks configuration.
  """

  @doc """
  Gets the complete YSP configuration from the upstream networks configuration.

  Returns the ysp_config section from either ysp_ssl or ysp_plain network configuration.
  Falls back to default values if configuration is not found.
  """
  def get_ysp_config do
    upstream_networks = Application.get_env(:da_product_app, :upstream_networks, %{})

    # Try to get from ysp_ssl first, then ysp_plain as fallback
    case upstream_networks do
      %{ysp_ssl: %{ysp_config: config}} when is_map(config) -> config
      %{ysp_plain: %{ysp_config: config}} when is_map(config) -> config
      _ -> default_ysp_config()
    end
  end

  @doc """
  Gets a specific configuration value from YSP config.
  """
  def get(key, default \\ nil) do
    get_ysp_config()
    |> Map.get(key, default)
  end

  @doc """
  Gets the required fields for a specific MTI.
  """
  def get_required_fields(mti) do
    required_fields_map = get(:required_fields, %{})
    Map.get(required_fields_map, mti, [2, 3, 4, 11])  # Default fallback
  end

  @doc """
  Gets processing code transformation for a given code.
  """
  def get_processing_code(original_code) do
    processing_codes = get(:processing_codes, %{})
    Map.get(processing_codes, original_code, original_code)
  end

  @doc """
  Gets the network identifier (NII).
  """
  def get_nii do
    get(:network_identifier, "782")
  end

  @doc """
  Gets the acquiring institution code.
  """
  def get_acquiring_institution_code do
    get(:acquiring_institution_code, "999999")
  end

  @doc """
  Gets default terminal ID.
  """
  def get_default_terminal_id do
    get(:default_terminal_id, "YSP00001")
  end

  @doc """
  Gets default merchant ID.
  """
  def get_default_merchant_id do
    get(:default_merchant_id, "MERCURYPAY001")
  end

  @doc """
  Gets the default master key (for development - replace with proper key management).
  """
  def get_default_master_key do
    get(:default_master_key, "0123456789ABCDEF0123456789ABCDEF")
  end

  @doc """
  Gets processing timeout in milliseconds.
  """
  def get_processing_timeout do
    get(:processing_timeout, 30_000)
  end

  @doc """
  Gets maximum retry attempts.
  """
  def get_max_retries do
    get(:max_retries, 3)
  end

  @doc """
  Gets retry delay in milliseconds.
  """
  def get_retry_delay do
    get(:retry_delay, 5_000)
  end

  @doc """
  Gets supported MTIs.
  """
  def get_supported_mtis do
    get(:supported_mtis, ["0100", "0200", "0220", "0400", "0800"])
  end

  @doc """
  Gets supported fields.
  """
  def get_supported_fields do
    get(:supported_fields, [2, 3, 4, 11, 12, 13, 14, 22, 23, 24, 25, 35, 37, 38, 39, 41, 42, 49, 52, 55, 62, 63])
  end

  @doc """
  Gets echo response code.
  """
  def get_echo_response_code do
    get(:echo_response_code, "301")
  end

  @doc """
  Gets PIN IPEK response code.
  """
  def get_pin_ipek_response_code do
    get(:pin_ipek_response_code, "161")
  end

  @doc """
  Gets message framing configuration.
  """
  def get_message_framing_config do
    get(:message_framing, %{
      type: :ysp_standard,
      length_prefix_size: 2,
      header_size: 2,
      header_value: <<0x30, 0x22>>,
      max_packet_size: 65535,
      endianness: :big
    })
  end

  @doc """
  Gets the YSP packet header value.
  """
  def get_packet_header do
    framing_config = get_message_framing_config()
    Map.get(framing_config, :header_value, <<0x30, 0x22>>)
  end

  @doc """
  Gets the maximum packet size for YSP.
  """
  def get_max_packet_size do
    framing_config = get_message_framing_config()
    Map.get(framing_config, :max_packet_size, 65535)
  end

  # Private helper for default configuration
  defp default_ysp_config do
    %{
      acquiring_institution_code: "999999",
      network_identifier: "782",
      nii: "782",  # Added for compatibility
      acquiring_inst_code: "784",  # Added for compatibility
      default_terminal_id: "YSP00001",
      default_merchant_id: "MERCURYPAY001",
      packager: DaProductApp.MercuryISO8583.Packagers.ISO87DPackager,
      message_framing: %{
        type: :ysp_standard,
        length_prefix_size: 2,
        header_size: 2,
        header_value: <<0x30, 0x22>>,  # Fixed YSP header (3022)
        max_packet_size: 65535,
        endianness: :big
      },
      defaults: %{
        terminal_id: "8900901 ",
        merchant_id: "01000006       ",
        merchant_name: "YSP Test Merchant",
        currency_code: "784"  # UAE Dirham
      },
      supported_mtis: ["0100", "0200", "0220", "0400", "0800"],
      supported_fields: [2, 3, 4, 11, 12, 13, 14, 22, 23, 24, 25, 35, 37, 38, 39, 41, 42, 49, 52, 55, 62, 63],
      echo_response_code: "301",
      pin_ipek_response_code: "161",
      default_master_key: "0123456789ABCDEF0123456789ABCDEF",
      processing_timeout: 30_000,
      max_retries: 3,
      retry_delay: 5_000,
      required_fields: %{
        "0100" => [2, 3, 4, 11, 12, 13, 14, 22, 24, 25, 35, 41, 42, 49, 55],
        "0200" => [2, 3, 4, 11, 12, 13, 14, 22, 24, 25, 35, 37, 41, 42, 49, 55],
        "0220" => [2, 3, 4, 11, 24, 25, 35, 37, 38, 39, 41, 42, 49],
        "0400" => [2, 3, 4, 11, 24, 25, 37, 41, 42, 49, 90],
        "0800" => [11, 24, 70],
        "0810" => [11, 24, 39, 70]
      },
      processing_codes: %{
        "000000" => "000000",  # Sale
        "000001" => "000000",  # Sale adjustment
        "020000" => "020000",  # Void
        "330000" => "330000",  # PreAuth
        "preauth" => "330000",
        "tmk" => "991380",
        "pin_ipek" => "990280"
      },
      timeouts: %{
        sale: 30_000,
        void: 25_000,
        preauth: 30_000,
        completion: 25_000,
        reversal: 20_000,
        network_mgmt: 15_000
      }
    }
  end
end