defmodule FileStorageApi.API.S3.Base do
  @moduledoc false

  @ex_aws_module Application.compile_env(:file_storage_api, [:s3_config, :module], ExAws)

  @spec config(atom | map | keyword) :: Keyword.t()
  def config(connection_name) when is_atom(connection_name) do
    s3_config =
      case connection_name do
        :default ->
          Application.get_env(:file_storage_api, :s3_config)

        name ->
          Application.get_env(:file_storage_api, String.to_existing_atom("#{name}_s3_config"))
      end

    build_config_keyword_list(http_opts(), s3_config)
  end

  def config(connection) do
    s3_config = Access.get(connection, :config, [])

    [
      access_key_id: Access.get(s3_config, :access_key),
      secret_access_key: Access.get(s3_config, :secret_key),
      s3_auth_version: Access.get(s3_config, :s3_auth_version, 4),
      host: Access.get(s3_config, :host),
      external_host: Access.get(s3_config, :external_host),
      scheme: Access.get(s3_config, :scheme),
      port: Access.get(s3_config, :port),
      http_opts: http_opts()
    ]
  end

  defp build_config_keyword_list(http_opts, s3_config) do
    [
      access_key_id: Keyword.get(s3_config, :access_key_id),
      secret_access_key: Keyword.get(s3_config, :secret_access_key),
      s3_auth_version: Keyword.get(s3_config, :s3_auth_version),
      host: Keyword.get(s3_config, :host),
      scheme: Keyword.get(s3_config, :scheme),
      port: Keyword.get(s3_config, :port),
      region: region(s3_config),
      http_opts: http_opts
    ]
  end

  @spec region(keyword) :: String.t()
  def region(s3_config \\ Application.get_env(:file_storage_api, :s3_config)) do
    region = Keyword.get(s3_config, :region)

    if(region, do: region, else: "")
  end

  @spec request(ExAws.Operation.t(), atom | map) :: {:ok, term} | {:error, term}
  def request(operation, connection) do
    @ex_aws_module.request(operation, config(connection))
  end

  @spec convert_options(FileStorageApi.Container.options()) :: [
          {:maxresults, non_neg_integer} | {:marker, String.t()}
        ]
  def convert_options(options) do
    Enum.map(options, fn
      {:max_results, value} -> {:max_keys, value}
      option -> option
    end)
  end

  defp http_opts do
    storage_api = Application.get_env(:file_storage_api, :storage_api, [])

    case Keyword.get(storage_api, :custom_ca_cert) do
      cert when is_binary(cert) and byte_size(cert) > 0 ->
        [
          {:ssl, [cacertfile: cert]},
          {:ssl_options, [cacertfile: cert, verify: :verify_peer]}
        ]

      _ ->
        []
    end
  end
end