baiji

defmodule Baiji.Config do
  alias Baiji.Operation

  @default_region "us-east-1"

  @doc """

  Merge Application configuration with the given

  Operation configuration

  """
  def merge(%Operation{} = op) do
    merge(op, Application.get_all_env(:baiji) || [])
  end

  @doc """

  Merge default config values from the given KeywordList into

  the provided Operation struct

  """
  def merge(%Operation{} = op, config) when is_list(config) do
    op
    |> debug(config)
    |> region(config)
  end

  @doc """

  Merge the debug configuration setting from the given Keyword List into

  the Operation configuration

  """
  def debug(%Operation{} = op, config) do
    if Operation.debug?(op) do
      op
    else
      Operation.debug!(op, Keyword.get(config, :debug, false))
    end
  end

  @doc """

  If the given Operation doesn't include a target region, set the region according

  to the :region key in the given keyword list. If the list doesn't include a region

  key, the output value will default to us-east-1

  """
  def region(%Operation{region: nil} = op, _), do: op
  def region(%Operation{options: opts} = op, config) do
    %{op | region: Keyword.get(config, :region, Keyword.get(opts, :region, @default_region))}
  end
end