defmodule PS2.API.Join do
  @moduledoc """
  A data structure representing a join on an API query. Create a join using %PS2.API.Join{} or the new/0 or new/1 functions.
  """

  alias PS2.API.Join

  defstruct [:collection, params: %{}, joins: []]

  @type t() :: %Join{
          collection: String.t() | nil,
          params: map(),
          joins: [t()]
        }

  @type opts :: [
          collection: String.t(),
          on: String.t(),
          to: String.t(),
          list: boolean(),
          show: list(term()),
          hide: list(term()),
          inject_at: String.t(),
          outer: boolean()
        ]

  @spec new() :: t()
  def new, do: %Join{}
  @spec new(opts) :: t()
  def new(opts),
    do: %Join{
      collection: Keyword.get(opts, :collection),
      params:
        for(
          {key, val} <- Keyword.delete(opts, :collection),
          into: %{},
          do: {Atom.to_string(key), val}
        )
    }
end