defmodule Rsh26pool.Voting.Participant do
  @moduledoc """
  A user taking part in a room. Identified across requests by a random `token`
  stored in the session cookie. Owners have `role == "owner"`.
  """
  use Ecto.Schema
  import Ecto.Changeset

  alias Rsh26pool.Voting.Room

  schema "participants" do
    field :token, :string
    field :name, :string
    field :role, :string, default: "member"

    # Grouping-mode results, filled in when voting closes.
    field :is_leader, :boolean, default: false

    belongs_to :room, Room
    belongs_to :assigned_leader, __MODULE__, foreign_key: :assigned_leader_id

    timestamps(type: :utc_datetime)
  end

  @doc "Changeset for the user-supplied fields (their display name)."
  def changeset(participant, attrs) do
    participant
    |> cast(attrs, [:name])
    |> validate_required([:name], message: "名前を入力してください")
    |> validate_length(:name, max: 40, message: "名前は40文字以内で入力してください")
    |> unique_constraint(:token)
  end

  @doc "Owner? convenience predicate."
  def owner?(%__MODULE__{role: "owner"}), do: true
  def owner?(%__MODULE__{}), do: false
end