chess/lib/chess/store/user.ex

defmodule Chess.Store.User do
  @moduledoc false

  use Ecto.Schema

  import Ecto.Changeset
  import Ecto.Query

  schema "users" do
    field(:name, :string)
    field(:email, :string)
    field(:password, :string, virtual: true)
    field(:password_hash, :string)

    has_many(:games, Chess.Store.Game)
    has_many(:games_as_opponent, Chess.Store.Game, foreign_key: :opponent_id)

    timestamps()
  end

  @profile_attrs ~w[name email]a
  @registration_attrs ~w[name email password]a

  @doc false
  def changeset(struct, params \\ %{}) do
    struct
    |> cast(params, @registration_attrs)
    |> validate_required(@registration_attrs)
    |> unique_validations()
    |> hash_password()
  end

  def profile_changeset(struct, params \\ %{}) do
    struct
    |> cast(params, @profile_attrs)
    |> validate_required(@profile_attrs)
    |> unique_validations()
  end

  def password_changeset(struct, params \\ %{}) do
    struct
    |> cast(params, [:password])
    |> validate_required([:password])
    |> hash_password()
  end

  def unique_validations(struct) do
    struct
    |> unique_constraint(:name)
    |> unique_constraint(:email)
  end

  def find_by_name(name) do
    from(user in __MODULE__,
      where: user.name == ^name
    )
  end

  def opponents(user) do
    from(user in __MODULE__,
      where: user.id != ^user.id
    )
  end

  def matches(query, query_string) do
    from(user in query,
      where:
        ilike(user.name, ^"%#{query_string}%") or
          user.email == ^query_string
    )
  end

  defp hash_password(changeset) do
    password = get_change(changeset, :password)

    if password do
      changeset
      |> change(Argon2.add_hash(password))
      |> change(password: nil)
    else
      changeset
    end
  end
end