defmodule <%= schema_module %>Token do
  use Ecto.Schema
  import Ecto.Query

  alias <%= schema_module %>

  @hash_algorithm :sha256
  @session_validity_in_days 60
  @reset_password_validity_in_days 1

  schema "users_tokens" do
    field :token, :binary
    field :context, :string
    belongs_to :user, <%= schema_module %>

    timestamps(type: :utc_datetime, updated_at: false)
  end

  def build_session_token(user) do
    token = Dialup.Auth.SessionToken.generate()
    {token, build_hashed_token(user, "session", token)}
  end

  def build_email_token(user, context) do
    token = Dialup.Auth.SessionToken.generate()
    {token, build_hashed_token(user, context, token)}
  end

  def verify_session_token_query(token) do
    query =
      from token in token_and_context_query(token, "session"),
        join: user in assoc(token, :user),
        where: token.inserted_at > ago(@session_validity_in_days, "day"),
        select: user

    {:ok, query}
  end

  def verify_email_token_query(token, context) do
    days =
      case context do
        "reset_password" -> @reset_password_validity_in_days
        _ -> 7
      end

    query =
      from token in token_and_context_query(token, context),
        join: user in assoc(token, :user),
        where: token.inserted_at > ago(^days, "day"),
        select: user

    {:ok, query}
  end

  defp build_hashed_token(user, context, token) do
    %<%= schema_module %>Token{
      token: Dialup.Auth.SessionToken.hash(token),
      context: context,
      user_id: user.id
    }
  end

  def token_and_context_query(token, context) do
    from <%= schema_module %>Token, where: [token: ^Dialup.Auth.SessionToken.hash(token), context: ^context]
  end

  def user_and_context_query(user, context) do
    from t in <%= schema_module %>Token, where: t.user_id == ^user.id and t.context == ^context
  end
end