defmodule BCUtils.UuidHelper do
  @moduledoc """
    Helper functions for working with UUIDs.
  """

  @uuid_regex ~r/^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i
  @doc """
  Validates if the given input is a valid UUID.

  Accepts either a UUID string or a binary UUID.

  ## Examples

      iex> UuidHelper.validate("550e8400-e29b-41d4-a716-446655440000")
      true

      iex> UuidHelper.validate("not-a-uuid")
      false

      iex> UuidHelper.validate(<<85, 14, 132, 0, 226, 155, 65, 212, 167, 22, 68, 102, 85, 68, 0, 0>>)
      true

  """
  @spec validate(String.t() | binary()) :: boolean()
  def validate(uuid) when is_binary(uuid) do
    case byte_size(uuid) do
      16 ->
        # Raw binary UUID (16 bytes)
        true

      36 ->
        # String UUID format (8-4-4-4-12 = 36 chars)
        uuid =~ @uuid_regex

      _ ->
        false
    end
  end

  def validate(_), do: false
end