live_query

defmodule LiveQuery.Query.Def do
  @moduledoc """
  TODO
  """

  @enforce_keys [:init]
  defstruct [:init, :handle_call, :handle_cast, :handle_info]

  @type data :: any
  @callback init(state :: %{required(:key) => any, required(:config) => map}) :: data
  @callback handle_call(
              msg :: any,
              from :: GenServer.from(),
              state :: %{required(:key) => any, required(:config) => map, optional(:data) => data}
            ) :: {:noreply, data} | {:reply, any, data}
  @callback handle_cast(
              msg :: any,
              state :: %{required(:key) => any, required(:config) => map, optional(:data) => data}
            ) :: data
  @callback handle_info(
              msg :: any,
              state :: %{required(:key) => any, required(:config) => map, optional(:data) => data}
            ) :: data

  @optional_callbacks [handle_call: 3, handle_cast: 2, handle_info: 2]

  @doc """
  TODO
  """
  defmacro __using__(_opts) do
    quote do
      @behaviour LiveQuery.Query.Def
    end
  end

  @doc """
  TODO
  """
  def new(opts) do
    %__MODULE__{
      init: opts.init,
      handle_call: opts[:handle_call],
      handle_cast: opts[:handle_cast],
      handle_info: opts[:handle_info]
    }
  end

  defimpl LiveQuery.Query.DefLike do
    def init(self, state) do
      self.init.(state)
    end

    def handle_call(self, msg, from, state) do
      self.handle_call.(msg, from, state)
    end

    def handle_cast(self, msg, state) do
      self.handle_cast.(msg, state)
    end

    def handle_info(self, msg, state) do
      self.handle_info.(msg, state)
    end
  end
end