# defmodule Kvasir.AgentServer.EchoAgent do
#   @moduledoc ~S"""
#   An Echo agent.
#   """
#   use Kvasir.Command.Dispatcher

#   @doc false
#   @impl Kvasir.Command.Dispatcher
#   def do_dispatch(cmd = %{__meta__: meta}) do
#     n = UTCDateTime.utc_now()

#     m =
#       case meta.wait do
#         :dispatch -> %{meta | dispatched: n}
#         :execute -> %{meta | dispatched: n, executed: n}
#         :apply -> %{meta | dispatched: n, executed: n, applied: n}
#       end

#     {:ok, %{cmd | __meta__: m}}
#   end

#   ### Fake Agent ###

#   @doc false
#   @spec child_spec(Keyword.t()) :: map
#   def child_spec(_opts \\ []), do: %{id: :echo, start: {Agent, :start_link, [fn -> 0 end]}}

#   @doc false
#   @spec dispatch!(Kvasir.Command.t(), Keyword.t()) :: Kvasir.Command.t() | no_return
#   def dispatch!(command, opts \\ []) do
#     case dispatch(command, opts) do
#       {:ok, cmd} -> cmd
#       {:error, err} -> raise "Command dispatch failed: #{inspect(err)}."
#     end
#   end

#   @doc false
#   @spec open(any) :: {:ok, pid} | {:error, atom}
#   def open(_id), do: {:error, :mock_agent}

#   # @doc false
#   # @spec inspect(any) :: {:ok, term} | {:error, atom}
#   # def inspect(_id), do: {:error, :mock_agent}

#   @doc false
#   @spec count :: non_neg_integer
#   def count, do: 0

#   @doc false
#   @spec list :: [term]
#   def list, do: []

#   @doc false
#   @spec whereis(any) :: pid | nil
#   def whereis(_id), do: nil

#   @doc false
#   @spec alive?(any) :: boolean
#   def alive?(_id), do: false

#   @doc false
#   @spec sleep(id :: any, reason :: atom) :: :ok
#   def sleep(_id, _reason \\ :sleep), do: :ok

#   @doc false
#   @spec config(component :: atom, opts :: Keyword.t()) :: Keyword.t()
#   def config(_component, opts), do: opts

#   defoverridable config: 2

#   @doc false
#   @spec __agent__(atom) :: term
#   def __agent__(:config),
#     do: %{
#       agent: __MODULE__,
#       cache: false,
#       source: false,
#       model: false,
#       registry: false,
#       topic: false,
#       key: false
#     }

#   def __agent__(:topic), do: false
#   def __agent__(:key), do: false
# end