ex_claw

defmodule Mix.Tasks.ExClaw.Chat do
  @moduledoc """
  Starts an interactive chat REPL with an ADK Elixir agent.

      mix ex_claw.chat

  Options:
    --model   LLM model to use (default: gemini-2.0-flash)
    --name    Agent name (default: ex_claw)
  """
  @shortdoc "Interactive chat with an ExClaw agent"

  use Mix.Task

  @impl Mix.Task
  def run(args) do
    Mix.Task.run("app.start")

    {opts, _, _} =
      OptionParser.parse(args, strict: [model: :string, name: :string])

    model = opts[:model] || "gemini-2.0-flash"
    name = opts[:name] || "ex_claw"

    IO.puts("ExClaw Chat — #{name} (#{model})")
    IO.puts("Type 'exit' or Ctrl-C to quit.\n")

    agent =
      ADK.Agent.LlmAgent.new(
        name: name,
        model: model,
        instruction: """
        You are ExClaw, a helpful AI assistant built on ADK Elixir.
        Be concise and helpful. You're running as a CLI chat agent.
        """
      )

    runner = ADK.Runner.new(app_name: name, agent: agent)

    loop(runner, name, "user-1", "chat-#{System.unique_integer([:positive])}")
  end

  defp loop(runner, name, user_id, session_id) do
    case IO.gets("you> ") do
      :eof ->
        IO.puts("\nBye!")

      input when is_binary(input) ->
        input = String.trim(input)

        if input in ["exit", "quit"] do
          IO.puts("Bye!")
        else
          if input == "" do
            loop(runner, name, user_id, session_id)
          else
            case ADK.Runner.run(runner, user_id, session_id, input) do
              {:ok, events} ->
                events
                |> Enum.filter(&match?(%ADK.Event{author: a} when a != "user", &1))
                |> Enum.each(fn event ->
                  text = extract_text(event)
                  if text && text != "", do: IO.puts("\n#{name}> #{text}\n")
                end)

                loop(runner, name, user_id, session_id)

              {:error, reason} ->
                IO.puts("\n[error] #{inspect(reason)}\n")
                loop(runner, name, user_id, session_id)
            end
          end
        end
    end
  end

  defp extract_text(%ADK.Event{content: %{parts: parts}}) when is_list(parts) do
    parts
    |> Enum.map(fn
      %{text: t} -> t
      _ -> nil
    end)
    |> Enum.reject(&is_nil/1)
    |> Enum.join("")
  end

  defp extract_text(_), do: nil
end