open_responses

defmodule OpenResponses.ToolRunner do
  @moduledoc """
  Dispatches hosted (server-side) tool calls to registered tool modules.

  When the model emits a `function_call` whose name is registered in
  `:hosted_tools`, the agentic loop calls `ToolRunner.run/4` instead of
  yielding the call back to the client. The result is injected as a
  `function_call_output` item and the loop continues automatically.

  Tool modules are registered in config:

  ```elixir
  config :open_responses, :hosted_tools, %{
    "get_weather" => MyApp.Tools.Weather,
    "search_docs" => MyApp.Tools.DocSearch
  }
  ```

  Each module must implement the `OpenResponses.Tool` behaviour. See that
  module and the [Tool Dispatch guide](tool_dispatch.html) for details.
  """

  @spec run(binary(), map(), map(), keyword()) ::
          {:ok, String.t()} | {:error, term()}
  def run(name, arguments, context, opts \\ []) do
    registry = Keyword.get(opts, :registry, default_registry())

    case Map.fetch(registry, name) do
      {:ok, module} -> module.execute(arguments, context)
      :error -> {:error, :not_found}
    end
  end

  defp default_registry do
    Application.get_env(:open_responses, :hosted_tools, %{})
  end
end