Teek::BackgroundRactor4x::BackgroundWork Class

def close
  @done = true
  # Send stop to let the worker terminate itself — Ruby 4.x doesn't
  # allow closing a Ractor from outside.
  begin
    @control_port&.send(:stop)
  rescue Ractor::ClosedError
    # Already closed
  end
  @control_port = nil
  self
end

def done?
  @done
end

def initialize(app, data, worker: nil, &block)
  @app = app
  @data = data
  @work_block = block || (worker && proc { |t, d| worker.new.call(t, d) })
  @callbacks = { progress: nil, done: nil, message: nil }
  @started = false
  @done = false
  @paused = false

  # Communication
  @output_queue = Thread::Queue.new
  @control_port = nil  # Set by worker, received back
  @pending_messages = []  # Queued until control_port ready
  @worker_ractor = nil
  @bridge_thread = nil
end

def on_done(&block)
  @callbacks[:done] = block
  maybe_start
  self
end

def on_message(&block)
  @callbacks[:message] = block
  self
end

def on_progress(&block)
  @callbacks[:progress] = block
  maybe_start
  self
end

def pause
  @paused = true
  send_message(:pause)
  self
end

def paused?
  @paused
end

def resume
  @paused = false
  send_message(:resume)
  self
end

def send_message(msg)
  if @control_port
    begin
      @control_port.send(msg)
    rescue Ractor::ClosedError
      # Port already closed, task is done - ignore
    end
  else
    @pending_messages << msg
  end
  self
end

def start
  return self if @started
  @started = true

  # Wrap in isolated proc for Ractor sharing. The block can only access
  # its parameters (task, data), not outer-scope variables.
  shareable_block = Ractor.shareable_proc(&@work_block)

  start_ractor(shareable_block)
  start_polling
  self
end

def stop
  send_message(:stop)
  self
end