class RubyWasmUi::Dispatcher

def after_every_command(handler)
  @after_handlers << handler
  -> {
    idx = @after_handlers.index(handler)
    @after_handlers.delete_at(idx) if idx
  }
end

def dispatch(command_name, payload)
  command_name_sym = command_name.to_sym
  if @subs.key?(command_name_sym)
    @subs[command_name_sym].each { |handler| handler.call(payload) }
  else
    warn "No handlers for command: #{command_name}"
  end
  @after_handlers.each(&:call)
end

def initialize
  @subs = {}
  @after_handlers = []
end

def subscribe(command_name, handler)
  @subs[command_name] ||= []
  handlers = @subs[command_name]
  return -> {} if handlers.include?(handler)
  handlers << handler
  -> {
    idx = handlers.index(handler)
    handlers.delete_at(idx) if idx
  }
end