module SvelteOnRails
  class TurboStream
    def self.dispatch(component = nil, event_detail = nil, event: 'stream-action', selector: nil, channel: nil)

      utils = SvelteOnRails::Lib::Utils
      conf = SvelteOnRails::Configuration.instance

      _comp = if component
                utils.validate_filename(component)
                "/#{conf.components_folder + component}"
              end

      if event != 'stream-action' && !selector
        raise "Another event name than the default one is only possible together with a selector"
      end

      args = {
        eventDetail: event_detail,
        component: _comp,
        event: event,
        selector: selector
      }

      args_enc = Base64.strict_encode64(args.to_json)

      Turbo::StreamsChannel.send(
        "broadcast_append_to",
        channel || configs['channel'],
        target: configs['target_html_id'],
        content: "<div style=\"display: none;\" data-controller=\"svelte-on-rails-turbo-stream\" data-args=\"#{args_enc}\"></div>"
      )

    end

    def self.dispatch_by_selector(selector, event_detail = nil, event: 'stream-action', channel: nil)

      if event != 'stream-action' && !selector
        raise "Another event name than the default one is only possible together with a selector"
      end

      args = {
        eventDetail: event_detail,
        component: ':false:',
        event: event,
        selector: selector
      }

      args_enc = Base64.strict_encode64(args.to_json)

      Turbo::StreamsChannel.send(
        "broadcast_append_to",
        require_channel(channel || configs['channel']),
        target: configs['target_html_id'],
        content: "<div style=\"display: none;\" data-controller=\"svelte-on-rails-turbo-stream\" data-args=\"#{args_enc}\"></div>"
      )

    end

    private

    def self.configs
      @configs ||= begin

                     conf = SvelteOnRails::Configuration.instance
                     unless conf.configs[:turbo_stream]
                       raise '[svelte-on-rails] missing configuration: :turbo_stream'
                     end
                     unless conf.configs[:turbo_stream]['target_html_id']
                       raise '[svelte-on-rails] missing configuration: turbo_stream/target_html_id'
                     end
                     unless conf.configs[:turbo_stream]['channel']
                       raise '[svelte-on-rails] missing configuration: turbo_stream/channel'
                     end

                     conf.configs[:turbo_stream]
                   end
    end

    def self.require_channel(channel)
      unless channel.present?
        raise 'Missing attribute or configuration: turbo_stream/channel'
      end
      channel
    end

  end
end