module AccessesHelper
  MAX_DISPLAYED_WATCHERS = 8

  def access_menu_tag(collection, **options, &)
    tag.menu class: [ options[:class], { "toggler--toggled": collection.all_access? } ], data: {
      controller: "filter toggle-class navigable-list",
      action: "keydown->navigable-list#navigate filter:changed->navigable-list#reset",
      navigable_list_focus_on_selection_value: true,
      navigable_list_actionable_items_value: true,
      toggle_class_toggle_class: "toggler--toggled" }, &
  end

  def access_toggles_for(users, selected:)
    render partial: "collections/access_toggle",
      collection: users, as: :user,
      locals: { selected: selected },
      cached: ->(user) { [ user, selected ] }
  end

  def access_involvement_advance_button(collection, user, show_watchers: true, icon_only: false)
    access = collection.access_for(user)

    turbo_frame_tag dom_id(collection, :involvement_button) do
      concat collection_watchers_list(collection) if show_watchers
      concat involvement_button(collection, access, show_watchers, icon_only)
    end
  end

  def collection_watchers_list(collection)
    watchers = collection.users
                         .without(User.system)
                         .where(accesses: { involvement: :watching })
                         .distinct

    displayed_watchers = watchers.limit(MAX_DISPLAYED_WATCHERS)
    overflow_count = watchers.count - MAX_DISPLAYED_WATCHERS

    tag.div(class: "collection-tools__watching") do
      safe_join([
        safe_join(displayed_watchers.map { |watcher| avatar_tag(watcher) }),
        (tag.span("+#{overflow_count}", class: "overflow-count") if overflow_count > 0)
      ].compact)
    end
  end

  def involvement_button(collection, access, show_watchers, icon_only)
    involvement_label_id = dom_id(collection, :involvement_label)

    button_to(
      collection_involvement_path(collection),
      method: :put,
      aria: { labelledby: involvement_label_id },
      class: class_names("btn", { "btn--reversed": access.involvement == "watching" && icon_only }),
      params: { show_watchers: show_watchers, involvement: next_involvement(access.involvement), icon_only: icon_only }
    ) do
      safe_join([
        icon_tag("notification-bell-#{icon_only ? 'reverse-' : nil}#{access.involvement.dasherize}"),
        tag.span(
          involvement_access_label(collection, access.involvement),
          class: class_names("txt-nowrap txt-uppercase", "for-screen-reader": icon_only),
          id: involvement_label_id
        )
      ])
    end
  end

  private
    def next_involvement(involvement)
      order = %w[ watching access_only ]
      order[(order.index(involvement.to_s) + 1) % order.size]
    end

    def involvement_access_label(collection, involvement)
      case involvement
      when "access_only"
        "Watch this"
      when "watching"
        "Stop Watching"
      end
    end
end