# frozen_string_literal: true

module Primer
  module Beta
    # Use `Subhead` as the start of a section. The `:heading` slot will render an `<h2>` font-sized text.
    #
    # - Optionally set the `:description` slot to render a short description and the `:actions` slot for a related action.
    # - Use a succinct, one-line description for the `:description` slot. For longer descriptions, omit the description slot and render a paragraph below the `Subhead`.
    # - Use the actions slot to render a related action to the right of the heading. Use <%= link_to_component(Primer::ButtonComponent) %> or <%= link_to_component(Primer::Beta::Link) %>.
    #
    # @accessibility
    #   The `:heading` slot defaults to rendering a `<div>`. Update the tag to a heading element with the appropriate level to improve page navigation for assistive technologies.
    #   <%= link_to_heading_practices %>
    class Subhead < Primer::Component
      status :beta

      DEFAULT_HEADING_TAG = :div
      HEADING_TAG_OPTIONS = [DEFAULT_HEADING_TAG, :h1, :h2, :h3, :h4, :h5, :h6].freeze

      # The heading
      #
      # @param tag [Symbol] <%= one_of(Primer::Beta::Subhead::HEADING_TAG_OPTIONS)%>
      # @param danger [Boolean] Whether to style the heading as dangerous.
      # @param system_arguments [Hash] <%= link_to_system_arguments_docs %>
      renders_one :heading, lambda { |tag: DEFAULT_HEADING_TAG, danger: false, **system_arguments|
        system_arguments[:tag] = fetch_or_fallback(HEADING_TAG_OPTIONS, tag, DEFAULT_HEADING_TAG)
        system_arguments[:classes] = class_names(
          system_arguments[:classes],
          "Subhead-heading",
          "Subhead-heading--danger": danger
        )

        Primer::BaseComponent.new(**system_arguments)
      }

      # Actions
      #
      # @param system_arguments [Hash] <%= link_to_system_arguments_docs %>
      renders_one :actions, lambda { |**system_arguments|
        deny_tag_argument(**system_arguments)
        system_arguments[:tag] = :div
        system_arguments[:classes] = class_names(system_arguments[:classes], "Subhead-actions")

        Primer::BaseComponent.new(**system_arguments)
      }

      # The description
      #
      # @param system_arguments [Hash] <%= link_to_system_arguments_docs %>
      renders_one :description, lambda { |**system_arguments|
        deny_tag_argument(**system_arguments)
        system_arguments[:tag] = :div
        system_arguments[:classes] = class_names(system_arguments[:classes], "Subhead-description")

        Primer::BaseComponent.new(**system_arguments)
      }

      # @example Default
      #   <%= render(Primer::Beta::Subhead.new) do |component| %>
      #     <% component.with_heading(tag: :h3) do %>
      #       My Heading
      #     <% end %>
      #     <% component.with_description do %>
      #       My Description
      #     <% end %>
      #   <% end %>
      #
      # @example With dangerous heading
      #   <%= render(Primer::Beta::Subhead.new) do |component| %>
      #     <% component.with_heading(tag: :h3, danger: true) do %>
      #       My Heading
      #     <% end %>
      #     <% component.with_description do %>
      #       My Description
      #     <% end %>
      #   <% end %>
      #
      # @example With long description
      #   <%= render(Primer::Beta::Subhead.new) do |component| %>
      #     <% component.with_heading(tag: :h3) do %>
      #       My Heading
      #     <% end %>
      #   <% end %>
      #   <p> This is a longer description that is sitting below the Subhead. It's much longer than a description that could sit comfortably in the Subhead. </p>
      #
      # @example Without border
      #   <%= render(Primer::Beta::Subhead.new(hide_border: true)) do |component| %>
      #     <% component.with_heading do %>
      #       My Heading
      #     <% end %>
      #     <% component.with_description do %>
      #       My Description
      #     <% end %>
      #   <% end %>
      #
      # @example With actions
      #   <%= render(Primer::Beta::Subhead.new) do |component| %>
      #     <% component.with_heading do %>
      #       My Heading
      #     <% end %>
      #     <% component.with_description do %>
      #       My Description
      #     <% end %>
      #     <% component.with_actions do %>
      #       <%= render(
      #         Primer::ButtonComponent.new(
      #           tag: :a, href: "http://www.google.com", scheme: :danger
      #         )
      #       ) { "Action" } %>
      #     <% end %>
      #   <% end %>
      #
      # @param spacious [Boolean] Whether to add spacing to the Subhead.
      # @param hide_border [Boolean] Whether to hide the border under the heading.
      # @param system_arguments [Hash] <%= link_to_system_arguments_docs %>
      def initialize(spacious: false, hide_border: false, **system_arguments)
        @system_arguments = deny_tag_argument(**system_arguments)

        @system_arguments[:tag] = :div
        @system_arguments[:classes] =
          class_names(
            @system_arguments[:classes],
            "Subhead",
            "Subhead--spacious": spacious,
            "border-bottom-0": hide_border
          )
        @system_arguments[:mb] ||= hide_border ? 0 : nil
      end

      def render?
        heading.present?
      end
    end
  end
end