module Pagy::Frontend

def pagy_nav(pagy, pagy_id: nil, link_extra: '', **vars)
  p_id   = %( id="#{pagy_id}") if pagy_id
  link   = pagy_link_proc(pagy, link_extra: link_extra)
  p_prev = pagy.prev
  p_next = pagy.next
  html = +%(<nav#{p_id} class="pagy-nav pagination">)
  html << if p_prev
            %(<span class="page prev">#{link.call p_prev, pagy_t('pagy.nav.prev'), 'aria-label="previous"'}</span> )
          else
            %(<span class="page prev disabled">#{pagy_t('pagy.nav.prev')}</span> )
          end
  pagy.series(**vars).each do |item| # series example: [1, :gap, 7, 8, "9", 10, 11, :gap, 36]
    html << case item
            when Integer then %(<span class="page">#{link.call item}</span> )
            when String  then %(<span class="page active">#{pagy.label_for(item)}</span> )
            when :gap    then %(<span class="page gap">#{pagy_t('pagy.nav.gap')}</span> )
            else raise InternalError, "expected item types in series to be Integer, String or :gap; got #{item.inspect}"
            end
  end
  html << if p_next
            %(<span class="page next">#{link.call p_next, pagy_t('pagy.nav.next'), 'aria-label="next"'}</span>)
          else
            %(<span class="page next disabled">#{pagy_t('pagy.nav.next')}</span>)
          end
  html << %(</nav>)
end