module Pagy::Frontend

def pagy_info(pagy, pagy_id: nil, item_name: nil, i18n_key: nil)
  p_id    = %( id="#{pagy_id}") if pagy_id
  p_count = pagy.count
  key     = if    p_count.zero?   then 'pagy.info.no_items'
            elsif pagy.pages == 1 then 'pagy.info.single_page'
            else                       'pagy.info.multiple_pages' # rubocop:disable Lint/ElseLayout
            end
  %(<span#{p_id} class="pagy-info">#{
      pagy_t key, item_name: item_name || pagy_t(i18n_key || pagy.vars[:i18n_key], count: p_count),
                  count: p_count, from: pagy.from, to: pagy.to
    }</span>)
end

def pagy_link_proc(pagy, link_extra: '')
  p_prev      = pagy.prev
  p_next      = pagy.next
  left, right = %(<a href="#{pagy_url_for(pagy, PAGE_PLACEHOLDER, html_escaped: true)}" #{
                    pagy.vars[:link_extra]} #{link_extra}).split(PAGE_PLACEHOLDER, 2)
  lambda do |page, text = pagy.label_for(page), extra_attrs = ''|
    %(#{left}#{page}#{right}#{ case page
                               when p_prev then ' rel="prev"'
                               when p_next then ' rel="next"'
                               else             ''
                               end } #{extra_attrs}>#{text}</a>)
  end
end

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

def pagy_t(key, opts = {})
  Pagy::I18n.translate(@pagy_locale ||= nil, key, opts)
end