module Pagy::Frontend

def nav_aria_label_attr(pagy, nav_aria_label, nav_i18n_key, count: pagy.pages)
  nav_aria_label ||= pagy_t(nav_i18n_key || pagy.vars[:nav_i18n_key], count:)
  %(aria-label="#{nav_aria_label}")
end

def next_aria_label_attr
  %(aria-label="#{pagy_t('pagy.aria_label.next')}")
end

def next_html(pagy, link, text: pagy_t('pagy.next'))
  if (p_next = pagy.next)
    %(<span class="page next">#{link.call(p_next, text, next_aria_label_attr)}</span>)
  else
    %(<span class="page next disabled"><a role="link" aria-disabled="true" #{
        next_aria_label_attr}>#{text}</a></span>)
  end
end

def pagy_info(pagy, pagy_id: nil, item_name: nil, item_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(item_i18n_key || pagy.vars[:item_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
  p_page      = pagy.page.to_s
  left, right = %(<a href="#{pagy_url_for(pagy, PAGE_PLACEHOLDER)}" #{
                    pagy.vars[:link_extra]} #{link_extra}).split(PAGE_PLACEHOLDER, 2)
  # lambda used by all the helpers
  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"'
                               when p_page then ' aria-disabled="true" aria-current="page"'
                               else             ''
                               end } #{extra_attrs}>#{text}</a>)
  end
end

def pagy_nav(pagy, pagy_id: nil, link_extra: '',
             nav_aria_label: nil, nav_i18n_key: nil, **vars)
  p_id = %( id="#{pagy_id}") if pagy_id
  link = pagy_link_proc(pagy, link_extra:)
  html = +%(<nav#{p_id} class="pagy-nav pagination" #{nav_aria_label_attr(pagy, nav_aria_label, nav_i18n_key)}>)
  html << prev_html(pagy, link)
  pagy.series(**vars).each do |item| # series example: [1, :gap, 7, 8, "9", 10, 11, :gap, 36]
    html << case item
            when Integer
              %(<span class="page">#{link.call(item)}</span> )
            when String
              %(<span class="page active">) +
              %(<a role="link" aria-disabled="true" aria-current="page">#{pagy.label_for(item)}</a></span> )
            when :gap
              %(<span class="page gap">#{pagy_t('pagy.gap')}</span> )
            else
              raise InternalError, "expected item types in series to be Integer, String or :gap; got #{item.inspect}"
            end
  end
  html << %(#{next_html(pagy, link)}</nav>)
end

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

def prev_aria_label_attr
  %(aria-label="#{pagy_t('pagy.aria_label.prev')}")
end

def prev_html(pagy, link, text: pagy_t('pagy.prev'))
  if (p_prev = pagy.prev)
    %(<span class="page prev">#{link.call(p_prev, text, prev_aria_label_attr)}</span> )
  else
    %(<span class="page prev disabled"><a role="link" aria-disabled="true" #{
         prev_aria_label_attr}>#{text}</a></span> )
  end
end