class Jekyll::PaginateV2::Generator::CompatibilityUtils


THIS CLASS IS ADAPTED FROM THE ORIGINAL IMPLEMENTATION AND WILL BE REMOVED, THERE ARE DELIBERATELY NO TESTS FOR THIS CLASS
(REMOVE AFTER 2018-01-01)
that sites still running the old gem work without problems
jekyll-paginate gem that this new version superseeds (this code is here to ensure)
Static utility functions that provide backwards compatibility with the old

def self.in_hierarchy(source, page_dir, paginate_path)

Returns whether the subdirectories are the same relative to source

paginate_path - the absolute paginate path (from root of FS)
page_dir - the directory of the Jekyll::Page
source - the site source

Determine if the subdirectories of the two paths are the same relative to source 
def self.in_hierarchy(source, page_dir, paginate_path)
  return false if paginate_path == File.dirname(paginate_path)
  return false if paginate_path == Pathname.new(source).parent
  page_dir == paginate_path ||
    CompatibilityUtils.in_hierarchy(source, page_dir, File.dirname(paginate_path))
end

def self.paginate(legacy_config, all_posts, page, page_add_lambda )


site-wide data.
directories, e.g.: page2/index.html, page3/index.html, etc and adds more
Paginates the blog's posts. Renders the index.html file into paginated 
def self.paginate(legacy_config, all_posts, page, page_add_lambda )
  pages = Utils.calculate_number_of_pages(all_posts, legacy_config['per_page'].to_i)
  (1..pages).each do |num_page|
    pager = Paginator.new( legacy_config['per_page'], page.url, legacy_config['permalink'], all_posts, num_page, pages, '', '' )
    if num_page > 1
      template_full_path = File.join(page.site.source, page.path)
      template_dir = File.dirname(page.path)
      newpage = CompatibilityPaginationPage.new(page.site, page.site.source, template_dir, template_full_path)
      newpage.pager = pager
      newpage.dir = CompatibilityUtils.paginate_path(page.url, num_page, legacy_config['permalink'])
      newpage.data['autogen'] = "jekyll-paginate-v2" # Signals that this page is automatically generated by the pagination logic

      page_add_lambda.call(newpage)
    else
      page.pager = pager
    end
  end
end

def self.paginate_path(template_url, cur_page_nr, permalink_format)

Returns the pagination path as a string

config - the current configuration in use
cur_page_nr - the pagination page number
site - the Jekyll::Site object

Static: Return the pagination path of the page 
def self.paginate_path(template_url, cur_page_nr, permalink_format)
  return nil if cur_page_nr.nil?
  return template_url if cur_page_nr <= 1
  if permalink_format.include?(":num")
    permalink_format = Utils.format_page_number(permalink_format, cur_page_nr)
  else
    raise ArgumentError.new("Invalid pagination path: '#{permalink_format}'. It must include ':num'.")
  end
  Utils.ensure_leading_slash(permalink_format)
end #function paginate_path

def self.pagination_candidate?(config_source, config_paginate_path, page)

between the site source and `paginate_path`.
Page's name must be `index.html` and exist in any of the directories
Static: Determine if a page is a possible candidate to be a template page. 
def self.pagination_candidate?(config_source, config_paginate_path, page)
  page_dir = File.dirname(File.expand_path(Utils.remove_leading_slash(page.path), config_source))
  paginate_path = Utils.remove_leading_slash(config_paginate_path)
  paginate_path = File.expand_path(paginate_path, config_source)
  page.name == 'index.html' && CompatibilityUtils.in_hierarchy(config_source, page_dir, File.dirname(paginate_path))
end

def self.template_page(site_pages, config_source, config_paginate_path)

Returns the Jekyll::Page which will act as the pager template

Public: Find the Jekyll::Page which will act as the pager template 
def self.template_page(site_pages, config_source, config_paginate_path)
  site_pages.select do |page|
    CompatibilityUtils.pagination_candidate?(config_source, config_paginate_path, page)
  end.sort do |one, two|
    two.path.size <=> one.path.size
  end.first
end