# frozen_string_literal: true

module Jekyll
  # Jekyll multilingual support
  #
  # * Posts are put under _LANGUAGE/ directories
  # * The first language on the config is default
  # * Translation strings are store in _data/LANGUAGE.yml
  # * The plugin generates a copy of the site for every language at
  #   _site/LANGUAGE
  class Site
    attr_reader :locale

    # We don't monkey patch because the Site is already instantiated
    alias process_single process

    # Process the site once per available locale
    def process
      locales.each do |locale|
        @locale = locale

        Jekyll.logger.info 'Generating locale:', locale

        locale_config

        Jekyll.logger.info 'Destination:', config['destination']
        Jekyll.logger.info 'Base URL:', config['baseurl']

        symlink
        process_single
        # The default locale is placed at the root of the
        # site and everything else is under a subdirectory, but we symlink
        # root to default_locale for compatibility
        self_symlink if default_locale? && !redirect?
      end

      # XXX: Default is expected by Sutty so we always create it
      default_delete
      default_symlink

      # If we enable the redirector, the root of the site will consist
      # of an index.html that allows visitors to select their locale.
      copy_redirector if redirect?
    end

    def locales?
      locales.length > 1
    end

    # Get locales from configuration
    def locales
      @locales ||= config.fetch('locales', [])
    end

    def default_locale
      @default_locale ||= locales.first
    end

    def default_locale?
      default_locale == locale
    end

    private

    # Redefine #render_docs so it doesn't render the locale collections
    # for each independent locale.
    #
    # XXX: Jekyll should render on demand instead of rendering and
    # writing separately.
    def render_docs(payload)
      collections.each do |name, collection|
        next if locales.include? name

        collection.docs.each do |document|
          render_regenerated(document, payload)
        end
      end
    end

    def locale_config
      # XXX: Retrocompatibility
      config['locale'] = config['lang'] = locale
      config['default_locale'] = default_locale

      # Don't touch the config unless there's more than one locale or we
      # aren't using a redirector
      return unless locales?

      other_locales_as_collections
      return if default_locale? && !redirect?

      @dest = config['destination'] = locale_destination
      config['baseurl'] = locale_baseurl
    end

    # Read the other locales as collections but don't render them, only
    # make them available to templates.
    #
    # The URL will be the permalink with the language prepended.
    #
    # {https://rubygems.org/gems/jekyll-linked-posts}
    def other_locales_as_collections
      locales.each do |l|
        next if l == locale

        config['collections'][l] = {
          'output' => false,
          'permalink' => [nil, l, config['permalink']].join('/')
        }
      end
    end

    # Cache original destination
    def root_destination
      @root_destination ||= config['destination']
    end

    def orig_baseurl
      @orig_baseurl ||= config.dig('baseurl') || ''
    end

    # Add locale to the site destination
    def locale_destination
      File.join(root_destination, locale)
    end

    # If the site has a baseurl, we add the locale to it.  But we add
    # it anyway so relative URLs include the locale
    def locale_baseurl
      [orig_baseurl, locale].join('/')
    end

    # Creates a symlink to the _posts/ directory so Jekyll believes
    # it's processing a single site.
    def symlink
      FileUtils.rm_f('_posts')
      FileUtils.ln_s("_#{locale}", '_posts')
    end

    def redirect?
      config.fetch('redirect', false)
    end

    # TODO: Make configurable
    def redirector
      @redirector ||= File.join(locale_destination, 'redirector.html')
    end

    def redirector_to_index(redir)
      File.join(root_destination,
                File.basename(redir
                    .sub('redirector', 'index')))
    end

    def copy_redirector
      return unless File.exist? redirector

      Dir.glob("#{redirector}*").each do |redir|
        FileUtils.cp(redir, redirector_to_index(redir))
      end
    end

    def default_delete
      FileUtils.rm_f default_destination
    end

    def default_destination
      @default_destination ||= File.join(root_destination, 'default')
    end

    def default_symlink
      FileUtils.ln_s(default_locale, default_destination)
    end

    def self_symlink
      FileUtils.rm_f(locale_destination)
      FileUtils.ln_s('.', locale_destination)
    end
  end
end