module Jekyll
  module OpenProjectHelpers

    # Below passes an array of posts of open hub blog
    # and from each individual project blog, combined and sorted by date,
    # to open hub blog index page.
    #
    # (It also does some processing on the posts.)

    class BlogIndexGenerator < Jekyll::Generator
      safe true

      def generate(site)
        site_posts = site.posts.docs

        if Jekyll::OpenProjectHelpers::is_hub(site)
          # Get documents representing projects
          projects = site.collections['projects'].docs.select do |item|
            pieces = item.url.split('/')
            pieces.length == 4 && pieces[-1] == 'index' && pieces[1] == 'projects'
          end
          # Add project name (matches directory name, may differ from title)
          projects = projects.map do |project|
            project.data['name'] = project.url.split('/')[2]
            project
          end

          # Get documents representnig posts from each project’s blog
          project_posts = site.collections['projects'].docs.select { |item| item.url.include? '_posts' }

          # Add parent project’s data hash onto each
          project_posts = project_posts.map do |post|
            project_name = post.url.split('/')[2]
            post.data['parent_project'] = projects.detect { |p| p.data['name'] == project_name }
            post
          end

          posts_combined = (project_posts + site_posts).sort_by(&:date).reverse

        else
          posts_combined = site_posts

        end

        # On each post, replace authors’ emails with corresponding md5 hashes
        # suitable for hotlinking authors’ Gravatar profile pictures.
        posts_combined = posts_combined.map do |post|
          if post.data.key? 'author'
            email = post.data['author']['email']
            hash = Digest::MD5.hexdigest(email)
            post.data['author']['email'] = hash
          end
          post
        end

        blog_index = site.site_payload["site"]["pages"].detect { |page| page.url == '/blog/' }
        blog_index.data['posts_combined'] = posts_combined
      end
    end

  end
end