require File.dirname(__FILE__) + '/helper'

module SitemapGenerator
  class LinkSet
    include SitemapGenerator::Helper
    include ActionView::Helpers::NumberHelper

    attr_accessor :default_host, :yahoo_app_id, :links
    attr_accessor :sitemaps
    attr_accessor :max_entries
    attr_accessor :link_count

    alias :sitemap_files :sitemaps

    # Create new link set instance.
    def initialize
      self.links       = []
      self.sitemaps    = []
      self.max_entries = SitemapGenerator::MAX_ENTRIES
      self.link_count  = 0
    end

    # Add default links to sitemap files.
    def add_default_links
      links.push Link.generate('/', :lastmod => Time.now, :changefreq => 'always', :priority => 1.0)
      links.push Link.generate("/#{index_file}", :lastmod => Time.now, :changefreq => 'always', :priority => 1.0)
      self.link_count += 2
    end

    # Add links to sitemap files passing a block.
    def add_links
      raise ArgumentError, "Default hostname not set" if default_host.blank?
      add_default_links if first_link?
      yield Mapper.new(self)
    end

    # Add links from mapper to sitemap files.
    def add_link(link)
      write_upcoming if enough_links?
      links.push link
      self.link_count += 1
    end

    # Write links to sitemap file.
    def write
      write_pending
    end

    # Write links to upcoming sitemap file.
    def write_upcoming
      write_sitemap(upcoming_file)
    end

    # Write pending links to sitemap, write index file if needed.
    def write_pending
      write_upcoming
      write_index
    end

    # Write links to sitemap file.
    def write_sitemap(file = upcoming_file)
      buffer = ""
      xml = Builder::XmlMarkup.new(:target => buffer)
      eval(File.read(SitemapGenerator.templates[:sitemap_xml]), binding)
      filename = File.join(RAILS_ROOT, "public", file)
      write_file(filename, buffer)
      show_progress("Sitemap", filename, buffer) if verbose
      links.clear
      sitemaps.push filename
    end

    # Write sitemap links to sitemap index file.
    def write_index
      buffer = ""
      xml = Builder::XmlMarkup.new(:target => buffer)
      eval(File.read(SitemapGenerator.templates[:sitemap_index]), binding)
      filename = File.join(RAILS_ROOT, "public", index_file)
      write_file(filename, buffer)
      show_progress("Sitemap Index", filename, buffer) if verbose
      links.clear
      sitemaps.clear
    end

    # Return sitemap or sitemap index main name.
    def index_file
      "sitemap_index.xml.gz"
    end

    # Return upcoming sitemap name with index.
    def upcoming_file
      "sitemap#{upcoming_index}.xml.gz" unless enough_sitemaps?
    end

    # Return upcoming sitemap index, first is 1.
    def upcoming_index
      sitemaps.length + 1 unless enough_sitemaps?
    end

    # Return true if upcoming is first sitemap.
    def first_sitemap?
      sitemaps.empty?
    end

    # Return true if sitemap index needed.
    def multiple_sitemaps?
      !first_sitemap?
    end

    # Return true if more sitemaps can be added.
    def more_sitemaps?
      sitemaps.length < max_entries
    end

    # Return true if no sitemaps can be added.
    def enough_sitemaps?
      !more_sitemaps?
    end

    # Return true if this is the first link added.
    def first_link?
      links.empty? && first_sitemap?
    end

    # Return true if more links can be added.
    def more_links?
      links.length < max_entries
    end

    # Return true if no further links can be added.
    def enough_links?
      !more_links?
    end

    # Commit buffer to gzipped file.
    def write_file(name, buffer)
      Zlib::GzipWriter.open(name) { |gz| gz.write buffer }
    end

    # Report progress line.
    def show_progress(title, filename, buffer)
      puts "+ #{filename}"
      puts "** #{title} too big! The uncompressed size exceeds 10Mb" if buffer.size > 10.megabytes
    end

    # Copy templates/sitemap.rb to config if not there yet.
    def install_sitemap_rb
      if File.exist?(File.join(RAILS_ROOT, 'config/sitemap.rb'))
        puts "already exists: config/sitemap.rb, file not copied"
      else
        FileUtils.cp(SitemapGenerator.templates[:sitemap_sample], File.join(RAILS_ROOT, 'config/sitemap.rb'))
        puts "created: config/sitemap.rb"
      end
    end

    # Remove config/sitemap.rb if exists.
    def uninstall_sitemap_rb
      if File.exist?(File.join(RAILS_ROOT, 'config/sitemap.rb'))
        File.rm(File.join(RAILS_ROOT, 'config/sitemap.rb'))
      end
    end

    # Clean sitemap files in output directory.
    def clean_files
      FileUtils.rm(Dir[File.join(RAILS_ROOT, 'public/sitemap*.xml.gz')])
    end

    # Ping search engines passing sitemap location.
    def ping_search_engines
      super index_file
    end

    # Create sitemap files in output directory.
    def create_files(verbose = true)
      start_time = Time.now
      load_sitemap_rb
      write
      stop_time = Time.now
      puts "Sitemap stats: #{number_with_delimiter(SitemapGenerator::Sitemap.link_count)} links, " + ("%dm%02ds" % (stop_time - start_time).divmod(60)) if verbose
    end
  end
end