class RSScache

# File lib/rsscache.rb, line 17
def initialize(rsslist=nil, filepath: '.', debug: false)

  rsslist ||= File.join(filepath, 'rsscache.xml')
  @dx = open_dynarex(rsslist)
  @filepath = filepath
  @cache_filepath = File.join(filepath, 'rsscache')
  FileX.mkdir_p @cache_filepath

  @err_report = []
  @debug = debug

end

# File lib/rsscache.rb, line 33
def import(raw_s)

  s, _ = RXFReader.read(raw_s)

  s.strip.lines.each do |raw_url|

    url = raw_url.chomp
    puts 'url : '  + url.inspect if @debug
    r = @dx.find_by_url url.chomp

    if r then
      puts 'exists' if @debug
    else
      puts 'new URL found' if @debug
      @dx.create url: url
    end

  end

  save()
end

# File lib/rsscache.rb, line 57
def refresh

  @err_report = []

  puts '@dx.to_xml'  + @dx.to_xml(pretty: true)  if @debug

  @dx.all.each do |feed|

    puts 'feed:' + feed.inspect if @debug

    if feed.next_refresh.empty? or \
                           Time.now >= Time.parse(feed.next_refresh) then

      any_new_items = updates? feed

      feed.refresh_rate = if feed.refresh_rate.empty? then

        10

      else

        if Time.now > Time.parse(feed.next_refresh) + \
                        feed.refresh_rate.to_i and not any_new_items then
          feed.refresh_rate.to_i + 10
        end

      end


      feed.next_refresh = Time.now + feed.refresh_rate.to_i * 60


    else

      feed.refresh_rate = feed.refresh_rate.to_i - 10 if feed.refresh_rate.to_i > 10

    end
  end

  puts '@dx: ' + @dx.to_xml(pretty: true) if @debug
  save()

end

# File lib/rsscache.rb, line 103
def save()

  @dx.save File.join(@filepath, 'rsscache.xml')
  FileX.write File.join(@filepath, 'rsscache.txt'), @dx.to_s

end

# File lib/rsscache.rb, line 129
def fetch(url, timeout: 2)

  puts 'inside fetch: url: '  + url.inspect if @debug

  begin
    Timeout::timeout(timeout){

      buffer = URI.open(url).read.force_encoding("utf-8")
      return [buffer, 200]
    }
  rescue Timeout::Error => e
    ['connection timed out', 408]
  rescue OpenURI::HTTPError => e
    ['400 bad request', 400]
  end

end

# File lib/rsscache.rb, line 147
def open_dynarex(raw_s)

  s, _ = RXFReader.read(raw_s)
  puts 'inside open_dynarex s: ' + s.inspect if @debug

  case s
  when /^<?dynarex/
    Dynarex.new.import s
  when /^</
    Dynarex.new s
  else
    Dynarex.new.import raw_doc(s)
  end

end

# File lib/rsscache.rb, line 113
  def raw_doc(s)

    heading = '<?dynarex schema="rsscache[title]/feed(uid, title, ' +
      'url, refresh_rate, next_refresh, filename)"?>'

raw_dx=<<EOF
#{heading}
title: RSS Feeds to be cached

--+

#{s.strip.lines.map {|x| 'url: ' + x }.join }
EOF

  end

# File lib/rsscache.rb, line 166
def updates?(feed)

  if @debug then
    puts 'inside updates?'
    puts 'feed: ' + feed.inspect
  end

  # fetch the feeds from the web
  begin
    buffer, code = fetch(feed.url)
  rescue
    puts 'RSScache::updates?: fetch() warning for feed ' + feed.url \
        + ' ' + ($!).inspect
    return
  end

  if code == 200 then
    begin
      rss = SimpleRSS.parse(buffer)
    rescue
      puts 'RSScache::updates?: err: 100 SimpleRSS warning for feed ' \
          + feed.url + ' ' + ($!).inspect
      return
    end
  else
    @err_report << [feed.url, code]
    return false
  end

  if feed.filename.empty? then

    filename = feed.url[6..-1].gsub(/\W+/,'').\
                        reverse.slice(0,40).reverse.downcase + '.xml'
    feed.filename = filename

  end

  rssfile = File.join(@cache_filepath, feed.filename)

  if FileX.exists? rssfile then

    begin
      rss_cache = SimpleRSS.parse FileX.read(rssfile)
    rescue
      puts 'RSScache::updates?: err: 200 SimpleRSS warning for feed ' \
          + feed.url + ' ' + ($!).inspect
      FileX.rm rssfile
      return false
    end
    new_rss_items = rss.items - rss_cache.items
    (FileX.write rssfile, rss.source; return true) if new_rss_items.any?

  else

    FileX.write rssfile, rss.source
    feed.title = rss.title if feed.title.empty?

    return true

  end

  return false
end