require 'simple-rss'
module Rss
  def self.fetch(url, limit = 10)
    cache_key = 'rss::' + url
    items = Cache.get( cache_key )
    return items if items

    begin
      Rails.logger.info "fetch rss... #{url}"
      response = UserAgent.request(url)
      if !response.success?
        raise "Can't fetch '#{url}', http code: #{response.code}"
      end
      rss     = SimpleRSS.parse response.body
      items   = []
      fetched = 0
      rss.items.each { |item|
        record = {
          id: item.id,
          title: Encode.conv( 'utf8', item.title ),
          summary: Encode.conv( 'utf8', item.summary ),
          link: item.link,
          published: item.published
        }
        items.push record
        fetched += 1
        break item if fetched == limit.to_i
      }
      Cache.write( cache_key, items, expires_in: 4.hours )
    rescue => e
      Rails.logger.error "can't fetch #{url}"
      Rails.logger.error e.inspect
      return
    end

    items
  end
end