module KaminariCache

# File lib/kaminari-cache.rb, line 4
def self.included(base)
  base.after_update :flush_pagination_cache
end

# File lib/kaminari-cache.rb, line 24
def flush_match(match) 
  Rails.logger.info "Cache flush: #{match.join}"
  case @store_class
  when "DalliStore"
    # DalliStore uses a Regexp
    regexp = Regexp.new match.join.gsub(/\*/,'.*?')
    Rails.cache.delete_matched /^#{Regexp.escape(:kaminari)}\/#{Regexp.escape(self.class.name.downcase)}/
  when "RedisStore"
    # RedisStore uses a String
    Rails.cache.delete_matched match.join
  end
end

# File lib/kaminari-cache.rb, line 8
def flush_pagination_cache
  @store_class = Rails.cache.class.name.split("::").last
  if Rails.cache.respond_to? "delete_matched"

    self.changed.each do |field|
      flush_match [:kaminari, "/#{self.class.name.downcase}", '*', "/#{:order}", '*', "/#{field}", '*']
    end
    # flush scoped pagings...
    flush_match [:kaminari, "/#{self.class.name.downcase}", '*', "/#{:scope}", '*']

  else
    Rails.cache.clear
    Rails.logger.warn "#{@store_class} does not support deleting matched keys. The entire cache was flushed. Consider using RedisStore (Redis) OR DalliStore (gem dalli) for memcached with dalli-store-extensions gem for improved performance."
  end
end