#This program is free software: you can redistribute it and/or modify
#it under the terms of the GNU General Public License as published by
#the Free Software Foundation, either version 3 of the License, or
#(at your option) any later version.
#
#This program is distributed in the hope that it will be useful,
#but WITHOUT ANY WARRANTY; without even the implied warranty of
#MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#GNU General Public License for more details.
#
#You should have received a copy of the GNU General Public License
#along with this program.  If not, see <http://www.gnu.org/licenses/>.

module ActionController 
  
  module Caching
    
    module Pages

      module ClassMethods
        # Expires the page that was cached with the +path+ as a key. Example:
        #   expire_memcached_page "/lists/show"
        def expire_memcached_page(path)
          return unless perform_caching

          Cache.delete(path, content)
        end

        # Manually cache the +content+ in the key determined by +path+. Example:
        #   memcache_page "I'm the cached content", "/lists/show"
        def memcache_page(content, path)
          return unless perform_caching
		  Cache.set(MemcachedPageKeyPrefix + path, content, MemcachedPageTtl, true)
        end

        # Caches the +actions+ using the page-caching approach that'll store the 
		# contents in the cache with the key matching the triggering url.
        def memcaches_page(*actions)
          return unless perform_caching
          actions = actions.map(&:to_s)
          after_filter { |c| c.memcache_page if actions.include?(c.action_name) }
        end
      end

      # Expires the page that was cached with the +options+ as a key. Example:
      #   expire_memcached_page :controller => "lists", :action => "show"
      def expire_memcached_page(options = {})
        return unless perform_caching

        if options.is_a?(Hash)
          if options[:action].is_a?(Array)
            options[:action].dup.each do |action|
              self.class.expire_memcached_page(url_for(options.merge(:only_path => true, :skip_relative_url_root => true, :action => action)))
            end
          else
            self.class.expire_memcached_page(url_for(options.merge(:only_path => true, :skip_relative_url_root => true)))
          end
        else
          self.class.expire_memcached_page(options)
        end
      end

      # Manually cache the +content+ in the key determined by +options+. If no content is provided, the contents of response.body is used
      # If no options are provided, the requested url is used. Example:
      #   memcache_page "I'm the cached content", :controller => "lists", :action => "show"
      def memcache_page(content = nil, options = nil)
        return unless perform_caching && caching_allowed

        path = case options
          when Hash
            url_for(options.merge(:only_path => true, :skip_relative_url_root => true, :format => params[:format]))
          when String
            options
          else
            request.path
        end

        self.class.memcache_page(content || response.body, path)
      end

      private
        def caching_allowed
          request.get? && response.headers['Status'].to_i == 200
        end
    end
    
  end
end