namespace :umlaut do
    desc "Perform nightly maintenance. Set up in cron."
    task :nightly_maintenance => [:load_sfx_urls, :expire_old_data]
  
  

    desc "Loads sfx_urls from SFX installation. SFX mysql login needs to be set in config."
    task :load_sfx_urls => :environment do
      # Get the configured searcher
      searcher = UmlautController.umlaut_config.lookup!("search.az_search_method", SearchMethods::Sfx4)
      if searcher.fetch_urls?
        puts "Loading SfxUrls (e.g. via direct access to SFX db)."
        # Grab the urls
        urls = searcher.fetch_urls
        ignore_urls = UmlautController.umlaut_config.lookup!("sfx.sfx_load_ignore_hosts", [])
        # We only want the hostnames
        hosts = urls.collect do |u|
          begin
            uri = URI.parse(u)
            # host should clearly never be more than 200 chars, but sometimes is usually
            # due to a malformed URL, and we don't want to trigger a too-big-for-db-column
            # error, so we trim it. 
            uri.host.slice(0..200)
          rescue Exception
          end
        end
        hosts.uniq!
        SfxUrl.transaction do
          SfxUrl.delete_all
          hosts.each {|h| SfxUrl.new({:url => h}).save! unless ignore_urls.find {|ignore| ignore === h }}      
        end
      else
        puts "Skipping load of SFXURLs via direct access to SFX db. No direct access is configured. Configure in config/database.yml sfx_db"
      end
    end



    desc "Cleanup of database for old data associated with expired sessions etc."
    task :expire_old_data => :environment do
      # There are requests, responses, and dispatched_service entries
      # hanging around for things that may be way old and no longer
      # need to hang around. 

      # Deleting things as aggressively as we're doing here doesn't leave
      # us much for statistics, but we aren't currently gathering any
      # statistics anyway. If statistics are needed, more exploration
      # is needed of performance vs. leaving things around for statistics. 

      # Current Umlaut never re-uses a request different between sessions, 
      # and never uses Referents between requests. 
      # Permalink architecture has been fixed to not rely on requests or 
      # referents, permalinks (post new architecture) store their own context
      # object.
      
      # To make efficient SQL queries to delete 'orphaned' records whose
      # foreign keys are neccesary... is tricky, with or without AR, and
      # may vary in different dbs -- this works for MySQL, it's possible
      # it will have a problem with Postgres, hasn't been tested. 

      begin_time = Time.now
      
      rdelete_time = Time.now - UmlautController.umlaut_config.lookup!("nightly_maintenance.request_expire_seconds", 1.day)
      puts "Deleting Requests older than #{rdelete_time}"
      rdelete = Request.where("created_at < ?", rdelete_time) 
                  
      count = rdelete.count
      rdelete.delete_all
      puts "  Deleted #{count} Requests in #{Time.now - begin_time}"

    


      
      # Now, let's get rid of any ServiceResponses that no longer have
      # Requests 
       
      puts "Deleting orphaned ServiceResponses...."
      begin_time = Time.now
      #  DELETE FROM `service_responses` WHERE (NOT (EXISTS (SELECT `requests`.* FROM `requests` WHERE (service_responses.request_id = requests.id))))
      sr_delete = ServiceResponse.where(
        Request.where("#{ServiceResponse.arel_table.name}.request_id = requests.id").exists.not 
       )
          
      count = sr_delete.count
      sr_delete.delete_all  
      puts "  Deleted #{count} ServiceResponses in #{Time.now - begin_time}"

      
      # And get rid of DispatchedServices for 'dead' requests too. Don't
      # need em.
      puts "Deleting DispatchedServices for dead Requests..."
      keep_failed = UmlautController.umlaut_config.lookup!("nightly_maintenance.failed_dispatch_expire_seconds", 4.weeks)
      begin_time = Time.now
      # DELETE FROM `dispatched_services` WHERE (NOT (EXISTS (SELECT `requests`.* FROM `requests` WHERE (dispatched_services.request_id = requests.id))))       
      ds_delete  = DispatchedService.where("status NOT IN (?) OR updated_at < ?", 
        [DispatchedService::FailedFatal, DispatchedService::FailedTemporary], Time.now - keep_failed
      ).where(
        Request.where("dispatched_services.request_id =  requests.id").exists.not 
      )        
      count = ds_delete.count
      ds_delete.delete_all
      puts "  Deleted #{count} DispatchedServices in #{Time.now - begin_time}"
      



      puts "Deleting orphaned Referents"
      begin_time = Time.now
      #  DELETE FROM `referents` WHERE (NOT (EXISTS (SELECT `requests`.* FROM `requests` WHERE (referents.id = requests.referent_id))))
      ref_delete = Referent.where(
        Request.where("referents.id = requests.referent_id").exists.not
       )        
      count = ref_delete.count
      ref_delete.delete_all
      puts "  Deleted #{count} Referents in #{Time.now - begin_time}"
      
      
      puts "Deleting orphaned ReferentValues"
      begin_time = Time.now
      # DELETE FROM `referent_values` WHERE (NOT (EXISTS (SELECT `referents`.* FROM `referents` WHERE (referents.id = referent_values.referent_id))))
      rv_delete = ReferentValue.where(
        Referent.where("referents.id = referent_values.referent_id").exists.not
       )               
      
      
      
      count = rv_delete.count
      rv_delete.delete_all
      puts "  Deleted #{count} ReferentValues in #{Time.now - begin_time}"
      
      
      # And turns out we have all Clickthroughs being stored for no apparent
      # reason, let's just delete any older than 3 months ago. 
      Clickthrough.delete_all(['created_at < ?', 3.months.ago])
      puts "Deleted Clickthroughs older than 3 months"              
    end
    
end