diff --git a/app/models/configuration.rb b/app/models/configuration.rb
deleted file mode 100644
--- a/app/models/configuration.rb
+++ /dev/null
@@ -1,176 +0,0 @@
-require 'yaml'
-
-#
-# This class also contains various login of the system.
-#
-class Configuration < ActiveRecord::Base
-
-  SYSTEM_MODE_CONF_KEY = 'system.mode'
-  TEST_REQUEST_EARLY_TIMEOUT_KEY = 'contest.test_request.early_timeout'
-  MULTICONTESTS_KEY = 'system.multicontests'
-  CONTEST_TIME_LIMIT_KEY = 'contest.time_limit'
-
-  cattr_accessor :config_cache
-  cattr_accessor :task_grading_info_cache
-  cattr_accessor :contest_time_str
-  cattr_accessor :contest_time
-
-  Configuration.config_cache = nil
-  Configuration.task_grading_info_cache = nil
-
-  def self.config_cached?
-    (defined? CONFIGURATION_CACHE_ENABLED) and (CONFIGURATION_CACHE_ENABLED)
-  end
-
-  def self.get(key)
-    if Configuration.config_cached?
-      if Configuration.config_cache == nil
-        self.read_config
-      end
-      return Configuration.config_cache[key]
-    else
-      return Configuration.read_one_key(key)
-    end
-  end
-
-  def self.[](key)
-    self.get(key)
-  end
-
-  def self.reload
-    self.read_config
-  end
-
-  def self.clear
-    Configuration.config_cache = nil
-  end
-
-  #
-  # View decision
-  #
-  def self.show_submitbox_to?(user)
-    mode = get(SYSTEM_MODE_CONF_KEY)
-    return false if mode=='analysis'
-    if (mode=='contest') 
-      return false if (user.site!=nil) and 
-        ((user.site.started!=true) or (user.site.finished?))
-    end
-    return true
-  end
-
-  def self.show_tasks_to?(user)
-    if time_limit_mode?
-      return false if not user.contest_started?
-    end
-    return true
-  end
-
-  def self.show_grading_result
-    return (get(SYSTEM_MODE_CONF_KEY)=='analysis')
-  end
-
-  def self.allow_test_request(user)
-    mode = get(SYSTEM_MODE_CONF_KEY)
-    early_timeout = get(TEST_REQUEST_EARLY_TIMEOUT_KEY)
-    if (mode=='contest') 
-      return false if ((user.site!=nil) and 
-        ((user.site.started!=true) or 
-         (early_timeout and (user.site.time_left < 30.minutes))))
-    end
-    return false if mode=='analysis'
-    return true
-  end
-
-  def self.task_grading_info
-    if Configuration.task_grading_info_cache==nil
-      read_grading_info
-    end
-    return Configuration.task_grading_info_cache
-  end
-  
-  def self.standard_mode?
-    return get(SYSTEM_MODE_CONF_KEY) == 'standard'
-  end
-
-  def self.contest_mode?
-    return get(SYSTEM_MODE_CONF_KEY) == 'contest'
-  end
-
-  def self.indv_contest_mode?
-    return get(SYSTEM_MODE_CONF_KEY) == 'indv-contest'
-  end
-
-  def self.multicontests?
-    return get(MULTICONTESTS_KEY) == true
-  end
-
-  def self.time_limit_mode?
-    mode = get(SYSTEM_MODE_CONF_KEY)
-    return ((mode == 'contest') or (mode == 'indv-contest')) 
-  end
-  
-  def self.analysis_mode?
-    return get(SYSTEM_MODE_CONF_KEY) == 'analysis'
-  end
-  
-  def self.contest_time_limit
-    contest_time_str = Configuration[CONTEST_TIME_LIMIT_KEY]
-
-    if not defined? Configuration.contest_time_str
-      Configuration.contest_time_str = nil
-    end
-
-    if Configuration.contest_time_str != contest_time_str
-      Configuration.contest_time_str = contest_time_str
-      if tmatch = /(\d+):(\d+)/.match(contest_time_str)
-        h = tmatch[1].to_i
-        m = tmatch[2].to_i
-        
-        Configuration.contest_time = h.hour + m.minute
-      else
-        Configuration.contest_time = nil
-      end
-    end  
-    return Configuration.contest_time
-  end
-
-  protected
-
-  def self.convert_type(val,type)
-    case type
-    when 'string'
-      return val
-      
-    when 'integer'
-      return val.to_i
-      
-    when 'boolean'
-      return (val=='true')
-    end
-  end    
-
-  def self.read_config
-    Configuration.config_cache = {}
-    Configuration.find(:all).each do |conf|
-      key = conf.key
-      val = conf.value
-      Configuration.config_cache[key] = Configuration.convert_type(val,conf.value_type)
-    end
-  end
-
-  def self.read_one_key(key)
-    conf = Configuration.find_by_key(key)
-    if conf
-      return Configuration.convert_type(conf.value,conf.value_type)
-    else
-      return nil
-    end
-  end
-
-  def self.read_grading_info
-    f = File.open(TASK_GRADING_INFO_FILENAME)
-    Configuration.task_grading_info_cache = YAML.load(f)
-    f.close
-  end
-  
-end