class ContactsSetting < ActiveRecord::Base  
  unloadable
  
  belongs_to :project   
  
  cattr_accessor :settings
  
  # Hash used to cache setting values
  @cached_settings = {}
  @cached_cleared_on = Time.now
  
  validates_uniqueness_of :name, :scope => [:project_id]
  
  
  def value
    v = read_attribute(:value)
    # Unserialize serialized settings
    v = YAML::load(v) if v.is_a?(String)
    v
  end

  def value=(v)
    v = v.to_yaml if v
    write_attribute(:value, v.to_s)
  end

  # Returns the value of the setting named name
  def self.[](name, project_id)
    v = @cached_settings[hk(name, project_id)]
    v ? v : (@cached_settings[hk(name, project_id)] = find_or_default(name, project_id).value)
  end
  
  def self.[]=(name, project_id, v)
    setting = find_or_default(name, project_id)
    setting.value = (v ? v : "")
    @cached_settings[hk(name, project_id)] = nil
    setting.save
    @cached_settings.clear
    @cached_cleared_on = Time.now
    
  #TODO: Create global contacts controller and add check_cache to it
    setting.value
  end
  
  # Checks if settings have changed since the values were read
  # and clears the cache hash if it's the case
  # Called once per request
  def self.check_cache
    settings_updated_on = ContactsSetting.maximum(:updated_on)
    if settings_updated_on && @cached_cleared_on <= settings_updated_on
      @cached_settings.clear
      @cached_cleared_on = Time.now
      logger.info "Settings cache cleared." if logger
    end
  end
  
  private
  
  def self.hk(name, project_id)
    "#{name}-#{project_id.to_s}"
  end
  
  # Returns the Setting instance for the setting named name
  # (record found in database or new record with default value)
  def self.find_or_default(name, project_id)
    name = name.to_s
    setting = find_by_name_and_project_id(name, project_id)
    setting ||= new(:name => name, :value => '', :project_id => project_id)
  end
  
end