require 'digest/sha1'

class User < ActiveRecord::Base
  validates_presence_of :username
  validates_uniqueness_of :username
  validates_presence_of :passwd
  has_many :tasks, :order => 'complete ASC, start DESC', :dependent => :nullify
  
  def passwd=(pwd)
    write_attribute('passwd', Digest::SHA1.hexdigest(pwd))
  end
  
  def self.authenticate(username, passwd)
    hashed_passwd = Digest::SHA1.hexdigest(passwd)
    user = self.find_by_username_and_passwd(username, hashed_passwd)
    return user
  end
end