require 'digest/sha1'
 
class User < ActiveRecord::Base
  # see http://www.regular-expressions.info/email.html
  EMAIL_REGEXP = /^[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,4}$/i
 
  validates_presence_of :email
  validates_format_of :email, :with => EMAIL_REGEXP
  validates_uniqueness_of :email
  validates_presence_of :hashed_password
 
  before_validation :hash_password
 
  attr_accessible nil
  attr_accessor :password
 
  class << self
    def authenticate(username, password)
      User.first(:conditions => { :email => username, :hashed_password => hash_password(password) })
    end
 
    def hash_password(password)
      Digest::SHA1.hexdigest(password)
    end
  end
 
  private
    def hash_password
      if password
        self[:hashed_password] = self.class.hash_password(password)
      end
    end
end