require 'digest/sha1'

class User < ActiveRecord::Base

  attr_accessor :password

  has_many :events, :dependent => :destroy
  has_many :registrations, :dependent => :destroy
  has_many :activities, :through => :registrations, :source => :event

  validates_presence_of :login
  validates_length_of :login, :within => 3..40
  validates_uniqueness_of :login, :case_sensitive => false
  validates_format_of :login, :with => /^[\w\.-]+$/i

  validates_presence_of :email
  validates_format_of :email, :with => /^[^@][\w.-]+@[\w.-]+[.][a-z]{2,4}$/i
  validates_presence_of :password, :if => :password_required?
  validates_length_of :password, :within => 4..40, :if => :password_required?
  validates_confirmation_of :password, :if => :password_required?

  before_save :encrypt_new_password

  def self.authenticate(login, password)
    user = find_by_login(login)
    return user if user && user.authenticated?(password)
  end

  def authenticated?(password)
    hashed_password == encrypt(password)
  end

protected

  def encrypt_new_password
    return if password.blank?
    self.hashed_password = encrypt(password)
  end

  def password_required?
    hashed_password.blank? || !password.blank?
  end

  def encrypt(string)
    Digest::SHA1.hexdigest(string)
  end

end