require 'digest'
class User < ActiveRecord::Base
  attr_accessor :password
  attr_accessible :name , :email , :password, :password_confirmation

  EmailRegex = /\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i
  validates_presence_of :name , :email
  validates_length_of :name, :maximum => 50
  validates_format_of :email, :with => EmailRegex
  validates_uniqueness_of :email, :case_sensitive => false

  #Automatically create the virtual attribute 'password confirmation'.
  validates_confirmation_of :password

  #Password validations.
  validates_presence_of :password
  validates_length_of :password, :within => 6..40

  before_save :encrypt_password

  def has_password?(submitted_password)
    encrypted_password == encrypt(submitted_password)
  end

  def remember_me!
    self.remember_token = encrypt("#{salt}--#{id}--#{Time.now.utc}")
    save_without_validation
  end

  def self.authenticate(email, submitted_password)
    user = find_by_email(email)
    return nil if user.nil?
    return user if user.has_password?(submitted_password)
  end

  private
  def encrypt_password
    unless password.nil?
      self.salt = make_salt
      self.encrypted_password = encrypt(password)
    end
  end

  def encrypt(string)
    secure_hash("#{salt}#{string}")
  end

  def make_salt
    secure_hash("#{Time.now.utc}#{password}")
  end

  def secure_hash(string)
    Digest::SHA2.hexdigest(string)
  end

end