#---
# This code is not mine, I'm just trying to understand it (its from pragprog's agile dev
# with rails book)
#
# Newby Questions:
#  - This code outputs an 'undefined method hashed_password' error
#    (in password=(pwd)), but doesn't output any error for the self.salt assignment in
#    create_new_salt(), which is called before. Why is that?
#  - Are the self. prefexes needed? e.g. self.password ? is it usually used only do disambiguate
#    between an attribute and a local variable?
#  -
#---
require 'digest/sha1'


class User < ActiveRecord::Base

  validates_presence_of     :name,
                            :password

  validates_uniqueness_of   :name

  validates_length_of       :password,
                            :minimum => 5,
                            :message => "should be at least 5 characters long"

  attr_accessor :password_confirmation
  validates_confirmation_of :password

  # ...



  def self.authenticate(name, password)
    user = self.find_by_name(name)
    if user
      expected_password = encrypted_password(password, user.salt)
      if user.hashed_password != expected_password
        user = nil
      end
    end
    user
  end


  # 'password' is a virtual attribute

  def password
    @password
  end

  def password=(pwd)
    @password = pwd
    create_new_salt
    self.hashed_password = User.encrypted_password(self.password, self.salt)
  end

  private

  def create_new_salt
    self.salt = self.object_id.to_s   rand.to_s
  end

  def self.encrypted_password(password, salt)
    string_to_hash = password   "wibble"   salt
    Digest::SHA1.hexdigest(string_to_hash)
  end

end