require 'digest/md5'

class User < ActiveRecord::Base
  belongs_to(:group)

  attr_protected(:id, :password_hash, :password_salt)


  validates_presence_of(:login, :password, :email,
                        :message => 'Bitte wähle mind. einen Benutzernamen, eine email Adresse und ein Passwort!')
  validates_uniqueness_of(:login,
                          :message => 'Dieser Benutzername ist bereits vergeben!')
  validates_length_of(:password, :within => 4..40,
                      :message => 'Bitte wähle ein Passwort mit mind. 4 Zeichen!')
  validates_length_of(:login, :within => 3..40,
                      :message => 'Bitte wähle einen Benutzernamen mit mind. 3 Zeichen!')
  validates_confirmation_of(:password,
                            :message => 'Diese Passwörter stimmen nicht überein!')
  validates_format_of(:email, :with => /^([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})$/i,
                      :message => "Keine gültige email Adresse!")

  public

    def password=(pass)
      @password = pass
      self.password_salt = Digest::MD5.hexdigest(User.random_string(8))
      self.password_hash = User.encrypt_password(@password, self.password_salt)
    end

    def self.login(login, password)
      login_user = User.find(:first, :conditions => ["login = ?", login], :limit => 1)
      return false if login_user.nil?
      return false unless User.encrypt_password(password, login_user[:password_salt]) == login_user[:password_hash]
      login_user[:password] = password
      login_user[:previous_login_time] = login_user[:last_login_time]
      login_user[:previous_login_ip] = login_user[:last_login_ip]
      login_user.save
      login_user[:password] = nil
      return login_user
    end

    def self.authenticate(login, password)
      login_user = User.find(:first, :conditions => ["login = ?", login], :limit => 1)
      return false if login_user.nil?
      return false unless User.encrypt_password(password, login_user[:password_salt]) == login_user[:password_hash]
      return login_user
    end

    def group=(group)
      if String == group.class
        self.group_id = Group.find_by_name(group, :limit => 1).id
      elsif Fixnum == group.class
        self.group_id = group
      end
    end

  private

    def self.encrypt_password(password,password_salt)
      Digest::MD5.hexdigest(password+password_salt)
    end

    def self.random_string(len)
      chars = ("a".."z").to_a + ("A".."Z").to_a + ("0".."9").to_a
      newpass = ""
      1.upto(len) { |i| newpass << chars[rand(chars.size-1)] }
      return newpass
    end


end