require 'digest/sha1'

class User < ActiveRecord::Base
  attr_accessor :password
  
  validates_length_of :name, :within => 2..20, :on => :create
  validates_format_of :name, :with => /\A[^\s;,]+\Z/, :on => :create, :message => "cannot have whitespace, commas, or semicolons"
  validates_uniqueness_of :name, :case_sensitive => false, :on => :create
  validates_uniqueness_of :email, :case_sensitive => false, :on => :create, :if => lambda {|rec| !rec.email.blank?}
  validates_confirmation_of :password

  before_save :encrypt_password
  after_save {|rec| Cache.put("user_name:#{rec.id}", rec.name)}

  scope :named, lambda {|name| where(["lower(name) = ?", name])}

  def self.authenticate(name, pass)
    authenticate_hash(name, sha1(pass))
  end

  def self.authenticate_hash(name, pass)
    where(["lower(name) = ? AND password_hash = ?", name.downcase, pass]).first != nil
  end

  def self.sha1(pass)
    Digest::SHA1.hexdigest("#{Danbooru.config.password_salt}--#{pass}--")
  end
  
  def self.find_name(user_id)
    Cache.get("user_name:#{user_id}") do
      select_value_sql("SELECT name FROM users WHERE id = ?", user_id) || Danbooru.config.default_guest_name
    end
  end
  
  def can_update?(object, foreign_key = :user_id)
    is_moderator? || is_admin? || object.__send__(foreign_key) == id
  end
  
  def pretty_name
    name.tr("_", " ")
  end
  
  def encrypt_password
    self.password_hash = self.class.sha1(password) if password
  end
end