employee login and authentication with session

app/models/employee.rb

@@ -1,17 +1,55 @@
 class Employee < ApplicationRecord
-  include BCrypt
+  has_secure_password
 
-  #attr_accessor :password
-
-  validates_presence_of :name, :role, :password
+  validates_presence_of :name, :role
+  validates_presence_of :password, :on => [:create]
+  validates :emp_id, uniqueness: true, numericality: true, length: {in: 1..4}, allow_blank: true
+  validates :password, numericality: true, length: {in: 3..9}, allow_blank: true
 
 
-  def password
-    @password ||= Password.new(password_hash)
+  def self.login(emp_id, password)
+    user = Employee.find_by_emp_id(emp_id).authenticate(password)
+
+    Rails.logger.debug user
+
+    if (user)
+      user.generate_token
+      user.session_expiry = DateTime.now.utc + 30.minutes
+      user.session_last_login = DateTime.now.utc
+      user.save
+
+      return user
+    end
+    return nil
+
   end
 
-  def password=(new_password)
-    @password = Password.create(new_password)
-    self.encrypted_access_code = @password
+  def self.authenticate_by_token(session_token)
+    user = Employee.find_by_token_session(session_token)
+    if user && user.session_expiry.utc > DateTime.now.utc
+      #Extend the login time each time authenticatation take place
+      user.session_expiry = DateTime.now.utc + 30.minutes
+      user.save
+      return true
+    else
+      return false
+    end
   end
+
+  def self.logout(session_token)
+    user = Employee.find_by_token_session(session_token)
+    if user
+      user.token_session = nil
+      user.session_expiry = nil
+      user.save
+    end
+  end
+
+  def generate_token
+      update_column :token_session, SecureRandom.hex(10)
+    rescue ActiveRecord::RecordNotUnique
+      retry
+  end
+
+
 end