text: from flask_wtf import FlaskForm
  from wtforms import StringField, PasswordField, SubmitField, BooleanField
  from flask_wtf.file import FileField, FileAllowed
  from wtforms.validators import DataRequired, EqualTo, Length, Email, ValidationError
  from flaskblog.models import User
  from flask_login import current_user
  
  
  
  
  
  class RegistrationForm(FlaskForm):
      username = StringField('Username', validators=[DataRequired(),Length(min=2, max=20)])
      email = StringField('Email', validators=[DataRequired(),Email()])
      password = PasswordField('Password', validators=[DataRequired()])
      confirm_password = PasswordField('Confirm Password', validators=[DataRequired(), EqualTo('password')])
      submit = SubmitField('Sign up')
  
      def validate_username(self, username):
          user = User.query.filter_by(username=username.data).first()
          if user:
              raise ValidationError('Username is already taken. Please choose a different one.')
  
      def validate_email(self, email):
          user = User.query.filter_by(email=email.data).first()
          if user:
              raise ValidationError('Email is already taken. Please choose a different one.')
  
  class LoginForm(FlaskForm):
      email = StringField('Email', validators=[DataRequired(),Email()])
      password = PasswordField('Password', validators=[DataRequired()])
      remember = BooleanField('Remember me')
      submit = SubmitField('Sign in')
  
  
  class UpdateAccountForm(FlaskForm):
      username = StringField('Username', validators=[DataRequired(),Length(min=2, max=20)])
      email = StringField('Email', validators=[DataRequired(),Email()])
      picture = FileField('Update Profile Picture', validators=[FileAllowed(['jpg', 'png','dng', 'jpeg', 'gif'])])
      submit = SubmitField('Update')
  
      def validate_username(self, username):
          if username.data != current_user.username:
              user = User.query.filter_by(username=username.data).first()
              if user:
                  raise ValidationError('Username is already taken. Please choose a different one.')
  
      def validate_email(self, email):
          if email.data != current_user.email:
              user = User.query.filter_by(email=email.data).first()
              if user:
                  raise ValidationError('Email is already taken. Please choose a different one.')
  
  
  class RequestResetForm(FlaskForm):
      email = StringField('Email', validators=[DataRequired(),Email()])
      submit = SubmitField('Request Reset Password')
  
      def validate_email(self, email):
          user = User.query.filter_by(email=email.data).first()
          if user is None:
              raise ValidationError('Entered email is not associated with any of the account. Please Register first!')
  
  
  class ResetPasswordForm(FlaskForm):
      password = PasswordField('New Password', validators=[DataRequired()])
      confirm_password = PasswordField('Retype New Password', validators=[DataRequired(), EqualTo('password')])
      submit = SubmitField('Reset Password')