import re
from flask_wtf import FlaskForm
from wtforms import StringField, PasswordField, HiddenField
from wtforms.validators import (
    DataRequired, Email, EqualTo, Length, ValidationError
)


def strong_password(form, field):
    """Validate password meets strong requirements."""
    password = field.data
    errors = []

    if len(password) < 8:
        errors.append("at least 8 characters")
    if not re.search(r'[A-Z]', password):
        errors.append("an uppercase letter")
    if not re.search(r'[a-z]', password):
        errors.append("a lowercase letter")
    if not re.search(r'\d', password):
        errors.append("a number")
    if not re.search(r'[!@#$%^&*(),.?":{}|<>]', password):
        errors.append("a special character (!@#$%^&*(),.?\":{}|<>)")

    if errors:
        raise ValidationError(f"Password must contain {', '.join(errors)}.")


class SignupForm(FlaskForm):
    email = StringField('Email', validators=[
        DataRequired(message="Email is required."),
        Email(message="Please enter a valid email address."),
        Length(max=255, message="Email must be less than 255 characters.")
    ])

    password = PasswordField('Password', validators=[
        DataRequired(message="Password is required."),
        strong_password
    ])

    confirm_password = PasswordField('Confirm Password', validators=[
        DataRequired(message="Please confirm your password."),
        EqualTo('password', message="Passwords must match.")
    ])

    altcha = HiddenField('altcha', validators=[
        DataRequired(message="Please complete the CAPTCHA challenge.")
    ])