from celery import shared_task
from celery.utils.log import get_task_logger
from django.core.mail import send_mail
from django.conf import settings
from django.utils.http import urlsafe_base64_encode
from django.utils.encoding import force_bytes
from django.template.loader import render_to_string
from .tokens import *
from .models import CustomUser

logger = get_task_logger(__name__)

@shared_task
def send_password_reset_email_task(user_id):
    try:
        user = CustomUser.objects.get(pk=user_id)
    except CustomUser.DoesNotExist:
        error_msg = f"Task send_password_reset_email has failed. Invalid User ID was sent."
        logger.error(error_msg)
        raise Exception(error_msg)
    uid = urlsafe_base64_encode(force_bytes(user.pk))
    token = password_reset_token.make_token(user)
    reset_url = f"{settings.FRONTEND_URL}/reset-password/{uid}/{token}"
    html_message = render_to_string(
        'emails/password_reset.html',
        {'reset_url': reset_url}
    )
    if settings.EMAIL_BACKEND == 'django.core.mail.backends.console.EmailBackend':
        logger.debug("\nEMAIL OBSAH:\n", html_message, "\nKONEC OBSAHU")
    send_email_with_context(
        recipients=user.email,
        subject="Obnova hesla",
        message=None,
        html_message=html_message
    )

# Only email verification for user registration
@shared_task
def send_email_verification_task(user_id):
    try:
        user = CustomUser.objects.get(pk=user_id)
    except CustomUser.DoesNotExist:
        error_msg = f"Task send_email_verification_task has failed. Invalid User ID was sent."
        logger.error(error_msg)
        raise Exception(error_msg)
    uid = urlsafe_base64_encode(force_bytes(user.pk))
    token = account_activation_token.make_token(user)
    verification_url = f"{settings.FRONTEND_URL}/email-verification/?uidb64={uid}&token={token}"
    html_message = render_to_string(
        'emails/email_verification.html',
        {'verification_url': verification_url}
    )
    if settings.EMAIL_BACKEND == 'django.core.mail.backends.console.EmailBackend':
        logger.debug("\nEMAIL OBSAH:\n", html_message, "\nKONEC OBSAHU")
    send_email_with_context(
        recipients=user.email,
        subject="Ověření e-mailu",
        message=None,
        html_message=html_message
    )
    
    

def send_email_with_context(recipients, subject, message=None, html_message=None):
    """
    General function to send emails with a specific context.
    """
    if isinstance(recipients, str):
        recipients = [recipients]

    try:
        send_mail(
            subject=subject,
            message=message if message else '',
            from_email=None,
            recipient_list=recipients,
            fail_silently=False,
            html_message=html_message
        )
        if settings.EMAIL_BACKEND == 'django.core.mail.backends.console.EmailBackend':
            logger.debug("\nEMAIL OBSAH:\n", html_message if html_message else message, "\nKONEC OBSAHU")
        return True
    except Exception as e:
        logger.error(f"E-mail se neodeslal: {e}")
        return False