from celery import shared_task
from celery.utils.log import get_task_logger
from django.conf import settings
from django.utils.http import urlsafe_base64_encode
from django.utils.encoding import force_bytes
from .tokens import *
from .models import CustomUser

# Re-exported so existing imports from account.tasks still work
from notifications.tasks import send_email_with_context  # noqa: F401

logger = get_task_logger(__name__)


@shared_task
def send_email_verification_task(user_id):
    from notifications.models import Notification
    try:
        user = CustomUser.objects.get(pk=user_id)
    except CustomUser.DoesNotExist:
        logger.info("send_email_verification_task: invalid user_id %s", user_id)
        return

    uid = urlsafe_base64_encode(force_bytes(user.pk))
    token = user.generate_email_verification_token()
    verify_url = f"{settings.FRONTEND_URL}/email-verification/?uidb64={uid}&token={token}"

    Notification.notify(
        user=user,
        title="Ověření e‑mailu",
        text="Prosím ověřte svou e-mailovou adresu kliknutím na odkaz v e-mailu.",
        action_url=verify_url,
        template_path="email/email_verification.html",
        email_context={
            "action_url": verify_url,
            "frontend_url": settings.FRONTEND_URL,
            "cta_label": "Ověřit e‑mail",
        },
    )


@shared_task
def send_email_change_verification_task(user_id, new_email, verify_url):
    """Sends confirmation link to the NEW email address."""
    from notifications.tasks import send_email_with_context
    try:
        user = CustomUser.objects.get(pk=user_id)
    except CustomUser.DoesNotExist:
        return
    send_email_with_context(
        recipients=new_email,
        subject="Potvrzení změny e-mailu — vontor.cz",
        template_path="email/action_confirm.html",
        context={
            "title": "Potvrďte novou e-mailovou adresu",
            "description": f"Obdrželi jsme žádost o změnu e-mailové adresy na účtu <strong>{user.username}</strong>. Klikněte na tlačítko níže pro potvrzení.",
            "action_url": verify_url,
            "cta_label": "Potvrdit nový e-mail",
            "note": "Pokud jste tuto změnu nepožadovali, ignorujte tento e-mail — vaše stávající adresa zůstane aktivní.",
        },
    )


@shared_task
def send_email_change_notification_task(user_id, old_email, new_email):
    """Notifies the OLD email address that a change was requested."""
    from notifications.tasks import send_email_with_context
    try:
        user = CustomUser.objects.get(pk=user_id)
    except CustomUser.DoesNotExist:
        return
    send_email_with_context(
        recipients=old_email,
        subject="Žádost o změnu e-mailu — vontor.cz",
        template_path="email/action_confirm.html",
        context={
            "title": "Vaše e-mailová adresa se mění",
            "description": f"Na účtu <strong>{user.username}</strong> byla zahájena změna e-mailové adresy na <strong>{new_email}</strong>.",
            "action_url": None,
            "cta_label": None,
            "note": "Pokud jste tuto akci nespustili, okamžitě kontaktujte podporu. Změna vstoupí v platnost až po potvrzení z nové adresy.",
        },
    )


@shared_task
def send_email_test_task(email):
    send_email_with_context(
        recipients=email,
        subject="Testovací e‑mail",
        template_path="email/test.html",
        context={
            "action_url": settings.FRONTEND_URL,
            "frontend_url": settings.FRONTEND_URL,
            "cta_label": "Otevřít aplikaci",
        },
    )


@shared_task
def send_password_reset_email_task(user_id):
    from notifications.models import Notification
    try:
        user = CustomUser.objects.get(pk=user_id)
    except CustomUser.DoesNotExist:
        logger.info("send_password_reset_email_task: invalid user_id %s", user_id)
        return

    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}"

    Notification.notify(
        user=user,
        title="Obnova hesla",
        text="Byl vyžádán reset vašeho hesla. Klikněte na odkaz pro nastavení nového hesla.",
        action_url=reset_url,
        template_path="email/password_reset.html",
        email_context={
            "action_url": reset_url,
            "frontend_url": settings.FRONTEND_URL,
            "cta_label": "Obnovit heslo",
        },
    )