"""Notifier interface + console (default) and SMTP backends (spec §10).

Console backend writes to stdout/log and persists a notifications row; real SMTP only when
env-configured. SMS is an off-by-default adapter (paid + network — do not enable without
confirmation).
"""
from __future__ import annotations

import logging
import smtplib
from abc import ABC, abstractmethod
from datetime import datetime, timezone
from email.message import EmailMessage

from sqlalchemy.orm import Session

from ..config import settings
from ..models import Notification
from ..models.base import NotificationChannel, NotificationStatus

logger = logging.getLogger("pawtrace.notify")


class Notifier(ABC):
    @abstractmethod
    def send(self, *, to: str, subject: str, body: str) -> bool:
        """Deliver a message; return True on success."""


class ConsoleNotifier(Notifier):
    def send(self, *, to: str, subject: str, body: str) -> bool:
        logger.info("EMAIL -> %s | %s\n%s", to, subject, body)
        print(f"\n[EMAIL] to={to} subject={subject!r}\n{body}\n")
        return True


class SMTPNotifier(Notifier):  # pragma: no cover - requires a live/dev SMTP server
    def send(self, *, to: str, subject: str, body: str) -> bool:
        msg = EmailMessage()
        msg["From"] = settings.smtp_from
        msg["To"] = to
        msg["Subject"] = subject
        msg.set_content(body)
        try:
            with smtplib.SMTP(settings.smtp_host, settings.smtp_port, timeout=10) as s:
                if settings.smtp_user:
                    s.starttls()
                    s.login(settings.smtp_user, settings.smtp_password)
                s.send_message(msg)
            return True
        except Exception:  # noqa: BLE001
            logger.exception("SMTP send failed")
            return False


def get_notifier() -> Notifier:
    if settings.notifier == "smtp" and settings.smtp_host:
        return SMTPNotifier()
    return ConsoleNotifier()


def send_notification(
    db: Session,
    *,
    user_id: int | None,
    to: str,
    subject: str,
    body: str,
    case_id: int | None = None,
    match_id: int | None = None,
) -> Notification:
    """Send via the configured Notifier and persist a notifications row (spec §7.8)."""
    notif = Notification(
        user_id=user_id,
        case_id=case_id,
        match_id=match_id,
        channel=NotificationChannel.email,
        to_address=to,
        payload=f"{subject}\n\n{body}",
        status=NotificationStatus.queued,
    )
    db.add(notif)
    db.flush()

    ok = get_notifier().send(to=to, subject=subject, body=body)
    notif.status = NotificationStatus.sent if ok else NotificationStatus.failed
    if ok:
        notif.sent_at = datetime.now(timezone.utc)
    db.flush()
    return notif