import json
import logging
import requests
from datetime import datetime, timezone, timedelta
from sqlalchemy.orm import Session

from config import get_settings
from models import Computer, Notification

settings = get_settings()
logger = logging.getLogger(__name__)


def create_notification(db: Session, computer: Computer, ntype: str, title: str, message: str) -> Notification:
    n = Notification(
        computer_id=computer.id,
        type=ntype,
        title=title,
        message=message,
    )
    db.add(n)
    db.commit()
    db.refresh(n)
    send_external_notifications(n, computer)
    return n


def check_offline_computers(db: Session):
    """Mark online computers that missed the threshold as offline and create notifications."""
    threshold = datetime.now(timezone.utc) - timedelta(minutes=settings.OFFLINE_THRESHOLD_MINUTES)
    stale = (
        db.query(Computer)
        .filter(Computer.status == "online", Computer.last_seen < threshold)
        .all()
    )
    for computer in stale:
        computer.status = "offline"
        db.add(computer)
        # avoid duplicate notifications for the same offline event
        existing = (
            db.query(Notification)
            .filter(
                Notification.computer_id == computer.id,
                Notification.type == "offline",
                Notification.is_read == False,
            )
            .first()
        )
        if not existing:
            msg = (
                f"ПК {computer.hostname} не присылал данные более "
                f"{settings.OFFLINE_THRESHOLD_MINUTES} минут. "
                f"Последний пользователь: {computer.current_user or '-'}, "
                f"IP: {computer.current_ip or '-'}"
            )
            create_notification(db, computer, "offline", f"ПК {computer.hostname} офлайн", msg)
    db.commit()


def send_external_notifications(notification: Notification, computer: Computer):
    if settings.NOTIFICATION_WEBHOOK_URL:
        try:
            requests.post(
                settings.NOTIFICATION_WEBHOOK_URL,
                json={
                    "type": notification.type,
                    "title": notification.title,
                    "message": notification.message,
                    "hostname": computer.hostname,
                    "user": computer.current_user,
                    "ip": computer.current_ip,
                },
                timeout=10,
            )
        except Exception as e:
            logger.error("Webhook notification failed: %s", e)

    if settings.NOTIFICATION_TELEGRAM_BOT_TOKEN and settings.NOTIFICATION_TELEGRAM_CHAT_ID:
        try:
            text = f"*{notification.title}*\n\n{notification.message}"
            requests.post(
                f"https://api.telegram.org/bot{settings.NOTIFICATION_TELEGRAM_BOT_TOKEN}/sendMessage",
                json={
                    "chat_id": settings.NOTIFICATION_TELEGRAM_CHAT_ID,
                    "text": text,
                    "parse_mode": "Markdown",
                },
                timeout=10,
            )
        except Exception as e:
            logger.error("Telegram notification failed: %s", e)


def mark_notification_read(db: Session, notification_id: int) -> bool:
    n = db.query(Notification).filter(Notification.id == notification_id).first()
    if not n:
        return False
    n.is_read = True
    n.read_at = datetime.now(timezone.utc)
    db.commit()
    return True


def get_unread_count(db: Session) -> int:
    return db.query(Notification).filter(Notification.is_read == False).count()