"""
Alert service for creating and dispatching system notifications.
"""

from datetime import datetime, timezone

from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.database import async_session_maker
from app.models.alert import Alert
from app.models.settings import Settings


class AlertService:
    """Manage system alerts and notifications."""

    async def create_alert(
        self,
        alert_type: str,
        severity: str,
        title: str,
        message: str,
        alert_metadata: dict | None = None,
    ) -> Alert:
        """Create a new alert and dispatch to configured channels."""
        async with async_session_maker() as session:
            # Check if similar alert already exists (prevent spam)
            existing = await self._find_similar_alert(session, alert_type, title)
            if existing:
                print(f"[AlertService] Similar alert already exists, skipping: {title}")
                return existing

            # Create alert
            alert = Alert(
                timestamp=datetime.now(timezone.utc),
                alert_type=alert_type,
                severity=severity,
                title=title,
                message=message,
                alert_metadata=alert_metadata or {},
                sent_dashboard=True,  # Always show in dashboard
            )

            session.add(alert)
            await session.commit()
            await session.refresh(alert)

            print(f"[AlertService] Created alert: [{severity}] {title}")

            # Dispatch to configured channels
            await self._dispatch_alert(session, alert)

            return alert

    async def _find_similar_alert(
        self, session: AsyncSession, alert_type: str, title: str
    ) -> Alert | None:
        """Find recent similar alert to prevent spam."""
        # Check if alert with same type and title was created in last 5 minutes
        from datetime import timedelta

        cutoff = datetime.now(timezone.utc) - timedelta(minutes=5)

        result = await session.execute(
            select(Alert)
            .where(Alert.alert_type == alert_type)
            .where(Alert.title == title)
            .where(Alert.timestamp > cutoff)
            .where(Alert.dismissed == False)
        )
        return result.scalar_one_or_none()

    async def _dispatch_alert(self, session: AsyncSession, alert: Alert):
        """Dispatch alert to configured channels (Telegram, Email, etc)."""
        # Get alert channels configuration
        result = await session.execute(
            select(Settings).where(Settings.key == "alert_channels")
        )
        settings = result.scalar_one_or_none()

        if not settings:
            return

        channels = settings.value

        # Telegram
        if channels.get("telegram", {}).get("enabled"):
            try:
                await self._send_telegram(alert, channels["telegram"])
                alert.sent_telegram = True
            except Exception as e:
                print(f"[AlertService] Failed to send Telegram: {e}")

        # Email
        if channels.get("email", {}).get("enabled"):
            try:
                await self._send_email(alert, channels["email"])
                alert.sent_email = True
            except Exception as e:
                print(f"[AlertService] Failed to send Email: {e}")

        await session.commit()

    async def _send_telegram(self, alert: Alert, config: dict):
        """Send alert via Telegram bot."""
        # TODO: Implement Telegram bot integration
        bot_token = config.get("bot_token")
        chat_ids = config.get("chat_ids", [])

        if not bot_token or not chat_ids:
            return

        # Format message
        severity_emoji = {
            "info": "ℹ️",
            "warning": "⚠️",
            "error": "❌",
            "critical": "🚨",
        }

        emoji = severity_emoji.get(alert.severity, "📢")
        text = f"{emoji} **{alert.title}**\n\n{alert.message}"

        print(f"[AlertService] Would send Telegram to {len(chat_ids)} chats: {text[:50]}...")
        # Import httpx and send message to Telegram API
        # await httpx.post(f"https://api.telegram.org/bot{bot_token}/sendMessage", ...)

    async def _send_email(self, alert: Alert, config: dict):
        """Send alert via Email."""
        # TODO: Implement Email SMTP integration
        smtp_server = config.get("smtp_server")
        recipients = config.get("recipients", [])

        if not smtp_server or not recipients:
            return

        print(f"[AlertService] Would send Email to {len(recipients)} recipients: {alert.title}")
        # Import smtplib and send email
        # ...

    async def get_active_alerts(self, session: AsyncSession) -> list[Alert]:
        """Get all active (non-dismissed) alerts."""
        result = await session.execute(
            select(Alert)
            .where(Alert.dismissed == False)
            .order_by(Alert.timestamp.desc())
        )
        return list(result.scalars().all())

    async def acknowledge_alert(
        self, session: AsyncSession, alert_id: int, user_id: int
    ):
        """Mark alert as acknowledged."""
        result = await session.execute(select(Alert).where(Alert.id == alert_id))
        alert = result.scalar_one_or_none()

        if alert:
            alert.acknowledged = True
            alert.acknowledged_at = datetime.now(timezone.utc)
            alert.acknowledged_by = user_id
            await session.commit()

    async def dismiss_alert(self, session: AsyncSession, alert_id: int):
        """Mark alert as dismissed."""
        result = await session.execute(select(Alert).where(Alert.id == alert_id))
        alert = result.scalar_one_or_none()

        if alert:
            alert.dismissed = True
            alert.dismissed_at = datetime.now(timezone.utc)
            await session.commit()


# Global instance
alert_service = AlertService()