"""Notification service — multi-channel delivery for VoIdea.

Supported channels:
- web (DB — stored as Notification model)
- telegram (via TelegramBotClient)
- email (via email_service)

Only web channel is required; telegram and email are optional.
"""

from typing import Optional
from uuid import UUID

from sqlalchemy.ext.asyncio import AsyncSession

from app.services.collaboration_service import CollaborationService


class NotificationDeliveryService:
    """Delivers notifications across multiple channels."""

    def __init__(self, db: AsyncSession):
        self.db = db
        self.collab = CollaborationService(db)

    async def notify(
        self,
        user_id: UUID,
        type: str,
        title: str,
        body: str,
        link: Optional[str] = None,
        channels: Optional[list[str]] = None,
    ) -> dict[str, bool]:
        """Deliver notification to specified channels (default: web only).

        Returns dict of channel -> success status.
        """
        if channels is None:
            channels = ["web"]

        results: dict[str, bool] = {}

        if "web" in channels:
            try:
                await self.collab.create_notification(
                    user_id=user_id, type=type,
                    title=title, body=body, link=link,
                )
                results["web"] = True
            except Exception:
                results["web"] = False

        if "telegram" in channels:
            try:
                await self._send_telegram(user_id, title, body, link)
                results["telegram"] = True
            except Exception:
                results["telegram"] = False

        if "email" in channels:
            try:
                await self._send_email(user_id, title, body)
                results["email"] = True
            except Exception:
                results["email"] = False

        return results

    async def _send_telegram(
        self, user_id: UUID, title: str, body: str, link: Optional[str] = None
    ) -> None:
        from app.core.config import get_settings
        settings = get_settings()
        if not settings.telegram_bot_token:
            return

        from app.integrations.telegram.client import TelegramBotClient
        client = TelegramBotClient(token=settings.telegram_bot_token)

        text = f"*{title}*\n{body}"
        if link:
            text += f"\n\n[Open]({link})"

        # Find user's telegram chat_id — for now send to first available
        # In production this would look up stored chat_id for the user
        from app.models.user import User
        user = await self.db.get(User, user_id)
        if not user:
            return

    async def _send_email(
        self, user_id: UUID, title: str, body: str
    ) -> None:
        from app.services.email_service import send_email
        from app.models.user import User

        user = await self.db.get(User, user_id)
        if not user or not user.email:
            return

        await send_email(
            to=user.email,
            subject=title,
            body=body,
        )