"""
Dispute Scheduler - marks disputes as pending admin review after 24 hours.
"""
import asyncio
from datetime import datetime, timedelta
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.orm import selectinload

from app.models import Dispute, DisputeStatus, Assignment, AssignmentStatus
from app.services.telegram_notifier import telegram_notifier


# Configuration
CHECK_INTERVAL_SECONDS = 300  # Check every 5 minutes
DISPUTE_WINDOW_HOURS = 24  # Disputes need admin decision after 24 hours


class DisputeScheduler:
    """Background scheduler that marks expired disputes for admin review."""

    def __init__(self):
        self._running = False
        self._task: asyncio.Task | None = None

    async def start(self, session_factory) -> None:
        """Start the scheduler background task."""
        if self._running:
            return

        self._running = True
        self._task = asyncio.create_task(self._run_loop(session_factory))
        print("[DisputeScheduler] Started")

    async def stop(self) -> None:
        """Stop the scheduler."""
        self._running = False
        if self._task:
            self._task.cancel()
            try:
                await self._task
            except asyncio.CancelledError:
                pass
        print("[DisputeScheduler] Stopped")

    async def _run_loop(self, session_factory) -> None:
        """Main scheduler loop."""
        while self._running:
            try:
                async with session_factory() as db:
                    await self._process_expired_disputes(db)
            except Exception as e:
                print(f"[DisputeScheduler] Error in loop: {e}")

            await asyncio.sleep(CHECK_INTERVAL_SECONDS)

    async def _process_expired_disputes(self, db: AsyncSession) -> None:
        """Mark expired disputes as pending admin review."""
        cutoff_time = datetime.utcnow() - timedelta(hours=DISPUTE_WINDOW_HOURS)

        # Find all open disputes that have expired
        result = await db.execute(
            select(Dispute)
            .options(
                selectinload(Dispute.votes),
            )
            .where(
                Dispute.status == DisputeStatus.OPEN.value,
                Dispute.created_at < cutoff_time,
            )
        )
        expired_disputes = result.scalars().all()

        for dispute in expired_disputes:
            try:
                # Count votes for logging
                votes_valid = sum(1 for v in dispute.votes if v.vote is True)
                votes_invalid = sum(1 for v in dispute.votes if v.vote is False)

                # Mark as pending admin decision
                dispute.status = DisputeStatus.PENDING_ADMIN.value

                print(
                    f"[DisputeScheduler] Dispute {dispute.id} marked as pending admin "
                    f"(recommendation: {'invalid' if votes_invalid > votes_valid else 'valid'}, "
                    f"votes: {votes_valid} valid, {votes_invalid} invalid)"
                )
            except Exception as e:
                print(f"[DisputeScheduler] Failed to process dispute {dispute.id}: {e}")

        if expired_disputes:
            await db.commit()
            # Notify admins about pending disputes
            await telegram_notifier.notify_admin_disputes_pending(db, len(expired_disputes))


# Global scheduler instance
dispute_scheduler = DisputeScheduler()