"""Cleanup tasks for old data.

T58: Task to clean up old usage stats data.
"""
import logging
from datetime import datetime, timedelta

from apscheduler.triggers.cron import CronTrigger
from sqlalchemy import delete

from openrouter_monitor.database import SessionLocal
from openrouter_monitor.models.usage_stats import UsageStats
from openrouter_monitor.config import get_settings
from openrouter_monitor.tasks.scheduler import scheduled_job


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


@scheduled_job(
    CronTrigger(day_of_week='sun', hour=3, minute=0),
    id='cleanup_old_usage_stats',
    replace_existing=True
)
async def cleanup_old_usage_stats():
    """Clean up usage stats older than retention period.
    
    Runs weekly on Sunday at 3:00 AM UTC.
    Removes UsageStats records older than usage_stats_retention_days
    (default: 365 days).
    
    The retention period is configurable via the
    USAGE_STATS_RETENTION_DAYS environment variable.
    """
    logger.info("Starting cleanup of old usage stats")
    
    try:
        with SessionLocal() as db:
            # Calculate cutoff date
            retention_days = settings.usage_stats_retention_days
            cutoff_date = datetime.utcnow().date() - timedelta(days=retention_days)
            
            logger.info(f"Removing usage stats older than {cutoff_date}")
            
            # Delete old records
            stmt = delete(UsageStats).where(UsageStats.date < cutoff_date)
            result = db.execute(stmt)
            deleted_count = result.rowcount
            
            db.commit()
            
            logger.info(
                f"Cleanup completed. Deleted {deleted_count} old usage stats records "
                f"(retention: {retention_days} days)"
            )
            
    except Exception as e:
        logger.error(f"Error in cleanup_old_usage_stats job: {e}")