import logging
import sys
import os

# Ensure we can import from src
# In container, app root handles this differently.
# If running from /app, we need /app/backend to see 'src'
sys.path.append('/app/backend')

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from src.utils.config import config
from src.models.activity import Activity
from src.services.parsers import extract_points_from_file

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

def backfill_location():
    db_string = config.DATABASE_URL
    db = create_engine(db_string)
    Session = sessionmaker(bind=db)
    session = Session()

    try:
        activities = session.query(Activity).filter(
            Activity.file_content != None,
            Activity.start_lat == None
        ).all()

        logger.info(f"Scanning {len(activities)} activities for backfill...")
        
        count = 0
        for act in activities:
            try:
                points = extract_points_from_file(act.file_content, act.file_type)
                if points and len(points) > 0:
                    first_point = points[0]
                    # points are [lon, lat] or [lon, lat, ele]
                    act.start_lng = first_point[0]
                    act.start_lat = first_point[1]
                    count += 1
                    
                    if count % 100 == 0:
                        session.commit()
                        logger.info(f"Processed {count} activities...")
            except Exception as e:
                logger.error(f"Failed to parse activity {act.id}: {e}")

        session.commit()
        logger.info(f"Backfill complete. Updated {count} activities.")

    finally:
        session.close()

if __name__ == "__main__":
    backfill_location()