#!/usr/bin/env python
"""
Initialize or upgrade the main database for this web application.

Usage:
    python initialize_db.py

Environment Variables:
    DB_URI (optional):
        The SQLAlchemy database URL (e.g., "sqlite:///main.db").
        Defaults to "sqlite:///main.db" if not set.

Description:
    Creates or updates all tables referenced by `Base.metadata`.
    If the database file/tables do not exist, they will be created.
"""

import os
import sys
import logging
import transaction

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from sqlalchemy.pool import StaticPool

# Adjust these imports to your actual project structure:
# Ensure 'Base' is imported from your 'app.py' where your models are defined.
from app import Base  # Assuming 'app.py' contains your models and 'Base'

def usage():
    script = os.path.basename(sys.argv[0])
    print(f"Usage: {script}")
    print("Example:")
    print(f"    python {script}")
    sys.exit(1)

def main():
    logging.basicConfig(level=logging.INFO)
    if len(sys.argv) > 1:
        # We only expect optional arguments. If needed, parse them here.
        usage()

    # Read environment variable for DB URL
    db_url = os.environ.get("DB_URI", "sqlite:///main.db")
    logging.info(f"Using DB URL: {db_url}")

    # Set up engine
    engine = create_engine(
        db_url,
        connect_args={"check_same_thread": False} if "sqlite" in db_url else {},
        poolclass=StaticPool if "sqlite" in db_url else None,
    )

    SessionFactory = sessionmaker(bind=engine)

    # Create or upgrade tables
    with transaction.manager:
        logging.info("Creating or upgrading tables using Base.metadata.create_all()")
        Base.metadata.create_all(engine)

    logging.info("Database initialization complete.")

if __name__ == "__main__":
    main()