"""
Database Configuration
SQLAlchemy setup for PostgreSQL connection.
"""

import os
from flask_sqlalchemy import SQLAlchemy

# Initialize SQLAlchemy instance
db = SQLAlchemy()


def init_db(app):
    """
    Initialize database with Flask app.

    Args:
        app: Flask application instance
    """
    # Get database URL from environment variable
    database_url = os.getenv('DATABASE_URL')

    if not database_url:
        # Fallback to individual environment variables
        db_user = os.getenv('POSTGRES_USER', 'balanceboard')
        db_password = os.getenv('POSTGRES_PASSWORD', 'changeme')
        db_host = os.getenv('POSTGRES_HOST', 'localhost')
        db_port = os.getenv('POSTGRES_PORT', '5432')
        db_name = os.getenv('POSTGRES_DB', 'balanceboard')

        database_url = f'postgresql+psycopg2://{db_user}:{db_password}@{db_host}:{db_port}/{db_name}'

    # Configure Flask app
    app.config['SQLALCHEMY_DATABASE_URI'] = database_url
    app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
    app.config['SQLALCHEMY_ENGINE_OPTIONS'] = {
        'pool_size': 10,
        'pool_recycle': 3600,
        'pool_pre_ping': True,  # Verify connections before using
    }

    # Initialize db with app
    db.init_app(app)

    # Create tables
    with app.app_context():
        db.create_all()
        print("✓ Database tables created")


def get_db():
    """Get database instance"""
    return db