from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from sqlalchemy.exc import OperationalError
import os

# Read database URL from environment or fallback to docker-compose default
SQLALCHEMY_DATABASE_URL = os.getenv("DATABASE_URL", "postgresql://admin:adminpassword@localhost:5432/bankbot")
USE_SQLITE = os.getenv("USE_SQLITE", "false").lower() in ("true", "1", "yes")

BASE_DIR = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
sqlite_db_path = os.path.join(BASE_DIR, "bankbot.db")

if USE_SQLITE:
    SQLALCHEMY_DATABASE_URL = f"sqlite:///{sqlite_db_path}"

connect_args = {}
if "sqlite" in SQLALCHEMY_DATABASE_URL:
    connect_args = {"check_same_thread": False}

try:
    engine = create_engine(SQLALCHEMY_DATABASE_URL, connect_args=connect_args)
    # Test connection
    with engine.connect() as conn:
        pass
except (OperationalError, Exception) as e:
    print(f"Database connection to {SQLALCHEMY_DATABASE_URL} failed: {e}")
    print(f"Falling back to SQLite database at sqlite:///{sqlite_db_path}...")
    SQLALCHEMY_DATABASE_URL = f"sqlite:///{sqlite_db_path}"
    connect_args = {"check_same_thread": False}
    engine = create_engine(SQLALCHEMY_DATABASE_URL, connect_args=connect_args)

SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

Base = declarative_base()

def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()