import os
from dotenv import load_dotenv
from sqlalchemy import create_engine, text
from sqlalchemy.orm import sessionmaker

# .env laden
load_dotenv()

# Datenbank-Zugangsdaten aus .env
DB_USER = os.getenv("DB_USER")
DB_PASSWORD = os.getenv("DB_PASSWORD")
DB_HOST = os.getenv("DB_HOST", "localhost")
DB_PORT = os.getenv("DB_PORT", "3306")
DB_NAME = os.getenv("DB_NAME")

# Pooling Parameter aus .env (optional mit Default-Werten)
POOL_SIZE = int(os.getenv("POOL_SIZE", 10))
MAX_OVERFLOW = int(os.getenv("MAX_OVERFLOW", 20))
POOL_TIMEOUT = int(os.getenv("POOL_TIMEOUT", 30))
POOL_RECYCLE = int(os.getenv("POOL_RECYCLE", 1800))

# Connection-String zusammenbauen
DATABASE_URL = (
    f"mysql+pymysql://{DB_USER}:{DB_PASSWORD}@{DB_HOST}:{DB_PORT}/{DB_NAME}"
)

# Engine mit Pooling konfigurieren
engine = create_engine(
    DATABASE_URL,
    pool_size=POOL_SIZE,
    max_overflow=MAX_OVERFLOW,
    pool_timeout=POOL_TIMEOUT,
    pool_recycle=POOL_RECYCLE,
    echo=True,  # für Debug, später False
)

# Session Factory
SessionLocal = sessionmaker(bind=engine, autoflush=False, autocommit=False)

def get_session():
    return SessionLocal()

def execute_query(query):
    with engine.connect() as connection:
        result = connection.execute(text(query))
        return [dict(row) for row in result]