from collections.abc import Generator
import os
from pathlib import Path
from urllib.parse import unquote, urlparse

from sqlalchemy import create_engine
from sqlalchemy.orm import Session, declarative_base, sessionmaker


DEFAULT_DB_PATH = Path(__file__).resolve().parents[1] / "cronogramas_v2.db"
DATABASE_URL = os.getenv("DATABASE_URL", f"sqlite:///{DEFAULT_DB_PATH}")
connect_args = {"check_same_thread": False} if DATABASE_URL.startswith("sqlite") else {}

engine = create_engine(DATABASE_URL, connect_args=connect_args)
SessionLocal = sessionmaker(bind=engine, autoflush=False, autocommit=False)
Base = declarative_base()


def sqlite_database_path() -> Path | None:
    if not DATABASE_URL.startswith("sqlite:///"):
        return None

    raw_path = DATABASE_URL.removeprefix("sqlite:///")
    if DATABASE_URL.startswith("sqlite:////"):
        parsed = urlparse(DATABASE_URL)
        raw_path = unquote(parsed.path)

    return Path(raw_path).expanduser().resolve()


def get_db() -> Generator[Session, None, None]:
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()