from collections.abc import Generator
from pathlib import Path

from sqlalchemy import create_engine, event
from sqlalchemy.orm import DeclarativeBase, Session, sessionmaker

from app.config import get_settings


class Base(DeclarativeBase):
    pass


def create_sqlite_engine(database_url: str):
    if database_url.startswith("sqlite:///") and database_url != "sqlite:///:memory:":
        db_path = Path(database_url.removeprefix("sqlite:///"))
        if db_path.parent != Path("."):
            db_path.parent.mkdir(parents=True, exist_ok=True)

    connect_args = {"check_same_thread": False, "timeout": 10}
    engine = create_engine(database_url, connect_args=connect_args)
    engine.dialect.connect_args = connect_args

    @event.listens_for(engine, "connect")
    def set_sqlite_pragma(dbapi_connection, _connection_record):
        cursor = dbapi_connection.cursor()
        cursor.execute("PRAGMA journal_mode=WAL")
        cursor.close()

    return engine


engine = create_sqlite_engine(get_settings().database_url)
SessionLocal = sessionmaker(bind=engine, autoflush=False, autocommit=False)


def init_db() -> None:
    import app.models  # noqa: F401

    Base.metadata.create_all(engine)


def get_db_session() -> Generator[Session]:
    with SessionLocal() as session:
        yield session