from collections.abc import Sequence
from typing import Any

from sqlalchemy.orm import Session


def get_db_dialect_name(db: Session) -> str:
    bind = db.get_bind()
    if bind is None:
        raise RuntimeError("Database session is not bound to an engine")
    return bind.dialect.name


def current_timestamp_sql(db: Session) -> str:
    if get_db_dialect_name(db) == "mysql":
        return "CURRENT_TIMESTAMP(3)"
    return "CURRENT_TIMESTAMP"


def select_for_update_clause(db: Session) -> str:
    if get_db_dialect_name(db) == "mysql":
        return " FOR UPDATE"
    return ""


def inserted_primary_key(result: Any) -> int:
    lastrowid = getattr(result, "lastrowid", None)
    if lastrowid is not None:
        return int(lastrowid)

    try:
        inserted_primary_key = result.inserted_primary_key
    except Exception:
        inserted_primary_key = None

    if isinstance(inserted_primary_key, Sequence) and inserted_primary_key:
        primary_key = inserted_primary_key[0]
        if primary_key is not None:
            return int(primary_key)

    raise RuntimeError("Could not determine inserted primary key")