# topology_api/db.py
import psycopg
from psycopg.rows import dict_row
from contextlib import contextmanager
from topology_api.config import READER_DATABASE_URL, WRITER_DATABASE_URL


def get_reader_connection():
    """Return a new read-only connection with dict_row rows."""
    return psycopg.connect(READER_DATABASE_URL, row_factory=dict_row)


def get_writer_connection():
    """Return a new write-capable connection with dict_row rows."""
    return psycopg.connect(WRITER_DATABASE_URL, row_factory=dict_row)


@contextmanager
def read_cursor():
    """Context manager for read queries. Returns a cursor."""
    with get_reader_connection() as conn:
        conn.execute("SET search_path TO topology, public")
        with conn.cursor() as cur:
            yield cur


@contextmanager
def write_cursor():
    """Context manager for write queries. Auto-commits on success, rollback on error."""
    with get_writer_connection() as conn:
        conn.execute("SET search_path TO topology, public")
        with conn.transaction():
            with conn.cursor() as cur:
                yield cur