"""Connections to the local electronics database.

settings.py has already refused to load unless DB_HOST is local and DB_NAME is
electronics_catalog, so nothing here can reach another database.
"""
from __future__ import annotations

import logging
from contextlib import contextmanager
from typing import Iterator

import psycopg
from psycopg.rows import dict_row

from app.infrastructure.settings import (
    DB_CONNECT_TIMEOUT_SECONDS,
    DB_HOST,
    DB_NAME,
    DB_PASSWORD,
    DB_PORT,
    DB_USER,
)

logger = logging.getLogger(__name__)


def connect(*, autocommit: bool = False) -> psycopg.Connection:
    conn = psycopg.connect(
        host=DB_HOST,
        port=DB_PORT,
        dbname=DB_NAME,
        user=DB_USER,
        password=DB_PASSWORD,
        connect_timeout=DB_CONNECT_TIMEOUT_SECONDS,
        autocommit=autocommit,
        row_factory=dict_row,
    )
    try:
        from pgvector.psycopg import register_vector

        register_vector(conn)
    except Exception:  # noqa: BLE001 - the extension is created by migration 0001
        pass
    return conn


@contextmanager
def transaction() -> Iterator[psycopg.Connection]:
    """A connection whose work is committed on success, rolled back on error."""
    conn = connect()
    try:
        yield conn
        conn.commit()
    except Exception:
        conn.rollback()
        raise
    finally:
        conn.close()


def check_connection() -> bool:
    try:
        with connect(autocommit=True) as conn:
            conn.execute("SELECT 1")
        return True
    except Exception as exc:  # noqa: BLE001 - a health probe reports, never raises
        logger.debug("Database unreachable: %s", exc)
        return False