import os

import psycopg2
from psycopg2.extras import RealDictCursor

_pool = None


def init_pool() -> None:
    global _pool
    if _pool is None:
        _pool = {
            "host": os.getenv("DB_HOST", "10.4.7.18"),
            "user": os.getenv("DB_USER", "aissa"),
            "password": os.getenv("DB_PASSWORD", "Foodlinkk#2026"),
            "dbname": os.getenv("DB_NAME", "foodlinkk"),
        }


def _conn():
    init_pool()
    return psycopg2.connect(**_pool, cursor_factory=RealDictCursor)


def fetch_one(sql: str, params: tuple = ()) -> dict | None:
    with _conn() as conn:
        with conn.cursor() as cur:
            cur.execute(sql, params)
            row = cur.fetchone()
            conn.commit()
            return dict(row) if row else None


def fetch_all(sql: str, params: tuple = ()) -> list:
    with _conn() as conn:
        with conn.cursor() as cur:
            cur.execute(sql, params)
            rows = cur.fetchall()
            conn.commit()
            return [dict(r) for r in rows]


def execute_returning(sql: str, params: tuple = ()) -> dict:
    with _conn() as conn:
        with conn.cursor() as cur:
            cur.execute(sql, params)
            row = cur.fetchone()
            conn.commit()
            return dict(row) if row else {}