from __future__ import annotations

from pathlib import Path
import os
from dotenv import dotenv_values


REPO_ROOT = Path(__file__).resolve().parent


def load_env(service: str | None = None) -> None:
    root_env = REPO_ROOT / ".env"
    root_values: dict[str, str] = {}
    service_values: dict[str, str] = {}

    if root_env.exists():
        root_values = {k: v for k, v in dotenv_values(root_env).items() if v is not None}

    if service:
        service_env = REPO_ROOT / service / ".env"
        if service_env.exists():
            service_values = {k: v for k, v in dotenv_values(service_env).items() if v is not None}

    # Precedence: explicit env > service env > root env
    merged = {**root_values, **service_values}
    for key, value in merged.items():
        os.environ.setdefault(key, value)