from __future__ import annotations

from os import environ
from pathlib import Path


class EnvLoader:
    """Loads Astrape env files without overriding process environment.

    The directory is resolved against the working directory, or
    ASTRAPE_ENV_DIR if set. Deliberately not derived from __file__: where a
    package happens to be installed says nothing about where the deployment
    keeps its secrets, and tying the two breaks the moment the package moves.
    Every unit sets WorkingDirectory=/srv/astrape, so the default is correct
    for the daemons and for a shell started in the project root.
    """

    def __init__(self, env_dir: Path | None = None) -> None:
        if env_dir is None:
            env_dir = Path(environ.get("ASTRAPE_ENV_DIR", "env"))
        self.env_dir = env_dir

    def load(self) -> None:
        if not self.env_dir.exists():
            return

        for path in sorted(self.env_dir.glob("*.env")):
            self._load_file(path)

    def _load_file(self, path: Path) -> None:
        for raw_line in path.read_text(encoding="utf-8").splitlines():
            line = raw_line.strip()
            if not line or line.startswith("#") or "=" not in line:
                continue

            key, value = line.split("=", 1)
            key = key.strip()
            value = self._clean_value(value.strip())
            if key and key not in environ:
                environ[key] = value

    def _clean_value(self, value: str) -> str:
        if len(value) >= 2 and value[0] == value[-1] and value[0] in {"'", '"'}:
            return value[1:-1]
        return value