"""Configuration management — persists Mealie and Tandoor connection settings to a JSON file."""

import json
import os
from pathlib import Path

DATA_DIR = Path(os.environ.get("DATA_DIR", "/data"))
CONFIG_FILE = DATA_DIR / "config.json"

# Optional internal URLs for Docker-to-Docker API calls (avoids Cloudflare hairpin).
# The user-facing URLs are still used for browser links.
MEALIE_INTERNAL_URL = os.environ.get("MEALIE_INTERNAL_URL", "").strip().rstrip("/")
TANDOOR_INTERNAL_URL = os.environ.get("TANDOOR_INTERNAL_URL", "").strip().rstrip("/")

_DEFAULTS = {
    "mealie_url": "",
    "mealie_api_key": "",
    "tandoor_url": "",
    "tandoor_api_key": "",
}

# Environment variable overrides for connection settings.
# When set, these take priority over values stored in config.json.
_ENV_OVERRIDES = {
    "mealie_url": os.environ.get("MEALIE_URL", "").strip().rstrip("/"),
    "mealie_api_key": os.environ.get("MEALIE_API_KEY", "").strip(),
    "tandoor_url": os.environ.get("TANDOOR_URL", "").strip().rstrip("/"),
    "tandoor_api_key": os.environ.get("TANDOOR_API_KEY", "").strip(),
}


def _ensure_dir():
    DATA_DIR.mkdir(parents=True, exist_ok=True)


def load() -> dict:
    """Return the current config dict, merged with defaults.

    Environment variables (MEALIE_URL, MEALIE_API_KEY, TANDOOR_URL,
    TANDOOR_API_KEY) take priority over file-based values when set.
    """
    cfg = dict(_DEFAULTS)
    if CONFIG_FILE.exists():
        try:
            with open(CONFIG_FILE, "r", encoding="utf-8") as f:
                cfg.update(json.load(f))
        except (json.JSONDecodeError, OSError):
            pass
    # Apply env overrides (only non-empty values).
    for key, val in _ENV_OVERRIDES.items():
        if val:
            cfg[key] = val
    return cfg


def save(cfg: dict):
    """Atomically persist *cfg* to disk."""
    _ensure_dir()
    tmp = CONFIG_FILE.with_suffix(".tmp")
    with open(tmp, "w", encoding="utf-8") as f:
        json.dump(cfg, f, indent=2, ensure_ascii=False)
    tmp.replace(CONFIG_FILE)