"""Small, local GUI preferences for the active Blueforce identity."""

from __future__ import annotations

import json
import os
from pathlib import Path
from typing import Any

from bfos.operations import dealer_is_valid

PREFERENCES_FILENAME = "blueforce-gui.json"


def preferences_path() -> Path:
    base = os.environ.get("XDG_CONFIG_HOME")
    if base:
        return Path(base) / "blueforce" / PREFERENCES_FILENAME
    return Path.home() / ".config" / "blueforce" / PREFERENCES_FILENAME


def load_preferences(path: Path | None = None) -> dict[str, str]:
    target = path or preferences_path()
    try:
        data: Any = json.loads(target.read_text(encoding="utf-8"))
    except (OSError, ValueError):
        return {}
    if not isinstance(data, dict):
        return {}
    dealer = str(data.get("dealer_id", "")).strip()
    if not dealer_is_valid(dealer):
        return {}
    return {"dealer_id": dealer, "active_user": f"bf-{dealer}"}


def save_dealer(dealer_id: str, path: Path | None = None) -> dict[str, str]:
    if not dealer_is_valid(dealer_id):
        raise ValueError("Bayi numarası tam 8 rakam olmalıdır.")
    target = path or preferences_path()
    target.parent.mkdir(parents=True, exist_ok=True)
    data = {"dealer_id": dealer_id, "active_user": f"bf-{dealer_id}"}
    temporary = target.with_suffix(target.suffix + ".tmp")
    temporary.write_text(json.dumps(data, ensure_ascii=False, indent=2) + "\n", encoding="utf-8")
    os.replace(temporary, target)
    return data


def clear_dealer(path: Path | None = None) -> None:
    target = path or preferences_path()
    try:
        target.unlink()
    except FileNotFoundError:
        pass