"""Persistent settings for the Silo Calc extension.

Settings are stored in ``~/.config/silo/calc-settings.json``.
The file is a flat JSON dict with known keys.
"""

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

_SETTINGS_DIR = (
    Path(os.environ.get("XDG_CONFIG_HOME", "~/.config")).expanduser() / "silo"
)
_SETTINGS_FILE = _SETTINGS_DIR / "calc-settings.json"

# Default values for every known key.
_DEFAULTS: Dict[str, Any] = {
    "api_url": "",
    "api_token": "",
    "ssl_verify": True,
    "ssl_cert_path": "",
    "auth_username": "",
    "auth_role": "",
    "auth_source": "",
    "projects_dir": "",  # fallback: SILO_PROJECTS_DIR env or ~/projects
    "default_schema": "kindred-rd",
    "openrouter_api_key": "",  # fallback: OPENROUTER_API_KEY env var
    "openrouter_model": "",  # fallback: ai_client.DEFAULT_MODEL
    "openrouter_instructions": "",  # fallback: ai_client.DEFAULT_INSTRUCTIONS
}


def load() -> Dict[str, Any]:
    """Load settings, returning defaults for any missing keys."""
    cfg = dict(_DEFAULTS)
    if _SETTINGS_FILE.is_file():
        try:
            with open(_SETTINGS_FILE, "r") as f:
                stored = json.load(f)
            cfg.update(stored)
        except (json.JSONDecodeError, OSError):
            pass
    return cfg


def save(cfg: Dict[str, Any]) -> None:
    """Persist the full settings dict to disk."""
    _SETTINGS_DIR.mkdir(parents=True, exist_ok=True)
    with open(_SETTINGS_FILE, "w") as f:
        json.dump(cfg, f, indent=2)


def get(key: str, default: Any = None) -> Any:
    """Convenience: load a single key."""
    cfg = load()
    return cfg.get(key, default)


def put(key: str, value: Any) -> None:
    """Convenience: update a single key and persist."""
    cfg = load()
    cfg[key] = value
    save(cfg)


def save_auth(username: str, role: str = "", source: str = "", token: str = "") -> None:
    """Store authentication info."""
    cfg = load()
    cfg["auth_username"] = username
    cfg["auth_role"] = role
    cfg["auth_source"] = source
    if token:
        cfg["api_token"] = token
    save(cfg)


def clear_auth() -> None:
    """Remove stored auth credentials."""
    cfg = load()
    cfg["api_token"] = ""
    cfg["auth_username"] = ""
    cfg["auth_role"] = ""
    cfg["auth_source"] = ""
    save(cfg)


def get_projects_dir() -> Path:
    """Return the resolved projects base directory."""
    cfg = load()
    d = cfg.get("projects_dir", "")
    if not d:
        d = os.environ.get("SILO_PROJECTS_DIR", "~/projects")
    return Path(d).expanduser()