from typing import Optional
from sqlalchemy.orm import Session
from models import Setting
from config import get_settings

_settings_cache = {}


def get_setting(db: Session, key: str) -> Optional[str]:
    """Get setting from DB, fallback to .env config."""
    s = db.query(Setting).filter(Setting.key == key).first()
    if s:
        return s.value

    config = get_settings()
    return getattr(config, key, None)


def set_setting(db: Session, key: str, value: Optional[str]) -> Setting:
    s = db.query(Setting).filter(Setting.key == key).first()
    if s:
        s.value = value
    else:
        s = Setting(key=key, value=value)
        db.add(s)
    db.commit()
    db.refresh(s)
    _settings_cache[key] = value
    return s


def get_all_settings(db: Session) -> dict:
    """Return merged DB settings and .env defaults."""
    config = get_settings()
    result = {}
    keys = [
        "AGENT_TOKEN",
        "OFFLINE_THRESHOLD_MINUTES",
        "NOTIFICATION_WEBHOOK_URL",
        "NOTIFICATION_TELEGRAM_BOT_TOKEN",
        "NOTIFICATION_TELEGRAM_CHAT_ID",
    ]
    for key in keys:
        db_val = db.query(Setting).filter(Setting.key == key).first()
        value = db_val.value if db_val else getattr(config, key, None)
        if key == "OFFLINE_THRESHOLD_MINUTES" and value is not None:
            try:
                value = int(value)
            except (TypeError, ValueError):
                value = getattr(config, key, None)
        result[key] = value
    return result