"""Effective Linux SSH admin credentials (DB overrides env)."""

from __future__ import annotations

from dataclasses import dataclass

from sqlalchemy.orm import Session

from app.config import get_settings
from app.models.ui_settings import UI_SETTINGS_ROW_ID, UiSettings


@dataclass(frozen=True)
class LinuxAdminConfig:
    user: str
    password: str
    source: str  # env | db

    @property
    def configured(self) -> bool:
        return bool(self.user.strip() and self.password.strip())


def _linux_admin_from_env() -> LinuxAdminConfig:
    settings = get_settings()
    return LinuxAdminConfig(
        user=settings.sac_linux_admin_user.strip(),
        password=settings.sac_linux_admin_password,
        source="env",
    )


def get_effective_linux_admin_config(db: Session | None = None) -> LinuxAdminConfig:
    if db is None:
        from app.database import SessionLocal

        session = SessionLocal()
        try:
            return get_effective_linux_admin_config(session)
        finally:
            session.close()

    row = db.get(UiSettings, UI_SETTINGS_ROW_ID)
    env_cfg = _linux_admin_from_env()
    if row is None:
        return env_cfg

    user = (row.linux_admin_user or "").strip() or env_cfg.user
    password = (row.linux_admin_password or "") or env_cfg.password
    has_db_values = bool((row.linux_admin_user or "").strip() or (row.linux_admin_password or "").strip())
    return LinuxAdminConfig(
        user=user,
        password=password,
        source="db" if has_db_values else env_cfg.source,
    )


def upsert_linux_admin_settings(
    db: Session,
    *,
    user: str | None = None,
    password: str | None = None,
) -> LinuxAdminConfig:
    row = db.get(UiSettings, UI_SETTINGS_ROW_ID)
    env_cfg = _linux_admin_from_env()
    if row is None:
        row = UiSettings(
            id=UI_SETTINGS_ROW_ID,
            show_sidebar_system_stats=True,
            linux_admin_user=env_cfg.user or None,
            linux_admin_password=env_cfg.password or None,
        )
        db.add(row)

    if user is not None and user.strip():
        row.linux_admin_user = user.strip()
    if password is not None and password.strip():
        row.linux_admin_password = password

    db.commit()
    db.refresh(row)
    return get_effective_linux_admin_config(db)