"""Effective Windows domain admin credentials (host → DB → env)."""

from __future__ import annotations

from dataclasses import dataclass

from sqlalchemy.orm import Session

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


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

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


def normalize_win_admin_user(user: str) -> str:
    """DOMAIN\\user — один обратный слэш; убрать лишнее экранирование из env/UI."""
    text = user.strip()
    if not text:
        return ""
    text = text.replace("\\\\", "\\")
    if "\\" not in text and "@" not in text and "/" not in text:
        # NETBIOS\user без слэша — не трогаем (оператор допишет в UI)
        return text
    return text


def _win_admin_from_env() -> WinAdminConfig:
    settings = get_settings()
    return WinAdminConfig(
        user=normalize_win_admin_user(settings.sac_win_admin_user),
        password=settings.sac_win_admin_password,
        source="env",
    )


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

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

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

    user = normalize_win_admin_user((row.win_admin_user or "").strip() or env_cfg.user)
    password = (row.win_admin_password or "") or env_cfg.password
    has_db_values = bool((row.win_admin_user or "").strip() or (row.win_admin_password or "").strip())
    return WinAdminConfig(
        user=user,
        password=password,
        source="db" if has_db_values else env_cfg.source,
    )


def upsert_win_admin_settings(
    db: Session,
    *,
    user: str | None = None,
    password: str | None = None,
) -> WinAdminConfig:
    row = db.get(UiSettings, UI_SETTINGS_ROW_ID)
    env_cfg = _win_admin_from_env()
    if row is None:
        row = UiSettings(
            id=UI_SETTINGS_ROW_ID,
            show_sidebar_system_stats=True,
            win_admin_user=env_cfg.user or None,
            win_admin_password=env_cfg.password or None,
        )
        db.add(row)

    if user is not None and user.strip():
        row.win_admin_user = normalize_win_admin_user(user)
    if password is not None and password.strip():
        row.win_admin_password = password

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


def get_effective_win_admin_for_host(db: Session, host: Host) -> WinAdminConfig:
    """Prefer per-host mgmt_* when both user and password are set; else global Settings/env."""
    host_user = normalize_win_admin_user((host.mgmt_user or "").strip())
    host_password = (host.mgmt_password or "").strip()
    if host_user and host_password:
        return WinAdminConfig(user=host_user, password=host_password, source="host")

    global_cfg = get_effective_win_admin_config(db)
    # Allow host to override only the username, still using global password (rare).
    if host_user and global_cfg.password.strip():
        return WinAdminConfig(user=host_user, password=global_cfg.password, source="host")
    return global_cfg