"""
Who owns this LIM instance.

LIM only had is_admin, which is fine for day-to-day administration but too
broad for things that expose the whole instance: the log viewer shows every
request, every error and every API call, including other admins' activity.

The owner is a single account:

  * whatever `owner_user_id` in site_settings points at, if that user exists;
  * otherwise the lowest-numbered admin (in practice the account created by
    `flask init_db`), which is then remembered.

Change it with `flask owner set <username>`.

Created by: Jess Rogerson (yelling commands at Claude.AI)
"""

from functools import wraps

from flask import flash, redirect, url_for
from flask_login import current_user

from app import db
from app.models.site_setting import SiteSetting
from app.models.user import User

OWNER_SETTING = 'owner_user_id'


def get_owner():
    """The User who owns this instance, or None on an empty database."""
    raw = SiteSetting.get(OWNER_SETTING, '')
    if raw and str(raw).strip().isdigit():
        owner = db.session.get(User, int(str(raw).strip()))
        if owner is not None:
            return owner

    # Nothing stored (or it points at a deleted account): fall back to the
    # first admin and remember the answer.
    owner = (User.query.filter_by(is_admin=True).order_by(User.id).first()
             or User.query.order_by(User.id).first())
    if owner is not None:
        try:
            SiteSetting.set(OWNER_SETTING, str(owner.id))
            db.session.commit()
        except Exception:
            db.session.rollback()
    return owner


def get_owner_id():
    owner = get_owner()
    return owner.id if owner else None


def set_owner(user):
    """Hand ownership to a user. Returns the user."""
    SiteSetting.set(OWNER_SETTING, str(user.id))
    if not user.is_admin:
        user.is_admin = True
    db.session.commit()
    return user


def is_owner(user=None):
    """Is this user (default: the logged-in one) the owner?"""
    user = user or current_user
    if user is None or not getattr(user, 'is_authenticated', False):
        return False
    owner_id = get_owner_id()
    return owner_id is not None and user.id == owner_id


def owner_required(f):
    """Stricter than admin_required: this account only."""
    @wraps(f)
    def decorated_function(*args, **kwargs):
        if not current_user.is_authenticated:
            flash('Please log in to access this page.', 'warning')
            return redirect(url_for('auth.login'))
        if not is_owner(current_user):
            flash('That area is restricted to the instance owner.', 'danger')
            return redirect(url_for('main.index'))
        return f(*args, **kwargs)
    return decorated_function