"""Shared owner identity constants and helpers."""

from __future__ import annotations

import os
from typing import Optional


DEFAULT_LOCAL_OWNER = "__odysseus_local__"
DEFAULT_LOCAL_OWNER_LABEL = "Local"
INTERNAL_TOOL_USER = "internal-tool"

REQUEST_SENTINEL_OWNERS = frozenset({INTERNAL_TOOL_USER, "api", "demo", "system"})
RESERVED_AUTH_USERNAMES = REQUEST_SENTINEL_OWNERS | {DEFAULT_LOCAL_OWNER}


def auth_disabled() -> bool:
    """Return True only when auth is explicitly disabled by configuration."""
    return os.getenv("AUTH_ENABLED", "true").strip().lower() == "false"


def normalize_owner(owner: str | None) -> Optional[str]:
    """Normalize an owner-like value without inventing a fallback identity."""
    value = str(owner or "").strip()
    return value or None


def owner_key(owner: str | None) -> Optional[str]:
    normalized = normalize_owner(owner)
    return normalized.lower() if normalized else None


def is_request_sentinel_owner(owner: str | None) -> bool:
    return owner_key(owner) in REQUEST_SENTINEL_OWNERS


def effective_storage_owner(owner: str | None, *, auth_is_disabled: bool | None = None) -> Optional[str]:
    """Resolve the owner used for storage writes that need a real bucket.

    ``None`` still means no authenticated owner when auth is enabled. In the
    explicit no-login mode, it resolves to the reserved local owner instead of
    conflating local-operator writes with legacy NULL/ownerless rows.
    """
    normalized = normalize_owner(owner)
    if normalized:
        if is_request_sentinel_owner(normalized):
            return None
        return normalized
    disabled = auth_disabled() if auth_is_disabled is None else auth_is_disabled
    if disabled:
        return DEFAULT_LOCAL_OWNER
    return None


def is_default_local_owner(owner: str | None) -> bool:
    return owner_key(owner) == DEFAULT_LOCAL_OWNER