"""Helpers shared by the admin endpoints."""

import re

import structlog
from fastapi import HTTPException

log = structlog.get_logger()

_MCP_NAME_RE = re.compile(r"^[\w_-]+$")


def _invalidate_prompt_cache() -> None:
    """Drop the cached system prompts after a profile's shape changed.

    Every other profile's prompt embeds the "Available profiles" block, so a
    toggle here invalidates all of them, not just this one. Best effort: the
    cache is an optimisation, and a failure must not fail the admin write.
    """
    try:
        from navi.api.deps import get_agent

        get_agent().invalidate_prompt_cache()
    except Exception:
        log.warning("admin.prompt_cache_invalidate_failed", exc_info=True)


def _validate_mcp_name(name: str) -> None:
    if not _MCP_NAME_RE.match(name):
        raise HTTPException(
            status_code=400,
            detail="Invalid server name. Use only letters, digits, underscores, and hyphens.",
        )