from __future__ import annotations

import json
from pathlib import Path
from typing import Any

from fastapi import APIRouter, Depends

from app.auth.dependencies import ApiPrincipal, require_scope

router = APIRouter(prefix="/schemas", tags=["schemas"])


@router.get("/campaign")
def get_campaign_schema(
    principal: ApiPrincipal = Depends(require_scope("campaign:read")),
) -> dict[str, Any]:
    """Return the authoritative campaign JSON Schema used by the backend.

    The WebUI can fetch this instead of carrying a stale copy. A future UI
    schema can be served alongside this endpoint.
    """

    schema_path = Path(__file__).resolve().parents[2] / "mailer" / "schemas" / "campaign.schema.json"
    return json.loads(schema_path.read_text(encoding="utf-8"))