from __future__ import annotations

from collections.abc import Mapping

from fastapi import Request

from qonto_assistant.config import Settings
from qonto_assistant.contracts import ActorClaims


def actor_claims_from_headers(headers: Mapping[str, str], settings: Settings) -> ActorClaims:
    """Shared REST/MCP claims parsing so both transports enforce identical actor identity.

    Real workload/OIDC auth for the MCP transport is QONTO-WP-0003-T03; until
    then MCP callers use the same X-Actor-* header convention as REST.
    """
    actor_id = headers.get("x-actor-id", "anonymous")
    tenant_id = headers.get("x-tenant-id", settings.default_tenant_id)
    lane = headers.get("x-actor-lane", settings.default_actor_lane)
    raw_scopes = headers.get("x-actor-scopes", "")
    scopes = frozenset(scope.strip() for scope in raw_scopes.split(",") if scope.strip())
    return ActorClaims(actor_id=actor_id, tenant_id=tenant_id, lane=lane, scopes=scopes)


def actor_claims_from_request(request: Request, settings: Settings) -> ActorClaims:
    return actor_claims_from_headers(request.headers, settings)