import type { UserRole } from "../env.js";

/** Foundation + forward-looking actions used by the RBAC matrix. */
export const RBAC_ACTIONS = [
  "read:me",
  "read:invoices",
  "write:invoices",
  "approve:invoices",
  "admin:settings",
] as const;

export type RbacAction = (typeof RBAC_ACTIONS)[number];

const MATRIX: Readonly<Record<UserRole, ReadonlySet<RbacAction>>> = {
  admin: new Set(RBAC_ACTIONS),
  ap_processor: new Set(["read:me", "read:invoices", "write:invoices"]),
  approver: new Set(["read:me", "read:invoices", "approve:invoices"]),
  viewer: new Set(["read:me", "read:invoices"]),
};

export function can(role: UserRole, action: RbacAction): boolean {
  return MATRIX[role].has(action);
}

export function requireRole(role: UserRole, action: RbacAction): void {
  if (!can(role, action)) {
    throw new RbacDeniedError(role, action);
  }
}

export class RbacDeniedError extends Error {
  readonly status = 403 as const;

  constructor(
    readonly role: UserRole,
    readonly action: RbacAction,
  ) {
    super(`Role ${role} is not allowed to ${action}.`);
    this.name = "RbacDeniedError";
  }
}