/*
  StarForth — Steady-State Virtual Machine Runtime

  Copyright (c) 2023–2025 Robert A. James
  All rights reserved.

  Licensed under the StarForth License, Version 1.0
*/

/**
 * zuse_eligibility.h - Read/add/membership-check over the on-disk
 * elevation eligibility list (FABRIC-2.md §H.5/§H.12 Phase 6,
 * zuse_eligibility_list.h's zuse_eligibility_devblock_t chain). Zuse
 * checks zuse_eligibility_is_member() before honoring any
 * ELEVATE-REQUEST (§H.7/§H.8) -- a gating layer on top of the
 * message-based elevation trigger, not a replacement for it. Adding an
 * entry (zuse_eligibility_add()) is meant to be reachable only from a
 * Zuse-only FORTH word (§H.12 item 19, gated by zuse_session), not
 * called directly from arbitrary session code.
 */

#ifndef STARKERNEL_ZUSE_ELIGIBILITY_H
#define STARKERNEL_ZUSE_ELIGIBILITY_H

#ifdef __STARKERNEL__

#include <stdint.h>

/**
 * zuse_eligibility_is_member - Check whether pubkey appears anywhere in
 * the eligibility list chain. Fail-closed: an empty/nonexistent list, a
 * corrupt/foreign devblock encountered mid-chain, or any I/O error all
 * read as "not eligible" (0), never "eligible" -- this gates elevation,
 * so an unreadable list must never be treated as permissive.
 *
 * @param pubkey  32-byte Ed25519 public key to look up.
 * @return        1 if found, 0 otherwise (including on any error).
 */
int zuse_eligibility_is_member(const uint8_t pubkey[32]);

/**
 * zuse_eligibility_add - Add pubkey to the eligibility list, creating
 * the list's head devblock if it doesn't exist yet and chaining a fresh
 * devblock onto the tail if the current tail is full. Idempotent: adding
 * an already-present pubkey is a no-op success, not a duplicate entry.
 *
 * @param pubkey  32-byte Ed25519 public key to add.
 * @return        0 on success (added, or already present), -1 on
 *                failure (fence write failed, fence budget exhausted, or
 *                a corrupt devblock was encountered mid-chain).
 */
int zuse_eligibility_add(const uint8_t pubkey[32]);

#endif /* __STARKERNEL__ */

#endif /* STARKERNEL_ZUSE_ELIGIBILITY_H */