// fg_tiny_gate_box.h - Tiny Front Gate guard box
// 役割: FG_DOMAIN_TINY 判定が出た時に Superslab 登録を確認し、誤分類なら MIDCAND に切替
// 境界: Tiny 経路へ入る前に 1 箇所でのみ実行する
#ifndef HAK_BOX_FG_TINY_GATE_H
#define HAK_BOX_FG_TINY_GATE_H

#include "../hakmem_super_registry.h"  // hak_super_lookup / SUPERSLAB_MAGIC
#include "front_gate_v2.h"
#include <stdatomic.h>
#include <stdio.h>

typedef struct {
    fg_classification_t fg;
    int misclassified;  // 1 when Tiny→MIDCAND に落とした
} fg_tiny_gate_result_t;

// 簡易ログ（初回のみ）
static inline void fg_tiny_gate_log(void* ptr, uint8_t hdr, uintptr_t off, int use_ss, int reg_init) {
    static _Atomic int log_budget = 4;
    int n = atomic_fetch_add_explicit(&log_budget, 1, memory_order_relaxed);
    if (n >= 4) return;
    fprintf(stderr,
            "[FG_TINY_MISCLASS] ptr=%p hdr=0x%02x off=0x%lx g_use_ss=%d reg_init=%d → reroute to MIDCAND\n",
            ptr, hdr, (unsigned long)off, use_ss, reg_init);
}

// Tiny判定のガード: Superslab登録が無ければ MIDCAND に変換
static inline fg_tiny_gate_result_t fg_tiny_gate(void* ptr, fg_classification_t fg) {
    fg_tiny_gate_result_t r = {.fg = fg, .misclassified = 0};
    if (fg.domain != FG_DOMAIN_TINY) return r;

    SuperSlab* fg_ss = hak_super_lookup(ptr);
    if (__builtin_expect(!(fg_ss && fg_ss->magic == SUPERSLAB_MAGIC), 0)) {
        extern int g_use_superslab;
        extern int g_super_reg_initialized;
        uint8_t hdrb = 0;
        if ((uintptr_t)ptr > 0) { hdrb = *((uint8_t*)ptr - 1); }
        uintptr_t off = (uintptr_t)ptr & 0xFFFu;
        fg_tiny_gate_log(ptr, hdrb, off, g_use_superslab, g_super_reg_initialized);
        r.fg.domain = FG_DOMAIN_MIDCAND;
        r.misclassified = 1;
    }
    return r;
}

#endif // HAK_BOX_FG_TINY_GATE_H