// hakmem_tiny_query.c
// Phase 2B-1: Query API
// Extracted from hakmem_tiny.c (lines 4295-4346)

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

#include "hakmem_tiny.h"
#include "hakmem_tiny_config.h"  // extern g_tiny_class_sizes
#include "hakmem_tiny_query_api.h"
#include "hakmem_tiny_superslab.h"
#include "hakmem_super_registry.h"
#include "hakmem_config.h"

// External globals (defined in hakmem_tiny.c)
extern int g_tiny_initialized;
extern int g_use_superslab;
// g_tiny_class_sizes is in hakmem_tiny.h (static const)

// External functions
extern TinySlab* hak_tiny_owner_slab(void* ptr);
// hak_super_lookup is static inline in hakmem_super_registry.h

int hak_tiny_is_managed(void* ptr) {
    if (!ptr || !g_tiny_initialized) return 0;
    // Phase 6.12.1: O(1) slab lookup via registry/list
    return hak_tiny_owner_slab(ptr) != NULL || hak_super_lookup(ptr) != NULL;
}

int hak_tiny_is_managed_superslab(void* ptr) {
    if (!ptr || !g_tiny_initialized) return 0;

    // Safety: Only check if g_use_superslab is enabled
    if (g_use_superslab) {
        SuperSlab* ss = hak_super_lookup(ptr);
        if (ss && ss->magic == SUPERSLAB_MAGIC) {
            // Phase 12: Use registry hit as "managed by SuperSlab"
            return 1;
        }
    }

    // Fallback to TinySlab check
    return hak_tiny_owner_slab(ptr) != NULL;
}

size_t hak_tiny_usable_size(void* ptr) {
    if (!ptr || !g_tiny_initialized) return 0;

    // Check SuperSlab first via registry (safe under direct link and LD)
    if (g_use_superslab) {
        SuperSlab* ss = hak_super_lookup(ptr);
        if (ss && ss->magic == SUPERSLAB_MAGIC) {
            // Phase 12: derive class from per-slab meta (no ss->size_class)
            void* base = (void*)((uint8_t*)ptr - 1);
            int slab_idx = slab_index_for(ss, base);
            if (slab_idx >= 0 && slab_idx < ss_slabs_capacity(ss)) {
                TinySlabMeta* meta = &ss->slabs[slab_idx];
                int k = (meta->class_idx < TINY_NUM_CLASSES) ? (int)meta->class_idx : -1;
                if (k >= 0) {
#if HAKMEM_TINY_HEADER_CLASSIDX
                    size_t stride = g_tiny_class_sizes[k];
                    return (stride > 0) ? (stride - 1) : 0;
#else
                    return g_tiny_class_sizes[k];
#endif
                }
            }
        }
    }

    // Fallback: TinySlab owner lookup
    TinySlab* slab = hak_tiny_owner_slab(ptr);
    if (slab) {
        int k = slab->class_idx;
        if (k >= 0 && k < TINY_NUM_CLASSES) {
            // Phase E1-CORRECT: g_tiny_class_sizes = total size (stride)
            // Usable = stride - 1 (for 1-byte header)
#if HAKMEM_TINY_HEADER_CLASSIDX
            size_t stride = g_tiny_class_sizes[k];
            return (stride > 0) ? (stride - 1) : 0;
#else
            return g_tiny_class_sizes[k];
#endif
        }
    }
    return 0;
}