#include "super_reg_box.h"

#include <stdatomic.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "hakmem_super_registry.h"

// プロファイル別の実容量・論理上限
static _Atomic int g_super_reg_effective_size = SUPER_REG_SIZE;
static _Atomic int g_super_reg_effective_mask = SUPER_REG_MASK;
static _Atomic int g_super_reg_effective_per_class = SUPER_REG_PER_CLASS;
static _Atomic int g_super_reg_profile_inited = 0;

// 動的に確保する実配列
static SuperRegEntry* g_super_reg_entries = NULL;
static SuperSlab** g_super_reg_by_class_slots = NULL;
static int g_super_reg_by_class_stride = SUPER_REG_PER_CLASS;
static _Atomic int g_super_reg_allocated = 0;

static inline int super_reg_clamp_power_of_two(int requested, int fallback) {
    // SUPER_REG_SIZE は 2 のべき乗なので、requested もそれ未満のべき乗に丸める。
    if (requested <= 0 || requested > SUPER_REG_SIZE) {
        return fallback;
    }
    // 丸め: 最上位ビットだけを残す（2 のべき乗に丸め下げ）
    int v = requested;
    v |= v >> 1;
    v |= v >> 2;
    v |= v >> 4;
    v |= v >> 8;
    v |= v >> 16;
    v = v - (v >> 1);
    // 有効値は最低でも 1024 にしておく
    if (v < 1024) {
        v = 1024;
    }
    return v;
}

static void super_reg_apply_profile(const char* profile) {
    if (g_super_reg_profile_inited) {
        return;
    }

    const char* env_profile = profile ? profile : getenv("HAKMEM_PROFILE");
    const int is_bench = (env_profile && strcmp(env_profile, "bench") == 0);

    int eff_size = SUPER_REG_SIZE;
    int eff_per_class = SUPER_REG_PER_CLASS;

    if (is_bench) {
        // 論理上の利用範囲だけ縮める（配列は従来サイズのまま）
        eff_size = SUPER_REG_SIZE >> 3;          // 1/8 に論理制限
        eff_per_class = SUPER_REG_PER_CLASS >> 4;  // 1/16
    }

    eff_size = super_reg_clamp_power_of_two(eff_size, SUPER_REG_SIZE);
    eff_per_class = eff_per_class > 0 ? eff_per_class : SUPER_REG_PER_CLASS;

    atomic_store_explicit(&g_super_reg_effective_size, eff_size, memory_order_relaxed);
    atomic_store_explicit(&g_super_reg_effective_mask, eff_size - 1, memory_order_relaxed);
    atomic_store_explicit(&g_super_reg_effective_per_class,
                          eff_per_class,
                          memory_order_relaxed);
    atomic_store_explicit(&g_super_reg_profile_inited, 1, memory_order_release);
}

void super_reg_init(SuperRegBox* box, const char* profile) {
    (void)box;
    super_reg_apply_profile(profile);

    if (atomic_load_explicit(&g_super_reg_allocated, memory_order_acquire)) {
        return;
    }

    int eff_size = super_reg_effective_size();
    int per_class = super_reg_effective_per_class();

    // Allocate registry table
    size_t reg_bytes = (size_t)eff_size * sizeof(SuperRegEntry);
    g_super_reg_entries = (SuperRegEntry*)calloc(eff_size, sizeof(SuperRegEntry));
    if (!g_super_reg_entries) {
        fprintf(stderr, "[SUPER_REG] failed to allocate %zu bytes for registry\n", reg_bytes);
        abort();
    }

    // Allocate per-class table (contiguous 1D block)
    size_t per_class_bytes = (size_t)TINY_NUM_CLASSES * (size_t)per_class * sizeof(SuperSlab*);
    g_super_reg_by_class_slots = (SuperSlab**)calloc(TINY_NUM_CLASSES * (size_t)per_class,
                                                     sizeof(SuperSlab*));
    if (!g_super_reg_by_class_slots) {
        fprintf(stderr, "[SUPER_REG] failed to allocate %zu bytes for per-class registry\n",
                per_class_bytes);
        abort();
    }
    g_super_reg_by_class_stride = per_class;

    atomic_store_explicit(&g_super_reg_allocated, 1, memory_order_release);
}

int super_reg_effective_size(void) {
    if (!atomic_load_explicit(&g_super_reg_profile_inited, memory_order_acquire)) {
        super_reg_apply_profile(NULL);
    }
    return atomic_load_explicit(&g_super_reg_effective_size, memory_order_relaxed);
}

int super_reg_effective_mask(void) {
    if (!atomic_load_explicit(&g_super_reg_profile_inited, memory_order_acquire)) {
        super_reg_apply_profile(NULL);
    }
    return atomic_load_explicit(&g_super_reg_effective_mask, memory_order_relaxed);
}

int super_reg_effective_per_class(void) {
    if (!atomic_load_explicit(&g_super_reg_profile_inited, memory_order_acquire)) {
        super_reg_apply_profile(NULL);
    }
    return atomic_load_explicit(&g_super_reg_effective_per_class, memory_order_relaxed);
}

SuperRegEntry* super_reg_entries(void) {
    if (!atomic_load_explicit(&g_super_reg_allocated, memory_order_acquire)) {
        super_reg_init(NULL, NULL);
    }
    return g_super_reg_entries;
}

SuperSlab** super_reg_by_class_slots(void) {
    if (!atomic_load_explicit(&g_super_reg_allocated, memory_order_acquire)) {
        super_reg_init(NULL, NULL);
    }
    return g_super_reg_by_class_slots;
}

int super_reg_by_class_stride(void) {
    if (!atomic_load_explicit(&g_super_reg_allocated, memory_order_acquire)) {
        super_reg_init(NULL, NULL);
    }
    return g_super_reg_by_class_stride;
}