// tiny_class_policy_box.c - Initialization of per-class Tiny policy table

#include "tiny_class_policy_box.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include "tiny_policy_learner_box.h"
#include "tiny_mem_stats_box.h"

TinyClassPolicy g_tiny_class_policy[TINY_NUM_CLASSES];
static _Atomic int g_tiny_class_policy_init_done = 0;
static _Atomic int g_tiny_class_policy_logged = 0;
static _Atomic int g_tiny_class_policy_profile_auto = 0;
static _Atomic int g_tiny_class_policy_mem_recorded = 0;

static inline TinyClassPolicy tiny_class_policy_default_entry(void) {
    TinyClassPolicy p = {0};
    p.page_box_enabled = 0;
    p.warm_enabled = 0;
    p.warm_cap = 0;
    p.tls_carve_enabled = 0;
    return p;
}

static void tiny_class_policy_set_legacy(void) {
    TinyClassPolicy def = tiny_class_policy_default_entry();
    for (int i = 0; i < TINY_NUM_CLASSES; i++) {
        g_tiny_class_policy[i] = def;
    }

    // legacy: Page Box は C5–C7、Warm は全クラス ON（C0–C4 は控えめ cap）
    for (int i = 0; i < TINY_NUM_CLASSES; i++) {
        g_tiny_class_policy[i].warm_enabled = 1;
        g_tiny_class_policy[i].warm_cap = (i < 5) ? 4 : 8;
        g_tiny_class_policy[i].tls_carve_enabled = (i >= 5) ? 1 : 0;
    }
    for (int i = 5; i < TINY_NUM_CLASSES; i++) {
        g_tiny_class_policy[i].page_box_enabled = 1;
    }
}

static void tiny_class_policy_set_c5_7_only(void) {
    TinyClassPolicy def = tiny_class_policy_default_entry();
    for (int i = 0; i < TINY_NUM_CLASSES; i++) {
        g_tiny_class_policy[i] = def;
    }
    for (int i = 5; i < TINY_NUM_CLASSES; i++) {
        g_tiny_class_policy[i].page_box_enabled = 1;
        g_tiny_class_policy[i].warm_enabled = 1;
        g_tiny_class_policy[i].warm_cap = 8;
        g_tiny_class_policy[i].tls_carve_enabled = 1;
    }
}

static void tiny_class_policy_set_tinyplus_all(void) {
    // いまは legacy と同じ挙動でエントリを用意しておく。
    tiny_class_policy_set_legacy();
}

static void tiny_class_policy_set_larson_guard(void) {
    // Start from legacy, then tighten warm caps to reduce RSS for larson-style loads.
    tiny_class_policy_set_legacy();
    for (int i = 0; i < TINY_NUM_CLASSES; i++) {
        if (i < 5) {
            g_tiny_class_policy[i].warm_cap = 2;
        } else {
            g_tiny_class_policy[i].warm_cap = 4;
        }
    }
}

static void tiny_class_policy_set_auto(void) {
    // auto プロファイルは legacy をベースにして、後段の learner に委譲
    tiny_class_policy_set_legacy();
    atomic_store_explicit(&g_tiny_class_policy_profile_auto, 1, memory_order_release);
}

static const char* tiny_class_policy_set_profile(const char* profile) {
    if (profile == NULL || *profile == '\0' || strcasecmp(profile, "legacy") == 0) {
        tiny_class_policy_set_legacy();
        atomic_store_explicit(&g_tiny_class_policy_profile_auto, 0, memory_order_release);
        return "legacy";
    } else if (strcasecmp(profile, "c5_7_only") == 0) {
        tiny_class_policy_set_c5_7_only();
        atomic_store_explicit(&g_tiny_class_policy_profile_auto, 0, memory_order_release);
        return "c5_7_only";
    } else if (strcasecmp(profile, "tinyplus_all") == 0) {
        tiny_class_policy_set_tinyplus_all();
        atomic_store_explicit(&g_tiny_class_policy_profile_auto, 0, memory_order_release);
        return "tinyplus_all";
    } else if (strcasecmp(profile, "larson_guard") == 0) {
        tiny_class_policy_set_larson_guard();
        atomic_store_explicit(&g_tiny_class_policy_profile_auto, 0, memory_order_release);
        return "larson_guard";
    } else if (strcasecmp(profile, "auto") == 0) {
        tiny_class_policy_set_auto();
        return "auto";
    } else {
        // 不明な値は安全側で legacy にフォールバック。
        tiny_class_policy_set_legacy();
        atomic_store_explicit(&g_tiny_class_policy_profile_auto, 0, memory_order_release);
        return "legacy";
    }
}

void tiny_class_policy_dump(const char* tag) {
    if (!tiny_policy_log_enabled()) {
        return;
    }
    const char* header = tag ? tag : "[POLICY_DUMP]";
    fprintf(stderr, "%s\n", header);
    for (int cls = 0; cls < TINY_NUM_CLASSES; cls++) {
        TinyClassPolicy* p = &g_tiny_class_policy[cls];
        fprintf(stderr,
                "  C%d: page=%u warm=%u cap=%u tls_carve=%u\n",
                cls,
                p->page_box_enabled,
                p->warm_enabled,
                p->warm_cap,
                p->tls_carve_enabled);
    }
}

void tiny_class_policy_init_once(void) {
    if (atomic_load_explicit(&g_tiny_class_policy_init_done, memory_order_acquire)) {
        return;
    }

    const char* profile = getenv("HAKMEM_TINY_POLICY_PROFILE");
    const char* active_profile = tiny_class_policy_set_profile(profile);

    if (atomic_exchange_explicit(&g_tiny_class_policy_mem_recorded, 1, memory_order_acq_rel) == 0) {
        tiny_mem_stats_add_policy_stats((ssize_t)sizeof(g_tiny_class_policy));
    }

    // 1-shot ダンプでポリシーの内容を可視化（デバッグ用）
    if (tiny_policy_log_enabled() &&
        atomic_exchange_explicit(&g_tiny_class_policy_logged, 1, memory_order_acq_rel) == 0) {
        fprintf(stderr, "[POLICY_INIT] profile=%s\n", active_profile);
        tiny_class_policy_dump(NULL);
    }

    atomic_store_explicit(&g_tiny_class_policy_init_done, 1, memory_order_release);
}

void tiny_class_policy_refresh_auto(void) {
    tiny_class_policy_init_once();
    if (!atomic_load_explicit(&g_tiny_class_policy_profile_auto, memory_order_acquire)) {
        return;
    }
    tiny_policy_learner_tick();
}

int tiny_class_policy_is_auto(void) {
    tiny_class_policy_init_once();
    return atomic_load_explicit(&g_tiny_class_policy_profile_auto, memory_order_acquire);
}